1. A laying machine for making a multiaxial fiber sheet by superimposing unidirectional fiber sheets in different directions, the machine comprising:
apparatus for advancing the multiaxial sheet, the apparatus comprising support means for supporting the multiaxial sheet that is being made and drive means for driving the support means in a direction of advance;
feed means for feeding longitudinal unidirectional sheet in a direction parallel to the direction of advance;
a plurality of cross-laying devices each including feed means for feeding the cross-laying device with continuous unidirectional sheet, a moving grasping head for taking hold of the free end of a sheet, and means for laying successive segments of sheet parallel to a transverse direction at a selected angle relative to the direction of advance, said laying means comprising means for driving the grasping head; and
bonding means for bonding the superposed unidirectional sheets together, the bonding means being located downstream from the support means in the direction of advance;
the machine being characterized in that each cross-laying device includes cutter means; and in that means are provided for performing successive cycles comprising, for each cross-laying device, grasping the free end of a unidirectional sheet by means of the grasping head, moving the grasping head to fetch a segment of unidirectional sheet, cutting off the fetched segment of unidirectional sheet, and laying the cutoff segment of unidirectional sheet on the support means.
2. A machine according to claim 1, characterized in that each cross-laying device comprises a grasping head that is movable in translation back and forth in one direction and in the opposite direction along a rectilinear path.
3. A machine according to claim 1, characterized in that each cross-laying device comprises a plurality of grasping heads movable along a closed-loop path.
4. A machine according to claim 1, characterized in that each cross-laying device further comprises reinforcement fixing means for reinforcing a unidirectional sheet in each zone where it is to be cut.
5. A machine according to claim 4, characterized in that the reinforcement fixing means comprises means for fetching a film onto at least one face of the sheet, transversely relative thereto, and means for fixing the film to the sheet.
6. A machine according to claim 5, characterized in that the fixing means include heating presser means.
7. A machine according to claim 1, characterized in that the advance device includes means for continuously driving the support means.
8. A machine according to claim 7, characterized in that each cross-laying device further includes means for transferring a cutoff unidirectional sheet segment so as to lay it on the continuously-driven support means.
9. A machine according to claim 1, characterized in that holding means are provided to hold sheet segments in place on the sheet support means.
10. A machine according to claim 9, characterized in that the holding means comprise bonding means for bonding contiguous sheet segments at their ends.
11. A machine according to claim 10, characterized in that the holding means comprise means for fixing at least one film at the longitudinal edges of a multiaxial sheet that is being made.
12. A machine according to claim 9, characterized in that the holding means comprise spikes carried by support means for the multiaxial sheet.
13. A machine according to claim 1, characterized in that the angle between the path of a grasping head and the direction of advance is adjustable.
14. A machine according to claim 1, characterized in that the longitudinal sheet feed means are disposed in such a manner as to fetch a longitudinal sheet onto the support means between two cross-laying devices.
15. A machine according to claim 1, characterized in that the means for bonding together the superposed unidirectional sheets include a needling device.
16. A machine according to claim 1, characterized in that the means for bonding together the superposed unidirectional sheets include a stitching or knitting device.
17. A machine according to claim 1, characterized in that the means for bonding together the superposed unidirectional sheets include a device for fetching an adhesive bonding agent between the sheets.
18. A machine according to claim 17, characterized in that the means for bonding together the superposed unidirectional sheets include a device for inserting heat-fusible thread between the sheets.
19. A machine according to claim 2, characterized in that each cross-laying device further comprises reinforcement fixing means for reinforcing a unidirectional sheet in each zone where it is to be cut.
20. A machine according to claim 3, characterized in that each cross-laying device further comprises reinforcement fixing means for reinforcing a unidirectional sheet in each zone where it is to be cut.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A device for heating target tissue comprising:
a housing including a tissue contacting surface;
an array of ultrasound transducers mounted within the housing on an array surface shaped so that ultrasound energy from the transducers converges on a target area a predetermined depth from the tissue contacting surface; and
a deflector member located at a selected position within a field through which a portion of the ultrasound energy generated will pass on its way to the target area, the deflector member refracting a selected portion of the ultrasound energy to control a distance of separation between the array and a proximal edge of a region at which a level of ultrasound energy exceeds a predetermined threshold level.
2. The device according to claim 1, wherein the deflector member extends from the array surface a predetermined distance toward the target area.
3. The device according to claim 2, wherein a profile of the deflector member in a plane substantially parallel to a plane tangent to a center of the array surface is selected to create a shadow area in which the level of ultrasound energy remains below the predetermined threshold level wherein, if not for the deflector member, the level of ultrasound energy in this shadow area would exceed the predetermined threshold level.
4. The device according to claim 1, wherein the deflector member includes a proximal end coupled to the array surface and a distal end expanded relative to the proximal end.
5. The device according to claim 4, wherein the deflector member expands gradually outward through a transition area from a central stem to form a substantially conical distal end.
6. The device according to claim 4, wherein the deflector member expands abruptly from a central stem to form a substantially disc-shaped distal end.
7. A device for heating target tissue comprising:
an array of ultrasound transducers mounted within a housing along a shape selected so that ultrasound energy from the transducers converges on a target area a predetermined distance from the array; and
a control unit deactivating various ones of the transducers to control a distance of separation between the array and a proximal edge of a region at which a level of ultrasound energy exceeds a predetermined threshold level.
8. A device for heating target tissue comprising:
an array of ultrasound transducers mounted within a housing along a shape selected so that ultrasound energy from the transducers converges on a target area a predetermined distance from the array; and
a shield element selectively mountable over one or more of the transducers to prevent ultrasound energy from these transducers from reaching a particular region to control a distance of separation between the array and a proximal edge of a region at which a level of ultrasound energy exceeds a predetermined threshold level.
9. A device for heating target tissue comprising:
an array of transducers mounted within a housing, the array shaped so that energy from the transducers converges on a target area a predetermined distance from the array; and
a deflector having a shape and location relative to the array selected so that a shape of a region of the target area within which an intensity of ultrasound energy from the transducers exceeds a predetermined threshold level corresponds to a desired shape of a lesion to be created in the target tissue.