阅读说明：本技术 一种用于穴盘育苗的精密播种装置 (A accurate seeder for plug seedling ) 是由 孙若兰 于 2019-10-08 设计创作，主要内容包括：本发明公开了一种用于穴盘育苗的精密播种装置,涉及农业机械领域。本发明包括第一基板；第一基板的上表面开设有一安装口；安装口内装设有一运输机构；运输机构上放置有穴盘；运输机构的一侧装设有一储种盒；储种盒与运输机构之间设置有一支撑筒；支撑筒固定装设于基板的上表面；支撑筒内转动装设有一转轴；转轴的下端贯穿延伸至基板的下方；转轴的上端固定装设有一具有空腔结构的活动柱；活动柱转动装设于支撑筒的上端；活动柱的上端装设有一负压筒；负压筒内沿环形方向均布设置有负压管。本发明不仅结构设计简单合理、操作便捷,而且有效地提高了穴盘育苗的精密播种效率及效果,具有较高的市场应用价值。(The invention discloses a precise seeding device for plug seedling, and relates to the field of agricultural machinery. The invention includes a first substrate; the upper surface of the first substrate is provided with a mounting port; a conveying mechanism is arranged in the mounting port; the transport mechanism is provided with a plug tray; one side of the transportation mechanism is provided with a seed storage box; a supporting cylinder is arranged between the seed storage box and the transportation mechanism; the supporting cylinder is fixedly arranged on the upper surface of the substrate; a rotating shaft is rotatably arranged in the supporting cylinder; the lower end of the rotating shaft penetrates and extends to the lower part of the substrate; the upper end of the rotating shaft is fixedly provided with a movable column with a cavity structure; the movable column is rotatably arranged at the upper end of the supporting cylinder; the upper end of the movable column is provided with a negative pressure cylinder; and negative pressure pipes are uniformly distributed in the negative pressure cylinder along the annular direction. The invention not only has simple and reasonable structural design and convenient operation, but also effectively improves the precision seeding efficiency and effect of plug seedling, and has higher market application value.)

1. A precision seeding device for plug seedling, comprising a first substrate (1); the upper surface of the first substrate (1) is provided with a mounting opening; a conveying mechanism (2) is arranged in the mounting opening; the hole tray (3) is arranged on the conveying mechanism (2); the method is characterized in that:

one side of the transportation mechanism (2) is provided with a seed storage box (4); a supporting cylinder (5) is arranged between the seed storage box (4) and the transportation mechanism (2); the supporting cylinder (5) is fixedly arranged on the upper surface of the substrate (1); a rotating shaft (501) is rotatably arranged in the supporting cylinder (5); the lower end of the rotating shaft (501) penetrates and extends to the lower part of the substrate (1);

the upper end of the rotating shaft (501) is fixedly provided with a movable column (6) with a cavity structure; the movable column (6) is rotatably arranged at the upper end of the supporting cylinder (5); the upper end of the movable column (6) is provided with a negative pressure cylinder (7); negative pressure pipes (8) are uniformly distributed in the negative pressure cylinder (7) along the annular direction; the lower end of the negative pressure pipe (8) penetrates through the top wall of the movable column (6) and extends into the movable column (6);

the lower end part of the negative pressure pipe (8) is sleeved with an adjusting column (9) with a cavity structure in a sliding manner; a limiting sleeve (10) is arranged in the adjusting column (9); the limiting sleeve (10) is fixedly sleeved at the lower port of the negative pressure pipe (8); a tension spring (11) is arranged above the limiting sleeve (10); the tensioning spring (11) is sleeved on the lower end part of the negative pressure pipe (8);

the side wall of the movable column (6) is uniformly provided with guide grooves (601) corresponding to the positions of the adjusting columns (9) along the annular direction; a suction pipe (12) is inserted in the guide groove (601) along the radial direction of the movable column (6); one end of the seed suction pipe (12) positioned in the movable column (6) is connected to the corresponding adjusting column (9); the partial section of the suction pipe (12) positioned outside the movable column (6) is provided with negative pressure suction nozzles (1201) along the axial direction;

the outer port of the guide groove (601) is provided with a movable sheet (13) corresponding to the position of the suction pipe (12); the movable sheet (13) is fixedly arranged on the corresponding seed suction pipe (12); a first electric push rod (14) is arranged below the movable sheet (13); the first electric push rod (14) is arranged between the transportation mechanism (2) and the support cylinder (5); a second electric push rod (15) is arranged above the other movable sheet (13); the second electric push rod (15) is arranged between the seed storage box (4) and the negative pressure cylinder (7).

2. A precision seeding device for plug seedling according to claim 1, characterized in that a pair of mounting frames (16) are fixedly arranged side by side on one side of the first base plate (1); an electromagnetic vibrator (17) is arranged between the two mounting frames (16); the electromagnetic vibrator (17) is arranged on the bottom wall of the seed storage box (4); the seed storage box (4) is arranged on the mounting frame (16).

3. A precision seeding device for plug seedling according to claim 1, characterized in that a second substrate (101) is arranged in parallel below the first substrate (1); the upper surface of the second base plate (101) is fixedly provided with a driving motor (18) and a gearbox (19); the output shaft of the driving motor (18) is connected with the input shaft of the gearbox (19); an output shaft of the gearbox (19) is provided with an active drive plate (20); a grooved pulley (21) is in transmission connection with the driving drive plate (20); the grooved wheel (21) is fixedly arranged at the lower end of the rotating shaft (501).

4. A precision seeding device for plug seedlings according to claim 3, wherein the second base plate (101) is connected with the first base plate (1) by a side supporting plate (102) towards the same edge; an F-shaped structure is formed among the first substrate (1), the second substrate (101) and the side supporting plate (102); the transportation mechanism (2) is arranged on one side surface of the side supporting plate (102); the conveying mechanism (2) comprises a driving wheel, a first driven wheel and a second driven wheel; the driving wheel is arranged between the second substrate (101) and the first substrate (1); the first driven wheel and the second driven wheel are arranged above the first substrate (1) side by side; the driving wheel, the first driven wheel and the second driven wheel are in transmission connection through a conveying belt.

5. The precision seeding apparatus for plug seedling of claim 4, wherein one end of the wheel shaft of the driving wheel is fixedly provided with a first bevel gear (22); a second bevel gear (23) is meshed with the first bevel gear (22); the second bevel gear (23) is fixedly arranged on the lower end part of the rotating shaft (501).

6. The precision seeding device for plug seedling of claim 4, wherein the upper surface of the side supporting plate (102) is fixedly provided with a connecting rod (24) with an L-shaped structure; one end of the connecting rod (24) is fixed on the upper end part of the negative pressure cylinder (7); the upper end part of the negative pressure cylinder (7) is connected with an air conveying pipe (25); one end of the air conveying pipe (25) is connected to a negative pressure fan (26).

Technical Field

The invention belongs to the field of agricultural machinery, and particularly relates to a precise seeding device for plug seedling.

Background

In the process of seedling raising of seeds, sowing is an important basic link. The seeding device is the premise and the foundation for realizing the transplanting and the cultivation of crops, can ensure that the seedling production achieves high quality and high efficiency, improves the purity and the survival rate of the seedling species, and is beneficial to the stable and rapid development of the seedling industry. With the rapid development of agricultural machinery technology in China, higher requirements are put forward on seeding and seedling raising technology, and the quality of the performance of a seeding device directly influences the quality and the growth condition of seedlings.

At present, most of precision seeding equipment for plug seedling in the prior art adopts a drum-type seeding mode. For example, the national intellectual property office of the people's republic of China discloses a patent document with an authorization publication number of CN105723887B in 2017, 12.01.A name of the patent document is an air-suction vibration drum-type precision seeding device which is provided with a seeding frame, a drum device, a transmission device, a positive and negative pressure air supply device and a seed box device, wherein the drum device is connected to a bracket through screws, the transmission device is positioned on an upper rack, the positive and negative pressure air supply device is positioned on the upper rack, and the seed box device is connected to the upper rack through bolts; although the device can realize accurate seed sucking action, when the suction nozzle with the seeds moves to the position right below the roller and is in a seed falling preparation stage, the roller is always in a rotating state, so that the seeds in the suction nozzle have certain forward movement initial speed in the process of falling downwards after being separated from negative pressure constraint, namely the seeds fall downwards in a parabola form, and the position of the seeds falling onto the plug tray has uncertainty factors, and the reduction of the void rate of the plug tray is difficult to ensure. Therefore, there is a need to develop a precision seeding apparatus for plug seedling in order to solve the above problems.

Disclosure of Invention

The invention provides a precise seeding device for plug seedling, and aims to solve the problems in the background technology.

In order to solve the technical problems, the invention is realized by the following technical scheme:

the invention relates to a precise seeding device for plug seedling, which comprises a first substrate; the upper surface of the first substrate is provided with a mounting opening; a conveying mechanism is arranged in the mounting opening; the tray is placed on the conveying mechanism; one side of the transportation mechanism is provided with a seed storage box; a supporting cylinder is arranged between the seed storage box and the transportation mechanism; the supporting cylinder is fixedly arranged on the upper surface of the substrate; a rotating shaft is rotatably arranged in the supporting cylinder; the lower end of the rotating shaft penetrates and extends to the lower part of the substrate; the upper end of the rotating shaft is fixedly provided with a movable column with a cavity structure; the movable column is rotatably arranged at the upper end of the supporting cylinder; the upper end of the movable column is provided with a negative pressure cylinder; negative pressure pipes are uniformly distributed in the negative pressure cylinder along the annular direction; the lower end of the negative pressure pipe penetrates through the top wall of the movable column and extends into the movable column; the lower end part of the negative pressure pipe is slidably sleeved with an adjusting column with a cavity structure; a limiting sleeve is arranged in the adjusting column; the limiting sleeve is fixedly sleeved at the lower port of the negative pressure pipe; a tension spring is arranged above the limiting sleeve; the tensioning spring is sleeved on the lower end part of the negative pressure pipe; the side wall of the movable column is uniformly provided with guide grooves corresponding to the positions of the adjusting columns along the annular direction; a suction pipe is inserted in the guide groove along the radial direction of the movable column; one end of the suction pipe, which is positioned in the movable column, is connected to the corresponding adjusting column; the partial section of the seed suction pipe positioned outside the movable column is uniformly provided with negative pressure suction nozzles along the axial direction; the outer port of the guide groove is provided with a movable sheet corresponding to the seed suction pipe; the movable sheet is fixedly arranged on the corresponding seed suction pipe; a first electric push rod is arranged below the movable sheet; the first electric push rod is arranged between the transportation mechanism and the support cylinder; a second electric push rod is arranged above the other movable sheet; the second electric push rod is arranged between the seed storage box and the negative pressure cylinder.

Furthermore, a pair of mounting frames are fixedly arranged on one side surface of the first substrate side by side; an electromagnetic vibrator is arranged between the two mounting frames; the electromagnetic vibrator is arranged on the bottom wall of the seed storage box; the seed storage box is placed on the mounting frame.

Furthermore, a second substrate is arranged below the first substrate in parallel; the upper surface of the second substrate is fixedly provided with a driving motor and a gearbox; an output shaft of the driving motor is connected with an input shaft of the gearbox; an output shaft of the gearbox is provided with an active drive plate; the driving plate is in transmission connection with a grooved pulley; the grooved wheel is fixedly arranged at the lower end of the rotating shaft.

Furthermore, one edge of the second substrate, which faces the same direction as the first substrate, is connected through a side supporting plate; an F-shaped structure is formed among the first substrate, the second substrate and the side supporting plate; the transportation mechanism is arranged on one side surface of the side supporting plate; the conveying mechanism comprises a driving wheel, a first driven wheel and a second driven wheel; the driving wheel is arranged between the second substrate and the first substrate; the first driven wheel and the second driven wheel are arranged above the first substrate side by side; the driving wheel, the first driven wheel and the second driven wheel are in transmission connection through a conveying belt.

Furthermore, one end of the wheel shaft of the driving wheel is fixedly provided with a first bevel gear; a second bevel gear is meshed with the first bevel gear; the second bevel gear is fixedly arranged on the lower end part of the rotating shaft.

Furthermore, the upper surface of the side supporting plate is fixedly provided with an L-shaped connecting rod; one end of the connecting rod is fixed on the upper end part of the negative pressure cylinder; the upper end part of the negative pressure cylinder is connected with a gas pipe; one end of the gas transmission pipe is connected to a negative pressure fan.

The invention has the following beneficial effects:

the invention realizes seed suction and seed discharge by designing the intermittent rotary structure, avoids the horizontal initial speed when the seeds fall into the hole tray, can ensure that the seeds accurately fall into corresponding positions in the hole tray, effectively reduces the hole rate and the multi-seed rate, has simple and reasonable structural design and convenient operation, effectively improves the precision seeding efficiency and effect of hole tray seedling culture, can realize the precision seeding of different varieties of grain seeds, and has higher market application value.

Of course, it is not necessary for any product in which the invention is practiced to achieve all of the above-described advantages at the same time.

Drawings

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

FIG. 1 is a schematic structural view of a precision seeding device for plug seedling of the present invention;

FIG. 2 is a front view of the structure of FIG. 1;

FIG. 3 is a top view of the structure of FIG. 1;

FIG. 4 is a side view of the structure of FIG. 1;

FIG. 5 is a schematic structural view of the connection between the support cylinder, the movable post and the negative pressure cylinder of the present invention;

FIG. 6 is a schematic structural view of a movable column of the present invention;

FIG. 7 is a front view of the structure of FIG. 6;

in the drawings, the components represented by the respective reference numerals are listed below:

1-a first base plate, 2-a transportation mechanism, 3-a hole tray, 4-a seed storage box, 5-a support cylinder, 6-a movable column, 7-a negative pressure cylinder, 8-a negative pressure pipe, 9-an adjusting column, 10-a limiting sleeve, 11-a tension spring, 12-a seed suction pipe, 13-a movable sheet, 14-a first electric push rod, 15-a second electric push rod, 16-a mounting rack, 17-an electromagnetic vibrator, 18-a driving motor, 19-a gearbox, 20-a driving dial, 21-a grooved wheel, 22-a first bevel gear, 23-a second bevel gear, 24-a connecting rod, 25-a gas pipe, 26-a negative pressure fan, 101-a second base plate, 102-a side supporting plate, 501-a rotating shaft, 601-a guide groove and 1201-a negative pressure suction nozzle.

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, the present invention is a precision seeding apparatus for plug seedling, including a first substrate 1; a second substrate 101 is arranged below the first substrate 1 in parallel; one edge of the second substrate 101 facing the same direction as the first substrate 1 is connected through a side supporting plate 102; an F-shaped structure is formed among the first substrate 1, the second substrate 101 and the side supporting plate 102; the upper surface of the first substrate 1 is provided with a mounting opening in a rectangular structure; a conveying mechanism 2 is arranged in the mounting opening; the hole tray 3 is arranged on the conveying mechanism 2;

the transportation mechanism 2 is arranged on one side surface of the side supporting plate 102; the conveying mechanism 2 comprises a driving wheel, a first driven wheel and a second driven wheel; the driving wheel is arranged between the second substrate 101 and the first substrate 1; the first driven wheel and the second driven wheel are arranged above the first substrate 1 side by side; the driving wheel, the first driven wheel and the second driven wheel are in transmission connection through a conveying belt; the driving wheel, the first driven wheel and the second driven wheel are arranged in an inverted triangle structure;

certainly, in order to ensure the transportation effect of the transportation mechanism 2, the driving wheel, the first driven wheel and the second driven wheel can be provided with chain wheels; then, the driving wheel, the first driven wheel and the second driven wheel are in transmission connection through a chain; the conveying belt is coated on the periphery of the chain;

one side of the transportation mechanism 2 is provided with a seed storage box 4; a pair of mounting frames 16 in a right-angled triangle structure are fixedly arranged on one side of the first substrate 1 side by side; an electromagnetic vibrator 17 is arranged between the two mounting frames 16; the electromagnetic vibrator 17 is arranged on the bottom wall of the seed storage box 4; the specific structure of the electromagnetic vibrator 17 is identical to that of the electromagnetic vibrator applied to the sieving apparatus, belonging to the prior art, and the structure thereof will not be described in detail herein; the seed storage box 4 can be connected to the mounting frame 16 through screws;

a supporting cylinder 5 with a cylindrical structure is arranged between the seed storage box 4 and the transportation mechanism 2; the supporting cylinder 5 is fixedly arranged on the upper surface of the substrate 1 through a bottom cover in a circular structure; a rotating shaft 501 is rotatably arranged in the supporting cylinder 5; the lower end of the rotating shaft 501 penetrates and extends to the lower part of the substrate 1; the rotating shaft 501 is in rotating fit with the substrate 1;

the upper surface of the second substrate 101 is fixedly provided with a driving motor 18 and a gearbox 19; the output shaft of the driving motor 18 is connected with the input shaft of the gearbox 19; an output shaft of the gear box 19 is provided with an active drive plate 20; the gearbox 19 is a two-stage speed reducer, and the specific structure of the gearbox is only required to meet the transmission between the driving motor 18 and the driving dial 20, which belongs to the conventional design in the field, and the structure of the gearbox is not described in detail herein; a grooved pulley 21 is in transmission connection with the driving drive plate 20; the sheave 21 is fixedly arranged at the lower end of the rotating shaft 501; one end of the wheel shaft of the driving wheel is fixedly provided with a first bevel gear 22; a second bevel gear 23 is meshed with the first bevel gear 22; the second bevel gear 23 is fixedly arranged on the lower end part of the rotating shaft 501;

the upper end of the rotating shaft 501 is fixedly provided with a movable column 6 with a cavity structure; the movable column 6 is of a cylindrical structure; the movable column 6 is rotatably arranged at the upper end of the supporting cylinder 5; the upper end of the movable column 6 is provided with a negative pressure cylinder 7; a sealing ring is arranged at the joint between the negative pressure cylinder 7 and the movable column 6; the top end of the negative pressure cylinder 7 is fixedly provided with a top cover in a circular structure; the upper surface of the side supporting plate 102 is fixedly provided with an L-shaped connecting rod 24; one end of the connecting rod 24 is fixed on the top cover of the negative pressure cylinder 7; negative pressure pipes 8 are uniformly distributed in the negative pressure cylinder 7 along the annular direction; the lower end of the negative pressure pipe 8 penetrates through the top wall of the movable column 6 and extends to the interior of the movable column 6; the negative pressure pipe 8 is in interference fit with the movable column 6;

the lower end part of the negative pressure pipe 8 is slidably sleeved with an adjusting column 9 with a cavity structure; a limiting sleeve 10 in an annular structure is arranged in the adjusting column 9; the limiting sleeve 10 is fixedly sleeved at the lower port of the negative pressure pipe 8; the outer diameter of the limiting sleeve 10 is smaller than the inner diameter of the adjusting column 9; a tension spring 11 is arranged above the limit sleeve 10; the tension spring 11 is sleeved on the lower end part of the negative pressure pipe 8; the upper end of the tension spring 11 is fixedly connected with the inner top wall of the adjusting column 9; the lower end of the tension spring 11 is fixedly connected with the upper surface of the limiting sleeve 10;

the side wall of the movable column 6 is uniformly provided with guide grooves 601 corresponding to the positions of the adjusting columns 9 along the annular direction; a suction pipe 12 is inserted in the guide groove 601 along the radial direction of the movable column 6; one end of the suction pipe 12 positioned in the movable column 6 is connected to the middle part of the corresponding adjusting column 9; a plurality of negative pressure suction nozzles 1201 are uniformly distributed on the partial section of the suction pipe 12 positioned outside the movable column 6 along the axial direction; the distance between the two farthest adjacent negative pressure suction nozzles 1201 is consistent with the length of the seed storage box 4; the diameter of the negative pressure suction nozzle 1201 is set according to the diameter of the seeds, and the negative pressure suction nozzle 1201 can only suck one seed at most each time;

the outer port of the guide groove 601 is provided with a movable sheet 13 corresponding to the position of the seed suction pipe 12; the inner side surface of the movable sheet 13 is attached to the outer wall of the movable column 6; the upper end and the lower end of the movable sheet 13 are both provided with an outer folded edge; a U-shaped structure is formed between the movable sheet 13 and the two outer folded edges; the movable plate 13 is fixedly arranged on the corresponding seed suction pipe 12; a first electric push rod 14 is arranged below the movable sheet 13; a first pushing block matched with the outer folded edge is fixed at the power output end of the first electric push rod 14; the first electric push rod 14 is arranged between the transportation mechanism 2 and the support cylinder 5, and the first electric push rod 14 is fixedly arranged on the upper surface of the bottom cover; a second electric push rod 15 is arranged above the other movable sheet 13; a second pushing block matched with the outer folded edge is fixed at the power output end of the second electric push rod 15; the second electric push rod 15 is arranged between the seed storage box 4 and the negative pressure cylinder 7, and the second electric push rod 15 is fixedly arranged on the lower surface of the top cover; the top cover of the negative pressure cylinder 7 is connected with a gas pipe 25; one end of the gas transmission pipe 25 is connected to a negative pressure fan 26; the negative pressure fan 26 is fixedly mounted on the upper surface of the second substrate 101.

Specifically, a controller is fixedly arranged on the upper surface of the first substrate 1; the controller is respectively electrically connected with the first electric push rod 14, the second electric push rod 15, the electromagnetic vibrator 17, the driving motor 18 and the negative pressure fan 26; the controller is connected with a plug through a lead; the plug is used for providing electric energy support for the first electric push rod 14, the second electric push rod 15, the electromagnetic vibrator 17, the driving motor 18 and the negative pressure air fan 26.

An operation mode of a precision seeding device for plug seedling comprises the following steps:

firstly, seeds are put into a seed storage box 4, a plug tray 3 is put at a proper position on a conveying mechanism 2, and then a controller starts a first electric push rod 14, a second electric push rod 15, an electromagnetic vibrator 17, a driving motor 18 and a negative pressure fan 26; wherein, the initial position of the seed suction pipe 12 is right above the seed storage box 4, namely, right below the second electric push rod 15;

step two, the second electric push rod 15 utilizes a second push block to push the seed suction pipe 12 positioned right above the seed storage box 4 downwards, and the negative pressure suction nozzle 1201 on the seed suction pipe 12 sucks the seeds in the seed storage box 4; then, the second electric push rod 15 is reset, and the suction pipe 12 is also reset under the elastic force action of the tension spring 11; the action process is in the intermittent time period of the sheave mechanism consisting of the driving dial 20 and the sheave 21;

step three, after the seed suction pipe 12 with the seeds is reset, the driving motor 18 drives the rotating shaft 501 to rotate through the gearbox 19, the driving dial 20 and the grooved pulley 21, the seed suction pipe 12 with the seeds moves to the next station, and the subsequent seed suction pipe 12 without the seeds repeats the action process of the step two;

fourthly, when the seed suction pipe 12 with the seeds moves to a position opposite to the seed suction pipe 12 which is positioned right above the seed storage box 4, the nth row (1, 2, 3 and 4) of the plug tray 3 is just positioned right below the negative pressure suction nozzle 1201 of the seed suction pipe 12; at this time, the first electric push rod 14 pushes the seed suction pipe 12 above the nth row of the plug 3 upwards by using the first push rod, the lower surface of the limit sleeve 10 is attached to the inner bottom surface of the adjusting column 9, the negative pressure suction nozzle 1201 above the nth row of the plug 3 loses the negative pressure state, and the seeds fall into the nth row of the plug 3; then, the first electric push rod 14 is reset, and the seed suction pipe 12 positioned above the nth row of the plug tray 3 is reset under the elastic force of the tension spring 11; the action process is in the intermittent time period of the sheave mechanism consisting of the driving dial 20 and the sheave 21;

step five, when the seeds on the seed suction pipe 12 fall into the hole disc 3 and become the seed suction pipe 12 without the seeds, the action process of the step two is continuously repeated; meanwhile, the rotating shaft 501 drives the conveying mechanism 2 to move by using the second bevel gear 23 and the first bevel gear 22, and the plug tray 3 moves to the next station;

and sixthly, repeating the steps to realize the precise seeding of the plug 3.

The preferred embodiments of the invention disclosed above are intended to be illustrative only. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention. The invention is limited only by the claims and their full scope and equivalents.