阅读说明：本技术 一种基于薄片基材的三维成型方法和装置 (Three-dimensional forming method and device based on thin sheet base material ) 是由 李清 刘旭飞 陈根余 陈焱 高云峰 于 2021-01-14 设计创作，主要内容包括：本发明公开了一种基于薄片基材的三维成型方法和装置。包括步骤步骤A：提供一承载基板和若干薄片基材；步骤B：将一薄片基材固定在承载基板上；步骤C：按预设切割路径切割承载基板上的薄片基材,得到三维半成品；步骤D：在三维半成品上熔接一薄片基材；步骤E：按预设切割路径切割熔接在三维半成品上的薄片基材,以成型三维半成品；步骤F：重复步骤D和步骤E,直至得到三维工件。本发明的基于薄片基材的三维成型方法,采用呈薄片状的薄片基材作为三维成型的原材料,加工过程中粉尘的产生少甚至几乎没有,每一层先熔接再切割,熔接和切合分开成型,融合度好,成型后的三维工件质量能够达到原材料的强度,强度好,外观佳。(The invention discloses a three-dimensional forming method and a three-dimensional forming device based on a thin substrate. Comprises the following steps: providing a bearing substrate and a plurality of thin substrate materials; and B: fixing a thin substrate on a bearing substrate; and C: cutting the thin substrate on the bearing substrate according to a preset cutting path to obtain a three-dimensional semi-finished product; step D: welding a thin substrate on the three-dimensional semi-finished product; step E: cutting the thin sheet base material welded on the three-dimensional semi-finished product according to a preset cutting path to form the three-dimensional semi-finished product; step F: and D, repeating the step D and the step E until a three-dimensional workpiece is obtained. The three-dimensional forming method based on the sheet base material adopts the sheet base material in a sheet shape as a raw material for three-dimensional forming, little or no dust is generated in the processing process, each layer is welded and then cut, and the welding and the cutting are separated for forming, so that the fusion degree is good, the quality of the formed three-dimensional workpiece can reach the strength of the raw material, the strength is good, and the appearance is good.)

1. A three-dimensional forming method based on a sheet substrate, characterized by comprising the steps of:

step A: providing a bearing substrate and a plurality of thin substrate materials;

and B: fixing a thin substrate on a bearing substrate;

and C: cutting the thin substrate on the bearing substrate according to a preset cutting path to obtain a three-dimensional semi-finished product;

step D: welding a thin substrate on the three-dimensional semi-finished product;

step E: cutting the thin sheet base material welded on the three-dimensional semi-finished product according to a preset cutting path to form the three-dimensional semi-finished product;

step F: and D, repeating the step D and the step E until a three-dimensional workpiece is obtained.

2. The three-dimensional forming method according to claim 1, wherein the step D is specifically:

on the three-dimensional semi-finished product, a thin sheet base material is welded by high-voltage electric arc.

3. The three-dimensional forming method of claim 2, wherein the step of welding the laminar substrate by high voltage arc comprises:

providing a movable electrode plate;

loading a low voltage on the bearing substrate and loading a high voltage on the electrode plate;

the bearing substrate and the electrode plate are pressed on the thin sheet base material so as to weld the thin sheet base material on the three-dimensional semi-finished product.

4. The three-dimensional forming method according to any one of claims 1 to 3, wherein the step E comprises the steps of:

and laser cutting the thin sheet base material welded on the three-dimensional semi-finished product according to a preset cutting path, and introducing inert gas to the outer side of the laser cutting to form the three-dimensional semi-finished product.

5. The three-dimensional forming method according to any one of claims 1 to 3, wherein the step C comprises the steps of:

and laser cutting the sheet base material welded on the bearing substrate according to a preset cutting path, and introducing inert gas to the outer side of the laser cutting to obtain a three-dimensional semi-finished product.

6. The three-dimensional forming method according to any one of claims 1 to 3, wherein the step B is specifically:

providing a movable electrode plate;

loading a low voltage on the bearing substrate and loading a high voltage on the electrode plate;

the bearing substrate and the electrode plate are pressed on the thin sheet base material to weld the thin sheet base material on the bearing substrate.

7. A three-dimensional forming device based on a sheet substrate, which applies the three-dimensional forming method of any one of claims 1 to 6, and is characterized by comprising:

mounting the main body;

a bearing substrate arranged on the mounting main body and used for bearing and fixing the sheet base material;

the cutting mechanism is arranged on the mounting main body and used for cutting the sheet base material according to a preset cutting path;

and the welding mechanism is arranged on the mounting main body, is opposite to the bearing substrate and is used for welding the sheet substrate on the three-dimensional semi-finished product.

8. The three-dimensional forming device according to claim 7, wherein the fusing mechanism comprises an electrode plate and a pressing die set; the pressing module is arranged on the mounting main body, the electrode plate is connected with the pressing module, the electrode plate is opposite to the bearing substrate, and the pressing module can drive the electrode plate to approach the bearing substrate; the electrode plate is loaded with high voltage, and the bearing substrate is loaded with low voltage.

9. The three-dimensional forming device according to claim 7, wherein the cutting mechanism comprises a laser cutting module, a first cutting protection gas path and a second cutting protection gas path for providing inert gas; the laser cutting module is arranged on the mounting main body, the first cutting protection gas circuit and the second cutting protection gas circuit are arranged on the laser cutting module, and inert gases are provided for two sides of the laser cutting module.

10. The three-dimensional forming device of claim 8, wherein the mounting body comprises a frame and a Z-axis motion module; the Z-axis motion module is arranged on the rack and connected with the bearing substrate; and the Z-axis motion module drives the bearing substrate to move up and down.

Technical Field

The invention relates to the field of additive manufacturing and forming processing, in particular to a three-dimensional forming method and device based on a thin substrate.

Background

The three-dimensional entity is formed by stacking and superposing the layers by the 3D printing technology, so that the three-dimensional model can be quickly obtained. Printing equipment of 3D printing technology that 3D printer adopted. The 3D printer is used for stacking and superposing liquid photosensitive resin materials, molten plastic wires, gypsum powder, powdered metals and other materials layer by layer in a binder spraying or extruding mode to form a three-dimensional entity, and is widely applied to various fields.

At present, because the printing material that 3D printed the adoption, can produce a large amount of dusts in the printing process. The dust can be attached to the three-dimensional workpiece in the printing process and is covered layer by layer into a loose state, so that the strength of the three-dimensional workpiece is insufficient, and the appearance is also influenced.

Disclosure of Invention

The invention aims to provide a three-dimensional forming method and a three-dimensional forming device based on a thin substrate, which are not easy to adhere dust, and the processed three-dimensional workpiece has good strength and appearance.

The invention discloses a three-dimensional forming method based on a thin substrate, which comprises the following steps:

step A: providing a bearing substrate and a plurality of thin substrate materials;

and B: fixing a thin substrate on a bearing substrate;

and C: cutting the thin substrate on the bearing substrate according to a preset cutting path to obtain a three-dimensional semi-finished product;

step D: welding a thin substrate on the three-dimensional semi-finished product;

step E: cutting the thin sheet base material welded on the three-dimensional semi-finished product according to a preset cutting path to form the three-dimensional semi-finished product;

step F: and D, repeating the step D and the step E until a three-dimensional workpiece is obtained.

Optionally, step D specifically includes:

on the three-dimensional semi-finished product, a thin sheet base material is welded by high-voltage electric arc.

Optionally, the step of welding the laminar substrate by high voltage arc comprises:

providing a movable electrode plate;

loading a low voltage on the bearing substrate and loading a high voltage on the electrode plate;

the bearing substrate and the electrode plate are pressed on the thin sheet base material so as to weld the thin sheet base material on the three-dimensional semi-finished product.

Optionally, the step E includes the steps of:

and laser cutting the thin sheet base material welded on the three-dimensional semi-finished product according to a preset cutting path, and introducing inert gas to the outer side of the laser cutting to form the three-dimensional semi-finished product.

Optionally, the step C includes the steps of:

and laser cutting the sheet base material welded on the bearing substrate according to a preset cutting path, and introducing inert gas to the outer side of the laser cutting to obtain a three-dimensional semi-finished product.

Optionally, step B specifically includes:

providing a movable electrode plate;

loading a low voltage on the bearing substrate and loading a high voltage on the electrode plate;

the bearing substrate and the electrode plate are pressed on the thin sheet base material to weld the thin sheet base material on the bearing substrate.

The invention also discloses a three-dimensional forming device based on the sheet base material, which applies the three-dimensional forming method and comprises the following steps:

mounting the main body;

a bearing substrate arranged on the mounting main body and used for bearing and fixing the sheet base material;

the cutting mechanism is arranged on the mounting main body and used for cutting the sheet base material according to a preset cutting path;

and the welding mechanism is arranged on the mounting main body, is opposite to the bearing substrate and is used for welding the sheet substrate on the three-dimensional semi-finished product.

Optionally, the welding mechanism includes an electrode plate and a pressing module; the pressing module is arranged on the mounting main body, the electrode plate is connected with the pressing module, the electrode plate is opposite to the bearing substrate, and the pressing module can drive the electrode plate to approach the bearing substrate; the electrode plate is loaded with high voltage, and the bearing substrate is loaded with low voltage.

Optionally, the cutting mechanism includes a laser cutting module, a first cutting protection gas path and a second cutting protection gas path for providing inert gas; the laser cutting module is arranged on the mounting main body, the first cutting protection gas circuit and the second cutting protection gas circuit are arranged on the laser cutting module, and inert gases are provided for two sides of the laser cutting module.

Optionally, the mounting main body comprises a frame and a Z-axis movement module; the Z-axis motion module is arranged on the rack and connected with the bearing substrate; and the Z-axis motion module drives the bearing substrate to move up and down.

The three-dimensional forming method based on the sheet base material adopts the sheet base material in a sheet shape as a raw material for three-dimensional forming, replaces the traditional raw materials such as gypsum powder, powdered metal and the like which are easy to generate powder, generates little or almost no dust in the processing process, and in the processing step, each layer is firstly welded and then cut, and is welded, spliced and separately formed, so that the fusion degree is good, the quality of the formed three-dimensional workpiece can reach the strength of the raw material, the strength is good, and the appearance is good.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:

FIG. 1 is a flow chart of a three-dimensional modeling method according to an embodiment of the present invention;

FIG. 2 is a schematic view of a three-dimensional modeling apparatus according to an embodiment of the present invention;

FIG. 3 is another schematic view of a three-dimensional modeling apparatus according to an embodiment of the present invention;

fig. 4 is a partially enlarged view of a portion a of fig. 3;

FIG. 5 is another schematic view of a three-dimensional modeling apparatus according to an embodiment of the present invention;

fig. 6 is a partially enlarged view of a portion B in fig. 5.

Wherein, 1, a sheet substrate; 100. mounting the main body; 110. a frame; 120. an X-axis motion module; 130. a Y-axis motion module; 140. a Z-axis motion module; 141. a fixing plate; 150. a roll shaft; 160. a motor; 170. a ball bearing; 180. pressing a plate; 190. a nut; 200. a carrier substrate; 210. connecting a power post; 300. a cutting mechanism; 310. a laser cutting module; 320. a first cutting protection gas circuit; 330. a second cutting protection gas circuit; 400. a welding mechanism; 410. an electrode plate; 420. and pressing the die set.

Detailed Description

It is to be understood that the terminology, the specific structural and functional details disclosed herein are for the purpose of describing particular embodiments only, and are representative, but that the present invention may be embodied in many alternate forms and should not be construed as limited to only the embodiments set forth herein.

The invention is described in detail below with reference to the figures and alternative embodiments.

As shown in fig. 1, as an embodiment of the present invention, a three-dimensional forming method based on a sheet substrate is disclosed, which comprises the steps of:

step A: providing a bearing substrate and a plurality of thin substrate materials;

and B: fixing a thin substrate on a bearing substrate;

and C: cutting the thin substrate on the bearing substrate according to a preset cutting path to obtain a three-dimensional semi-finished product;

step D: welding a thin substrate on the three-dimensional semi-finished product;

step E: cutting the thin sheet base material welded on the three-dimensional semi-finished product according to a preset cutting path to form the three-dimensional semi-finished product;

step F: and D, repeating the step D and the step E until a three-dimensional workpiece is obtained.

The three-dimensional forming method based on the sheet base material 1 comprises the steps of fixing a first sheet base material 1 on a bearing substrate 200, cutting the sheet base material 1 on the bearing substrate 200 according to a preset cutting path, welding a new sheet base material on the cut sheet base material, and continuously cutting the new sheet base material. And then, after welding a new thin plate base material on the cut thin plate base material every time, performing cutting once, and repeating the steps in a circulating way to finally obtain a completely welded and cut three-dimensional workpiece.

The three-dimensional forming method based on the sheet base material 1 adopts the sheet base material 1 in a sheet shape as a three-dimensional forming raw material to replace the traditional raw materials such as gypsum powder, powdered metal and the like which are easy to generate powder, the generation of dust is little or almost zero in the processing process, in the processing step, each layer is firstly welded and then cut, and the welding, the cutting, the splicing and the separating and forming are carried out, the fusion degree is good, the quality of the formed three-dimensional workpiece can reach the strength of the raw material, the strength is good, and the appearance is good.

Specifically, the specific material and size of the sheet substrate 1 may be selected and set according to the processing requirements. The sheet base 1 may be fixed to the carrier substrate 200 in such a manner that the sheet base 1 is directly welded to the carrier substrate 200. Thus, the three-dimensional workpiece can be firmly fixed on the bearing substrate 200, and the processing is convenient. Therefore, the step B may specifically be:

providing a movable electrode plate;

loading a low voltage on the bearing substrate and loading a high voltage on the electrode plate;

the bearing substrate and the electrode plate are pressed on the thin sheet base material to weld the thin sheet base material on the bearing substrate.

In this embodiment, the sheet base material 1 is placed on the carrier substrate 200, and the sheet base material 1 can be instantaneously welded to the carrier substrate 200 by the high-voltage arc formed by laminating the carrier substrate 200 and the electrode plate 410. The electrode plate 410 is made of a material having a melting point higher than that of the sheet base material 1, and for example, the electrode plate 410 may be a tungsten alloy electrode made of a tungsten alloy. The carrier substrate 200 and the electrode plate 410 may be directly used for welding between the sheet bases 1 in step D. After the three-dimensional workpiece is processed, the three-dimensional workpiece may be cut from the carrier substrate 200 by various methods, which are not described herein.

In step C, the sheet base material 1 can be cut by laser, which is easy to control and has a good cutting effect. Therefore, the step C specifically includes:

and laser cutting the sheet base material welded on the bearing substrate according to a preset cutting path, and introducing inert gas to the outer side of the laser cutting to obtain a three-dimensional semi-finished product.

The laser-cut outer side refers to a side of the sheet base material 1 that is cut and the cut faces, and the inner side opposite to the laser-cut outer side is a three-dimensional workpiece formed. In this embodiment, for example, when the left side of the sheet base material 1 is laser-cut, the left side is the outer side of the laser-cut, and the inert gas is introduced into the first cutting protection gas path 320 on the left side, and at this time, the inert gas can protect the cutting position more accurately with respect to the right side or other positions. Similarly, when the right side of the laser cutting sheet substrate 1 is cut, the right side is the outer side of the laser cutting, and the second cutting protection gas circuit 330 is introduced into the inert gas on the right side, and at this time, the inert gas can protect the cutting position more accurately relative to the left side or other positions.

Further, the step D specifically includes: on the three-dimensional semi-finished product, a thin sheet base material is welded by high-voltage electric arc. By high-voltage arc welding, the effect, degree, etc. of welding are easily controlled. Specifically, the step of welding the sheet base material by high-voltage arc welding includes:

providing a movable electrode plate;

loading a low voltage on the bearing substrate and loading a high voltage on the electrode plate;

the bearing substrate and the electrode plate are pressed on the thin sheet base material so as to weld the thin sheet base material on the three-dimensional semi-finished product.

In this embodiment, a new sheet base material 1 can be instantaneously welded to the three-dimensional semi-finished product by the high-voltage arc formed by pressing and bonding the carrier substrate 200 and the electrode plate 410. After welding, the electrode plate 410 is separated from the welding site and the next cutting step is performed.

Similar to step C above, in order to make the laser-cut cuts uniform and consistent, step E includes the steps of:

and laser cutting the thin sheet base material welded on the three-dimensional semi-finished product according to a preset cutting path, and introducing inert gas to the outer side of the laser cutting to form the three-dimensional semi-finished product.

In this embodiment, the areas on both sides of the sheet substrate 1 are respectively supplied with inert gas through the first cutting protection gas path 320 and the second cutting protection gas path 330, and the cuts of the laser cutting are uniform and consistent. For example, when the left side of the sheet base material 1 is laser-cut, the first cutting gas protection path 320 introduces an inert gas to the cutting position; when the right side of the sheet base material 1 is laser-cut, the second cutting protection gas path 330 supplies an inert gas to the cutting position.

In the present invention, a three-dimensional workpiece is cut by stacking the sheet base materials 1 one upon another, and a very large number of sheet base materials 1 are necessarily used. In order to improve the processing efficiency, the sheet substrate 1 may be provided in a roll shape. The web-shaped sheet substrate 1 is continuously unwound during the processing, and a new, non-welded and cut portion is supplied to the processing. Correspondingly, the height of the bearing substrate 200 can be adjusted up and down, and the height of the bearing substrate 200 can be adjusted down when the height of the three-dimensional workpiece is continuously increased. Thus, the roll-shaped sheet substrate 1 and the electrode plate 410 can be kept unchanged without changing the initial mounting position.

As shown in fig. 2, as another embodiment of the present invention, a three-dimensional molding apparatus based on a sheet substrate 1 is disclosed, to which the three-dimensional molding method according to the above embodiment is applied, including a mounting body 100, a carrier substrate 200, a cutting mechanism 300, and a fusing mechanism 400. The supporting substrate 200 is disposed on the mounting body 100, and is used for supporting and fixing the sheet base material 1; the cutting mechanism 300 is provided on the mounting body 100, and is configured to cut the sheet base material 1 according to a preset cutting path; the fusing mechanism 400 is provided on the mounting body 100, and is opposed to the carrier substrate 200, and fuses the sheet base material 1 to the three-dimensional semi-finished product.

According to the three-dimensional forming device based on the sheet base material 1, the sheet base material 1 in a sheet shape is processed into the three-dimensional workpiece, the traditional raw materials such as gypsum powder and powdered metal which are easy to generate powder are replaced, little or almost no dust is generated in the processing process, each layer of the three-dimensional workpiece is welded and then cut, and the three-dimensional workpiece is welded, spliced, separated and formed, and is good in fusion degree, the quality of the formed three-dimensional workpiece can reach the strength of the raw materials, the strength is good, and the appearance is good.

Specifically, as shown in fig. 2, the welding mechanism 400 includes an electrode plate 410 and a pressing module 420; the pressing module 420 is disposed on the mounting body 100, the electrode plate 410 is connected to the pressing module 420, the electrode plate 410 is opposite to the carrier substrate 200, and the pressing module 420 can drive the electrode plate 410 to approach the carrier substrate 200; a high voltage is applied to the electrode plate 410, and a low voltage is applied to the carrier substrate 200. The sheet base material 1 can be welded to the carrier substrate 200 or the three-dimensional semi-finished product by pressing and welding the sheet base material 1 with a high-voltage arc formed between the electrode plate 410 and the carrier substrate 200. The pressing module 420 is used for driving the electrode plate 410 to move up and down. As shown in fig. 2, in the initial state, the pressing module 420 does not drive the electrode plate 410 to move down, and the electrode plate 410 is in a lifted state; after the start, when the welding mechanism 400 moves to the welding position, the pressing module 420 drives the electrode plate 410 to move downward and press the sheet substrate 1, so as to weld the sheet substrate 1. The pressing module 420 may be an air cylinder, and the electrode plate 410 is connected to a push rod of the pressing module 420. The electrode plate 410 may be a tungsten alloy electrode having a high melting point and not participating in welding due to self-melting.

Specifically, as shown in fig. 2, the mounting body 100 includes a frame 110 and an X-axis movement module 120, the X-axis movement module 120 is mounted on the frame 110, and the pressing module 420 is mounted on the X-axis movement module 120. The X-axis movement module 120 drives the lower press module 420 to move in the X-axis direction to align or move the electrode plate 410 to or from the welding position.

On the other hand, as shown in fig. 2, the cutting mechanism 300 includes a laser cutting module 310, a first cutting protection gas path 320 for providing inert gas, and a second cutting protection gas path 330; the laser cutting module 310 is disposed on the mounting body 100, and the first cutting protection gas circuit 320 and the second cutting protection gas circuit 330 are disposed on the laser cutting module 310 and are divided into two sides for providing inert gas to the laser cutting module 310. In this embodiment, for example, when the regions on the left and right sides of the sheet base material 1 are laser-cut, the inert gas is introduced into the first cutting protection gas path 320 on the left side when the left side is cut, and at this time, the inert gas can protect the cutting position more accurately with respect to the right side or other positions. Similarly, when cutting the right side, the second cutting protection gas circuit 330 lets in inert gas on the right side, and at this time, relative to the left side or other positions, the inert gas can protect the cutting position more accurately.

Specifically, the mounting body 100 further includes a Y-axis movement module 130; the laser cutting module 310 is installed on the Y-axis moving module 130, and the Y-axis moving module 130 is installed on the X-axis moving module 120. The X-axis motion module 120 drives the Y-axis motion module 130 to move in the X-axis direction, and the Y-axis motion module 130 drives the laser cutting module 310 to move in the Y-axis direction, so that the laser cutting module 310 can cut at any plane position on the sheet substrate 1.

Further, as preferred, because electrode plate 410 and laser cutting module 310 are certainly to carrying out processing to the same position of thin slice substrate 1, so, electrode plate 410 and laser cutting module 310 connect the setting at X axle motion module 120, and X axle motion module 120 can control electrode plate 410 and laser cutting module 310 syntropy motion simultaneously, realizes that one-time control accomplishes electrode plate 410 and laser cutting module 310 position simultaneously and removes, and control is simple and high-efficient. For example, after the welding of the electrode plate 410 is completed, the X-axis motion module 120 drives the electrode plate 410 to move away from the welding position, and at the same time, the X-axis motion module 120 drives the laser cutting module 310 to move to the welding position to perform the next cutting operation.

On the other hand, as shown in fig. 2, the mounting body 100 includes a frame 110 and a Z-axis movement module 140; the Z-axis motion module 140 is disposed on the frame 110 and connected to the carrier substrate 200; the Z-axis motion module 140 drives the carrier substrate 200 to move up and down. Through the adjustment of the Z-axis movement module 140, the height of the bearing substrate 200 can be adjusted, and when the height of the three-dimensional workpiece is continuously increased, the height of the bearing substrate 200 can be adjusted to be low, so that the processing is convenient.

Further, as shown in fig. 3 to 6, the Z-axis moving module 140 is mounted on the frame 110 through a fixing plate 141. The carrier substrate 200 may be applied with a voltage through the electrical connection posts 210. A roll shaft 150 may be disposed at both sides of the frame 110; correspondingly, the sheet base material 1 is arranged into a roll shape and sleeved on the roll shaft 150; one end of the roller 150 may be connected to a motor 160 to tension the sheet base material 1 and replace the welding position of the sheet base material 1.

The other end of the roll shaft 150 is provided with a ball 170, a pressure plate 180 and a nut 190; the pressing plate 180 is sleeved on the roller shaft 150, and the ball 170 is located between the pressing plate 180 and the frame 110 and is limited by the pressing plate 180. The nut 190 is in threaded engagement with the roller shaft 150 and is located on a side of the pressure plate 180 remote from the frame 110. In this scheme, through adjusting nut 190, clamp plate 180 compresses tightly or loosens ball 170, changes ball 170 and frame 110, the damping of clamp plate 180 to make roller 150 rotate the damping and be adjusted. In particular, when the nut 190, the pressing plate 180 and the balls 170 are pressed to generate a certain damping force, so that the roller shaft 150 is not easy to rotate, and after the sheet base material 1 is tensioned by the motor 160, the roller shaft 150 can continuously maintain the tensioned state of the sheet base material 1 even if the motor 160 stops, thereby realizing a certain self-locking function.

It should be noted that, the limitations of the steps involved in the present disclosure are not considered to limit the order of the steps without affecting the implementation of the specific embodiments, and the steps written in the foregoing may be executed first, or executed later, or even executed simultaneously, and as long as the present disclosure can be implemented, all should be considered to belong to the protection scope of the present disclosure.

The foregoing is a more detailed description of the invention in connection with specific alternative embodiments, and the practice of the invention should not be construed as limited to those descriptions. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.