Claims
- 1. A bending machine for bending tubes with small diameters, which are pre-cut such as to have a predetermined length, and are provided with connection systems at both ends, the bending machine comprising: a frame, on which there is mounted at least one bending head, and means for longitudinal displacement of the tube relative to the frame along a longitudinal axis (X), wherein:the means for longitudinal displacement comprise means for grasping the rear end of the tube, and means for entrainment of the grasping means along the longitudinal axis (X); each bending head comprises: two forming rollers, each of which has at least one peripheral groove with a semi-circular cross-section, which, in a coupled position of the rollers, is designed to form a guide duct having a neck with a diameter which is substantially larger than that of the tube; means for relative displacement of the forming rollers, which can position the rollers either in their coupled position, or in an open position which permits passage of the tube along a first axis which is perpendicular to the longitudinal axis (X); a folding finger disposed downstream and in the vicinity of the forming rollers; means for displacement of the folding finger along a circular path which is centered on a second axis (Y) at right angle to the longitudinal axis (X); means for displacement in translation of the folding finger along a third axis (Y1) which is parallel to the second axis (Y); and guide units for guiding the tube, disposed on both sides of the longitudinal axis (X), such as to come into contact with the tube upstream and in the vicinity of the forming rollers; said guide units being structured and arranged to retract transversely, under the effect of a longitudinal force exerted by the grasping means.
- 2. The bending machine according to claim 1, wherein:the forming rollers comprise two superimposed grooves having cross-sections designed to form two guide ducts, which have necks with different diameters; means for displacement in translation of the forming rollers according to an axis (Y2), (Y3), parallel to the second axis (Y), designed to position the rollers such that one or the other of their grooves is centered relative to the longitudinal axis (X).
- 3. The bending machine according to claim 1, further comprising additional means for displacement in translation of the folding finger, which can displace the finger radially relative to the second axis (Y).
- 4. The bending machine according to claim 1, further comprising a rule disposed upstream of the forming rollers in contact therewith, and having a support surface which forms a support for the tube; said rule being associated with means for displacement, which are designed to bring the rule into a retracted position, thus making it possible to advance the grasping means into contact with the forming rollers.
- 5. The bending machine according to claim 4, wherein the rule is in the shape of a “U”, and the means for displacement of the rule comprise pivoting means, which can make the rule pivot around an axis at right-angles to the longitudinal axis (X) and the second axis (Y).
- 6. The bending machine according to claim 2, wherein the means for relative displacement of the forming rollers comprise means for entrainment in rotation of each of these rollers around axes (Y2), (Y3); said rollers having a non-circular shape, which is designed to release a space when the rollers are rotated from their coupled position.
- 7. The bending machine according to claim 6, wherein each forming roller has a generally semi-circular or semi-elliptical shape.
- 8. The bending machine according to claim 6, wherein each forming roller is mounted on a shaft, which extends respectively according to the axis (Y2), (Y3); the means for entrainment in rotation of the rollers comprising two pinions, each of which is mounted on one of the shafts, a rack, which his provided with two toothed lateral surfaces, each of which is designed to engage with a pinion; and means for entrainment of the rack along a longitudinal axis (X1) which is parallel to the longitudinal axis (X).
- 9. The bending machine according to claim 8, wherein the shaft of each forming roller comprises a rod a jack, which is designed to displace in translation the roller respectively according to the axes (Y2) (Y3).
- 10. The bending machine according to claim 4, further comprising a support unit, which is retractable laterally relative to the longitudinal axis (X) and is designed to be positioned in contact with a generatrix of the tube, diametrically opposite that which is supported on the support surface of the rule, upstream and in the vicinity of the forming rollers.
- 11. The bending machine according to claim 10, wherein the support unit comprises a cable which extends inside a sheath, a first end of said cable being integral with a rod a jack designed to make the cable slide inside the sheath, and a second end of said cable extending according to a plane at right angles to the planes (X) and (Y), such as to be positioned in contact with the tube, during displacement of the jack.
- 12. The bending machine according to claim 1, further comprising two support plates, which have a convex support surface, and are disposed at right angles relative to the longitudinal axis (X) and on both sides thereof upstream of the forming rollers; said support plates being offset relative to the forming rollers, along an axis which is parallel to the second axis (Y), such that during formation of coils, after being bent, the tube is displaced on the support surface of one of the support plates.
- 13. The bending machine according to claim 12, further comprising means for adjustment of the position of the support plates along an axis which is parallel to the second axis (Y).
- 14. The bending machine according to claim 1, wherein the guide units for the tube are each disposed on an end of an arm, which is mounted such as to pivot relative to the frame, and is associated with resilient means which can maintain the arm in a position which is inclined rearwards, relative to the direction of displacement of the tube.
- 15. The bending machine according to claim 12, further comprising:two detection cells disposed symmetrically on both parts of the longitudinal axis (X), upstream of the forming rollers, such that according to the direction of bending, a beam of one of said cells is intersected by the end of the tube during the formation of the coils; numerical control means designed to calculate the length paid out for formation of each revolution of a coil, to compare this value with a value stored, which is representative of the theoretical paid out length necessary for formation of a revolution of a coil, and according to the result of this comparison, to command displacement of the folding finger along its circular path, in order to form the following revolution of a coil, such that the total length paid out for formation of a coil is always strictly identical for a series of identical products.
- 16. A bending head for a machine for bending pre-cut tubes with a small diameter, which are provided with connection systems at both ends, the bending head comprising:two forming rollers each of which having at least one peripheral groove with a semi-circular cross-section, which, in a coupled position of the rollers, is designed to form a guide duct which is centered according to a longitudinal axis (X), and has a neck with a diameter which is substantially larger than that of the tube; means for relative displacement of the forming rollers, which can position the roller either in their coupled position, or in an open position which permits passage of the tube along a first axis which is perpendicular to the longitudinal axis (X); a folding finger disposed upstream and in the vicinity of the forming rollers; means for displacement of the folding finger along a circular path which is centered on a second axis (Y) at right angles to the longitudinal axis (X); means for displacement in translation of the folding finger along a third axis (Y1) which is parallel to the second axis (Y); and guide units for guiding the tube disposed on both sides of the longitudinal axis (X), such as to come into contact with the tube upstream and in the vicinity of the forming rollers; said guide units being structured and arranged to retract transversely under the effect of a longitudinal force exerted by a grasping means.
Priority Claims (1)
Number |
Date |
Country |
Kind |
97-00437 |
Jan 1997 |
FR |
|
CROSS REFERENCE TO RELATED APPLICATION
This is the national stage of international application PCT/FR98/00033 filed on Jan. 9, 1998, which designated the United States of America.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
PCT/FR98/00033 |
|
WO |
00 |
7/13/1999 |
7/13/1999 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO98/31484 |
7/23/1998 |
WO |
A |
US Referenced Citations (6)
Foreign Referenced Citations (4)
Number |
Date |
Country |
0 319 400 |
Jun 1989 |
EP |
0 538 207 |
Apr 1993 |
EP |
2 554 021 |
Mar 1985 |
FR |
4-127919 |
Apr 1992 |
JP |