Patent Number: 
Section: description

Referring to FIG. 1, a typical container 1 for receiving nuclear fuel elements (not shown) comprises an elongate cylindrical casing 2 within which is housed a plurality of compartments 3. The compartments 3 are located within the casing 2 by a plurality of baffle plates 4 positioned at intervals along the container 1. The compartments 3 are of rectangular cross section and are formed by two sets of elongate plates 5, 6. A first set of plates 5 extends perpendicularly with respect to the second set of plates 6 so as to form opposing walls of the compartments 3. Although four compartments have been shown in FIG. 1, the number of compartments will be chosen to suit a particular application. Each compartment 3 is of a size that is sufficient to accommodate a nuclear fuel element. Referring now to FIGS. 2, 3 and 4, the first set of plates 5 comprises a plurality of interconnected individual plates, two of which plates 7, 8 are shown. Similarly, the second set of plates 6 comprises a plurality of individual plates, two of which plates 9, 10 are shown. A joint at a typical cross junction of the two sets of plates if shown in FIGS. 2, 3 and 4. The, plates 7, 8 of the first set are formed with a series of alternating projections 11 and recesses 12 along the longitudinal edge, the projections and recesses being arranged at a regular pitch or spacing. Each projection 11 is generally T-shaped defined by a first portion 13 extending from the longitudinal edge and two arm portions 14. The arm portions 14 extend laterally from an end of the first portion 13 at each side thereof. Each recess 12 is formed to correspond in shape to the T-shaped projections 11. An initial passage 15 of the recess 12 extends from the longitudinal edge. At an end of the passage 15 are two laterally extending side portions 16 which are formed so as to define two shoulders 17 behind the arm portions 14 of a projection 11. Along the longitudinal edges of the plates 8 of the first set is a series of alternating projections 11 and recesses 12 which are formed in a manner similar to those on plates 7. When the plates 7 and 8 are joined together the projections 11 on one of the plates interlock with the recesses 12 on the other plate. The shoulders 17 are engaged by the arm portions 14 which thereby serve as retaining means. Separation of the plates 7 and 8 in a direction normal to the longitudinal edges along the plane containing the first set is not possible. Formed along the longitudinal edges of the plate 9 of the second set 6 is a series of projections in the form of tenons 18. The tenons 18 project from the edge by a distance substantially equal to the thickness of the plates 7, 8 of the first set. Similarly, a series of tenons 19 is formed along the longitudinal edges of the plates 10 of the second set 6. As seen in FIG. 4, at a mid-position of the upper surface of the tenon 18 is stepped to form a latch 20. An upwardly and rearwardly inclined portion 21 of the upper surface extends to the latch 20 from a leading end of the tenon 18. A lower surface of the tenon 19 is also stepped at a mid-portion thereof to form a latch 22. A downwardly and rearwardly inclined portion 23 of the lower surface extends from a leading end of the tenon 19 to the latch 22. The tenons 18, 19 are received in rectangular slots 24 formed in the plates 7, 8 of the first set, each slot being located within the periphery defining a projection 11. To assemble the compartments 3, the plates 7, 8 of the first set 5 are joined together by interlocking the projections 11 and recesses 12 along mutually adjacent longitudinal edges of the plates. Several plates 7, 8 may be joined together in this manner to obtain the desired width of plates of the first set 5. An end plate 25 (see FIG. 1) is provided at each end of the plates 7, 8. Along a longitudinal edge of each end plate 25 is a series of projections 11 and recesses 12 in the form as provided on the end plates 7, 8. These projections and recesses interlock with complementary projections and recesses in an adjacent plate 7, 8 of the first set. Rectangular slots 24 are provided within the peripheries defining the projections 11. After assembling the plates 6, 7 of the first set 5, the plates 8, 9 of the second set 6 are interlocked therewith. This is effected by inserting the tenons 18 of a plate 9, and tenons of a plate 8 into the slots 24. The leading end of the tenons 18, 19 are inserted from opposite sides of the plates 7, 8 so that the inclined surfaces 21, 23 slide along one another. The plates 7, 8 are forced together so that latches 20, 22 become interengaged. The latches 20, 22 are positioned so that the plates 8, 9 are clamped against the plates 6, 7 thereby forming a strong interlocking joint at the cross junction of the four plates. An end plate 26 (see FIG. 1) is provided at each end of the plates 9, 10 of the second set 6. Along the longitudinal edge of the plate 26 is a series of tenons 18 which interengage with tenons 19 on a mating plate 10 within a slot 24. A container 31 incorporating an alternative type of interlocking joint according to the present invention is illustrated in FIGS. 5 to 8. The container 31 comprises an elongate cylindrical casing 32 within which is housed a plurality of compartments 33. The compartments 33 are located within the casing 32 by a plurality of baffle plates 34 positioned at intervals along the container. The compartments 33 are of rectangular cross section and are formed by two sets of elongate plates 35, 36. A first set of plates 35 extends perpendicularly with respect to a second set of plates 36 so as to form opposing walls of the compartments 33. Seven compartments 33 have been illustrated in FIG. 5 by way of example, but the number of compartments will be selected to suit a particular application. FIG. 6 illustrates a typical interlocking joint for connecting individual plates in the first set of plates 35 to obtain a wider plate to extend across the container. A plate 35a of the first set has a series of projections 37 arranged at a regular pitch or spacing along a longitudinal edge of the plate. Each projection 37 comprises a first portion 38 extending forwardly from the longitudinal edge of the plate. Two arm portions in the form of resilient tabs 39 extends rearwardly and outwardly from an end of the first portion 38. A series of recesses 40 is provided on the longitudinal edge of the mating plate 35b. The recesses 40 are arranged at spaced intervals so as to receive the projections 37. Each recess 40 has a first passage region 41 extending into an enlarged region 42. A shoulder 43 is formed at the junction of the first passage region 41 and the enlarged region 42. When assembling the plates 35a, 35b, the projections 37 are forced through the first passage region 41. The dimensions of the passage region 41 are such as to cause the two resilient tabs 39 to be deflected inwardly. When the projections 37 are completely located in the recesses 40, the enlarged region 42 allows the resilient tabs 39 to move towards their undeflected positions. The free ends of the tabs 39 locate behind the shoulders 43 which act to retain the projections 37 thereby interlocking the plates 35a, 35b.  The strength of the interlocking joint is enhanced by the provision of a series of rectangular extensions 44 along the longitudinal edge of plate 35a which mate with a series of correspondingly shaped rectangular cavities 45 formed in the longitudinal edge of the plate 35b.  A typical interlocking joint for interconnecting plates at a T-junction of the first and second set of plates 35, 36 is shown in FIGS. 7 and 8. A series of projections 37 is arranged at a regular pitch along the longitudinal edge of the plate 36. These projections 37 correspond in form to the projections 37 described with reference to the joint shown in FIG. 6. A series of recesses 40 is formed in the plate 35 which extends perpendicularly with respect to the plate 36. Again, the recesses 40 are formed in a similar manner to those described with reference to the joint shown in FIG. 6. In this embodiment, however, the enlarged region 46 is in the form of a slot having semi-circular ends. A series of rectangular extensions 44 is formed along the longitudinal edge of the plate 36. These extensions are received in rectangular slots 47 formed in the plate 36. The plates 35, 36 are interlocked by forcing the projections 37 into the recesses 40 so that the resilient tabs 39 locate behind the shoulders 43 in the manner previously described.