Device for cutting volumes of expanded polystyrene foam or similar, producing double-curvature surfaces

Abstract

Device for cutting double curvature surfaces into expanded polystyrene foam volumes comprising a first pair of linear guides; over each of the linear guides two pairs of plates arranged over skids are moving, where a horizontal beam connects each pair of plates; the two pairs of plates and the pair of horizontal beams; a block of material supported on the plates is displaced by a first pair by of step motors simultaneously activated; where the block of material in its movement faces a rectangular frame which is arranged perpendicularly to the movement path of the block, with the rectangular frame having a fixed position and a flexible foil, which is covered with a sheath of thermal and electrical insulation, over which a resistive heating wire is helically wound where electrical current heats the wire and vaporizes the zone previous to physical contact with the block of material during displacement.

Claims

1. A device (100) for cutting expanded polystyrene foam volumes and obtaining double-curvature surfaces, comprising: a first pair of linear guides (160); over each of the linear guides (160), two pairs of plates (170) arranged over skids are moving, where each pair of plates (170) is connected by a horizontal beam (165); the two pairs of plates (170) and the pair of horizontal beams (165) allow supporting and fixing a block of material (10) of expanded polystyrene foam, for cutting; the block of material (10) supported on the plates (170) is displaced by a first pair of synchronous belts (163) and pulleys (162), which are driven by a first pair of step motors (161), which are simultaneously activated; where the block of material (10) in its movement faces a rectangular frame (110) which is arranged perpendicularly to the movement path of the block of material (10), passing through this rectangular frame during cutting, said rectangular frame (110) having a fixed position and being supported on a horizontal frame (150) having four support legs (140), whereby the cutting device (100) remains sustained on the floor; where the rectangular frame (110) has a flexible foil (50), which is covered with a sheath of thermal and electrical insulation, over which a resistive heating wire (45) is helically wound, through which an electrical current circulates that heats the resistive heating wire (45) and vaporizes the zone that is previous to physical contact with the block of material (10) during the displacement thereof.

2. The device (100) for cutting foam volumes according to claim 1, wherein the flexible foil (50) is sustained at its ends by crowns (20, 30).

3. The device (100) for cutting foam volumes according to claim 1, wherein the rectangular frame (110) is formed by four sides, and in its upper and lower sides (115, 116), each one of them supports a vertical rail (120, 125), where each vertical support rail (120, 125) has a step motor (23) in its lower side that can be simultaneously or alternately activated; where each one of them moves a pinion (21, 31) to drive the crown (20, 30), so as to have a reducing movement in the crown (20, 30); each vertical support rail (120, 125) slides through skids fixed to a plate (121, 126) respectively, so as to obtain a vertical motion for each of the vertical support rail (120, 125); each one of the plates (121, 126) is supported on a horizontal sliding plate (122, 127) respectively, so that they can move on the respective rail corresponding to the upper and lower sides (115, 116) of the rectangular frame (110) respectively, which allows each vertical support rail (120, 125) to horizontally move within a limit lower than the length of the side (115, 116); the vertical movements are transmitted through spindles rotated by step motors (123), which can be simultaneously or alternately activated; the horizontal movements are transmitted through synchronous pulleys (118) and belts (119), which are rotated by step motors (117), which can be simultaneously or alternately activated.

4. The device (100) for cutting foam volumes according to claim 3, wherein the pinion (21, 31) that drives the crown (20, 30), transmits the movement to the ends of the flexible foil (50).

5. The device (100) for cutting foam volumes according to claim 4, further comprising a microprocessor, wherein during the process of cutting the block of material (10), the three spatial axes are controlled by the microprocessor; thus, the cutting line forming the flexible foil (50) varies during the advancement of the block of material (10) on the Y axis, which corresponds to the movement of the block of material (10) to the rectangular frame (110); the cutting process starts when the block of material (10) faces the flexible foil (50); at the start of cutting the block of material (10), the shape of the flexible foil (50) begins to vary on the X and Z axes; on the X axis, the ends of the flexible foil (50) perform a parallel movement to the upper and lower sides (115, 116) of the rectangular frame (110) respectively; this is done by the horizontal displacement of each vertical support rail (120, 125) by the step motors (117); on the Z axis, the ends of the flexible foil (50) perform an orthogonal movement to the upper and lower sides (115, 116) of the rectangular frame (110) respectively; this is done by means of the vertical displacement of the ends of each vertical support rail (120, 125) through the step motors (117); a combination of horizontal and vertical movements of the ends of each vertical support rail (120, 125) allows to give a particular shape to the flexible foil (50) while cutting the block of material (10), wherein said particular shape may vary during the advance of the block of material (10) on the Y axis; since the length of the flexible foil (50) is fixed, the pinions (21, 31) that drive the crowns (20, 30) during the cutting process need to transmit a movement towards the ends of a flexible foil (50), so that to obtain a curvature with the particular shape.

6. The device (100) for cutting foam volumes according to claim 5, wherein the movements of the entire cutting device (100) are made by the step motors (23, 117, 123, 161), which are controlled by the microprocessor that sends the signals to said step motors (23, 117, 123, 161), according to parameter values on each X, Y, Z axes; where the control of parameters on each axis allows for different types of cutting curves to be obtained from the flexible foil (50).

7. The device (100) for cutting foam volumes according to claim 6, wherein prior to cutting, using a CAD/CAM software, the desired geometry is modeled and parameters for each cutting stage are calculated, where the cutting curve varies during the cutting process to obtain a double-curvature surface in a block of material (10); the software generates a text file that is sent to the machine-controlling microprocessor, which interprets each line of the code and translates those units into digital pulses that are sent to the microprocessor which is controlling the step motors.

8. The device (100) according to claim 4, wherein the flexible foil (50) is steel.

9. The device (100) according to claim 1, wherein the flexible foil (50) is steel.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 describes a main isometric view of the invention,

(2) FIG. 2 describes a front view of the invention.

(3) FIG. 3 describes a side view of the invention.

(4) FIG. 4 describes a plan view of the invention.

(5) FIG. 5 describes a detail of the gear and of the flexible hot knife.

(6) FIG. 6 describes a front view of the control elements of the flexible hot knife.

(7) FIGS. 7, 8, 9, 10 and 11 describe the sequence of cutting curves along a block of material.

(8) FIG. 12 describes the surface of the resulting double curvature in the block of material.

DESCRIPTION OF A PREFERRED EMBODIMENT

(9) The present invention relates to a device for cutting expanded polystyrene foam volumes or the like, obtaining double-curvature surfaces. FIG. 1 shows the cutting device (100) comprising a first pair of linear guides (160); on each of the linear guides (160) there are two pairs of plates (170) moving, arranged over skids moving, where each pair of plates (170) is connected by a horizontal beam (165); the two pairs of plates (170) and the pair of horizontal beams (165) allow supporting and fixing the block of material (10) for cutting; the block of material (10) supported on the plates (170) is displaced by a first pair of synchronous belts and pulleys, which are driven by a first pair of step motors (161), which are simultaneously activated.

(10) In its movement, the block of material (10) faces a rectangular frame (110) which is arranged perpendicularly to the movement path of the block of material (10) passing through this rectangular frame (110) during the cutting, as shown by FIGS. 2 to 4. The rectangular frame (110) has a fixed position and is supported on a horizontal frame (150) having four support legs (140), whereby the cutting device (100) remains sustained on the floor.

(11) The rectangular frame (110) is formed by four sides, and in its upper and lower sides (115, 116), each one of them supports a vertical supporting rail (120, 125), where each vertical support rail (120, 125) has a step motor (23) in its lower side that can be simultaneously or alternately activated; where each one of them moves a pinion (21, 31) to drive a crown (20, 30), so as to have a reducing movement in the crown (20, 30), as shown in FIG. 5; each vertical support rail (120, 125) slides through skids fixed to a plate (121, 126) respectively, so as to obtain a vertical motion for each of the vertical support rails (120, 125); each one of the plates (121, 126) is supported on a horizontal sliding plate (122, 127) respectively, so that they can move on the respective rail corresponding to the upper and lower sides (115, 116) respectively of the rectangular frame (110); the configuration described above, as shown by FIG. 6, allows each vertical support rail (120, 125) to horizontally move within a limit lower to the length of the side (115, 116); the vertical movements are transmitted through spindles rotated by step motors (123), which can be simultaneously or alternately activated; the horizontal movements are transmitted through synchronous pulleys (118) and belts (119), which are rotated by step motors (117), which can be simultaneously or alternately activated.

(12) The pinion (21, 31) that drives the crown (29, 30), transmits the movement to the ends of a flexible foil (50), which can be of steel or similar material, which is covered by a heating and electric insulation sheath, over which a heating resistive wire (45) is helically wound and through which an electrical current circulates that heats the resistive heating wire (45) and vaporizes the zone that is previous to physical contact with the block material (10) during the displacement thereof.

(13) During the process of cutting the block of material (10), the three spatial axes are controlled; thus, the cutting line forming the flexible foil (50) varies during the advance of the block of material (10) on the Y axis, which corresponds to the movement of the block of material (10) to the rectangular frame (110); the cutting process starts when the block of material (10) faces the flexible foil (50) as shown in FIG. 3; at the start of cutting the block of material (10), the shape of the flexible foil (50) begins to vary on the X and Z axes; on the X axis, the ends of the flexible foil (50) perform a parallel movement to the upper and lower sides (115, 116) of the rectangular frame (110) respectively; this is done by the horizontal displacement of each vertical support rail (120, 125) by the step motors (117); on the Z axis, the ends of the flexible foil (50) perform an orthogonal movement to the upper and lower sides (115, 116) of the rectangular frame (110) respectively; this is done by means of the vertical displacement of the ends of each vertical support rail (120, 125) through the step motors (123); a combination of horizontal and vertical movements of the ends of each vertical support rail (120, 125) allows to give a particular shape to the flexible foil (50) while cutting the block of material (10), wherein said particular shape may vary during the advance of the block of material (10) on the Y axis; since the length of the flexible foil (50) is fixed, the pinions (21, 31) that drive the crowns (20, 30) during the cutting process need to transmit a movement towards the ends of a flexible foil (50), so that to obtain a curvature with the particular shape; the movements of the entire cutting device (100) are made by the aforementioned step motors (23, 117, 123, 161), which are controlled by a microprocessor that sends the signals to said step motors, (23, 117, 123, 161) according to parameter values on each X, Y, Z axes. The control of parameters on each axis allows for different types of cutting curves to be obtained from the flexible foil (50).

(14) Prior to cutting, using a CAD CAM software, the desired geometry is modeled and parameters for each cutting stage are calculated. As an example, a sequence is shown in FIGS. 7 to 11 describing five stages where the cutting curve varies during the cutting process in order to obtain a double curvature surface in a block of material (10) as shown in FIG. 12. The software generates a text file that is sent to the machine-controlling microprocessor, which interprets each line of the code and translates those units into digital pulses. These pulses are sent to the step motors controllers.

(15) The electric current heating the resistive heating wire (45) helically winding around the flexible foil (50) can be variable and only a waiting time is required until achieving the proper temperature to start cutting.

(16) The cutting curve can take all possible shapes, and it can even be straight as shown in FIGS. 6 and 7; the flexible foil (50) is flat, this being why its profile is contained in the X Z plane. According to the complexity of geometry to be cut, the block of material (10) can move forwards and backwards during or at the end of each cutting passing.