WO2003011491A1

WO2003011491A1 - Fibreboard container with plastic closure

Info

Publication number: WO2003011491A1
Application number: PCT/GB2002/003352
Authority: WO
Inventors: David Thomas Weller
Original assignee: David Thomas Weller
Priority date: 2001-07-28
Filing date: 2002-07-22
Publication date: 2003-02-13
Also published as: AU2002314392A1; WO2003011491B1; GB0118424D0; GB2378143A

Abstract

A beam is formed from a rectangular strip (11) of metal having Laser cut parallel longitudinal edges by, first, bending the strip (11), using a jig arrangement, about two fold lines respectively inset from the longitudinal edges (13A, 13b) of the strip (11), such as to create two upstanding marginal flanges. Next, the so-flanged sheet is bent about a longitudinal central fold line (35) such as to create a longitudinally-folded sheet of V-form cross-section, but with in-turned flanges at the mouth of the V-form section. Finally, the V-form folded sheet is braced using either a metal strip (39) or external constraint members that embrace the V-form folded sheet at intervals therealong. The beam may serve as a trackway means for a machine tool, a tool-carrying carriage (57) having wheels rotatable about vertical axes, with the wheels (61,63) in running contact with the trackway means at surfaces adjacent to the bend positions of the flanges (33A, 33b).

Description

BEAMS, THEIR FORMATION, AND THEIR USE AS A TRACKWAY

This invention relates to a method of forming a beam, to beams formed using the method, and to apparatus, such, for example, as wood-working lathes, in which the beam is employed as a trackway for a carriage. Problems are commonly experienced in machine tools as a result of the natural deflection of beams called upon to support running carriages. The loop: increase in beam stability—> increase in beam-depth section —> increase in weight —> increase in deflection —> increase in cost in construction in order to increase stability, is frequently encountered by machine tool (and other) designers.

According to the invention, a method of forming a beam, a beam formed using the method, and an apparatus incorporating the beam so formed as a trackway means for a carriage, are as set out in the claims contained in the claims schedule hereof, the wording employed in said claims, being, notionally, set out here, mutatis mutandis, also. The method of forming beams and beams and apparatus in accordance with the invention are hereinafter set out with reference to the accompanying drawings in which:

Fig.l depicts a flat metal sheet prior to its formation to a beam in accordance with the invention; Fig.2 shows the first stage of formation from the sheet of Fig.l, of the beam; Fig.3 shows the second stage of beam formation;

Fig.4 to 9 show, in cross-section, an apparatus, in use, in the process of forming the flat sheet of Fig.l to the state depicted in Fig.3; Fig.10 shows a beam in cross-section, being a sheet folded as shown in Fig.9, and with a first form of bracing means;

Fig.11 shows a beam in cross-section, being a folded sheet as shown in Fig.10 and with second bracing means, being a variant of the bracing means depicted in Fig.10;

Fig.12 shows a beam in cross-section, being a folded sheet as shown in Fig.9 and with a bracing means of an alternative form to that of Fig.10 or Fig.11;

Fig.13 shows, pictorially, the beam and bracing means of Fig.12;

Fig.14 shows an apparatus comprising a beam as depicted in Fig.11, constituting a trackway means and a trolley runnable on wheels along the trackway means;

Fig.15 shows a variant of the arrangement of Fig 14; Fig.16 shows an apparatus comprising a beam as depicted in Fig.11 constituting a trackway means and a trolley slidably runnable along the trackway means;

Fig.17 illustrates features of an apparatus comprising first and second beams each as depicted in Fig.11 incorporated in and constituting essential elements of trackway means means for the conveyance of a carriage therealong; and,

Fig.18 shows an end-view of the trackway means of Fig.17.

The flat metal sheet 11 is first cut such as to ensure that the longitudinal edges 13a, 13b, respectively, are accurately straight and parallel to one another. For the formation of beams suitable for use as trackway means for the tool-carrying carriage of a machine tool, a lathe, for example, the flat metal sheet 11 from which the trackway means is to be formed, should have edges that are parallel to one another to within an accuracy of width/length parallelism of the order 0.01mm/100mm. Whilst such accuracy in parallelism of the edges of the metal sheet might be achieved by other, e.g. CNC controlled water-jet methods, current practice favours the use of CNC controlled Laser cutting procedures . The sheet 11 having been cut accurately to a width X and with the edges 13a, 13b, of the sheet with a requisite parallelism, the sheet is converted to the form represented in Fig.3, using the apparatus depicted in each of Figs.4 to 9. The apparatus comprises an anvil 15, an adjustably fixable stop 17, and a press tool 19.

The anvil 15 comprises an elongate steel block 21 in the upper surface of which there is a V-shaped channel 23 extending lengthwise of the block 21 between two flat coplanar surface portions 25a, 25b. The stop 17 is constituted as an elongate steel bar 27 having an accurately flat face 29. The bar 27 is adjustably fixably connected to the block 21, with its face 29 spaced accurately, with requisite spacing, from the line of the apex of the V-shaped channel 23 to extend parallel to the direction of length of the channel, with a parallelism of the order five times greater than that between the edges 13 of the metal sheet 11. Such an order of accuracy may be achieved using optical methods. Conventionally, however, such accuracy is achieved empirically, using fine manual adjustment angularly of the stop 17.

The press tool 19 which, also, is of steel, has an elongate nose portion 19a of V-shaped cross section, the angle of the nose portion 19a being less than that of the V-shaped channel 23 of the block 21. In forming a beam B, a sheet 11 is brought (Fig.4) to lie flat upon the coplanar surface portions 25a, 25b, of the block 21 with one 13a of its edges pressed firmly against the face 29 of the block 21.

With the sheet 11 so supported, the action of the press tool 19 and the block 21, at entry of the tool 19 into the channel 23, to an extent determined by a depth- travel limiting stop (not shown), results (Figs.2 and 5) in the bending of the sheet 11 about a fold line 31a inset from the edge 13a of the sheet 11 to produce an upstanding flange 33a of predetermined height along one of the longitudinal margins of the sheet.

The sheet 11 is, next, turned around through 180 degrees thereby to present (Fig.6) the other of its longitudinal edges 13b for abutment with the stop 17, and the action of the press tool 19 and block 21 is repeated, the sheet 11 being bent (Fig.2 and 7) about a second fold line 31b, inset from the edge 13b with a spacing identical to that of the fold line 31a, thereby to produce, in the sheet, an upstanding flange 33b extending along the other longitudinal margin of the sheet.

The two lateral flanges 33a, 33b, of equal angle, normal in the example, with respect to the web portion 33c therebetween, the adjustably-fixable stop 17 is reset to a position such that (Fig.8), with the flanged sheet 11 supported on the upper surface portions 25a, 25b, of the block 21, with the flange 33a pressed against the face 29a of the stop 27, the longitudinally- extending lines defined by the apices of the V-shaped nose portion 19a and the V-shaped channel 23, of press tool 19 and of the block 21, respectively, are at positions such that the upon operation of the press tool, the web portion 33c is bent (Figs.3 and 9) about a longitudinal central fold line 35 to form walls 37a, 37b, inclined to one another at, in the example, a right angle, the inclined walls 37a, 37b, of the flanges 33a, 33b, being symmetrical, at an angle of 45 , that is to say, with respect to the plane P containing the junctures of said inclined walls 37a, 37b, with said flanges 33a, 33b, respectively.

The final step in the formation of the beam comprises reinforcing the innate stiffness of the folded sheet, as represented in Fig.9, bracing it against bending under load.

The aforesaid final step may (Fig.10) involve the provision, within the mouth of the folded sheet depicted in Fig.9, of bracing means having the form of a strip 39 of sheet steel, longitudinal edges 41a, 41b, respectively, of which are parallel with one another, the strip 39 being united, by tack welds between the mutually inclined walls 37a, 37b, and the edges 41a, 41b, respectively, of the strip.

The bracing strip 39 may (Fig.11), instead of being wholly flat, be provided with longitudinally-extensive marginal flat portions 43a, 43b, respectively, each at an angle such that these may lie in face to face contact with the inclined walls 37a, 37b, spot welds uniting the flat marginal portions with the inclined walls 37a, 37b, at intervals along said marginal portions. In either case, the folded form of Fig.9 is, whilst the strip 39 is being tack or spot welded, held between surfaces 45a, 45b, of two rigid bodies.

An alternative method of bracing the folded form, shown in Figs.12 and 13, comprises embracing the folded form with a multiplicity of external constraint members, as 47, spaced apart at intervals along the folded form as depicted in Fig.9. Each constraint member 47 comprises a body 49 of flat sheet steel cut-away such as to define a re-entrant recess, the boundary of the recess being such that first and second portions 51a, 51b, respectively, thereof match the external local contour of the folded form shown in Fig.9, with a snug fit around each of the junction lines 31a, 31b, between the flanges 33a, 33b, and the inclined walls 37a, 37b, of the folded form. Except in the neighbourhood of such junction lines, there is clearance 55 between the inclined walls 37a, 37b, and the boundary of the reentrant recess of the member 43. A primary application for a beam produced as hereinbefore described is a trackway means for the tool carriage of a machine tool, a lathe, for example. Such trackway means is represented schematically in cross- section in Fig.14. The carriage 57 has two pairs of wheels, one wheel-pair 59, only, of which is to be seen in Fig.14, said wheel-pairs being spaced apart in the fore and aft dirction of the carriage, i.e. in he longitudinal direction of the beam.

The wheels, as 61, 63, of each of the two wheel- pairs, are rotatable with respect to the body of the carriage 57 about laterally spaced vertical axes

Y' Y', Y" Y" .

As may be observed in Fig.14, one 61 of the wheels is trapped against movement, other than rotary movement about the axis Y' Y' , first and second peripheral surfaces 65a, 65b, of the wheel 61 being in contact, respectively, with first and second surfaces 67a, 67b, the one 67a on the inwards facing surface of one 33a of the flanges, the other 65b on the inwards facing surface 37a' of the inclined wall 37a, at a position adjacent to said one flange 33a. The second wheel 63 is trapped, as before, against movement, other than rotary movement, first and second peripheral surfaces 69a, 69b, respectively, thereof being in contact, respectively, with first and second surfaces 71a, 71b, the one 71a on the inwards facing surface of the other 33b of the flanges, the other 71b on the inwards facing surface of the inclined wall 37b, adjacent to said other flange 33b.

In the apparatus described with reference to Fig.15 the wheels 61, 63, of the carriage 57 have peripheral surfaces, that are in contact with appropriate ones of the outwards facing surfaces of the flanges 37a, 37b, and of the inclined walls 37a, 37b, as the case may be.

In the apparatus of Fig.16, the carriage 57, suitably the tail-stock of a lathe, has a slidable runner part 65 which as before is constructed, arranged and adapted to cooperate with the beam such as, by sliding movement along the beam, to enable positional adjustment of the carriage along the trackway means.

Whilst the apparatus of Fig.13 or Fig.14 is depicted as having two pairs of fore and aft spaced wheels, as 59, in engagement with the trackway means, the means whether constituted by the second pair of wheels or (Fig. 16} by a sliding element 65 of substantial fore and aft dimension or by two such elements of lesser length suitably spaced apart, must be provided to counter any tendency of the carriage to rotate about vertical axis and/or transverse axes. Of the two means mentoned, it is thought that the most generally satisfactory means for avoiding any tendency of the unwanted carriage movement, as mentioned, is the former solution , that is to say, the provision in the carriage of two pairs of wheels spaced apart in the fore and aft direction. The apparatus as previously described employs a single beam formed as hereinbefore described. Whilst for some applications such an arrangement might prove to be adequate, the possibility of undue angular movement about the third axis, that extending parallel to the for and aft direction of the apparatus, remains.

In the embodiment depicted in Figs.17 and 18, the trackway means incorporates first and second beams each formed as hereinbefore described. Wheels 59 of the two fore and aft spaced pairs of wheels trap the carriage, represented, diagramatically, at 61 against substantially any unwanted motion about a fore and aft axis. Two fore and aft spaced apart wheels 63 constrain the carriage 57 against any tendency, present in the absence of the latter two wheels, to unwanted angular movement about a vertical axis.

Claims

CLAIMS 1. A method of forming a beam, being a method characterized by the steps comprising:

. bending a body of flat sheet metal (11) , having longitudinally-extensive, substantially parallel, edges (13a, 13b) , about notional parallel fold lines, respectively inset with respect to said parallel edges, such as to render said sheet metal body to a channel-form, that is to say, a body having a flat web portion (33c) with upstanding lateral flange portions (33a, 33b) ;

. bending said web portion about a longitudinal medial fold line (35) thereof such as to convert said web portion from a flat to a substantially V-shaped channel part; and, subjecting the inclined walls (37a, 37b) of said channel part to the action of bracing means (as 39) serving to oppose any tendency of the channel part to bend under load.

2. The method as claimed in claim 1 characterized in that:

. lateral flange portions (33a, 33b) of said channel are at equal angles with respect to the web portion (33c) of the channel.

3. The method as claimed in claim 1 or 2 characterized in that:

. said bracing means comprises a strip (39) of sheet metal having longitudinal edges parallel with one another, said strip being disposed within said V- shaped channel and being united with said inclined walls by welds between the strip and said walls at intervals therealong.

4. The method as claimed in claim 3 characterized in that:

. said bracing strip is united with said walls at tack welds along the edges thereof.

5. The method as claimed in claim 1 or 2 characterized in that:

. said bracing strip has longitudinally-extensive marginal flat portions (43a, 43b) at an angle such that these lie in contact with said walls, and spot welds unite said flat marginal portions with said walls at intervals along said marginal portions.

6. The method as claimed in claim 1 or 2 characterized in that:

. said bracing means comprises: a multiplicity of bracket members (49) spaced apart externally along said V-shaped channel, being bracket members having opposed re-entrant portions within which said flanges and adjacent portions of said walls have a snug fit.

7. The method as claimed in any preceding claim characterized in that: . said web portion is bent to a V-shaped channel the inclined walls of which subtend an angle the magnitude of which is such that said inclined walls and said lateral flanges make angles of equal magnitude with respect to the plane containing the opposed lines (P—P) defining the junctures of said inclined walls with said flanges.

8. The method as claimed in claim 7 characterized in that: . the web portion is bent such that inclined walls and said flanges make angles of forty-five degrees (45 ) with respect to said plane.

9. A beam produced using the method as claimed in any of the preceding claims.

10. An apparatus which is characterized by:

. trackway means means comprising at least one beam B as claimed in claim 9, and carriage means 61 constructed arranged and adapted to co-act with said trackway means such as to be held captive thereto whilst being permitted movement, substantially solely, therealong.