阅读说明：本技术 一种橡胶挤出机的螺杆排气可调结构 (Screw exhaust adjustable structure of rubber extruder ) 是由 姚央军 徐荣国 应再兴 朱建国 王均委 于 2021-07-15 设计创作，主要内容包括：本发明公开了一种橡胶挤出机的螺杆排气可调结构,包括设备外壳以及调节组件；所述调节组件穿孔连接在设备外壳中；所述调节组件由一号外壳、螺母以及螺纹拉杆组成；所述螺母转动连接在一号外壳内；通过在现有筒体的基础上,在其内壁增加调节槽,且在现有的螺纹杆的结构基础上增加卡槽,并与调节环相配合,在螺纹杆受到螺纹拉杆的带动而前后移动时,带动调节环与调节槽之间发生位移的变化,从而改变调节槽与调节环之间的空隙大小,当橡胶通过调节槽与调节环之间的空隙时,会受到挤压而被压缩为薄片,实现将橡胶内部水蒸汽挤出的目的,进一步的利用外接的抽真空泵将挤出的水蒸汽排出,避免成品橡胶制品在硫化成型时内部产生气孔影响其物理强度。(The invention discloses a screw exhaust adjustable structure of a rubber extruder, which comprises an equipment shell and an adjusting component, wherein the equipment shell is provided with a screw inlet and a screw outlet; the adjusting component is connected in the equipment shell in a penetrating way; the adjusting component consists of a first shell, a nut and a threaded pull rod; the nut is rotatably connected in the first shell; through on the basis at present barrel, increase the adjustment tank at its inner wall, and increase the draw-in groove on the structure basis of current threaded rod, and cooperate with the adjustable ring, receive the drive of screw thread pull rod and when the back-and-forth movement at the threaded rod, the change of taking place the displacement between drive adjustable ring and the adjustment tank, thereby change the space size between adjustment tank and the adjustable ring, when rubber passes through the space between adjustment tank and the adjustable ring, can receive the extrusion and be compressed into the thin slice, realize the purpose of extruding the inside vapor of rubber, further utilize the vapor discharge of external evacuation pump will extruding, avoid finished product rubber goods inside production gas pocket to influence its physical strength when vulcanization molding.)

1. The utility model provides a screw rod of rubber extruder exhausts adjustable structure which characterized in that: comprises an equipment shell (1) and an adjusting component (2); the adjusting component (2) is connected in the equipment shell (1) in a perforation way;

the adjusting component (2) consists of a first shell (21), a nut (24) and a threaded pull rod (25); the nut (24) is rotatably connected in the first shell (21); the threaded pull rod (25) is in threaded rotary connection with the inner side of the nut (24); the other end of the threaded pull rod (25) is rotatably connected in the equipment shell (1); a first cavity (26) is formed in the first shell (21); the nut (24) is rotatably connected to the first cavity (26); a first bearing (22) and a second bearing (23) are fixedly connected to the side wall of the first cavity (26) respectively; the second bearing (23) is arranged between the adjacent first bearings (22); the outer side wall of the nut (24) is fixedly connected to the inner side walls of the first bearing (22) and the second bearing (23).

2. The screw exhaust adjustable structure of a rubber extruder as set forth in claim 1, wherein: the bottom end of the equipment shell (1) is provided with a transmission assembly (11); a connecting cavity (12) is formed in the equipment shell (1); the other end of the threaded pull rod (25) is rotatably connected in the connecting cavity (12); a threaded rod (5) is rotationally connected in the connecting cavity (12); a clamping groove (51) is formed in the middle of the threaded rod (5); one end of the threaded rod (5) positioned in the connecting cavity (12) is provided with a fitting hole (52); the other end of the threaded pull rod (25) is matched and connected in the matching hole (52); the clamping groove (51) is sleeved with an adjusting ring (53).

3. The screw exhaust adjustable structure of a rubber extruder as set forth in claim 2, wherein: one end of the equipment shell (1) is fixedly connected with a head flange (13); the other end of the machine head flange (13) is fixedly connected with a cylinder body (4).

4. The screw exhaust adjustable structure of a rubber extruder as set forth in claim 3, wherein: a connecting flange (41) is fixedly connected between the adjacent cylinder bodies (4); a rubber pad (46) is arranged between the adjacent connecting flanges (41); one end of the cylinder (4) close to the equipment shell (1) is communicated with a charging hopper (3); one end of the cylinder body (4) far away from the equipment shell (1) is fixedly connected with a discharging seat (42).

5. The screw exhaust adjustable structure of a rubber extruder as set forth in claim 4, wherein: a second cavity (44) is formed in the cylinder body (4); the main body of the threaded rod (5) is arranged in the cavity II (44); the bottom end of the middle part of the barrel (4) is communicated with a water injection pipe (43); an adjusting groove (441) is formed in the position, close to the right side of the water injection pipe (43), of the inner wall of the barrel body (4).

6. The screw exhaust adjustable structure of a rubber extruder as set forth in claim 5, wherein: the position of a clamping groove (51) on the threaded rod (5) is correspondingly arranged in the adjusting groove (441); the adjusting ring (53) rotates correspondingly in the adjusting groove (441).

7. The screw exhaust adjustable structure of a rubber extruder as set forth in claim 6, wherein: the interior of the discharging seat (42) is hollow; the interior of the discharging seat (42) is communicated with a cavity II (44); the front end of the discharging seat (42) is in fit connection with a pore plate (45).

Technical Field

The invention relates to the technical field of screw extruders, in particular to a screw exhaust adjustable structure of a rubber extruder.

Background

With the rapid development of rubber industry in China, the design and manufacture level of rubber mixing equipment in China has reached the end level of 20 century 90 years abroad, and the requirement of the tire manufacturing industry in China can be completely met; in addition, the rubber mixing equipment in China is exported in batches, the rubber mixing equipment is indispensable key equipment in the production of tires and other rubber products, the quality of rubber mixing is determined by the performance level, the most common modern open mill, internal mixer and auxiliary machines are used in the rubber mixing equipment, and an extrusion tabletting system is used as an important component of the whole production line and has very strict requirements on the pressure and speed control.

At present, in the prior art, after rubber raw materials enter a feeding port of an extruder, air can be mixed in through a screw stirring process, the air is compressed into rubber in a conveying section of the screw through continuous stirring and conveying of the screw, so that the density of the rubber is poor, moisture absorbed by the raw materials and moisture in the air entering through feeding stirring are absorbed when the rubber is vulcanized and shaped, and water vapor is gasified to generate air holes, so that the physical strength of rubber products is further reduced and the appearance defects are further caused.

Therefore, the screw exhaust adjustable structure of the rubber extruder is provided for solving the problems.

Disclosure of Invention

In order to make up for the defects of the prior art that air is mixed in the rubber raw material after the rubber raw material enters the feeding port of the extruder and the air is compressed into the rubber at the conveying section of the screw after the rubber raw material is continuously stirred and conveyed by the screw, so that the density of the rubber is poor, the screw exhaust adjustable structure of the rubber extruder is provided by the invention.

A screw exhaust adjustable structure of a rubber extruder comprises an equipment shell and an adjusting component; the adjusting component is connected in the equipment shell in a penetrating way;

the adjusting component consists of a first shell, a nut and a threaded pull rod; the nut is rotatably connected in the first shell; the threaded pull rod is in threaded connection with the inner side of the nut in a rotating mode; the other end of the threaded pull rod is rotatably connected in the equipment shell; a first cavity is formed in the first shell; the nut is rotatably connected to the first cavity; the side wall of the first cavity is fixedly connected with a first bearing and a second bearing respectively; the second bearing is arranged between the adjacent first bearings; the outer side wall of the nut is fixedly connected to the inner side walls of the first bearing and the second bearing; the screw thread of the screw thread pull rod is driven to rotate through the screw thread, the nut is limited in the first shell, and therefore when the nut rotates, the screw thread pull rod can move inwards or outwards horizontally along with the rotation direction of the nut, and when the screw thread pull rod moves, the other end of the screw thread pull rod is engaged with the connecting threaded rod, so that the screw thread pull rod can drive the threaded rod to move horizontally in the barrel, and the function of adjusting the position of the threaded rod in the barrel is achieved.

Preferably, a transmission assembly is arranged at the bottom end of the equipment shell; a connecting cavity is formed in the equipment shell; the other end of the threaded pull rod is rotatably connected in the connecting cavity; a threaded rod is rotatably connected in the connecting cavity; a clamping groove is formed in the middle of the threaded rod; one end of the threaded rod, which is positioned in the connecting cavity, is provided with a matching hole; the other end of the threaded pull rod is in fit connection with the fit hole; the clamping groove is sleeved with an adjusting ring; the threaded rod drives the adjusting ring in the middle of the threaded rod and the adjusting groove in the barrel to change the size of a gap between the adjusting ring and the adjusting groove, and when rubber passes through the gap between the adjusting groove and the adjusting ring, the gap between the adjusting ring and the adjusting groove can be changed under the driving of the adjusting assembly, so that the adjusting function of the rubber passing speed is realized, and when the adjustment is not needed, the threaded pull rod is rotated backwards, so that the threaded pull rod is separated from the threaded rod.

Preferably, one end of the equipment shell is fixedly connected with a machine head flange; the other end of the machine head flange is fixedly connected with a cylinder body; the machine head flange is used for connecting the equipment shell and the barrel, and a rubber pad is arranged at the joint of the machine head flange and the barrel, so that the connection tightness between the machine head flange and the barrel can be effectively improved.

Preferably, a connecting flange is fixedly connected between the adjacent cylinders; a rubber pad is arranged between the adjacent connecting flanges; one end of the cylinder body close to the equipment shell is communicated with a feeding hopper; one end of the cylinder body, which is far away from the equipment shell, is fixedly connected with a discharging seat; the rubber pad is used for waterproof, and improves the tight degree of connection between the adjacent barrel to a certain extent, and wherein the loading hopper that communicates on the barrel that is close to equipment shell is used for adding the rubber material, and the barrel of keeping away from equipment shell one end fixes out the material seat.

Preferably, a second cavity is formed in the cylinder body; the main body of the threaded rod is arranged in the cavity II; the bottom end of the middle part of the cylinder body is communicated with a water injection pipe; an adjusting groove is formed in the position, close to the right side of the water injection pipe, of the inner wall of the cylinder body; the bottom of one section of the cylinder body is provided with a water injection pipe for injecting water into the cylinder body at regular time, and the inner wall of the cylinder body on the right side of the water injection pipe is provided with an adjusting groove which is similar to the structure of an adjusting ring.

Preferably, the position of the clamping groove on the threaded rod is correspondingly arranged in the adjusting groove; the adjusting ring correspondingly rotates in the adjusting groove; along with the regulation of adjusting part, can change the space between adjustable ring and the adjustment tank, specifically be when the threaded rod moves left, the space between adjustable ring and the adjustment tank dwindles, consequently the raw materials passes through the corresponding reduction in the rate in space between adjustment tank and the adjustable ring, otherwise, the raw materials passes through the rate increase in space between adjustment tank and the adjustable ring to through the regulation of adjusting part, can realize adjusting the rate that the raw materials was extruded.

Preferably, the discharging seat is hollow; the interior of the discharging seat is communicated with a cavity II; the front end of the discharging seat is in fit connection with a pore plate; the inside of discharging seat sets up to cavity, and communicates with the cavity No. two that are closest to the barrel inside, after the raw materials process the adjustment tank, is extruded through the orifice plate that discharging seat front end set up, and can extrude rubber for the rubber strip of various sizes according to the trompil size of orifice plate.

The invention has the advantages that:

1. according to the invention, the adjusting groove is additionally arranged on the inner wall of the existing cylinder body, the clamping groove is additionally arranged on the structure basis of the existing threaded rod and is matched with the adjusting ring, when the threaded rod is driven by the threaded pull rod to move back and forth, the adjusting ring and the adjusting groove are driven to change in displacement, so that the size of a gap between the adjusting groove and the adjusting ring is changed, when rubber passes through the gap between the adjusting groove and the adjusting ring, the rubber is extruded and compressed into a thin sheet, the purpose of extruding water vapor in the rubber is realized, the extruded water vapor is further discharged by using an external vacuum pump, and the phenomenon that the physical strength of a finished rubber product is influenced by air holes generated in the rubber product during vulcanization molding is avoided.

2. According to the invention, through arranging the adjusting component, when external force acts on the nut, the nut is rotated in the first shell, the nut is rotated to indirectly drive the threaded pull rod to rotate relative to the threaded pull rod, and the nut is limited in the first shell, so that the threaded pull rod can realize the effect of inward or outward movement along with the change of the rotation direction of the nut, and the threaded pull rod is moved inward or outward to indirectly drive the threaded rod to move, thereby realizing the function of adjusting the internal threaded rod by the external adjusting component to move back and forth, realizing the function of changing the position between the adjusting ring and the adjusting groove, and further changing the rubber passing rate and the function of passing through the gap.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

FIG. 1 is a perspective view of one embodiment of the present invention;

FIG. 2 is a first cross-sectional view of one embodiment of the present invention;

FIG. 3 is a second cross-sectional view of one embodiment of the present invention;

FIG. 4 is a perspective view of a threaded rod in one embodiment of the present invention;

FIG. 5 is a perspective view of an adjustment ring in an embodiment of the present invention;

FIG. 6 is an enlarged view of the part A of FIG. 2;

fig. 7 is an enlarged schematic view of a part B of fig. 3.

In the figure: 1. an equipment housing; 11. a transmission assembly; 12. a connecting cavity; 13. a machine head flange; 2. an adjustment assembly; 21. a first housing; 22. a first bearing; 23. a second bearing; 24. a nut; 25. a threaded pull rod; 26. a first cavity; 3. a hopper; 4. a barrel; 41. a connecting flange; 42. a discharging seat; 43. a water injection pipe; 44. a cavity II; 441. an adjustment groove; 45. an orifice plate; 46. a rubber pad; 5. a threaded rod; 51. a card slot; 52. fitting the hole; 53. an adjusting ring.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-7, a screw exhaust adjustable structure of a rubber extruder includes an apparatus housing 1 and an adjusting assembly 2; the adjusting component 2 is connected in the equipment shell 1 in a perforation way;

the adjusting component 2 consists of a first shell 21, a nut 24 and a threaded pull rod 25; the nut 24 is rotatably connected in the first shell 21; the threaded pull rod 25 is in threaded rotation connection with the inner side of the nut 24; the other end of the threaded pull rod 25 is rotatably connected in the equipment shell 1; a first cavity 26 is formed in the first shell 21; the nut 24 is rotatably connected with the first cavity 26; a first bearing 22 and a second bearing 23 are fixedly connected to the side wall of the first cavity 26 respectively; the second bearing 23 is arranged between the adjacent first bearings 22; the outer side wall of the nut 24 is fixedly connected to the inner side walls of the first bearing 22 and the second bearing 23.

When the adjusting device works, an external instrument is utilized to rotate the adjusting component 2 arranged outside the equipment shell 1, specifically, the nut 24 is rotated, wherein the outer end of the nut 24 protrudes out of the first shell 21, when the external instrument drives the adjusting component to rotate, the nut 24 rotates relative to the first bearing 22 and the second bearing 23 in the first shell 21, and the nut 24 is limited by the first bearing 22 and the second bearing 23 when rotating, when the nut 24 rotates, the nut drives the threaded pull rod 25 in the first shell 21 to rotate through threads, because the nut 24 is limited in the first shell 21, when the nut 24 rotates, the threaded pull rod 25 moves inwards or outwards horizontally along with the rotating direction of the nut 24, and when the threaded pull rod 25 moves, the other end of the threaded pull rod is engaged with the threaded rod 5, so that the threaded rod 5 can be driven to move horizontally in the barrel 4, the function of adjusting the position of the threaded rod 5 in the cylinder 4 is realized.

As an embodiment of the present invention, the bottom end of the equipment housing 1 is provided with a transmission assembly 11; a connecting cavity 12 is formed in the equipment shell 1; the other end of the threaded pull rod 25 is rotatably connected in the connecting cavity 12; a threaded rod 5 is rotationally connected in the connecting cavity 12; a clamping groove 51 is formed in the middle of the threaded rod 5; one end of the threaded rod 5 positioned in the connecting cavity 12 is provided with a fitting hole 52; the other end of the threaded pull rod 25 is matched and connected in the matching hole 52; the clamping groove 51 is sleeved with an adjusting ring 53.

When the rubber adjusting device works, the other end of the threaded pull rod 25 is arranged in the connecting cavity 12 of the equipment shell 1, the other end of the threaded rod 5 is arranged in the connecting cavity 12 of the equipment shell 1, when the position of the threaded rod 5 needs to be adjusted, the threaded rod 5 is inwards extruded by the threaded pull rod 25, so that the threaded rod 5 drives the adjusting ring 53 in the middle of the threaded rod 5 and the adjusting groove 441 in the cylinder 4 to change the position, the size of a gap between the adjusting ring 53 and the adjusting groove 441 is changed, when rubber passes through the gap between the adjusting groove 441 and the adjusting ring 53, the gap between the adjusting ring 53 and the adjusting groove 441 can be changed under the driving of the adjusting assembly 2, and therefore the adjusting function of the rubber passing rate is achieved.

As an embodiment of the present invention, a machine head flange 13 is fixedly connected to one end of the equipment housing 1; the other end of the machine head flange 13 is fixedly connected with a cylinder 4.

During operation, the head flange 13 is used for connecting the equipment shell 1 and the barrel 4, and a rubber pad 46 is arranged at the joint of the head flange 13 and the barrel 4, so that the connection tightness between the head flange 13 and the barrel 4 can be effectively improved.

As an embodiment of the present invention, a connecting flange 41 is fixedly connected between adjacent cylinders 4; a rubber pad 46 is arranged between the adjacent connecting flanges 41; one end of the cylinder 4 close to the equipment shell 1 is communicated with a feeding hopper 3; and a discharging seat 42 is fixedly connected to one end of the cylinder 4 far away from the equipment shell 1.

During operation, connect through flange 41 and rubber pad 46 between the adjacent barrel 4, wherein rubber pad 46 is used for waterproof, and improves the closeness of connection between the adjacent barrel 4 to a certain extent, wherein is close to the loading hopper 3 that communicates on the barrel 4 of equipment shell 1 and is used for adding the rubber material, and the solid material seat 42 of expecting of barrel 4 of keeping away from equipment shell 1 one end.

As an embodiment of the present invention, a second cavity 44 is opened inside the cylinder 4; the main body of the threaded rod 5 is arranged in the cavity II 44; the bottom end of the middle part of the cylinder 4 is communicated with a water injection pipe 43; the inner wall of the cylinder 4 is provided with an adjusting groove 441 at the position close to the right side of the water injection pipe 43.

During operation, be the connected state between the adjacent barrel 4, and name it as cavity 44 No. two, during operation, threaded rod 5 sets up in cavity 44 No. two of constituteing between the adjacent barrel 4, and is provided with water injection pipe 43 in the bottom of one section barrel 4 for the inside water injection of timing, and the adjusting groove 441 of seting up on the barrel 4 inner wall on water injection pipe 43 right side, it is similar with the structure of adjustable ring 53.

As an embodiment of the present invention, the position of the locking groove 51 on the threaded rod 5 is correspondingly arranged in the adjusting groove 441; the adjusting ring 53 correspondingly rotates in the adjusting groove 441.

During operation, because the slot 51 on the threaded rod 5 is correspondingly arranged in the adjusting groove 441 on the inner wall of the cylinder 4, and after the adjusting ring 53 is sleeved in the slot 51, along with the rotation of the threaded rod 5, the raw material filled at one side of the second cavity 44 is extruded out from the gap between the adjusting groove 441 and the adjusting ring 53 and reaches the other side of the second cavity 44, along with the adjustment of the adjusting assembly 2, the gap between the adjusting ring 53 and the adjusting groove 441 can be changed, specifically, when the threaded rod 5 moves leftwards, the gap between the adjusting ring 53 and the adjusting groove 441 is reduced, so that the speed of the raw material passing through the gap between the adjusting groove 441 and the adjusting ring 53 is correspondingly reduced, otherwise, the speed of the raw material passing through the gap between the adjusting groove 441 and the adjusting ring 53 is increased, thereby, through the adjustment of the adjusting assembly 2, the speed of extruding the raw material can be adjusted, and by setting the adjusting ring with an adjustable position, it is when producing relative position relation between with the adjustment tank, the space between adjustment tank and the adjustable ring changes thereupon, rubber materials is when this position, can receive the extrusion and be compressed into slice, moisture content and the vapor that contains in the rubber materials this moment can be extruded, and taken out by the external evacuation equipment who sets up with the adjustment tank adjacent position, thereby realize moisture content and vapor in the rubber materials before the rubber vulcanization shaping and discharge, the physical strength that has the bubble to influence rubber in the rubber materials of production shaping has been avoided.

As an embodiment of the present invention, the discharging seat 42 is hollow inside; the interior of the discharging seat 42 is communicated with a cavity II 44; the front end of the discharging seat 42 is in fit connection with a pore plate 45.

During operation, the inside of discharging seat 42 sets up to the cavity, and communicates with No. two cavities 44 that are closest to barrel 4 inside, and after raw materials passed through adjustment tank 441, the orifice plate 45 through discharging seat 42 front end setting is extruded, and can extrude rubber for the rubber strip of various sizes according to the trompil size of orifice plate 45.

The working principle is that an external instrument is utilized to rotate an adjusting component 2 arranged outside an equipment shell 1, specifically a rotating nut 24, wherein the outer end of the nut 24 protrudes out of a first shell 21, so that when the external instrument drives the adjusting component to rotate, the nut 24 rotates relative to a first bearing 22 and a second bearing 23 inside the first shell 21, and the nut 24 is limited by the first bearing 22 and the second bearing 23 when rotating, when the nut 24 rotates, a threaded pull rod 25 inside the nut 24 is driven to rotate through threads, and because the nut 24 is limited in the first shell 21, when the nut 24 rotates, the threaded pull rod 25 moves inwards or outwards horizontally along with the rotating direction of the nut 24, so that when the threaded pull rod 25 moves, the other end of the threaded pull rod is engaged with a connecting threaded rod 5, so that the threaded rod 5 can be driven to move horizontally in a barrel 4, the function of adjusting the position of the threaded rod 5 in the cylinder 4 is realized, specifically, when the position of the threaded rod 5 needs to be adjusted, the threaded rod 5 is pressed inwards by the threaded pull rod 25, so that the threaded rod 5 drives the adjusting ring 53 in the middle of the threaded rod 5 and the adjusting groove 441 in the cylinder 4 to change the position, thereby changing the size of the gap between the adjusting ring 53 and the adjusting groove 441, when rubber passes through the gap between the adjusting groove 441 and the adjusting ring 53, because the gap between the adjusting ring 53 and the adjusting groove 441 can be changed under the driving of the adjusting assembly 2, the function of adjusting the rubber passing rate is realized, and because the clamping groove 51 on the threaded rod 5 is correspondingly arranged in the adjusting groove 441 on the inner wall of the cylinder 4, and after the adjusting ring 53 is sleeved in the clamping groove 51, along with the rotation of the threaded rod 5, the raw material filled on one side of the second cavity 44 is extruded by the gap between the adjusting groove 441 and the adjusting ring 53, reaching the other side of the cavity number two 44, the clearance between the adjusting ring 53 and the adjusting groove 441 can be changed along with the adjustment of the adjusting assembly 2, in particular, when the threaded rod 5 moves to the left, the clearance between the adjusting ring 53 and the adjusting groove 441 is reduced, the rate of passage of the material through the gap between the regulating groove 441 and the regulating ring 53 is correspondingly reduced, whereas, the rate of passage of the material through the gap between the regulating groove 441 and the regulating ring 53 is increased, therefore, the speed of extruding the raw materials can be adjusted through the adjustment of the adjusting component 2, so that when the raw materials pass through the adjusting groove, is blocked by the clearance between the adjusting ring and the adjusting groove and is compressed into thin slices, so that the water vapor in the raw material passing through the position is completely discharged, in the subsequent vulcanization molding process, the conditions of poor physical strength and defective appearance of the finished rubber product caused by water vapor or moisture contained in the rubber raw material are avoided.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed.