WO2004027134A2 - Mounting frame and loom fitted with said mounting frame - Google Patents

Abstract

The frame, which is obtained by assembling two struts (21) with two cross-bars (22) each of which is provided with a heald-carrier rod (29), comprises at least one hoop (40) surrounding a tubular extremity (28) of said cross-bar (22) in an area in which it is joined to the adjacent strut (21) and an area in which at least one locking member (25,26) of part (21a) of said strut is received. The area of junction is created in part (35) of the extremity (28) provided with an external transversal profile which is essentially convex. The hoop is provided in order to resist a locking effort (F3, F'3) exerted by the locking member (23, 24).

Description

 STRING FRAME AND WEAVING EQUIPMENT PROVIDED WITH SUCH A FRAME

The present invention relates to a heald frame and a loom equipped with such a frame.

It is known to equip a loom with heald frames intended to be controlled in a movement of vertical oscillations by means of an appropriate device, such as a weaving mechanism or an dobby. It is known to produce a heald frame by reversible assembly of two uprights and two crosspieces, the uprights being substantially vertical in the configuration of use of the heald frame, while the crosspieces are substantially horizontal.

FR-A-2 681 614 discloses a removable elastic joining device which can be used in a corner of a heald frame, that is to say in the junction zone between a cross member and an upright. In this device, a protuberance formed on an upright is intended to be wedged between two jaws integral with two rigid parts forming heads intended to be wedged inside a crosspiece. Given the acceleration and deceleration efforts undergone by a heald frame, such a junction device induces very significant stresses on the cross member, which can lead to tearing of the side walls of such a cross member. Similar problems arise with the known device of DE-A-33 08 371 in which a rigid type connection is made between an upright and a cross member of heddle frame, by means of a tensioning of the lateral faces of the crosses. The problems identified above are more and more crucial insofar as it is wished to operate the weaving looms at increasingly high speeds, which implies to lighten the heald frames as much as possible to reduce their inertia, thereby reducing the mechanical resistance of the sleepers. Conversely, the mechanical connections between the uprights and the crosspieces must be increasingly robust to resist the increasingly violent accelerations and decelerations to which these moving parts are subjected.

The invention aims to solve the problems of prior devices by proposing a robust heald frame capable of being mounted on a loom operating at high speed. In this spirit, the invention relates to a heald frame for a weaving loom, this frame being obtained by assembling two uprights with two sleepers each provided with a one-piece heald carrying strip with the corresponding sleeper or attached thereto on substantially its entire length, at least one of the ends of at least one of the crosspieces being equipped with at least one member for blocking part of an adjacent upright, inside a portion of end of the crosspiece which forms a junction zone with this upright. This frame is characterized in that the aforementioned end portion comprises a part with a generally convex transverse external profile and at least one hoop which surrounds the aforementioned part and the blocking member, in order to resist a blocking force exerted by that -this. Thanks to the invention, the hoop, which can be produced by a tubular sleeve or a folded sheet, makes it possible to improve the resistance of the cross-member to the forces transmitted by the adjacent upright and resulting from the blocking of the aforementioned part of this upright. This limits in consequently the risks of deterioration of the crosspiece at this junction zone. In other words, the mechanical forces undergone by the crosspiece in the junction zone are reduced by the hoop, which improves the overall mechanical characteristics of the heald frame. The invention takes advantage of the fact that the generally convex profile of the junction zone allows it to be associated with a hoop, whereas this would not be the case if this profile had an opening or a cavity, for example for the hooking the ends of the beams.

Other advantageous aspects of the invention, which can be associated with one another in any technically feasible combination, emerge from the appended dependent claims. The invention also relates to a weaving loom equipped with at least one heald frame as previously described. Such a loom can operate at higher speed and is more reliable than those of the prior art.

The invention will be better understood and other advantages will appear more clearly in the light of the following description of a weaving loom and of several heald frames in accordance with its principle, given solely by way of example and made in reference to the accompanying drawings in which: - Figure 1 is a schematic representation of the principle of a weaving loom according to the invention;

- Figure 2 is an exploded partial section of a heald frame of the loom of Figure 1 at the respective ends of one of its uprights and one of its crosspieces;

- Figure 3 is a section along line III-III in Figure 2;

- Figure 4 is a principle section, on a smaller scale, of the upper and lower parts of a cross a heald frame according to a second embodiment of the invention;

- Figure 5 is a section along the line N-N in Figure 4; - Figure 6 is a section similar to the upper part of Figure 5 for a frame according to a third embodiment;

- Figure 7 is a section similar to Figure 4 for a frame according to a fourth embodiment of the invention;

- Figure 8 is a section similar to Figure 4 for a frame according to a fifth embodiment of the invention;

- Figure 9 is a section similar to Figure 4 for a frame according to the sixth embodiment of

The invention;

- Figure 10 is a section similar to Figure 4 for a frame according to a seventh embodiment of the invention; FIG. 11 is a side view of the end of a cross member of a heddle frame according to an eighth embodiment of the invention,

FIG. 12 is a view similar to FIG. 11 for a heald frame according to a ninth embodiment of the invention,

FIG. 13 is a view similar to detail XIII in FIG. 2, for a frame according to a tenth embodiment of the invention,

- Figure 14 is a view similar to Figure 2 for a frame according to an eleventh embodiment of

The invention,

FIG. 15 is a section along the line XV-XN in FIG. 14, FIG. 16 is a section similar to FIG. 15 for a heald frame according to a twelfth embodiment of the invention,

- Figure 17 is a partial section along the line XVII-XVII in Figure 16 and

- Figure 18 is a view similar to Figure 2 for a frame according to a thirteenth embodiment of the invention.

In Figure 1, a dobby 1 is intended to drive a heald frame 2 of a loom M in a vertical oscillating movement represented by the arrows F _x and F _x '. To do this, an actuating arm 1a of the dobby 1 is coupled by connecting rods and oscillating levers to each heald frame 2. Each frame 2 is formed by the assembly of two uprights 21 and two crosspieces 22. The uprights 21 extend generally in a direction parallel to the direction ZZ 'of vertical oscillation of the frames 2, while the crossbeams 22 extend generally in a direction YY' perpendicular to the direction ZZ 'and generally horizontal in configuration of use of loom M.

In the following of this description, we study in more detail the junction between the left upright 21 and the upper cross member 22 of a frame 2. It is understood that the assembly of this cross member with the right upright 21 or the lower crossmember with one or the other of the uprights 21 can incorporate the same structural and functional characteristics. As can be seen more particularly from FIG. 2, the upright 21 is provided with a protuberance 21a intended to be introduced between two jaws 23 and 24 each secured to a mass piece 25, respectively 26, articulated one on the other inside the end 28 of the crosspiece 22. For this purpose, the crosspiece 22 is hollow and constituted by a tube with a generally rectangular cross section from which extends, over substantially its entire length, a tab 29 forming a heald bar on which can be attached to the heddles 30 for guiding the chain wires of the loom M.

In its middle part, the crosspiece 22 is advantageously filled with a stiffening and / or soundproofing material. The lower cross member is also provided with a heald support rod.

The rod 29 is in one piece with the crosspiece 22 and connected thereto, over most of its length, by a web 29c. We note respectively 31 and 32 the small upper and lower sides of the tubular part of the crosspiece 22. We note respectively 33 and 34 the large lateral sides of this part. We note 35 the tubular part of the end 28 into which the parts 25 and 26 are introduced. This part 35 is separated from the end part 29a of the heald bar 29 by a groove 36 which extends, starting from the end face 28a of the end 28, in a direction Y ₃ g-Y ' ₃ 6 parallel to a longitudinal axis Y ₂ -Y' ₂₂ of the crosspiece 22. The assembly of the elements 21 and 22 takes place by immobilizing the protuberance 21a between the jaws 23 and 24 by tightening an operating screw 37. Due to the approximation of the jaws 23 and 24, represented by the arrows F ₂ and F ' ₂ , the parts 25 and 26 exert on the sides 31 and 32 a blocking force represented by the arrows F ₃ and F ' ₃ . This force is exerted through an elastomer element 27 placed under stress between each part 25 or 26 and the nearest short side 31 or 32. This elastomer element conforms to the technical teaching of FR-A-2 681 614.

In order to be able to effectively resist this blocking force without risk of tearing of the part 35, a hoop 40 is arranged around this part 35 while being partially engaged in the groove 36. This hoop 40 is constituted by a sheet metal plate folded around of part 35 and immobilized around it by cooperation of shapes and by means of two screws 41 screwed into tapped orifices 42a of a counterplate 42 introduced inside part 35. The screws 41 also pass through a plate 43 for distributing over the length of the hoop 40 a force F ₅ for clamping its respective edges 40a and 40b on the side 31 of the part 35. The part 35 and the hoop 40 together form an end portion P of the crosspiece 22 which contains the locking means 25 and 26 and resists the locking force F ₃ and F ' ₃ .

The hoop 40 can effectively play its role of reinforcing the part 35, because this part has a transverse external profile, consisting of the external surfaces of the sides 31 to 34, which is convex and therefore suitable for the use of such a hoop. Indeed, if the hoop was placed at the same time around the part 35 and the end part 29a of the bar 29, the attachment of the heddles in this zone would not be possible and the bar 29 could be crushed due to the existence of a cavity or a hollow between it and the short side 32 of the part 35.

Thus, the groove 36 allows suitable positioning of the hoop 40 around the part 35. The groove 36 has a length L _3S greater than or equal to the width 1 ₄₀ of the hoop 40, the part 29a of the bar 29 being in door - overhang on the length L _3S . In practice, the length L ₃₆ is slightly greater than the width ₁₄₀ . In the second embodiment of the invention shown in Figures 4 and 5, elements similar to those of the first embodiment bear identical references increased by 100. The cross member 122 of this embodiment is equipped with a hoop 140 which surrounds a part 135 with a convex transverse profile at its end 128. The short sides are noted 131 and 132, 133 and 134 the long sides of the part 135, respectively.

This embodiment differs from the previous essentially in that the immobilization of the hoop 140 around the part 135 takes place by blocking two corners 144 and 144 'connected by a screw 145 and able to cooperate with a complementary corner 146 wedged against the internal surface 140c of the hoop 140 which is constituted by a tubular steel sleeve.

There are respectively 144a, 144 'a, 146a and 146' a the wedging surfaces provided on the corners 144, 144 'and 146, the surface 146' a being that of the corner 146 intended to cooperate with the surface 144 'a. The end portion P formed by the parts 135 and 140 may contain locking means, like that of the first embodiment.

Unlike the first embodiment where the parts 29 and 35 are in one piece, the bar 129 for attaching the heddles of this second embodiment is attached to the main tubular part 135. To do this, the short side 132 of the part 135 is provided with a groove 138 into which can be inserted a rod 129b integral with the bar 129 and whose section is complementary to that of the groove 138, which allows the bar 129 to be suspended from the part 135. note 129c the connecting veil between the rod 129b and the part of the bar 129 on which the beams are hung. As before, this veil stretches over substantially the entire length of the crosspiece 122 and is interrupted at an end portion 129a of the bar 129, which forms a groove 136 allowing the positioning of the hoop 140. As shown in FIG. 6, the hoop 140 can be rounded above the complementary corner 146.

In the fourth embodiment of the invention shown in FIG. 7, elements similar to those of the first embodiment bear identical references increased by 200. The crosspiece 222 of this embodiment is provided with an inclined surface 222b relative to its longitudinal axis 222 ^_ Y'222 and intended to cooperate with the inclined surface 244a of a corner 244 associated by a screw 245 with a stop 247 disposed against a lateral edge 24Od of a hoop 240 in the form of a metal sleeve tubular. The traction exerted by the screw 245 on the corner 244 makes it possible to tension the hoop 240 and thus immobilize it around a part 235 with a convex profile of the crosspiece 22 which forms with it an end portion P of the crosses 222.

In the fifth embodiment represented in FIG. 8, elements similar to those of the first embodiment of the invention bear identical references increased by 300. A hoop 340 is arranged around a part 335 of a crosspiece 322 and forms with it an end portion P. A corner 344 is provided with an active surface 344a which cooperates with an active surface 340c constituted by the internal face of the hoop 340, this face being inclined relative to a longitudinal axis Y ₃₂₂ / Y'322 of the crosspiece 322. The displacement of the corner 344 is controlled by a screw passing through a stop 347 disposed against a lateral edge 340d of the hoop 340.

In the sixth embodiment of the invention represented by FIG. 9, the elements similar to those of the first embodiment bear identical references increased by 400. The hoop 440 of this embodiment is immobilized, by a layer of glue 448, around a part 435 of a crosspiece 422 with which it constitutes a portion of end P. At the level of the small upper side 431 of the part 435, this layer of glue 448 is thick enough for a wedge 444 to be inserted therein in the direction of the arrow F _s in FIG. 9, which has for effect of positioning the hoop 440 and ensuring a good distribution of the adhesive.

In the seventh embodiment of the invention shown in FIG. 10, elements similar to those of the first embodiment bear identical references increased by 500. A hoop 540 is immobilized around a part 535 of a crosspiece 522 by means of a screw 541 which passes through an orifice 540e formed in the hoop 540 and which is screwed into a small upper side 531 of the part 535. As a variant, several screws of the type of screw 541 can be used. An end portion P of the crosspiece 522 is formed by the elements 535 and 540.

As shown in Figures 11 and 12 respectively, the longitudinal shape of a hoop 640 or 740 can be adapted to improve the progressiveness of the transmission of forces between the hoop and the crosspiece. Thus, the edge 640d of the hoop 640, which is opposite to the end face 628a of the crosspiece 622, can have a pointed shape on one or the other of the sides of this crosspiece or on both. Conversely, and as shown in FIG. 12, this edge 74Od can have a hollow shape. These edge geometries 640d and 740d are particularly suitable for the case where the connection between the crosspiece and the hoop takes place by gluing. They make it easier to locate the transmission of forces between the cross member and the hoop at the end portion P.

In the tenth embodiment of the invention shown in FIG. 13, elements similar to those of the first embodiment bear identical references increased by 800. A hoop 840 is immobilized around a part 835 of the end 828 of a crosspiece 822 of a heddle frame. The part 835 has a generally convex transverse external profile, while the cross member 822 is equipped with a heald-carrying rod 829. A groove 836 is formed between the part 835 and the rod 829 for the passage of the hoop 840 which is constituted of a sheet metal plate folded around the part 835, like the hoop 40 of the first embodiment. The groove 836 does not open onto the end face 828a of the end 828 but is formed by an oblong opening, the largest axis s36 ^_ Y '836 of which is generally parallel to the longitudinal axis s22-' 822 of the cross member 822.

In the eleventh embodiment of the invention shown in Figures 14 and 15, elements similar to those of the first embodiment bear identical references increased by 900. The frame of this embodiment comprises an upright 921 provided with a beak or protuberance 921a intended to be introduced inside an end 928 of a crosspiece 922.

To this end, the cross-member 922 is hollow, at least in its end zone, and formed in this zone, by a tube with a generally rectangular cross section from which extends, over substantially its entire length, a tab 929 forming a heald bar on which healds 930 for guiding the warp threads of the loom M can be hung.

The lower cross member is also provided with a heald support rod. There are respectively 931 and 932 the small upper and lower sides of the tubular part of the cross member 922. There are respectively 933 and 934 the large lateral sides of this part. We note 935 the tubular part of the end 928 into which the spout 921a is introduced. This part 935 is separated from the end part 929a of the heald bar 929 by a groove 936 which extends, from the end face 928a of the end 928, in a direction Y936- '936 parallel to an axis longitudinal Y 922 -Y '922 of cross member 922.

A hoop 940 is arranged around the part 935 while being partially engaged in the groove 936. The elements 935 and 940 together form an end portion P of the cross-member 922. The hoop 940 is tensioned around the part 935 of the cross member 922 by virtue of two corners 944 and 944 'connected by a screw 945 and able to cooperate with a complementary corner 946 wedged against the internal surface 940c of the hoop 940. There are respectively 944a, 944'a, 946a and 946'a the surfaces ^' or sliding ramps provided on the corners 944, 944' and 946, the surface 946'a being that of the corner 946 intended to cooperate with the surface 944'a. The surfaces 944a and 944'a are inclined relative to the longitudinal axis of the screw 945, that is to say to the longitudinal axis Y ₉ 22-Y'9 ₂ 2 / by two angles ai and α ₂ of opposite meaning and of the same absolute value.

Each large side 933 and 934 of the part 935 is provided with a softening slot 949 which allows the introduction of the spout 921a into the part 935 and then the tightening of this part around this spout, when the corners 944 are brought together and 944.

Thus, the mechanical members 944 to 946 alone make it possible both to immobilize the nozzle 921a in the part 935 and tension the hoop 940 around this part. In practice, the screwing of the screw 945 in the corner 944 has the effect of bringing the corners 944 and 944 'closer together, the surfaces or ramps 944a and 944'a of which slide against the surfaces or ramps 946a and 946'a, which effect of moving the corners towards the rod 929.

These corners exert on the part 935 a force F ₉ directed towards the rod 929 and the part 935 deforms, thanks to the flexibility obtained by the slot 949. This deformation of the part 935 results in an immobilization force F ₁₀ of the spout 921a in this section.

In addition, the relative sliding of the corners 944 and 944 ', on the one hand, and 946, on the other hand, has the effect of transmitting to the hoop a force Pu of tensioning this element. Note that, given the closed nature of the hoop 940, the force Fu is transferred to the level of the part of the hoop passing through the groove 936, which has the effect of tightening the protuberance 921a by the combination of the forces Fι ₀ and Fu. In practice, the forces Fχ ₀ and Fu are balanced.

It is noted that the geometry of the upright 921 is particularly simple because the spout 921a is in one piece with a main part 921b of the upright 921 which extends parallel to the direction ZZ 'of oscillations of the frame. The hoop 940 can effectively play its role of reinforcing the part 935, because this part has a transverse external profile, consisting of the external surfaces of the sides 931 to 934, which is convex and therefore suitable for the use of such a hoop. Furthermore, the spout 921a is provided, at its respective upper and lower sides with two pointed parts 921g and 92lh intended to penetrate into recesses of corresponding shape 932g and 93lh provided respectively in the short sides 932 and 931 the part 935. Parts 921c [and 921h are each defined between two V-shaped surfaces 921i_ and 921j_ which are generally flat and parallel to the Y axis ₉ 22-Y'922- These surfaces are inclined, in the plane of FIG. 3 , with an angle γ of the order of 45 ° relative to a plane P ' ₂ perpendicular to the main plane P ₂ of the frame 2. The angle γ can, in practice, have a value between 20 and 70 °. In other words, the upper and lower sides of the nozzle 921a are of generally triangular section. As a variant, only one of these sides can have such a geometry.

The internal geometry of the crosspiece 922 is adapted to that of the spout 921a and the housings 932g_ and 931h are defined between two inclined surfaces, 932ji and 932j_ _/ respectively 93li and 931j_, making the same angle γ with the plane P ' ₂ .

Thus, the span between the crosspiece 922 and the element 921a which it contains takes place by two sets of surfaces 921i, 931i and 932i, on the one hand, and 921j_, 931j_ and 932j_ on the other hand, distributed on the one hand and on the other side of the plane P ₂ and inclined relative to it.

The surfaces 92li and 921j_ are oblique to each other, as are the surfaces 931i and 931 "on the one hand, 932i. and 932_ _/ on the other hand.

The inclined nature of the surfaces 921i, 921 / 931i., 931j_ / 932i and 932j_ makes it possible to improve the adhesion between the elements 921 and 922.

In the twelfth embodiment represented in FIGS. 16 and 17, elements similar to those of the first embodiment bear identical references increased by 100. The upright 1021 of this embodiment also comprises a monobloc spout 1021a with an elongated part 1021b , this spout being intended to be inserted into a part 1035 of the end 1028 of a crosspiece 1022. As before, a hoop 1040 is disposed around the part 1035 and forms with it an end portion P.

In this embodiment, the mechanical means for immobilizing the spout and for tensioning the hoop are not disposed between the part 1035 and the hoop, as in the first embodiment, but inside the part 1035. More specifically, two corners 1044 and 1044 'are controlled, in a movement of movement parallel to a longitudinal axis Yιo22-Y'ιo22 of the cross member 1022, by a screw 1045.

We note respectively 1044a and 1044 'at the ramp surfaces of these corners 1044 and 1044'. These surfaces cooperating respectively with surfaces forming a ramp 1021c and 1021d provided on the spout 1021a, with angles of inclination βi and β ₂ , relative to the longitudinal axis of the screw 1045 and to the axis Yιo2 ₂ - 'ιo2 ; of opposite direction and of the same absolute values.

The spout 1021 is also provided with a tab 1021e provided with an orifice 1021f for the passage of the screw 1045. Depending on the tightening of the screw 1045, a force Fu is transmitted on the short sides 1031 and 1032 of the part 1035. to the hoop 1040 for its tensioning. As before, the force F is transferred by the hoop 1040 in the lower part of the protuberance 1021a in FIG. 16. Furthermore, the ramps 1044 and 1044 'exert on the corresponding ramps of the spout 1021a an effort F _xo of immobilization of this beak.

As can be seen more particularly from FIG. 5, the generally convex character of the profile of the part 1035 can be obtained by integrating a filling element 1050 in a hollow part 1022a of the cross member 1022. As a variant, the filling element can be secured to the hoop 1040 before positioning it around the part 1035. The screw 945 is offset, perpendicular to the axis Y ₉₂ 2-Y'922 and relative to the part 921b of the upright 921, beyond the spout 921a. Likewise, the screw 1045 is offset relative to the part 1021b. Thus, these screws are easily maneuverable without the need to drill the main parts of the uprights.

In the thirteenth embodiment shown in FIG. 18, elements similar to those of the first embodiment bear identical references increased by 1100. The metal upright 1121 of this embodiment is provided with a tenon or protuberance 1121a in one piece with the main part 1121b of the amount.

The cross member 1122 of this embodiment comprises a main part 1122a advantageously made of synthetic material. This part 1122a is in one piece with a heald bar 1129 to which it is connected by a web 1129c. The cross member 1122 also comprises a metal band 1140 which is bonded around one end 1128a of the part 1122a. 1148 denotes the layer of adhesive interposed between the elements 1140 and 1128a. The hoop 1140 extends in the direction of the main part 1121b of the upright 1121 beyond the end 1128a. 1140a denotes the part of the hoop surrounding the end 1128a of the synthetic portion 1122a of the cross member 1122. We denote 1140b the part of the hoop 1140 which extends beyond the part 1128a and which defines a tubular portion 1135 of the cross member 1122 provided to receive the stud 1121a. The elements 1128a and 1140 together form an end portion P of the cross member 1122. As before, a notch 1136 is formed between the main part 1122a of the cross member 1122 and the heald-carrying strip by means of a localized recess in the web. 1129c. The heald bar 1129 is cantilevered over part of its length. A nut 1126 is immobilized on an internal face of the part 1140b of the hoop and is crossed by the rod

1125a of a locking screw 1125. The rod 1125a and the nut

1126 constitute means for blocking the post 1121a situated inside the part 1140b of the hoop 1140.

This embodiment has the particular advantage that the removable connection between the pin 1121a and the hoop 1140 only involves parts of high resistance bearing against one another, which are advantageously metallic. In addition, the entire interior volume of the hoop 1140 is available for the installation of the stud 1121a, the height and thickness of which can be increased relative to that of the corresponding parts of the frames of the other embodiments. According to a variant not shown of the invention applicable to different embodiments, the hoop can be immobilized on the crosspiece by hot crimping.

Whatever the embodiment considered, the hoop remains in place on the cross member during disassembly of the frame, which allows it, in particular, to protect the ends of the parts of this cross member which are advantageously made of synthetic material.

Whatever the embodiment of the invention considered, the heald-carrying rod remains integral with the cross-member, which implies that the heddles used are of the “open” type.

The invention has been shown with mechanical means comprising two corners cooperating for the immobilization of the upright and the tensioning of the hoop. It is however applicable with a single corner provided with a single force transmission ramp.

The invention applies independently of the material used for the constituent parts of the frames, especially the uprights and crosspieces. It applies in particular to light alloy frames, such as aluminum, and to frames made of composite materials, with an organic resin and carbon or glass reinforcing fibers. In addition, the frets can be metallic or made of composite material.

The invention is applicable independently of the geometry of the heald-rods of the crosspieces which may have different shapes adapted to that of the ends of the healds.

The characteristics of the various embodiments described above can be combined with one another within the scope of the present invention. In particular, inclined surfaces similar to the surfaces 92li, 921J_ _Λ 931i, 931j_ etc. of the eleventh embodiment may be provided in the twelfth embodiment at the spout 1021a, between the crosspiece 1022 and this spout, at the level of the short lower side 1032, and / or between the cross member 1022 and the corners 1044 and 1044 ', at the small upper side 1031.

Claims

1. heald frame for weaving loom, said frame being obtained by assembling two uprights with two crosspieces each provided with a one-piece heald-carrying strip with the corresponding crosspiece or attached to it over substantially its entire length, the at least one of the ends of at least one of said crosspieces being equipped with at least one member for blocking part of an adjacent upright, inside an end portion of said crosspiece forming a zone of junction with said upright, characterized in that said end portion (P) comprises a part (35; 135; 235; 335; 435; 535; 835; 935; 1035; 1135) with generally convex transverse external profile and at least one hoop (40; 140; 240; 340; 440; 540 ; 640; 740; 840; 940; 1040; 1140) surrounding said generally convex transverse external profile part and said locking member (25, 26; 944-946; 1044, 1046; 1125a, 1126), in order to resist a locking force (F ₃ , F ' ₃ ) exerted by said locking member. 2. A heald frame according to claim 1, characterized in that said hoop (40; 140; 240; 340; 440; 540; 640; 740; 840; 940; 1040) surrounds said portion with generally convex transverse external profile. (35; 135; 235; 335; 435; 535; 835; 935; 1035) which is tubular and itself surrounds said blocking member (25, 26; 1044, 1046) and / or said part (921a; 1021a) of said amount. 3. Frame according to one of the preceding claims, characterized in that said crosspiece (22; 122; 222; 322; 422; 522; 622; 822; 922; 1022; 1122) is provided between said junction zone (35 ; 135; 235; 335; 435; 535; 835; 935; 1035; 1128a) and said heald wand (29; 129; 829; 929; 1129), of a volume (36; 136; 436; 836; 936; 1136) for partial reception of said hoop (40; 140; 240; 340; 440; 540; 640; 740; 840; 940; 1040; 1140). 4. Frame according to claim 3, characterized in that said volume is formed by a groove (36; 136; 436; 836; 936; 1136) extending between said junction zone (35; 135; 435; 935; 1128a ; 1135) and said rod (29; 129; 829; 939; 1129), in a direction (Y ₃₅ -Y ' ₃ 6; a36-' 8 ₃ 6) generally parallel to - a longitudinal axis (Y ₂ 2 ^_ Y '22;Ys22-Y'822) of the said crosspiece (22; 122; 822; 922; 1122). 5. Frame according to claim 4, characterized in that said groove (36; 136; 436) opens onto an end face (28a) of the end (28; 928; 1028) of the crosspiece (22; 122; 222; 322; 422; 522; 622; 922; 1022; 1122). 6. Frame according to claim 3, characterized in that said groove is formed by an oblong slot (836) formed between said generally convex transverse external profile portion (835) and said heald-carrying strip (829), said lumen not opening onto an end face (828a) of the end (828) of the crosspiece (822 ). 7. Frame according to one of claims 1 to 5, characterized in that said heald-carrying rod (29; 129; 829; 929; 1129) extends in overhang over ^" a part (29a; 129a ; 929a) of its length arranged opposite said junction zone (35; 135; 935; 1128a; 1135). 8. Frame according to one of the preceding claims, characterized in that it comprises means (40-42; 144- 146; 244-247; 344-347; 444, 448; 541; 944-946; 1044, 1046 ; 1148) of immobilization of said hoop (40; 140; 240; 340; 440; 540; 640; 740; 840; 940; 1040; 1140) on said junction zone (35; 135; 235; 335; 435; 535; 835; 935; 1035; 1128a; 1135). 9. Frame according to claim 8, characterized in that said immobilization means comprise a corner (144, 144 '; 244; 344) adapted to cooperate with a corresponding ramp (146a, 146a'; 222b; 340c) provided on an external face (222b) of said crosspiece (222), on an intermediate piece (146) or on an internal face (340c) of said hoop (340) for the tensioning of said hoop (140; 240; 340). 10. Frame according to claim 9, characterized in that said corner (144; 244; 344) is controlled, in its movement relative to said ramp (146a, 146 'a, 222b; 340c), by means of a connection screw-nut (144-145; 244-245; 344-345). 11. Frame according to claim 8, characterized in that said hoop (440; 1140) is glued (448; 1148) around said end (435; 1128a) of crosspiece (422; 1122a). 12. Frame according to claim 8, characterized in that said hoop (540) is provided with at least one orifice (540e) for the passage of a locking member (541) on said cross end (535). 13. Frame according to one of the preceding claims, characterized in that said hoop (40) is formed by folding a sheet formed around said junction zone (35). 14. Frame according to one of the preceding claims, characterized in that it comprises mechanical means (944-946; 1044-1045) capable of ensuring both the immobilization (F _i0 ) of a part (921a, 1021a) of said upright (921; 1021) in said end portion (935; 1035) and the tensioning (Fu) of said hoop (940; 1040). 15. Frame according to claim 14, characterized in that said mechanical means comprise at least one corner (944, 944 ', 946; 1044, 1044') interposed between said part (921a, 1021a) of said upright (921; 1021) and said hoop (940; 1040). 16. Frame according to claim 15, characterized in that said corner (944, 944 '; 1044, 1044') is controlled, in a translational movement generally parallel to a longitudinal axis (Y922- '92; ιo22- 'ιo22) of said crosspiece (922; 1022), by a screw-nut type connection (944-945; 1044-1045). 17. Frame according to one of claims 15 or 16, characterized in that said mechanical means comprise two corners (944, 944 '; 1044, 1044') provided with ramps (944a, 944'a; 1044a, 1044 'a) of force transmission inclined at angles (α _x , α; βi, β2) opposite with respect to a longitudinal axis (Y ₉ 22-Y'922;i022-Y'i022) of said crosspiece (922; 1022). 18. Frame according to one of claims 14 to 17, characterized in that the part (921a, 1021a) of said upright (921; 1021) inserted in said end part (935; 1035) of the crosspiece (922; 1022 ) is in one piece with the elongated main part (921b; 1021b) of said upright. 19. Frame according to one of claims 14 to 18, characterized in that the part (1021a) of said upright (1021) inserted in said end part (1035) of the crosspiece (922 -; 1022) is provided with a member (1021e) for holding said mechanical means (1044-1045). 20. Frame according to claims 16 and 19, characterized in that said member is a lug (1021e) provided with an orifice (1021f) for the passage of a screw (1045) for tightening two corners (1044, 1044 ') against ramps (1021c, 1021d) formed on said part (1021a) of said upright (1021), on either side of said tab. 21. Frame according to one of claims 14 to 20, characterized, at at least one of its upper (932, 1032) or lower (931, 1031) zones of contact with the upright (921) and / or with corners (1044, 1044 ') carried by said upright (1021), said crosspiece (922, 1022) is provided with at least two bearing surfaces (931i, 931j_ _r 932i., 932j_) generally flat, parallel to a longitudinal axis (Y ₉ 22-Y'922) of the cross member and oblique to each other, while said part (921a) of said upright (921) introduced into said cross member and / or corners (1044, 1044 ') carried by said part (1021a) is and / or are provided with complementary bearing surfaces (921i, 921j_) also oblique to each other. 22. Frame according to one of claims 14 to 21, characterized in that said mechanical means comprise at least one control screw (945; 1045) offset, in a direction perpendicular to a longitudinal axis (X922- X '₉₂₂; Yιo22 -Y'ιo22) of said crosspiece (922; 1022) and beyond 'the part (921a; 1021a) introduced into said crosspiece, relative to a main part (921b; 1021b) of said upright (921; 1021). 23. Frame according to one of the preceding claims, characterized in that said hoop (1140) surrounds (in 1140a) one end (1128a) of a main part (1122a) of said crosspiece (1122) and extends beyond this end into a tubular part (1140b) for receiving and immobilizing said part (1121a) of said amount (1121). 24. Frame according to one of the preceding claims, characterized in that said hoop is crimped hot around said crosspiece. 25. Frame according to one of the preceding claims, characterized in that said crosspiece (922) is provided with at least one softening slot (949). 26. Frame according to claim 25, characterized in that said part of said end (935) with a generally convex profile is of generally rectangular section and in that said slot (949) is formed in a large side (933, 934) of said section. 27. Frame according to one of the preceding claims, characterized in that the generally convex profile of said part (1035) of said end of the cross member is obtained by adding a filling element (1050) between said part (1035) and said hoop (1040). 28. Weaving loom (M) equipped with at least one heald frame (2) according to at least one of the preceding claims.