Exit lever with follow-up rollers of an eccentric drive and method for its manufacture

Description

[0001] The present invention relates to a follower roller output lever used in a cam-operated armor mechanism and to a method for manufacturing such a lever.

[0002] In the field of weaving, cam-operated warp mechanisms are well-known. These mechanisms comprise a series of oscillating levers, the number of which corresponds to the number of heddle frames in the loom. Each oscillating lever is designed to be attached to one of the heddle frames and is equipped with two rollers that cooperate with the two tracks of a complementary cam, which is driven in rotation by a common shaft. The two tracks of the same cam are axially offset, and the rollers carried by the associated output lever must have the same axial offset as the cam tracks.

[0003] During operation, only one of the output lever's rollers is engaged at any given time. Due to the axial offset of the engaged roller, the output lever is subjected to significant mechanical stresses, which can lead to deformation of certain lever components, particularly the elements receiving the rollers.

[0004] To limit these deformations, it is known, for example from CN-203 807 652-U, to mount the rollers between a flange machined in the thickness of the lever body and an added flange, fixed to the lever body by means of a deformable rivet.

[0005] Furthermore, it is known from WO2005 / 098106A1 that the rollers can be mounted between two flanges attached to the lever body, one of the flanges being placed in a hollow recess on a lateral surface of the lever body. The attached flanges are fixed by means of deformable rivets.

[0006] Mounting the flanges onto the lever body requires pre-drilling both the levers and the flanges to allow for the insertion of the deformable rivets. This pre-drilling step and the use of deformable rivets create play that is detrimental to the assembly of the flanges onto the lever body, to the accuracy of the roller positioning, weakens the connection between the flanges and the lever body, and disrupts the lever drive kinematics. Documents DE-299 08 928-U1, DE-10 2018 117387-A1, and DE-23 45 017-A1 describe alternative mechanical assembly methods.

[0007] It is these drawbacks that the invention intends to remedy in particular by proposing a new lever with follower rollers which allows a rigid and play-free assembly of the flanges on the lever body.

[0008] For this purpose, the invention relates to an output lever with follower rollers according to claim 1.

[0009] Thanks to the invention, grooved rivets and the recesses in the assembled elements between the inner and outer flanges allow for precise assembly of the outer and inner flanges of the lever. Also thanks to the invention, an assembly method using grooved rivets and recessing a portion of the first or second element allows the outer and inner flanges to be joined. The recess provides sufficient material within the first or second element to form the portion engaged in the rivet groove. The element into which the rivet is inserted perfectly conforms to the shape of the rivet, and the interaction between the peripheral groove of the rivet and the portion of the first or second element received in this groove ensures effective anchoring of the rivet in this element.The use of grooved rivets and ridges formed by a portion of material corresponding to an indentation imprint allows for a follower roller lever with good mechanical strength and ensures optimal operation of the cam armor mechanism.

[0010] According to other advantageous aspects of the invention, the roller follower output lever comprises one or more of the features described in the dependent claims and which can be taken in isolation or in all technically possible combinations.

[0011] The invention also relates to a method for manufacturing an exit lever as described above, the method being in accordance with claim 19.

[0012] According to other advantageous aspects of the invention, the method for manufacturing an exit lever comprises one or more of the features described in the dependent claims and which can be taken in isolation or in all technically possible combinations.

[0013] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which: [ Fig. 1 ] there figure 1 is a partial schematic representation of the principle of a loom comprising an output lever according to the invention; [ Fig. 2 ] there figure 2 is a larger-scale view of detail II of the figure 1 , insert A) corresponding to a front view and insert B) to a perspective view; Fig. 3 ] there figure 3 is a partial cut along line III-III at the figure 2 ; Fig 4 ] there figure 4 is a larger-scale view of detail IV at the figure 3 ; Fig. 5 ] there figure 5 is a view analogous to insert A) of the figure 2 , the cam and the rollers being omitted; Fig. 6 ] there figure 6 is a schematic representation of the basic principles of the steps in a manufacturing process according to the invention; [ Fig. 7 ] there figure 7 is a view analogous to insert B) of the figure 2 for a lever conforming to a second embodiment of the invention.

[0014] The M loom shown at the figure 1 includes several heddle frames 2, only one of which is shown. The different heddle frames 2 of the loom M are animated by a vertical oscillating movement represented by the double arrow F1 and imparted by a cam-driven armature mechanism 4. The output levers 6 of the cam-driven armature mechanism 4, only one of which is shown, each drive a draw mechanism which actuates a respective heddle frame 2 and which consists of a transmission rod 8 associated with angled levers 10 connected to each other and to the corresponding heddle frame 2 by connecting rods 12.

[0015] The levers 6 are provided in a number equivalent to the number of rail frames 2 and mounted pivotally, as represented by the double arrow F2, around a lever shaft 14 supported by the frame 16 of the cam mechanism 4 and protected by a cover 18. The lever shaft 14 defines a main axis X1 of the cam armor mechanism 4. Each output lever 6 is placed along the lever shaft 14 in a division whose width is fixed and equal to 12 millimeters.

[0016] The lever tree 14 has ten divisions.

[0017] The cam-armor mechanism 4 includes several complementary cams 20, only one of which is shown, and which each define two conjugate tracks 20A and 20B on which two follower rollers 22A and 22B respectively rest, supported by an output lever 6.

[0018] Each output lever 6 comprises a flat steel body 24. The flat body 24 is cut from a sheet of constant thickness. The flat body 24 supports at its end 24A a clip 26 for connecting the output lever 6 to the transmission rod 8.

[0019] The flat body 24 defines a mounting bore 24B on the lever shaft 14. As illustrated in the example in the figures, the bore 24B receives a roller bearing 28. In variants not shown, the bore 24B receives a ball bearing or a bushing.

[0020] The flat body 24 also includes a first external face 24C and a second external face 24D. The external faces 24C and 24D are opposite and define between them a median plane P1 perpendicular to the principal axis X1. The flat body 24 also includes a slice 24E, which connects the first external face 24C to the second external face 24D. The height of the slice 24E, measured parallel to the axis X1, defines the thickness of the flat body 24.

[0021] The flat body 24 also includes a first inner flange 30A that is one-piece with the flat body 24. A first outer flange 32A is attached to the first outer face 24C of the flat body 24 opposite the first inner flange 30A. The first outer flange 32A is positioned directly on the flat body 24, without a spacer. The first outer flange 32A is fixed to the flat body 24 by means of rivets 40, which are described later. The first outer flange 32A is formed from a piece of steel of constant thickness, this thickness being measured along the principal axis X1 when the outer flange 32A is integral with the flat body 24. The first outer flange 32A has a rounded triangular shape, visible in insert A) of the figure 2 .

[0022] The first follower roller 22A is held in a first space provided between the first outer flange 32A and the first inner flange 30A. According to an aspect of the invention detailed later, during the manufacture of the lever 6, the first outer flange 32A is fixed to the flat body 24 before a portion of the first outer flange 32A and a portion of the flat body 24 are jointly machined to provide the first space receiving the first follower roller 22A.

[0023] The flat body 24 comprises a second inner flange 30B that is integral with the flat body 24. A second outer flange 32B is attached to the second outer face 24D of the flat body 24, opposite the second inner flange 30B. The second outer flange 32B is similar in design to the first outer flange 32A. The second outer flange 32B is positioned directly on the flat body 24, without a spacer. The second outer flange 32B is a steel piece of constant thickness and a rounded triangular shape.

[0024] The second follower roller 22B is held in a second space provided between the second outer flange 32B and the second inner flange 30B.

[0025] The first follower roller 22A and the second follower roller 22B advantageously have the same structure, or are even identical. Follower roller 22A is primarily described below, and this description can be applied to roller 22B as well.

[0026] The follower roller 22A, all of whose elements are visible on the figure 3 The assembly comprises an inner ring 220, which has a disc shape centered on a roller axis X22, an outer ring 222, and interposed rolling elements 224, radially to the roller axis X22, between the inner ring 220 and the outer ring 222, such that the outer ring 222 is free to rotate relative to the inner ring 220 around the corresponding roller axis X22. When the follower roller 22A is received in the space between the first outer flange 32A and the first inner flange 30A, in an operating position, the roller axis X22 is parallel to the main axis X1.

[0027] Advantageously, the use of one-piece inner flanges 30A and 30B with the flat body 24 minimizes shear stresses on the rivets 40 and torsion of the outer flange 32A / 32B, which allows for riveting closer to the centers of the rollers 22A and 22B. In other words, in operation of the cam mechanism 4, the load conditions on the rivets 40 are halved when the inner flanges 30A / 30B are one-piece with the flat body 24 compared to prior art levers, in particular such as the levers described by WO-2005 / 098106-A1.

[0028] The rolling elements 224, which in the illustrated example are rollers, are held axially relative to the roller axis X22 by two sheet metal flanks 226, located on either side of the inner ring 220 along the roller axis X22.

[0029] The outer ring 222 has a contact surface 222A which is radial to the roller axis X22 and is configured to be in contact with the track 20A of the cam 20.

[0030] Two holes are provided on the outer flange 32A, on the inner flange 30A, on the sides 226 of the roller 22A, and on the inner ring 220 of the roller 22A to receive two fastening elements 229 for attaching the roller 22A to the flat body 24. In the illustrated example, the fastening elements 229 are so-called "roller rivets." Each roller rivet 229 is centered on an axis parallel to the roller axis X22, and each roller rivet 229 is radially offset from the roller axis X22.

[0031] Preferably, two roller rivets 229 secure each follower roller 22A, 22B to the flat body 24. In other variants not shown, one roller rivet 229 secures each follower roller 22A, 22B to the lever 6 or more than two roller rivets 229 secure each follower roller 22A, 22B to the lever 6.

[0032] The follower rollers 22A, 22B here have an outside diameter D22 of 88 millimeters. The outside diameter D22 is the diameter of the contact surface 222A of each roller 22A, 22B.

[0033] The first outer flange 32A and the second outer flange 32B are secured to the flat body 24 by rivets 40. In this embodiment, and according to an advantageous but not mandatory aspect of the invention, the rivets 40 are self-piercing rivets. In other words, the rivets 40 are capable of piercing the elements in which they are positioned without themselves deforming significantly. To this end, the self-piercing rivets 40 are, in the illustrated example, made of hardened steel, while the outer flanges 32A, 32B and the flat body 24 are made of steel. Any other grade of steel or steel alloys which includes for example manganese, nickel, carbon, molybdenum can be used to make a piercing rivet 40, without departing from the scope of the invention, insofar as this piercing rivet 40 is less ductile than the outer flanges 32A, 32B and the flat body 24.In comparison, in prior art levers as described in CN-203 807 652-U, the flange fixing rivets are made of a more ductile steel, that is to say, softer or more deformable, than the outer flanges 32A, 32B and the flat body 24. The fixing rivets used in the prior art are deformed in the flange holes so that the connection is made with mechanical play.

[0034] Advantageously, the outer flanges 32A and 32B have identical geometries and are fixed in a similar way by piercing rivets 40 on the flat body 24.

[0035] The following mainly describes the first outer flange 32A and one of the piercing rivets 40, this description being transposable to the second outer flange 32B and to all the piercing rivets 40.

[0036] The structure and positioning of the 40 piercing rivets are shown in detail on the figures 3 And 4 .

[0037] As seen at the figure 2 Two piercing rivets 40 fix the outer flange 32A to the flat body 24. With reference to figures 3 And 4 Each piercing rivet 40 defines an external peripheral surface S40, of contact between the piercing rivet 40 and the elements in which the piercing rivet 40 is inserted, and a rivet axis X40. When the rivet 40 is placed in the elements 24 and 32A, the rivet axis X40 is parallel to the main axis X1.

[0038] Rivet 40 comprises a rivet body 42 in the form of a solid of revolution about the rivet axis X40. In the illustrated example, the rivet body 42 is generally cylindrical. In an alternative variant not shown, the rivet body 42 is frustoconical.

[0039] The piercing rivet 40 first penetrates the outer flange 32A and then the flat body 24 so that the rivet body 42 extends along the rivet axis X40 between a rivet head 44 flush on an outer face S32A of the outer flange 32A and a rivet foot 46 flush on the outer face 24D of the flat body 24.

[0040] In an unshown variant, the piercing rivet 40 penetrates the flat body 24 first, the rivet head 44 then being flush with the external face 24D of the flat body 24 and the rivet foot 46 being flush with the external face S32A of the outer flange 32A. Generally, the first element is defined as the element between the flat body 24 and the flange 32A, such that the rivet head 44 is flush with an external face of the first element, while the second element is defined as the element such that the rivet foot 46 is flush with an external face of the second element.

[0041] In an unrepresented variant, the inner flange 30A and / or the inner flange 30B are attached to the body 24 of the lever 6.

[0042] The height H 40 of the piercing rivet 40, measured parallel to the rivet axis X40, is equal to the cumulative thickness of the flat body 24, here with a thickness e 24 equal to 6 millimeters, and of the outer flange 32A, here with a thickness e 32 equal to 5.5 millimeters, such that the piercing rivet 40 does not protrude from the output lever 6 and thus the maximum thickness e 6, measured along the main axis X1, of the output lever 6 is less than the width of a division of the cam-operated armor mechanism 4. Advantageously, the height H 40 is less than the thickness e 24 so that the risk of interference of the rivet 40 with the neighboring elements of the lever 6 in the cam-operated mechanism 4 is minimized.

[0043] The maximum thickness of the output lever 6 is preferably configured to leave sufficient clearance between the multiple output levers 6 of the cam armor mechanism 4 to avoid interference during operation, which would cause premature wear of the cam armor mechanism 4.

[0044] The rivet body 42 comprises an external peripheral surface S42. When the piercing rivet 40 is positioned within the first and second elements, the first element being, in the illustrated example, the outer flange 32A and the second element being the flat body 24, the external peripheral surface S42 of the rivet body 42 comprises a first portion S42A of the external peripheral surface received in the first element and a second portion S42B of the external peripheral surface received in the second element. The first portion S42A and the second portion S42B of the external peripheral surface are concentric and of the same diameter.

[0045] The rivet body 42 has a diameter D 42. The diameter D 42 of the rivet body 42 is also, by definition, the diameter of the piercing rivet 40. Generally, for a given element with a diameter, the radius of that element is equal to half the diameter. The diameter D 42 of the piercing rivet 40 is advantageously greater than the combined thickness e 24 + e 32, measured along the rivet axis X40, of the flat body 24 and the outer flange 32A. In this way, the area of ​​the peripheral external surface S40 of the piercing rivet is large relative to its height, which allows optimal guidance of the piercing rivet 40 in the outer flange 32A and in the flat body 24 and good anchoring of the piercing rivet 40 in the outer flange 32A and the flat body 24. In addition, during the use of the loom M, the forces exerted on the connection between the outer flange 32A and the flat body 24 will be distributed over a large contact area, namely the surface S40.Advantageously, the rivet head 44 is frustoconical in shape, with a maximum diameter D 44, and includes a side wall S44A converging towards the rivet foot 46. The maximum diameter D 44 of the rivet head 44 is strictly greater than the diameter D 42 of the rivet body 42. The frustoconical side wall S44A is defined by a vertex angle α. The vertex angle α is less than 90°, preferably less than 60°, and even more preferably less than 40°.

[0046] In an unshown variant of the invention, the apex angle α is greater than 90°.

[0047] The truncated conical shape of the rivet head 44 increases the contact area between the outer flange 32A and the piercing rivet 40 and allows for better mechanical holding of the piercing rivet 40 in the outer flange 32A.

[0048] Preferably, the rivet head 44 also includes a centering hole 44B allowing centering of the rivet 40 during the manufacture of the output lever 6.

[0049] The rivet foot 46 comprises an end face 46A perpendicular to the rivet axis X40. A cylindrical edge 46B, connecting the end face 46A to the outer peripheral surface S40 of the piercing rivet 40, forms a right angle. Thanks to this right-angled cylindrical edge 46B, the piercing rivet 40 can cleanly pierce the outer flange 32A and the flat body 24 without deformation.

[0050] By construction, the external peripheral surface S40 includes the external peripheral surface S42 of the rivet body 42, the frustoconical side wall S44A of the rivet head 44 and the cylindrical edge 46B of the rivet foot 46.

[0051] A first groove 48 is formed on the external peripheral surface S40 of the piercing rivet 40. In the illustrated example, the first groove 48 is formed around the rivet foot 46.

[0052] The first groove 48 has a depth P 48 measured perpendicular to the rivet axis X40 between the peripheral external surface S42 of the rivet body 42 and the bottom of the groove 48. The depth P 48 of the groove 48 is greater than 0.2 millimeters, preferably greater than 0.4 millimeters, and preferably even greater than 0.5 millimeters.

[0053] We denote P2 a reference plane intersecting with the first groove 48 and perpendicular to the axis of rivet X40. The reference plane P2 is located at a distance d, measured along the axis of rivet X40, from the external face 24D of the flat body 24. The distance d is less than 3 millimeters, preferably less than 2 millimeters, and preferably even less than 1 millimeter.

[0054] The flat body 24 includes, on its second external face 24D, a recess 50. The recess 50 is formed such that a portion of the flat body 24, with a shape complementary to the groove 48, forms a bead 52, by indenting the portion of the material constituting the flat body 24 that is initially present at the location of the recess 50. The bead 52 of the flat body 24 is received in the groove 48 of the piercing rivet 40. In other words, the first groove 48 being formed around the rivet foot 46, the first groove 48 receives a portion of the second element 24 forming a bead 52 with a shape complementary to the first groove 48, and the external face of the second element includes a recess 50 of the portion of the second element that has been displaced to form the bead 52.The indentation imprint 50 and the bead 52 are formed by plastic deformation of the material of the flat body 24 during the setting of the piercing rivet 40.

[0055] The cooperation between the first groove 48 and the bead 52 allows robust retention of the piercing rivet 40 in the outer flange 32A and the flat body 24.

[0056] In variants not shown, the ridge 52 does not occupy all the available volume in the first groove 48.

[0057] The recess 50 is centered on the rivet axis X40 and is annular around the rivet axis X40. The recess 50 has an inner diameter D50 measured perpendicular to the rivet axis X40. The inner diameter D50 of the recess 50 is equal to the diameter D42 of the rivet body 42.

[0058] In an unrepresented variant, the inner diameter D 50 of the recess 50 is greater than the diameter D 42 of the rivet body 42.

[0059] The recess 50 defines a base 50A. The base 50A of the recess 50 is located, along the rivet axis X40, between the first groove 48 and the external face 24D of the flat body 24.

[0060] The recess 50 has a depth P 50 measured along the rivet axis X40 between the bottom 50A of the recess 50 and the outer face 24D of the flat body 24. The depth P 50 of the recess 50 is greater than 0.5 millimeters, preferably greater than 0.8 millimeters, preferably even greater than 1 millimeter.

[0061] Let C be a circle circumscribed about the indentation 50, which is visible on the insert B of the figure 2 Let Rc be the radius of the circumscribed circle C. Let R42 = D42 / 2 be the radius of the piercing rivet 40. A ratio between the radius Rc of the circumscribed circle C and the radius R42 of the piercing rivet 40 is greater than 1.25, preferably greater than 1.5, and even more preferably greater than 2. This dimensional ratio allows sufficient material from the flat body 24 to be embedded to form the bead 52 cooperating with the groove 48.

[0062] The recess 50 provides enough material for the bead 52 to cooperate with the groove 48, allowing the piercing rivet 40 to be anchored in the flat body 24, with its rivet head 44 bearing against the flange 32A. To ensure the mechanical strength of the flat body 24, which includes the recess 50, it is necessary that the flat body 24 extend beyond the recess 50. More precisely, the flat body 24 extends, at least, over a semi-circular area with a radius greater than 1.5 times the radius of the piercing rivet 40, preferably greater than 2 times the radius of the piercing rivet 40, and preferably even greater than 3 times the radius of the piercing rivet 40, around the rivet axis X40. This minimum dimension of the flat body 24 around the rivet axis X40 ensures that there is enough material around the recess 50 so as not to weaken the exit lever 6 when the piercing rivet 40 is being installed.

[0063] Each piercing rivet 40, which connects the outer flange 32A to the flat body 24, is located from the geometric center of the corresponding roller 22A, i.e., from its roller axis X22, by a distance D measured in a plane parallel to the median plane P1 and corresponding to the distance between the axes X22 and X40. Advantageously, the distance D is less than 80 millimeters, preferably less than 70 millimeters, and even more preferably less than 65 millimeters.

[0064] The quality of the connection between the outer flange 32A and the flat body 24, achieved by the piercing rivets 40, allows the outer flanges 32A and 32B to be positioned as close as possible to the roller axes X22. This minimizes the overlap area 36, ​​which is the area where the outer flange 32A and 32B and the flat body 24 are in contact. Minimizing this overlap area 36 allows the use of smaller outer flanges 32A and 32B, thus reducing manufacturing costs.

[0065] We now describe the manufacturing process of an output lever 6 comprising outer flanges 32A, 32B joined together by means of piercing rivets 40 as described previously.

[0066] The flat body 24 of the output lever 6 and the outer flanges 32A and 32B are obtained in a known way by fine cutting of steel sheets.

[0067] The assembly of the outer flanges 32A, 32B onto the flat body 24 of the output lever 6 is carried out in several stages within an external press tooling P comprising several tools. These stages are shown in the figure 6 .

[0068] The external press tooling P includes two side clamps 60A, 60B, two punches 62A, 62B and two dies 64A, 64B. In the example shown on the figure 6 , the first outer flange 32A is secured to the flat body 24 by means of two piercing rivets 40 which are mounted in parallel and in a synchronized manner in the press tooling P.

[0069] The orientation of the representation of the side clamps 60A, 60B of the press tooling P to the figure 6 is not limiting. Side brace 60A can be positioned above side brace 60B relative to the ground, or below side brace 60B relative to the ground, or the side braces can be oriented so that the X40 axis is parallel to the ground.

[0070] The side clamps 60A and 60B are configured to maintain the flat body 24 and the outer flange 32A in contact and fixed position. In the illustrated example, the side clamps 60A and 60B are parallelepiped-shaped and are in contact with the outer flange 32A and the flat body 24, respectively, by means of flat surfaces. In variants not shown, the side clamps 60A and 60B have different geometries, such as a convex contact surface.

[0071] Punches 62A, 62B are configured to guide each a 40 piercing rivet during the cutting and driving stages.

[0072] Each die 64A and 64B is configured to push a portion of the flat body 24 towards the flange 32A when the piercing rivet is in place in the elements 32A and 24, to form the ridge 52 whose shape complements the groove of the corresponding piercing rivet 40. The dies 64A and 64B are aligned respectively with the punches 62A and 62B.

[0073] The first step shown on insert A) of the figure 6 is a positioning step. The flat body 24 and the outer flange 32A are positioned relative to each other so as to overlap to form, after manufacturing, the overlap area 36.

[0074] Preferably, the outer flange 32A is supported plan on plan against the flat body 24 over most of the inner surface of the outer flange 32A. More precisely, the outer flange 32A is supported on the outer surface 24C of the flat body 24, an area of ​​the contact surface between the outer flange 32A and the outer surface 24C being substantially equal to an area of ​​the outer face S32A of the outer flange 32A.

[0075] By substantially equal, we mean that the area of ​​the contact surface between the outer flange 32A and the flat body 24 is greater than or equal to 90% of the area of ​​the outer face S32A of the outer flange 32A.

[0076] The process includes a preliminary step a0, prior to step a), in which the first element is positioned on the second element, the inner face of each of the elements overlapping over a substantially equal area of ​​the surface of the outer flange.

[0077] During positioning, the overlap area 36 of the flat body 24 is larger than the final overlap area after machining, which facilitates the positioning of the outer flange 32A on the flat body 24. The flat body 24 and the outer flange 32A are also positioned in the external press tooling P between the two flange clamps 60A and 60B, so that the punches 62A and 62B are aligned with the desired locations of the piercing rivets 40. Positioning prior to riveting is optimized because it is a plane-to-plane alignment with a large overlap area. The flat body 24 and the flange body have a constant thickness before machining.

[0078] The second step is a cutting step. This cutting step is shown in insert B) of the figure 6 A force F3 is applied by the press P along the rivet axis X40 to punches 62A and 62B synchronously. Punches 62A and 62B each push a piercing rivet 40 along the rivet axis X40 so as to cut the first element, here the outer flange 32A, through its thickness, and then to cut the second element, here the flat body 24, through its thickness. Advantageously, each punch 62A, 62B is engaged at the rivet head 44 of each rivet 40 in the central centering hole 44B of that rivet.

[0079] The third step is a driving step, during which each piercing rivet 40 is driven in until the rivet foot 46 is flush with the outer face 24D of the flat body 24.

[0080] The fourth step is a embossing step and is shown on insert C) of the figure 6 A force F4 is applied along the rivet axis to each die 64A, 64B so as to push back a portion of the flat body 24 to form a ridge 52 complementary in shape to the groove 48 of the corresponding piercing rivet 40. Each die 64A, 64B leaves an imprint 50 around the rivet foot 46 on the outer face 24D of the flat body 24.

[0081] The process mentioned above is implemented for the joining of each of the outer flanges 32A and 32B with the flat body 24. Advantageously, the press P applies the cutting forces on the piercing rivets 40 in a synchronized manner, and the driving forces on the piercing rivets 40 in a synchronized manner, in other words, during the same operation of closing the press tooling for the piercing rivets 40.

[0082] This results in an output lever 6 on which the outer flanges 32A and 32B are secured to the flat body 24 by means of piercing rivets 40. The installation of the piercing rivets 40 without pre-drilling and the fact that the assembly is simultaneous with the cutting step ensures that there is no play between the piercing rivets 40, the outer flanges 32A and 32B and the flat body 24. The mechanical strength of the output levers 6 during use of the loom M is greatly reinforced.

[0083] Once the outer flanges 32A, 32B are assembled onto the flat body 24, a clevis space 70 is machined by a milling tool at the level of the space intended to receive the rollers 22A and 22B on the flat body 24 and on the flanges 32A, 32B. In other words, the machining step is subsequent to the spinning step. The clevis space 70 is visible by tearing on the figure 5 and is delimited by a machining step 71.

[0084] More specifically, an internal surface of the outer flange 32A, opposite the roller 22A, is machined in a plane parallel to the median plane P1 to create a hollow recess 70A extending over the internal surface. Similarly, the external surface 24C of the flat body 24, opposite the roller 22A, is machined in a plane parallel to the median plane P1 to create a hollow recess 70B extending over the external surface 24C. The union of the hollow recesses 70A and 70B forms the clevis space 70.

[0085] In the illustrated example, the outer flange 32A has a generally triangular shape, one side of the triangle being formed by a slice 72 of the outer flange 32A, the slice 72 being generally parallel to the two rivets 40. The slice 72 and the machining step 71 are thus located on either side of the rivets 40. The overlap area 36 defined by the machining step 71 and the corresponding slice 72 of the outer flange 32A / 32B is minimal, but sufficient to withstand the torque applied by the cams on the lever. This arrangement allows the rivets 40 to be brought closer to the center of the roller 22A, 22B. The minimal overlap is made possible by the strong, play-free bond of the self-drilling rivets 40. As a corollary, the implementation of the invention makes it possible to manufacture a more compact exit lever 6 compared to levers of the prior art, in particular with smaller overlap surfaces 36.The exit lever according to the invention is therefore lighter, and less subject to inertial forces generated during its use.

[0086] Advantageously, each rivet 40 is located as close as possible to the edge 24E of the flat body 24. For each rivet 40, a distance D24 is defined between this rivet and the edge 24E of the flat body 24 as a minimum distance, measured radially to the rivet axis X40, between the rivet axis X40 and the edge 24E of the flat body 24. Thus, the distance D24 between this rivet and the edge 24E of the flat body 24 is less than 2.5 times the radius of the rivet 40 in question, and preferably even less than 2 times the radius of the rivet 40. This arrangement is particularly advantageous because it allows for an increase in the center distance between the two rivets 40 associated with the same roller 22, which reduces the torsion of the flanges 32A / 32B and the lever 6.

[0087] Similarly, the outer flange 32B and the external surface 24D of the flat body 24 are machined to form a clevis space 70 receiving the roller 22B.

[0088] Once the clevis spaces 70 are machined opposite each roller 22A, 22B, the rollers 22A and 22B are put in place and riveted by two rivets 229 in the outer flanges 32A, 32B and in the flat body 24.

[0089] In an unrepresented variant of the method of the invention, in a step prior to driving the rivet, only the outer flange 32A, 32B is positioned in the outer tooling of the press P. Then, the outer flange 32A, 32B is perforated by the piercing rivets 40. The disc of material resulting from this perforation is removed from the press tooling P. Once this step has been carried out, the flat body 24 and the outer flange 32A, 32B are stacked and the flat body 24 is in turn perforated by the piercing rivets 40 through the hole resulting from the previous perforation of the outer flange 32A, 32B.

[0090] The assembly method described above is compatible with a stack of more than two elements. This assembly method is thus compatible, for example, with the assembly of an output lever 6 which comprises, for each follower roller, two external flanges attached to the flat body.

[0091] The exit lever 6, as previously described, is particularly compatible with an armor mechanism described in CN-215 800 175-U.

[0092] A second embodiment of a 6' exit lever is shown on the figure 7 In the following description, elements analogous to those of the first embodiment bear the same reference numerals and are not described in detail. If a reference numeral is mentioned in the description but not shown in a figure, or shown in a figure but not mentioned in the description, it refers to the same element as the one bearing the same reference numeral in the first embodiment. The following primarily describes what distinguishes this second embodiment from the first.

[0093] The 6' exit lever includes outer flanges 80A with a different shape than the outer flanges 32A, 32B of the first embodiment. Only the outer flange 80A opposite the roller 22A is visible on the figure 7 . The piercing rivets 40 for fixing the outer flanges 80A onto the flat body 24 of the lever 6 are positioned differently compared to the first embodiment.

[0094] The outer flange 80A is triangular in shape and includes a tab 81A. A notch 82A, defining an opening between the roller 22A and the flat body 24, is formed in the outer flange 80A. It is understood that in the second embodiment, the overlap area of ​​the outer flange 80A on the flat body 24 is even smaller than in the first embodiment. The notch 82A further reduces the amount of moving material of the output lever 6. This is made possible by the strong, backlash-free connection of the self-piercing rivets 40.

[0095] The 81A lug extends between the 82A notch and the central bore 24B along a lubrication axis X2.

[0096] Let Dg be the distance measured in the median plane P1 between the roller axis X22 and the main axis X1. Let L81 be the length of the leg 81A along the axis X2 from the bottom of the notch 82A on the axis X2 to the end B81 of the leg 81A. The ratio between the length L81 of the leg 81A and the distance Dg between the roller axis X22 and the main axis X1 is greater than 2 / 3.

[0097] The lug 81A allows the oil from the cam armor mechanism 4, projected around the roller 22A through the notch 82A, to be guided to the central bore 24B which receives the lever shaft 14. This supply of oil is beneficial to the operation of the output levers 6 and the lever shaft 14 over time.

[0098] The assembly of this 6' output lever is done using the same process as the assembly of the 6' output lever of the first embodiment.

[0099] For both embodiments, in a variant of the invention not shown, the first groove 48 is formed on the outer peripheral surface S42 of the rivet body 42 around the rivet head 44 and receives a bead of the first element with a shape complementary to the first groove. In this configuration, the reference plane P2 is at a distance d along the rivet axis X40 from the outer surface of the first element.

[0100] In an unshown embodiment of the invention, the first groove 48 is formed around the rivet foot as described above, and a second groove is formed on the outer peripheral surface S42 of the rivet body 42 near the rivet head 44. The second groove receives a ridge from the first element, the shape of which is complementary to that of the second groove. Each groove is connected to a recess 50. The recess 50 connected to the second groove is formed by the die 64A, 64B along the axis X40 of the piercing rivet 40 comprising two grooves 48. The recess connected to the first groove is formed by a movable die in the flange 60A.

[0101] In another variant not shown, the indentation impressions 50 associated with the two grooves 48 are made one by one by the die 64A, 64B along the axis X40 of the piercing rivet 40, by turning over the whole of the outer flanges 32A and 32B and the flat body 24, between the two forging steps of the two indentation impressions 50.

[0102] In unrepresented variants of the invention, other geometries and positions of grooves formed on the external peripheral surface of the piercing rivets 40 are possible.

[0103] In an unshown embodiment of the invention, each outer flange 32A, 32B is fixed to the flat body 24 by means of two piercing rivets 40 such that a first piercing rivet 40 is first inserted into the outer flange 32A, 32B and then into the flat body 24, and a second piercing rivet 40 is first inserted into the flat body 24 and then into the outer flange 32A, 32B. In this configuration, the flat body 24 and the outer flange 32A, 32B each have a recess 50.

[0104] In variants not shown, the shape of the 40 piercing rivet may be different, in particular the 40 piercing rivet may be hollow or have an alternatively shaped head.

[0105] In an unshown embodiment of the invention, the lever body and flanges are pre-drilled, and the rivets are driven in and the rivet heads are formed in the rivet grooves to assemble the first and second elements, without a prior rivet cutting step. In this case, the rivets are not self-piercing rivets. Thus, the invention covers the case where the rivets have not pierced the elements in which they are positioned, these elements having been pre-drilled, either one or both. The invention also covers the case where the self-piercing rivets have partially pierced one or both elements, for example, when these elements have been pre-drilled to a diameter smaller than that of the rivets.

[0106] In another, unshown, embodiment of the invention, the first inner flange 30A and / or the second inner flange 30B is attached to the flat body 24. The rivet head 44 is flush with the outer face of the inner flange, and the rivet foot 46 is flush with the outer face of the outer flange. The first and second elements with which the rivet head 44 and the rivet foot 46 are flush are then, on the one hand, the first or second outer flange 32A, 32B and, on the other hand, the first or second inner flange 30A, 30B, or vice versa.

[0107] In another, unshown variant of the invention, the screed spaces are not machined.

[0108] It will be understood that the rivet head is flush with the outer face of the first element and the rivet foot is flush with the outer face of the second element, even though an axial play along the X40 axis along the rivet, amounting to a few hundredths of a millimeter, may be observed. In other words, the planes of the rivet head and the outer face of the first element are essentially coincident, and the planes of the rivet foot and the outer face of the second element are essentially coincident.

[0109] Insofar as it is technically feasible, the embodiments and variants mentioned above may be combined with each other, within the scope of the invention as defined by the claims.

Claims

1. An output lever (6; 6') with cam followers (22A, 22B) of a cam shedding mechanism (4), the output lever (6; 6') comprising: - a flat body (24) for supporting an articulation (26) with a transmission rod (8) of the rocker movement of the output lever (6) to a heddle frame (2) and including: • a first face (24C) and a second face (24D) opposite each other and defining a median plane (P1) therebetween, • a bore (24B) centered on a main axis (X1) intended to accommodate a bearing (28) or a bearing bush mounted on a shaft of the levers (14) of the cam shedding mechanism (4), - a first inner flange (30A) integral with the body (24) or directly mounted on the second face (24D) of the lever body (24); - a second inner flange (30B) integral with the body (24) or directly mounted on the first face (24C) of the lever body (24); - a first outer flange (32A), directly mounted on the first face (24C) of the lever body (24), facing the first inner flange (30A); - a second outer flange (32B), directly mounted on the second face (24D) of the lever body (24), opposite the second inner flange (30B); - a first roller (22A) intended to follow a first track (20A) of a cam (20) of the shedding mechanism (4) and taken held in a clevis in a first space (70) provided between the first outer flange (32A) and the first inner flange (30A); - a second roller (22B) intended to follow a second track (20B) of the cam (20) of the shedding mechanism (4) and held in a clevis in a second space (70) provided between the second outer flange (32B) and the second inner flange (30B); - at least two rivets (40) for fastening at least one of the outer flanges (32A, 32B) to the flat body (24), the rivets (40) extending through the lever body (24) and the outer flange (32A, 32B), characterized in that each rivet (40) comprises: - a rivet body (42) in the form of a solid of revolution around a rivet axis (X40) extended between: • a rivet head (44) flush with an outer face (24C, 24D, S32A) of a first element amongst the outer flange (32A, 32B) and the inner flange (30A, 30B, 24), • a rivet foot (46) flush with an outer face (24C, 24D, S32A) of the second element amongst the outer flange (32A, 32B) and the inner flange (30A, 30B, 24); - at least a first rivet throat (48) provided on an outer peripheral surface (S40) of the rivet (40) wherein a portion of the first (32A, 32B, 30A, 30B, 24) or the second (32A, 32B, 30A, 30B, 24) element forms a bead (52) with a shape matching the first throat (48); in that the first and / or second elements (32A, 32B, 30A, 30B, 24) comprise, on the outer face (S32A, 24C, 24D) thereof, a driven-in imprint (50) for driving in the portion of the first or second element (32A, 32B, 24) which forms the bead (52), in that the driven-in imprint (50) is centered on the rivet axis (X40), and in that in that the inner flange (30A, 30B) and the corresponding outer flange (32A, 32B) together define the first or second space (70), which is formed by machining the inner flange (30A, 30B) and the outer flange (32A, 32B) together after each rivet (40) has been set, in such a way that a machined step (71) on the inner flange (30A, 30B) is aligned with a machined step (71) on the outer flange (32A, 32B).

2. The output lever (6; 6') according to claim 1, wherein: - the rivet head (44) has a maximum diameter (D44) strictly greater than the diameter (D42) of the rivet body (42), and - the first throat (48) is formed around the rivet foot (46).

3. The output lever (6; 6') according to claim 2, wherein: - The rivet head (44) comprises a frustoconical sidewall (S44A) converging toward the rivet foot (46), and - an apex angle (α) of the frustoconical sidewall (S44A) is less than 90°, preferably less than 60°, preferably less than 40°.

4. The output lever according to any one of claims 1 to 3, wherein: - a second throat is formed on the outer peripheral surface (S40) of the rivet (40) around the rivet body (42) in the vicinity of the rivet head (44), in that the first throat (48) is formed on the outer peripheral surface (S40) of the rivet (40), around the rivet foot (46), - the first throat (48) accommodates a bead (52) of the second element (24, 32A, 32B) with a shape matching the first throat (48), and - the second throat accommodates a bead of the first element (24, 32A, 32B), with a shape matching the second throat.

5. The output lever (6; 6') according to any one of claims 1 to 4, wherein a depth (P48) of the first throat or at least one of the throats is greater than 0.2 millimeters, preferably greater than 0.4 millimeters, or again preferably greater than 0.5 millimeters.

6. The output lever (6; 6') according to any one of claims 1 to 5, wherein: - the driven-in imprint (50) is annular, - the driven-in imprint (50) has an internal diameter (D50) equal to the diameter (D42) of the rivet body (42), and - a bottom of the cavity (50A) is arranged along the rivet axis (X40) between the first throat (48) of the drilling rivet (40) and the outer face (S32A, 24C, 24D) of the first and / or second element (32A, 32B, 24) which comprises the driven-in imprint (50).

7. The output lever (6; 6') according to any one of claims 1 to 6, wherein a ratio between the radius (Rc) of the circumscribed circle (C) of the driven-in imprint (50) and the radius of the drilling rivet (R42) is greater than 1.25, preferably greater than 1.5, or again preferably greater than 2.

8. The output lever (6; 6') according to any one of claims 1 to 7, wherein a depth (P50) of the driven-in imprint (50), measured along the rivet axis (X40), is greater than 0.5 millimeters, preferably greater than 0.8 millimeters, or again preferably greater than 1 millimeter.

9. The output lever (6; 6') according to any one of claims 1 to 8, wherein the outer face (24C, 24D, S32A) of the first and / or second member (32A, 32B, 24) which comprises the driven-in imprint (50) extends in a semicircular area centered on the rivet axis (X40) with a circle radius preferably greater than or equal to 1.5 times the radius (R42) of the rivet (40), preferably greater than or equal to 2 times the radius (R42) of the rivet (40) and or again preferably greater than or equal to 3 times the radius (R42) of the rivet (40).

10. The output lever (6; 6') according to any one of claims 1 to 9, wherein the outer face (24C, 24D, S32A) of the first element extends in a quarter-circle area centered on the rivet axis with a circle radius preferably less than or equal to 2.5 times the radius of the rivet, preferably less than or equal to 2 times the radius of the rivet, or again preferably less than or equal to 1.5 times the radius of the rivet (40).

11. The output lever (6) according to any one of claims 1 to 10, wherein: - each roller (22A, 22B) is centered on a roller axis (X22) and has an outer diameter (D22), - for each roller and for at least one rivet associated with the roller fastening at least one of the outer flanges (32A, 32B) to the flat body (24), a ratio between a distance (D) between the roller axis (X22) and the rivet axis (X40) considered, divided by half the outer diameter (D22) of the roller, is less than 1.8, preferably less than 1.6, or again preferably less than 1.5.

12. The output levers (6) according to any one of claims 1 to 11, wherein, for at least one of the rivets (40), a minimum distance between the rivet axis (X40) and the edge (24E) of the flat body (24), measured radially to the rivet axis (X40), is less than 2.5 times the radius of the rivet, or again preferably less than 2 times the radius of the rivet (40).

13. The output lever (6) according to any one of claims 1 to 12, wherein a reference plane (P2) intersecting with the first throat (48) is arranged at a distance (D) from the outer face (24C, 24D, S32A) of the first or of the second element (32A, 32B, 24), measured along the rivet axis (X40), less than 3 millimeters, preferably less than 2 millimeters, or again preferably less than 1 millimeter.

14. The output lever (6) according to any one of claims 1 to 13, wherein the rivet foot (46) has an end face (46A) perpendicular to the rivet axis (X40) and in that a cylindrical edge (46B) joining the end face (46A) and the outer peripheral surface (S40) of the rivet (40) forms a right angle.

15. The output lever (6) according to any one of claims 1 to 14, wherein a diameter (D42) of the rivet (40) is greater than a cumulative thickness (e24+e32), measured along the rivet axis (X40), of the flat body (24) of the lever (6) and of an outer flange (32A, 32B).

16. An output lever (6) according to any one of claims 1 to 15, wherein the outer flange (80A) comprises a lug (81A) extending along a lubrication axis (X2) and configured to guide lubricant from a roller (22A, 22B) to the bore (24B) of the lever body (24).

17. The output lever (6) according to any one of claims 1 to 16, wherein: - an outer peripheral surface (S42) of the rivet body (42) comprises a first outer peripheral surface portion (S42A) accommodated in the first element (32A, 32B, 24) and a second outer peripheral surface portion (S42B) accommodated in the second element (24, 32A, 32B), and - the first outer peripheral surface portion (S42A) and the second outer peripheral surface portion (S42B) are concentric and have the same diameter.

18. The output lever (6) according to any one of claims 1 to 17, wherein the rivet is a drilling rivet (40).

19. A method of manufacturing an output lever (6; 6') according to any one of claims 1 to 18, the manufacturing method comprising, fora first of the rivets (40) of the output lever (6), at least the following steps: a) driving in the rivet (40) until the rivet foot (46) is flush with the outer face of the second element (24C, 24D, S32A), the rivet (40) being pushed by an outer press tool (P) configured to exert a pushing force (F3) on the rivet (40) along the rivet axis (X40); and b) push back a portion of the second member (32A, 32B, 24) to form a bead (52) with a shape matching the throat (48) of the rivet (40) by means of an outer die (64A, 64B) centered on the rivet axis (X40) and marking a driven-in imprint (50) around the rivet foot (46) on the outer face of the second element (24C, 24D, S32A) and / or a portion of the first element (32A, 32B, 24) to form a bead (52) with a shape matching the throat (48) of the drilling rivet (40) by means of an outer die (64A, 64B) centered on the rivet axis (X40) and marking a driven-in imprint (50) around the rivet head (44) on the outer face of the first element (24C, 24D, S32A), wherein the manufacturing method comprises at least the following preliminary steps: c) cutting, with the rivet (40) which is a drilling rivet, the first element (32A, 32B, 24) through thickness thereof, then d) cutting, with the drilling rivet (40), the second element (32A, 32B, 24) into the thickness thereof, the drilling rivet (40) being pushed by means of the outer press tool (P) along the rivet axis (X40), wherein the manufacturing method comprises a machining step, subsequent to the back compression step b), during which the first or second space (70) is machined between the inner flange (30A, 30B) and the outer flange (32A, 32B) in a plane parallel to the median plane (P1), by means of a milling tool, in such a way that a machined step (71) on the inner flange (30A, 30B) is aligned with a machined step (71) on the outer flange (32A, 32B).

20. The manufacturing method according to claim 19, wherein the manufacturing method comprises a further step, subsequent to step c) and prior to step d), the further step of positioning the second element (32A, 32B, 24) on the first element (32A, 32B, 24) at an overlap area (36) in the outer press tool (P).

21. The manufacturing method according to claim 19, wherein the method comprises a prior step a0, prior to step c), in which the first element is positioned on the second element in plane-to-plane support, an area of the contact surface between the first element and the second element being substantially equal to the surface area of the outer flange.

22. The manufacturing method according to any one of claims 19 to 21, wherein the manufacturing method comprises cutting, driving-in and back compression steps similar to steps a) to d) for a second rivet (40), which is a drilling rivet positioned away from the first rivet (40).