Abstract: A protective helmet has an outer shell and one or more absorption elements of impact shock energy operatively coupled with the outer shell. The absorption elements include a working portion interposed between the end portions. The section of the working portion along a surface transverse to the development axis has an area smaller than the areas of the corresponding sections of the end portions. The absorption elements have a breaking load lower than the breaking load of the outer shell, so that in the event of an impact the working portion is subject to breaking before the outer shell and before the end portions to allow the absorption of the impact shock energy.

Abstract: The invention is a stereolithography method for the production of a three-dimensional object (10) through the superimposition of a succession of layers (1-5) obtained by solidifying a liquid material through exposure to predefined radiation (6), comprising the following operations: defining a geometric representation of the layers (1, 2, 3, 4, 5); selecting one or more layers (2) that precede a reference layer (4) in the succession; defining a mask area (9) corresponding to the logical conjunction of the geometric representations of the reference layer (4) and of the selected layers (2) reproduced on the plane of the reference layer (4); exposing the liquid material to the predefined radiation (6) in the mask area (9).

Abstract: The invention is a method for controlling the activity of two light radiation sources (2, 3) belonging to a stereolithography machine (1) and suited to act at the level of a portion (104) of a superimposition area (101) defined on the work surface (100) of the stereolithography machine (1) for the production of a three-dimensional object (200) through stereolithography. For each one of the lines (210) with generic length L that define each layer (201) of the three-dimensional object (200) within the portion (104), the method provides for activating: a first light radiation source (2) for a first section (211) of the line (210) having length X; a second light radiation source (3) for the remaining second section (212) of the line (210) having length Y, wherein the value X of the first section (211) is selected within the interval 0<=X<=L and wherein Y is calculated as equal to L?X.

Abstract: The invention is a method for producing a three-dimensional object in layers through stereolithography, comprising the following operations: moving a supporting surface (6a, 7a) near the bottom (2a) of a container (2) containing a liquid substance (3), so as to arrange it in a predefined operating position (17); selectively irradiating a layer (6) of liquid substance (3) with pre-defined radiation (4), in such a way as to solidify it against the supporting surface (6a, 7a). The approaching movement (11) comprises a plurality of approaching moves (12, 12a, 12b, 12c) having corresponding predefined lengths (13, 13a, 13b, 13c), spaced by corresponding intermediate stops (14, 14a, 14b) for corresponding predefined time intervals (15, 15a, 15b), the intermediate stops (14, 14a, 14b) being carried out when the supporting surface (6a, 7a) is at least partially immersed in the liquid substance (3).

Abstract: The invention is a method for controlling the activity of two light radiation sources (2, 3) belonging to a stereolithography machine (1) and suited to act at the level of a portion (104) of a superimposition area (101) defined on the work surface (100) of the stereolithography machine (1) for the production of a three-dimensional object (200) through stereolithography. For each one of the lines (210) with generic length L that define each layer (201) of the three-dimensional object (200) within the portion (104), the method provides for activating: a first light radiation source (2) for a first section (211) of the line (210) having length X; a second light radiation source (3) for the remaining second section (212) of the line (210) having length Y, wherein the value X of the first section (211) is selected within the interval 0<=X<=L and wherein Y is calculated as equal to L?X.

Abstract: The invention is a stereolithography method for the production of a three-dimensional object (10) through the superimposition of a succession of layers (1-5) obtained by solidifying a liquid material through exposure to predefined radiation (6), comprising the following operations: defining a geometric representation of the layers (1, 2, 3, 4, 5); selecting one or more layers (2) that precede a reference layer (4) in the succession; defining a mask area (9) corresponding to the logical conjunction of the geometric representations of the reference layer (4) and of the selected layers (2) reproduced on the plane of the reference layer (4); exposing the liquid material to the predefined radiation (6) in the mask area (9).

Abstract: Method for producing a three-dimensional object in layers by way of a stereolithography machine (1) including a container (2) suited to contain a liquid substance (3), structure (5) suited to emit predefined radiation (4) suited to selectively solidify a layer (6) of the liquid substance (3) adjacent to the bottom (2a) of the container (2), and an actuator (8) suited to move the solidified layer (6a) with respect to the bottom (2a). The method includes selectively solidifying the liquid layer (6); separating the solidified layer (6a) from the bottom (2a) through a movement (11) suited to move them away from each other, including a plurality of shifts (12, 12a, 12b, 12c) for corresponding predefined lengths, spaced by corresponding intermediate stops (14, 14a, 14b) for corresponding predefined time intervals (15, 15a, 15b). The intermediate stops are carried out before the solidified layer has become completely detached from the bottom.

Abstract: The invention is a method for producing a three-dimensional object in layers through stereolithography, comprising the following operations: moving a supporting surface (6a, 7a) near the bottom (2a) of a container (2) containing a liquid substance (3), so as to arrange it in a predefined operating position (17); selectively irradiating a layer (6) of liquid substance (3) with pre-defined radiation (4), in such a way as to solidify it against the supporting surface (6a, 7a). The approaching movement (11) comprises a plurality of approaching moves (12, 12a, 12b, 12c) having corresponding predefined lengths (13, 13a, 13b, 13c), spaced by corresponding intermediate stops (14, 14a, 14b) for corresponding predefined time intervals (15, 15a, 15b), the intermediate stops (14, 14a, 14b) being carried out when the supporting surface (6a, 7a) is at least partially immersed in the liquid substance (3).

Abstract: Method for producing a three-dimensional object in layers by way of a stereolithography machine (1) including a container (2) suited to contain a liquid substance (3), structure (5) suited to emit predefined radiation (4) suited to selectively solidify a layer (6) of the liquid substance (3) adjacent to the bottom (2a) of the container (2), and an actuator (8) suited to move the solidified layer (6a) with respect to the bottom (2a). The method includes selectively solidifying the liquid layer (6); separating the solidified layer (6a) from the bottom (2a) through a movement (11) suited to move them away from each other, including a plurality of shifts (12, 12a, 12b, 12c) for corresponding predefined lengths, spaced by corresponding intermediate stops (14, 14a, 14b) for corresponding predefined time intervals (15, 15a, 15b). The intermediate stops are carried out before the solidified layer has become completely detached from the bottom.