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EP-4474543-B1 - FOLLOWER ROLLER OUTPUT LEVER OF A CAM GEAR MECHANISM AND METHOD FOR MANUFACTURING SAME

EP4474543B1EP 4474543 B1EP4474543 B1EP 4474543B1EP-4474543-B1

Inventors

  • BONNEAU, DAVID
  • LEGER, Sylvain
  • PORRET, Robin

Dates

Publication Date
20260513
Application Date
20240605

Claims (20)

  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 (P 48 ) 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 (D 50 ) equal to the diameter (D 42 ) 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 (R 42 ) 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 (P 50 ) 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 (R 42 ) of the rivet (40), preferably greater than or equal to 2 times the radius (R 42 ) of the rivet (40) and or again preferably greater than or equal to 3 times the radius (R 42 ) 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 (D 42 ) of the rivet (40) is greater than a cumulative thickness (e 24 +e 32 ), 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).

Description

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. 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. 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. To limit these deformations, it is known, for example, to CN-203 807 652-U to mount the rollers between a flange machined into the thickness of the lever body and an added flange, fixed to the lever body by means of a deformable rivet. Furthermore, it is known that WO2005/098106A1 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. 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. The documents DE-299 08 928-U1 , DE-10 2018 117387-A1 And DE-23 45 017-A1 describe other methods of mechanical assembly. 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. For this purpose, the invention relates to an output lever with follower rollers according to claim 1. 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. 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. The invention also relates to a method for manufacturing an exit lever as described above, the method being in accordance with claim 19. 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. 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