FRAME STRUCTURE COMPRISING MAIN BEAMS AND TRANSVERSE BEAMS AND METHOD OF MOUNTING SUCH STRUCTURE

Abstract: Frame structure comprising main beams and transverse beams to be used in carriages of compact storage systems, i.e. carriages supporting shelves, movable on rails towards and away from each other to form passageways between the shelves. The main beams and transverse beams are joined by a snap action mechanism which is an integral part of the beams. The transverse beams (32) are mainly U-shaped and their legs (32b) are provided with hooks (35, 36), whereas the waist (32a) has a groove (38) extending perpendicular to the length direc­ tion of the beam. Each main beam (31) has a vertical leg (31a), intended to abut one end of the transverse beam (32), and a horizontal leg (31b), having at its end a bent portion (34) to engage the groove (38). The vertical leg (31a) has a number of slots (33) perpendicular to the length direction of the beam to receive the hooks (35, 36) of the transverse beam.

Description: Frame structure comprising main beams and transverse beams and method of mounting such structure This invention relates to a frame structure comprising profiled main beams and transverse beams of metal or the like and to a method of mounting such structure. It is previously known to build up load-bearing frame structures or the like by joining main beams and transverse beams by weld, rivet or screw joints. For instance such structures are used in carriages in storage systems of the so-called compact type. These carriages are movable on rails and support shelves, compartments or the like on which goods may be stored. By moving the carriages to different positions adjacent each other or spaced from each other one can form passageways between adjacent shelves. The systems are very space-saving and have therefore become widely used. However, the known systems have the drawback that the carriages are expensive to manufacture because joining of the beams is time-consuming. In order to get a rational manufacturing of the system in spite of this the joining operation usually is concentrated to one single place in a large geografic area on which large investment in the form of automatic spotwelding machines, assembly lines and so on is made. However, this kind of rationalizing effect is partly decreased by the heavy transport charges following on the low weight-volume relation for the carriages. The purpose of this invention is to achieve a frame structure, for instance a carriage, of the type described above, which by a particular design of the beams can be simply and rapidly assembled, the beam joints being such that self-locking is achieved. Since no expensive tools are necessary for the mounting operation, this can be done more locally than before. This means that the beams can be stowed together and be transported directly from a factory to an area where they are to be assembled, without involving too high transportation costs. The invention also gives the possibility of reducing the storing costs for the carriages since the system is very flexible. Thus, carriages of suitable length and width can be built up from a few standardized components. An upper limit of the length of the carriages with respect to the space available is often set in systems of the described type. This adjustment of the length is very simple to make when using this invention and it is realized by cutting the main beams from their standard lengths to the lengths in question. The advantages described are achieved by the invention as defined in the following claims. Some embodiments of the invention will now be described in connection with the drawings in which Fig. 1 schematically in a perspective view shows a carriage provided with load-carrying shelves, Fig. 2 in a side elevation view shows the connection between a main beam and a transverse beam before assembly, and Fig. 3 in the same view shows these beams after being assembled. Fig. 4 is a sectional view taken along the line IV - IV in Fig. 3. Fig. 5 shows to an enlarged scale the lower part of the beam in Fig. 3 having a safety device. Fig. 6 is a perspective view of another embodiment of the invention, and Fig. 7 is a side elevation view of the structure shown in Fig. 6 when assembled. Fig. 1 shows a system to which the invention is to be applied. The system comprises a number of carriages 10 placed adjacent each other. The carriages are moved on wheels on a number of rails 11 in the floor, The carriages support storage shelves 12 and comprise main beams 13 and transverse beams 14 which are connected to each other in a manner which will be described more in detail below. By moving the carriages towards respectively away from each other one can form passageways between the carriages, whereby the shelves become accessible for depositing and taking out goods, The beams are made of profile steel sheet having a thickness of 1 - 4 mm, preferably 2 - 3 mm. As appears from Figs. 2 - 4 each main beam 13 has a partly U-shaped profile with a leg 13a which is extended and at its end has a bent portion 15. The other leg 13b of the profile is via a waist 13c connected to the leg 13a and continues into an L-shaped part, one leg 13d of which is paral lel to the waist 13c. The other leg 13e of the L-shaped part is placed straight under and parallel to the extension of the leg 13a of the U-shaped profile. The leg 13e can also be provided with an upwardly bent part, not shown, forming a shelf for cables on the leg 13e. The main beam 13 also has a number of parallel vertical slots. These slots comprise upper slots 16 extending through the short legs 13b of the U-shaped profiles and a short distance down into the vertical legs 13d of the L-shaped profiles, and lower slots 17 each being aligned with an upper slot in a leg 13d. The transverse beam is U-shaped in section. The section may be slightly conical in order to make it possible to pile the profiles in each other during transportation. The beam comprises two parallel legs 14a and 14b, respectively, which are joined by a waist 14c. The free ends of the legs 14a and 14b are bent through 900 and form two outwardly extending flanges 14d and 14e, respectively, at either side of the beam. The two ends of the beam are provided with two downwardly extending hooks 18 forming an extension of the legs 14a and 14b, respectively. Perpendicular to the length direction of the transverse beam they have a groove 19 in the waist 14c. One side of the groove is bevelled in order to safely hold the bent portion 15 of the main beam. At each end of the legs 14a, 14b there is a shoulder 20 the purpose of which will appear from the following. The transverse beams may have a somewhat lower end portion to the left of the groove 19 so that the upper sides of the beams will be in the same plane as the upper sides of the main beams. The transverse beams enclose a number of wheels 21 which are supported by shafts 22. Each shaft has two grooves 23, co-operating with recesses 24 in the legs 14a, 14b, and is secured by lugs 25 of the flanges 14d and 14e, respectively, Carriages of the above type are preferably driven by one or several electric motors which in any suitable manner are connected to the wheels. Joining the beams together to a frame structure takes place in the following manner. The hooks 18 of a transverse beam 14 are guided through the upper slots 16 in one of the main beams, after which the transverse beam is turned counter-clockwise around a point 26 of abutment between the two beam Thereby the bent portion 15 of the leg 13a will be guided along the waist 14c and at the same time be resiliently bent away. When the transverse beam has been turned enough the bent portion 15 falls into the groove 19 and locks the two beams to each other. The shoulder 20 gives a certain degree of spring influence on the waist 13c so that there iS no play between the beams after mounting. When all transverse beams 14 have been fastened to one- main beam 13 they are fastened to the other main beam by placing their free ends into the main beam, which after turning snaps together with the transverse beams. Of course it is possible within the scope of the invention first to localize all the transverse beams into the two main beams and then by turning the main beams to join them with the other beams into a complete frame structure. The frame structure is thereafter completed with the wheels 21 by pressing each wheel shaft 22 with the wheel into the recesses 24 in the legs 14a and 14b against the forces of the lugs 25. As appears from Fig, 5, the joint described above gives the possibility of easily equipping the carriages with safety devices in the form of a strip along the whole length of the lower part of the carriage. Such strips are commonly used on carriages of the above type in order to prevent injuries if a person should stay between the carriages when they are moved towards each other. The safety strip is denoted by 27 and consists of a bent elongated sheet metal. The strip is in its upper part provided with fastening means 28, formed by a part of the sheet metal, and is supported by a shaft 29. The shaft extends through and between the hooks 18 of a transverse beam. The safety strip 27 with its lower part abuts one or several switches 30 which are connected to the circuit for the drive of the electric motors. Pushing the safety strip inwards causes the motors and thereby the carriages to stop, The beam joint shown in Figs, 6 and 7 in the same way as the joint described above comprises a main beam 31 and a transverse beam 32. The main beam has a vertical leg 31a continuing into a horizontal leg 31b. The vertical leg is stepped having an upper part 31c and a lower part 31d and a portion 31e connecting these parts. The lower part 31d continues into a flange-shaped part 31f which is parallel to the horizontal leg 31b, The flange-shaped part in turn has an upwardly bent edge portion 31g which is parallel to the vertical leg. Moreover the vertical leg has a number of vertical slots 33 in the area of the portion 31e. The horizontal leg has at its outer end a bent portion 34. As in the embodiment according to Figs, 1 - 5, the transverse beam 32 13 mainly U-shaped in section. The section is slightly conical and has a waist 32a joining two stepped legs 32b. The legs 32b continue into a part J;i: Wnieh extends outwards from the plane of symmetry of the beam which in turn continues into a flange 32d, which mainly is parallel to the leg 32b. Tne flange 32d and the lower parts of the legs 32b have at their ends hooks 35, 36. Outer end parts 37 of the waists and flanges of the beams are bent towards the inner part of the profile in order to make the beam stable. The waist 32a of the beam 32 has near the ends a groove 38 which extends over the complete width of the beam and is perpendicular to its length direction. The groove is intended to co-operate with the bent portion 34 of the main beam. The portion 34 is preferably bent through more than 900 with respect to the horizontal leg. The transverse beam is upset in the area between the groove 38 and the end part 37 so that a comparatively thick bead 39 is formed which is directed towards the inner part of the profile. The beams shown in Figs. 6 and 7 are assembled by guiding the hooks 35 and 36 of the transverse beam 32 through the slots 33 in the main beam 31 after which the transverse beam is turned counter-clockwise in Fig. 7. Thereby the horizontal leg 31b with the bent portion 34 at first is pressed upwards in the Figure and when the end of the transverse beam abuts the upper part 31c of the vertical leg of the main beam 31, the bent portion 34 snaps into the groove 38 and locks the beams to each other. When all of the transverse beams have been fastened to one of the main beams, the other main beam is fastened to the transverse beams by localizing the hooks 35, 36 of the free ends of the beams into the slots 33 in the other main beam after which this is turned and the beams thereby snap together. The invention is of course not limited to the embodiments shown but can be modified within the scope of the following claims.

Claims: Claims 1. Frame structure comprising profiled main beams and transverse teams, preferably of metal or the like, the wall thickness of the beam being such that the beams are capable of taking up and transmitting considerable loads, such as loads originating from shelves supported on the frame, c h a r a c t e r i z e d in that the main beams (13, 31) are joined to the transverse beams (14, 32) mainly by snap action. 2. Frame structure according to Claim 1, c h a r a c t e r i z e d in that each transverse beam mainly is U-shaped and at the ends of its legs (14a, 14b,32b) is provided with hooks (18,36), whereas the waist (lhc,32a) of the beam near its ends has a groove (19,38) or the like which extends perpendicular to the length direction of the beam, each main beam having a mainly vertical leg (13c,13d,31a), intended to abut one end of the respective transverse beam, and a horizontal leg (13a,31b), intended to abut the waist (14c,32a) of the transverse beam and at its end having a 0 bent portion (15,34) which preferably is bent through more than 90 with respect to the horizontal leg and is intended to be entered into the groove (19,38), the vertical leg having a number of slots (16,17,33) which extend perpendicular to the length direction of the beam and are intended to receive the hooks (18,36) of the respective transverse beam, 3, Frame structure according to Claim 1 or Claim 2, c h a r a c t e r i z e d in that the wall thickness of the beams is 1 - 4 mm, preferably 2 - 3 nm. 4. Frame structure according to Claim 2 or Claim 3, c h a r a c t e r i z e d in that the legs (32b) of each transverse beam continues into a part (32c) which extends outwardly from the plane of symmetry of the beam whose end part abuts the vertical leg (31a) of the corresponding main beam. 5. Frame structure according to Claim 4, c h a r a c t e r i z e a in that the part (32c) extending outwards continues into a flange (32d2 which mainly is parallel to the legs (32b) of the transyrse beam, each end part of the flange being provided with a hook (35) intended to engage with one of the slots (33) in the corresponding main beam. 6. Frame structure according to any preceding claim, c h a r a c t e r i z e d in that the outer parts (37) of the legs (32b) and the waist (32a) of the transverse beams are bent towards the inner part of the beam, 7. Frame structure according to any preceding claim, c h a r a c t e r i z e d in that the end parts of the transverse beam are reinforced by an pset (39) or the like, 8, Frame structure according to any preceding c3.ajpl, c h a r a c t e r i z e d in that the vertical leg (31a} of each min beam is stepped and continues into a flange-shaped part (31f) which is parallel to the horizontal leg (31b) of the beam, 9. Frame structure according to Claim 8, c h a r a c t e r i z e d in that the flange-shaped part (31f) has a bent edge portion (31g) which is mainly parallel to the vertical leg (31a). 10. Method of mounting a frame structure of the type described in Claim 1, c h a r a c t e r i z e d in that a transverse beam having fastening means at its ends is localized with these means in corresponding means of the main beam, after which the transverse beam is turned about the point of localization so that a part integral with one of the beams during the turning movement is forced away from the other beam and when the turning has been completed snaps back and locks the beams to each other, that the other transverse beams in the frame structure are fastened to the main beams in the same way, after which the other ends of the transverse beams are localized into a second main beam and this beam after being turned about the point of localization with respect to the frame structure which has been partly mounted, is locked to the transverse beams in the same way as described above.

Inventors: ANDERSSON, INGVAR KARL-HENRIK
Applicants: AKTIEBOLAGET ELECTROLUX
Application year: 1979
Main classification: F16B12
IPC codes: F16B12, A47B53