Sheet with alternate protrusions and recesses

Claim 2

A sheet of material having a succession of alternate protrusions and recesses with spaces between successive protrusions on the one hand and successive recesses on the other, the walls of each such protrusion and recess containing elementary surfaces joining each other in an undulatory manner at the ridges of said protrusions and recesses along a single line having a plurality of points at which it changes direction to form a plurality of undulations and at each of which points border lines of at least four of said elementary surfaces converge, said surfaces being ruled in a direction extending from one ridge line to another, the sum of the angles formed on said surfaces between said border lines at each of said points being equal to 360°, said sheet being of such configuration that it (1) is completely developable on the plane to which it is expanded and (2) cannot be completely contracted so that each of its ruled elementary surfaces is in complete surface area contact with its next adjacent ruled elementary surface.

Claim 3

A sheet of material according to claim 1 in which said walls consist exclusively of adjacent flat surfaces in the form of parallelograms, said lines along which said surfaces join each other being composed of segments whose points of intersection are points at which said lines change direction and at each of which points terminates one of the border lines of each of four parallelograms.

Claim 4

A sheet of material according to claim 1 in which said walls consist exclusively of adjacent flat surfaces in the form of parallelograms, said lines along which said surfaces join each other being composed of segments whose points of intersection are points at which said lines change direction and at each of which points terminates one of the border lines of each of four parallelograms, said protrusions and recesses forming a plurality of said lines which are identical and substantially parallel to one another.

Claim 5

A sheet of material according to claim 1 in which said walls consist exclusively of adjacent flat surfaces in the form of parallelograms, said lines along which said surfaces join each other being composed of segments of equal length whose points of intersection are points at which said lines change direction and at each of which points terminates one of the border lines of each of four parallelograms.

Claim 6

A sheet of material according to claim 1 in which said walls consist exclusively of adjacent flat surfaces in the form of parallelograms, each of said surfaces being bounded in one direction by a surface which is its mirror image and in another direction by a surface identical to it, said lines along which said surfaces join each other being composed of segments of equal length whose points of intersection are points at which said lines change direction and at each of which points terminates one of the border lines of each of four parallelograms.

Claim 7

A sheet of material according to claim 1 in which said walls consist exclusively of adjacent flat surfaces in the form of parallelograms, each of said surfaces being bounded in one direction by a surface which is its mirror image, said lines along which said surfaces join each other being composed of segments whose points of intersection are points at which said lines change direction and at each of which poins terminates one of the border lines of each of four parallelograms.

Claim 8

A sheet of material according to claim 1 in which said walls consist exclusively of adjacent flat surfaces in the form of parallelograms, said lines along which said surfaces join each other being composed of segments of equal length whose points of intersection are points at which said lines change direction and at each of which points terminates one of the border lines of each of four parallelograms, the height of all the walls being substantially identical to one another.

Claim 9

A sheet of material according to claim 1 in which said walls consist of a number of ruled elementary surfaces which can be reduced respectively to the generating lines of said surfaces, said lines along which said surfaces join each other being non-rectilinear undulated lines all of whose points are points at which said non-rectilinear undulated lines change direction.

Claim 10

A sheet of material according to claim 1 in which said walls consist of a number of ruled elementary surfaces which can be reduced respectively to the generating lines of said surfaces, said lines along which said surfaces join each other being non-rectilinear undulated lines all of whose points are points at which said non-rectilinear undulated lines change direction, said protrusions and recesses forming a plurality of said non-rectilinear undulated lines which are identical and substantially parallel to one another.

Claim 11

A sheet of material according to claim 1 in which said walls consist of a number of ruled elementary surfaces which can be reduced respectively to the generating lines of said surfaces, said lines along which said surfaces join each other being non-rectilinear undulated lines all of whose points are points at which said non-rectilinear undulated lines change direction, the height of all of the walls being substantially identical to one another.

Claim 12

A sheet of material having a plurality of bends forming a succession of alternate protrusions and recesses with spaces between successive protrusions on the one hand and successive recesses on the other, the walls of each such protrusion and recess containing non-rectangular elementary surfaces joining each other in an undulatory manner at the ridges of said protrusions and recesses along a single line having a plurality of points at which it changes direction to form a plurality of undulations and at each of which points border lines of at least four of said elementary surfaces converge, said surfaces being ruled in a direction extending from one ridge line to another, the sum of the angles formed on said surfaces between said border lines at each of said points being equal to 360°, said sheet being of such configuration that it (1) is completely developable on the plane to which it is expanded and (2) cannot be completely contracted so that each of its ruled elementary surfaces is in complete surface area contact with its next adjacent ruled elementary surface.

Claim 13

A sheet of material having a plurality of bends forming a succession of alternate protrusions and recesses with spaces between successive protrusions on the one hand and successive recesses on the other, the walls of each such protrusion and recess containing non-rectangular elementary surfaces joining each other in an undulatory manner at the ridges of said protrusions and recesses along a single line having a plurality of points at which it changes direction to form a plurality of undulations and at each of which points border lines of at least four of said elementary surfaces converge, said surfaces being ruled in a direction extending from one ridge line to another, the sum of the angles formed on said surfaces between said border lines at each of said points being equal to 360°, said sheet being of such configuration that it (1) is completely developable on the plane to which it is expanded and (2) cannot be completely contracted so that each of its ruled elementary surfaces is in complete surface area contact with its next adjacent ruled elementary surface.

Claim 14

A sheet of material having a succession of alternate protrusions and recesses with spaces between successive protrusions on the one hand and successive recesses on the other, the walls of each such protrusion and recess being composed exclusively of non-rectangular elementary surfaces joining each other in an undulatory manner at the ridges of said protrusions and recesses along a single line having a plurality of undulations at each of which points border lines of at least four of said elementary surfaces converge, said surfaces being ruled in a direction extending from one ridge line to another, the sum of the angles formed on said surfaces between said border lines at each of said points being equal to 360°.

Claim 15

A sheet of material having a succession of alternate protrusions and recesses with spaces between successive protrusions on the one hand and successive recesses on the other, the walls of each such protrusion and recess being composed exclusively of non-rectangular elementary surfaces joining each other in an undulatory manner at the ridges of said protrusions and recesses along a single line having a plurality of undulations at each of which points border lines of at least four of said elementary surfaces converge, said surfaces being ruled in a direction extending from one ridge line to another, the sum of the angles formed on said surfaces between said border lines at each of said points being equal to 360°.

Claim 16

A sheet of material having a succession of alternate protrusions and recesses with spaces between successive protrusions on the one hand and successive recesses on the other, the walls of each such protrusion and recess containing non-rectangular elementary surfaces joining each other in an undulatory manner at the ridges of said protrusions and recesses along a single line having a plurality of points at which it changes direction to form a plurality of undulations and at each of which points border lines of at least four of said elementary surfaces converge, said surfaces being ruled in a direction extending from one ridge line to another, the sum of the angles formed on said surfaces between said border lines at each of said points being equal to 360°, said sheet being of such configuration that it (1) is completely developable on the plane to which it is expanded and (2) cannot be completely contracted so that each of its ruled elementary surfaces is in complete surface area contact with its next adjacent ruled elementary surface.

Claim 17

A sheet of material having a succession of alternate protrusions and recesses with spaces between successive protrusions on the one hand and successive recesses on the other, the walls of each such protrusion and recess containing non-rectangular elementary surfaces joining each other in an undulatory manner at the ridges of said protrusions and recesses along a single line having a plurality of points at which it changes direction to form a plurality of undulations and at each of which points border lines of at least four of said elementary surfaces converge, said surfaces being ruled in a direction extending from one ridge line to another, the sum of the angles formed on said surfaces between said border lines at each of said points being equal to 360°, said sheet being of such configuration that it (1) is completely developable on the plane to which it is expanded and (2) cannot be completely contracted so that each of its ruled elementary surfaces is in complete surface area contact with its next adjacent ruled elementary surface.

Claim 18

A sheet of bendable material having a succession of alternate protrusions and recesses with spaces between successive protrusions on the one hand and successive recesses on the other, the walls of each such protrusion and recess containing elementary surfaces joining each other in an undulatory manner at the ridges of said protrusions and recesses along a single line having a plurality of points at which it changes direction to form a plurality of undulations and at each of which points border lines of at least four of said elementary surfaces converge, said surfaces being ruled in a direction extending from one ridge line to another, the sum of the angles formed on said surfaces between said border lines at each of said points being equal to 360°, said sheet being of such configuration that it (1) is completely developable on the plane to which it is expanded and (2) cannot be completely contracted so that each of its ruled elementary surfaces is in complete surface area contact with its next adjacent ruled elementary surface.

Claim 19

A sheet of bendable material having a succession of alternate protrusions and recesses with spaces between successive protrusions on the one hand and successive recesses on the other, the walls of each such protrusion and recess containing elementary surfaces joining each other in an undulatory manner at the ridges of said protrusions and recesses along a single line having a plurality of points at which it changes direction to form a plurality of undulations and at each of which points border lines of at least four of said elementary surfaces converge, said surfaces being ruled in a direction extending from one ridge line to another, the sum of the angles formed on said surfaces between said border lines at each of said points being equal to 360°, said sheet being of such configuration that it (1) is completely developable on the plane to which it is expanded and (2) cannot be completely contracted so that each of its ruled elementary surfaces is in complete surface area contact with its next adjacent ruled elementary surface.

Claim 20

A sheet of material having a succession of alternate protrusions and recesses with spaces between successive protrusions on the one hand and successive recesses on the other, the walls of each such protrusion and recess containing elementary surfaces joining each other in an undulatory manner at the ridges of said protrusions and recesses along a single line having a plurality of points at which it changes direction to form a plurality of undulations and at each of which points border lines of at least four of said elementary surfaces converge, said surfaces being ruled in a direction extending from one ridge line to another, the sum of the angles formed on said surfaces between said border lines at each of said points being equal to 360°, said sheet being of such configuration that it (1) is completely developable on the plane to which it is expanded and (2) is contractible from its planar form only to a point at which it is locked against further contraction notwithstanding the fact that less than all of the ruled elementary surfaces are in complete surface area contact with their next adjacent ruled elementary surfaces.

Claim 21

A sheet of material having a succession of alternate protrusions and recesses with spaces between successive protrusions on the one hand and successive recesses on the other, the walls of each such protrusion and recess containing elementary surfaces joining each other in an undulatory manner at the ridges of said protrusions and recesses along a single line having a plurality of points at which it changes direction to form a plurality of undulations and at each of which points border lines of at least four of said elementary surfaces converge, said surfaces being ruled in a direction extending from one ridge line to another, the sum of the angles formed on said surfaces between said border lines at each of said points being equal to 360°, said sheet being of such configuration that it (1) is completely developable on the plane to which it is expanded and (2) is contractible from its planar form only to a point at which it is locked against further contraction notwithstanding the fact that less than all of the ruled elementary surfaces are in complete surface area contact with their next adjacent ruled elementary surfaces.

Claim 22

A sheet of material having a plurality of bends forming a succession of alternate protrusions and recesses with spaces between successive protrusions on the one hand and successive recesses on the other, the walls of each such protrusion and recess containing non-rectangular elementary surfaces joining each other in an undulatory manner at the ridges of said protrusions and recesses along a single line having a plurality of points at which it changes direction to form a plurality of undulations and at each of which points border lines of at least four of said elementary surfaces converge, said surfaces being ruled in a direction extending from one ridge line to another, the sum of the angles formed on said surfaces between said border lines at each of said points being equal to 360°, said sheet being of such configuration that it (1) is completely developable on the plane to which it is expanded and (2) is contractible from its planar form only to a point at which it is locked against further contraction notwithstanding the fact that less than all of the ruled elementary surfaces are in complete surface contact with their next adjacent ruled elementary surfaces.

Claim 23

A sheet of material having a plurality of bends forming a succession of alternate protrusions and recesses with spaces between successive protrusions on the one hand and successive recesses on the other, the walls of each such protrusion and recess containing non-rectangular elementary surfaces joining each other in an undulatory manner at the ridges of said protrusions and recesses along a single line having a plurality of points at which it changes direction to form a plurality of undulations and at each of which points border lines of at least four of said elementary surfaces converge, said surfaces being ruled in a direction extending from one ridge line to another, the sum of the angles formed on said surfaces between said border lines at each of said points being equal to 360°, said sheet being of such configuration that it (1) is completely developable on the plane to which it is expanded and (2) is contractible from its planar form only to a point at which it is locked against further contraction notwithstanding the fact that less than all of the ruled elementary surfaces are in complete surface contact with their next adjacent ruled elementary surfaces.