FR2676484A1 - SHEET COMPRISING MARGINAL REINFORCEMENT STRIPS PROVIDED WITH PERFORATIONS. - Google Patents

Abstract

For the production of a tarpaulin comprising marginal reinforcing bands comprising perforations, in which the distribution of the forces exerted in the zone of the perforations is carried out under better conditions in the surface of the tarpaulin, so as to reduce or to eliminate the so-called sliding closure effect, the recommended solution consists in having the perforations (3) formed in the marginal reinforcing strip (2) therein disposed eccentrically and are offset towards the edge (4 ) of the tarpaulin which is contiguous to the marginal reinforcement strip (2).

Description

y t 2676484 The invention relates to a cover comprising

  marginal reinforcement strips provided with perforations.

  Tarpaulins of this type are used for example as scaffolding tarpaulins. They are preferably constituted by canvas, by fabric covered with plastic material, by sheets of plastic material reinforced by loose fabric, mesh fabric, networks. of yarn or webs of fiberfill These

  sheets have margina- reinforcing strips

  which are provided with perforations in which can engage fastening bands, tightening ropes or similar devices Patent DE 23 56 028 C 3 describes for example a tarpaulin of the type in question

  in which perforations are provided exclusively

  In the marginal reinforcement strips and in which these marginal reinforcement strips provided with perforations are applied, sideways or on both sides, to the non-perforated edge of the sheet and are connected to the sheet in a manner There are also tarpaulins in which this is not only the marginal reinforcement strips which are perforated, but also the cover itself which is previously perforated at the perforations formed in the marginal reinforcement strips.

  also knows of tarpaulins in which the

  holes are made by means of tarpaulin elements and / or reinforcing tape which can be removed or pushed back, so that the user can open and use the perforations made in this way at will. The tarpaulins in question can be used

  not only as scaffolding tarpaulins, but also

  as tarpaulins for the protection of any material against the weather or as tarpaulins for trucks, -as tarpaulins for road or postal transport or for many other uses The category of tarpaulins envisaged also includes those which, for the resistance to tearing in the area of the perforations is greater, are provided with eyelets or other suitable devices to reinforce the edges of the perforations. In the case of tarpaulins known up to now, experience has shown that when the ropes or similar fastening devices are engaged in the corresponding perforations formed in the marginal reinforcement strips and that the forces come to be exerted, for example. example under the action of the wind

  or similar causes, it is not the corresponding hole

  inside which tears towards the edge of the sheet, but it is the marginal reinforcement strip which tears on the side opposite the edge of the sheet, following

  what is called in technical language "the effect of iron-

sliding block "l.

  From this state of the art, the object of the invention is the production of a sheet comprising

  marginal reinforcement strips provided with perfo-

  rations in which the distribution of the forces exerted in the area of the perforations is carried out in better conditions in the surface of the sheet so as to attenuate or eliminate the said effect

slide closure.

  This object is achieved, according to the invention, by different

annuities solutions.

  A first solution is characterized by the fact

  that the perforations in the reinforcing strip

  marginal cement are disposed there in an excen-

  trée and are shifted towards the edge of the tarpaulin which is

  adjacent to the marginal reinforcement strip.

  This arrangement ensures a better distribution of forces in the surface of the sheet, because the forces

  which, in the hypothesis of a force exerted perpendicularly-

  -3- on the edge of the tarp, develop at the level

  perforations and marginal reinforcement strips

  nales are distributed over a surface delimited by angles of 450 of the two sides of the line along which the force is exerted and the hypotenuse of this surface, which is formed by the active edge of the

  reinforcement strip which is located furthest inside

  laughs, is greater when household perforations

  in the marginal reinforcement strip are dis-

  eccentrically laid In principle, it is advantageous, in this embodiment, to use a reinforcement-marginal strip wider than those which have been used until now, so that the width of the part lying between the perforation and the edge of the reinforcing strip located on the side of the edge of the sheet is at least equal to what it was usual until now in the state of the art, while the width of the part of the reinforcement strip located on the other side, that is to say towards the surface of the tarpaulin, must be significantly greater The width between the perforation and the edge of the reinforcement strip situated on the side of the sheet the tarpaulin can be for example equal to twice the width between the perforation and the edge of the reinforcing strip located on the side

from the edge of the sheet.

  Another solution which answers the problem is posed, but which can be combined and combined with the characteristic according to which the perforations formed in the marginal reinforcement strip are arranged there in an eccentric manner and offset towards the edge of the sheet which is adjacent to the marginal reinforcement strip is characterized in that the marginal reinforcement strip widens, in the region of its perforations, towards the part of the sheet which is situated in the direction of the body of the

  tarpaulin which adjoins the reinforcement strip.

  In an advantageous embodiment, the lar-

  gor of the widened area, measured in the plane of the sheet transversely to the direction of the length of the marginal reinforcing strip, is at least equal to half the width that the marginal reinforcing strip has in its non-widened area . Furthermore, in another advantageous embodiment, the length of the enlarged zone is at least twice the width of the marginal reinforcement strip, measured between the perforation and the edge of the reinforcement strip which is located at the opposite the edge of the sheet which is contiguous to the

reinforcement tape.

  In a particularly embodiment

  advantageous, the marginal reinforcement strip pre-

  feels a curved line in the form of a corrugated ripple

  from the non-enlarged zone to the enlarged zone.

  Because in the area of the perforations mena-

  in the marginal reinforcement strip, the

  marginal perforation strip widens in direction

  tion of the part of the sheet which is located opposite

  placed on the edge of the sheet which is contiguous to the reinforcement strip, the distribution of the forces in the surface of the sheet is effected in better

  conditions, which is the goal, broadens it-

  ment having in this case to increase the length of the hypotenuse of the triangle of the lines of force resulting from the forces exerted The width and

  the length of the widened part must be determined

  undermined according to the logger that the hypotenuse of this

  triangle should have It is best that the long

  of this hypotenuse is substantially equal to twice the width of the reinforcing strip, measured between the perforation and the edge of the marginal reinforcing strip which is located opposite the edge of the sheet which is contiguous to the strip of reinforcement In the preferred embodiment in which the widened part has a curved outline of wavy shape, the force transmission line (separation line) between the marginal reinforcement strip and the cover (on the side opposite to the edge of the cover) is even longer, because the shape of the wave gives a longer force transmission line. This arrangement has the additional advantage of

  allow, as in the case of a reinforcement strip

  serrated shape, saving material at

  stage of manufacture of the reinforcing strip.

  It is possible, if necessary, to obtain without any waste a reinforcement strip of wavy or serrated shape from a strip with parallel longitudinal edges by carrying out a stamping giving two symmetrical reinforcement strips one of the other compared to a plan They can then be

  attached to the sheet in a known manner.

  According to another solution, the tarpaulin is reinforced in the zone of the marginal reinforcement strip and in an adjoining zone situated opposite the edge of the tarpaulin which is contiguous to the reinforcement strip, by an inserted reinforcement piece comprising parts in relief, arranged and fixed flat on the tarpaulin and constituted by a covering, a trellis, a fabric

or a tablecloth.

  The insertion of a reinforcement piece of this type ensures a better distribution of the forces over a

  larger surface in the surface of the tarpaulin

  said above, because the transmission of forces from the element which exerts its action at the level of the hole made in the marginal reinforcement strip is effected by the reinforcement piece up to its edge situated at

inside the tarpaulin.

  _ 6 _ The reinforcement piece inserted can be arranged in an eccentric manner, the perforations formed in the reinforcement strip therein also being arranged in an eccentric manner and offset towards the edge of the sheet which is contiguous to the reinforcement strip marginal, but it is also possible that the reinforcement piece inserted is produced in such a way that the reinforcement strip widens, in the plane of the perforations, towards the part of the strip which is situated opposite from the edge of the sheet which is contiguous

  to the marginal reinforcement strip and / or that the lar-

  gor of the enlarged area, m & urea in the plane of the

  btche transversely to the direction of the length

  marginal reinforcement strip sd t at least

  equal to 1 1/2 times the width of the reinforcement strip

  marginal a in its non-enlarged zone and / or that the length of the enlarged zone is at least twice the width of the marginal reinforcement strip measured between the perforation and the edge of the marginal reinforcement strip which is opposite from the edge of the sheet which is contiguous to the reinforcement strip and / or that the reinforcement strip has a curved undulating shape connecting the non-enlarged zone to the

enlarged area.

  Another advantageous embodiment

  in particular because of the association and the combination

  sound with the features that the

  tarpaulin is reinforced, in the area of the reinforcing strip

  cement and in a contiguous area opposite the

  edge of the sheet which adjoins the reinforcement strip

  ment, by an inserted reinforcement piece comprising raised parts, arranged and fixed flat on the sheet and constituted by a covering, a trellis, a fabric or a sheet, is characterized in that at least in the reinforcement zone marginal, preferably

- 7 _ 2676484

  7 - in a fairly wide area, the device comprises, between the inserted reinforcement piece and the second

  sheet of plastic covering it, a tablecloth.

  which is compressed with the sheets in such a way that the tarpaulin is reinforced over its entire surface by a reinforcement piece inserted between them and

  constituted by a trellis or a network.

  In this case, the enlarged zones are characterized above all in that the perforations formed in the marginal reinforcement strip are arranged there in an eccentric manner and are offset towards the edge of the

  tarpaulin which is contiguous to the marginal reinforcement strip

  and / or that the reinforcement strip widens, in the area of the perforations, in the direction of the part of the sheet which is situated opposite the edge of the

  tarpaulin which is contiguous to the marginal reinforcement strip

  nale and / or that the width of the enlarged area, measured in the plane of the sheet transversely to

  in the direction of the length of the reinforcing strip

  ginal, is at least equal to 1 1/2 times the width that the marginal reinforcement strip has in its widened zone and / or in that the length of the widened zone is at least equal to twice the width of the strip of marginal reinforcement measured between the perforation and the edge of the marginal reinforcement strip which is opposite the edge of the sheet which is contiguous to the reinforcement strip and / or in that the

  reinforcement presents a curved wave-shaped trace

  lation connecting the non-enlarged zone to the enlarged zone

  and / or in that in the area of the reinforcement strip

  mentally marginal and in a contiguous zone situated opposite the edge of the tarpaulin which is contiguous to the reinforcing bard, the tarpaulin is reinforced by an inserted reinforcing part comprising raised parts, arranged and fixed flat on the tarpaulin and constituted by a covering, a trellis, a fabric or

a tablecloth.

  In this case, an embodiment is characterized in that the ply has a thickness equal to or greater than the thickness of the inserted reinforcement piece.

  Experience has shown that b & ches with parts

  these reinforcement applied over their entire surface

  and constituted by trellises or similar devices

  logues tear, in addition, in particular, in the marginal zone of the reinforcement strip, because the trellis produces a "notch effect" t in this zone due

  that the trellis or the like has a structure

  ture oriented parallel to the edge of the reinforcement area

  This is particularly the case for bêches whose manufacture is carried out by first placing on a sheet of plastic material previously spread a lattice, then ean raisant-ar extrusion a second sheet on the lattice These conditions of manufacture mean that at the level of the mesh the second sheet applied by extrusion is thinner, which

  makes it less solid and increases the risk of tearing.

  If, however, according to the solution recommended in the invention, a sheet is applied to the lattice structure before the extrusion of the second sheet and if this is done, then the application by extrusion of the second sheet is carried out plastic for the

  construction of the tarp, the trellis wires are prepared

  ticks masked by the sheet which covers them, which excludes or makes insignificant any thinning of the material in the zone of the second sheet produced by extrusion The extrusion rolls moreover anyway ensure the compacting of the whole of the sheet , but at the same time gives 4 t 'as a bearing surface for the second extruded sheet a flat surface

  having no structure of three.

9 2676484

  9 9- I 1 already follows that in principle the tendency to

  tear is attenuated and it is particularly

  It is advantageous for the perforations formed in the reinforcement strip to be arranged there eccentrically and offset towards the edge of the sheet which is contiguous to the marginal reinforcement strip and / or for the reinforcement strip to widen, in the area of the perforations, in the direction of the part of the sheet which is situated opposite the edge of the sheet which is contiguous

  to the marginal reinforcement strip and / or that the lar-

  gor of the widened zone, measured in the covering plane transversely with respect to the direction of the length of the marginal reinforcement strip, is at least equal to 1 1/2 times the width that the marginal reinforcement strip has in its non-widened zone and / or that the length of the enlarged zone is at least twice the width of the marginal reinforcement strip measured between the perforation and the edge of the marginal reinforcement strip which is opposite the edge of the sheet which is adjacent to the reinforcing strip and in that the reinforcing strip has a curved undulating shape connecting the non-enlarged zone to the enlarged zone and / or that, in the zone of the

  marginal reinforcement strip and in a conti-

  ford located opposite the edge of the sheet which is contiguous to the reinforcement strip, the sheet is reinforced by an inserted reinforcement piece comprising parts

  embossing, arranged and fixed flat on the tarpaulin and

  formed by a covering, a trellis, a fabric or a tablecloth and that the inserts have a similar structure. - The invention is described below in more detail by means of exemplary embodiments

referring to the drawing.

  Figure 1 is a very schematic view of a pre-

  mier embodiment. Figure 2 to 4 show, in the same

  conditions, other embodiments.

  Figures 5 and 6 are sections along the lines V oi VI of the embodiments shown

by figure 4.

  Figure-1 shows a sheet 1 which has a marginal reinforcing strip 2 in which were formed perforations 3 The perforations 3 formed in the reinforcing band 2 are arranged there eccentrically and offset towards the

  edge 4 of the sheet which is contiguous to the reinforcement strip

  forcing marginal The embodiment known in the state of the art and used until now

  for making a marginal reinforcement strip

11 -

  nale is indicated by the dashed line 5.

  In the state of the art, the perforation 3 is found

  goes in the middle of the marginal reinforcement strip

  2 As a result, the line on which the effort is exerted

  this was practically limited to the LM part The eccentric arrangement of the perforations 3 has the effect of lengthening this line, on which the force is exerted over the entire part L 2, the principle being that the force which is exerted in the direction of the arrow K produces a

  force field which is delimited by lines

  ending angles of 450 and whose hypotenuse is

  constituted by the edge of length L 2.

  In the embodiment represented by the figure

  gure 2, the marginal reinforcement strip 2 widens, in the area of the perforations 3, in the direction of the part of the sheet 1 which is situated opposite the edge

  4 of the sheet which is contiguous to the reinforcement strip

  However, in the area that does not

  does not have perforations, the marginal reinforcement strip 2 is not widened The width of the area

  enlarged, measured in the plane of the transverse tarpaulin

  relative to the direction of the length of the marginal reinforcement strip 2 is at least equal to half the width that the marginal reinforcement strip 2 has in its non-enlarged zone The length of the enlarged zone is at least twice the

  width of marginal reinforcement strip 2

  between the perforation 3 and the edge of the marginal reinforcement strip which is opposite the edge 4 of

  the sheet which is contiguous to the reinforcement strip.

  The example of embodiment described corresponds to a mode

  preferred embodiment in which the reinforcing strip

  marginal 2 has a curved waveform

  lation connecting the non-enlarged zone to the enlarged zone.

  Therefore, the force transmission line is 12 - a line of length L 3 significantly longer than that which is produced in the state of the art (length L1), which improves the conditions of transmission of the forces and, therefore, attenuated the so-called slide closure effect. In the embodiment shown in FIG. 3, the sheet is reinforced, in the region of the marginal reinforcement strip 2 and in a contiguous area 7 situated opposite the edge 4 of the sheet which is contiguous to the strip reinforcement, by an inserted reinforcement piece 8 comprising raised parts, arranged and fixed flat on the sheet 1 and constituted by a covering, a trellis, a fabric or a sheet The insertion of the reinforcement piece 8 ensures a better distribution of forces, because when forces are exerted in the direction of arrow K and their transmission takes place on the

  lines 6, they are transmitted to the reinforcement piece

  ment 8, so that's practically the length

  L 4 which intervenes for the transmission of forces.

  In this embodiment, a combination is

  obviously possible with the men-

  in the corresponding example

in Figures 1 and 2.

  Figures 4 and 6 show a tarpaulin 1

  carrying marginal reinforcement strips 2, this sheet 1 being reinforced over its entire surface by two plastic sheets 9, 10 and by a reinforcement piece inserted between them and constituted by a trellis 11 In the zone subjected to the action of the marginal strip 2, the device comprises, between the insertion part II and the second plastic sheet 10 which covers it, a ply 12

  applied by pressing against the leaves.

  res 5 and 6 clearly show the effect 13 - resulting from this device FIG. 5 represents an area of the sheet 2 which does not have a ply 12 For the manufacture, one begins by placing the lower sheet 1 then, on this, the lattice 11 Then, the sheet 10 is produced by extrusion This results, at the level of the wires of the lattice (lattice 11), that is to say in zone 13, a weakening of the material constituting the sheet 2, which causes, at these locations, a "notch effect" when forces are exerted on the sheet, in particular in the direction of the arrow K FIG. 6 represents a zone in which a sheet 12 is applied to the trellis 11 In this case also, one begins by setting up the sheet 9, then, on this one, the trellis 11 and the sheet 12,

  after which the sheet 10 is produced by extrusion.

  Despite the action of the pressure cylinders, there does not occur in this case any weakening in the wires of the mesh 11, so that the sheet in

  its whole is less prone to tearing at ni-

  calf son of the mesh 11 It is advantageous to give the sheet 12 a thickness equal to or greater than the thickness of the reinforcing piece formed

by the trellis 11.

  The embodiment represented by FIGS. 4 to 6 can be used in an advantageous manner> in particular in combination with the characteristics

  indicated for the other exemplary embodiments.

  The invention is not limited to the examples of

  achievement, but can result in multiple mo-

  modifications within the framework of the invention.

  All new features mentioned-

  born individually or in combination in the

  description and / or drawing are considered to be

essential for the invention.

14 -

Claims (7)

  1 Tarpaulin comprising marginal reinforcement strips provided with perforations, characterized in that the perforations (3) formed in the marginal reinforcement strip (2) are arranged there in an eccentric manner and are offset towards the edge (4) of the tarp is   adjacent to the marginal reinforcement strip (3).   2 Tarpaulin comprising marginal reinforcement strips provided with perforations, characterized in that the marginal reinforcement strip (2) widens, in the area O of its perforations (3), towards the part of the covering ( 1) which is located opposite the edge (4)   of the sheet which is contiguous to the reinforcement strip.   3 Tarpaulin with marginal reinforcement strips   provided with perforations, characterized in that the width   gor of the enlarged area, measured in the plane of the   log transversely to the direction of the length   of the marginal reinforcement strip (2), is at least equal to 1 1/2 times the width of the   marginal reinforcement (2) a in its non-enlarged area.   4 Tarpaulin with marginal reinforcement strips   provided with perforations according to one of claims   2 or 3, characterized in that the length of the enlarged zone is at least twice the width of the marginal reinforcement strip (2 Y, measured between   the perforation (3) and the edge of the reinforcing strip -   cement (2) which is located opposite the edge (4) of the   tarpaulin which adjoins the reinforcement strip.   Tarpaulin with marginal reinforcement strips provided with perforations   according to one of claims 2 to 4, characterized in that   the marginal reinforcement strip (2) has a curved wave-like layout, connecting   the area not enlarged to the enlarged area.   - 6 Tarpaulin comprising a marginal reinforcement strip provided with perforations, characterized in that the   tarpaulin is reinforced, in the area of the reinforcement strip   forcing marginal (2) and in a contiguous zone located opposite the edge (4) of the sheet which is contiguous to the reinforcement strip, by a reinforcement piece (8) inserted having raised parts, arranged and fixed flat on the sheet (1) and formed by a covering, a trellis, a fabric or a tablecloth.   7 Tarpaulin comprising a marginal reinforcement strip provided with perforations according to claim 6, characterized in that the reinforcement piece (8) and / or the marginal reinforcement strip (2) is produced under conditions corresponding to one at   less of the characteristics indicated by the res- dication 1 to 5.   8 Tarpaulin with a marginal reinforcement strip   provided with perforations, in particular according to one of the   vendications 6 or 7, in which the tarpaulin is   forced over its entire surface by two sheets of plastic material and by a reinforcement piece, inserted between them and constituted by a trellis or a covering, characterized in that at least in the region of the marginal reinforcement strip (2 ), preferably in a fairly wide area, especially   in areas with particular characteristics   as indicated by claims t to 7, it   comprises, a sheet (12) interposed between the reinforcement piece (11) and the second plastic sheet (10) and compressed against the sheets (9,).