Disclosure of Invention
For solving above-mentioned technical problem, provide an ink jet printer's nozzle structure, above-mentioned problem has been solved to this technical scheme, can conveniently realize the cleanness of filter core, very big reduction the human cost, clean efficiency and environmental friendliness are high, through a plurality of work units of connecting piece with modular mode independent assortment, convenient operation satisfies different filtration demands, through setting up the switching components, can conveniently switch two kinds of working modes of supplying ink and wasing, convenient operation.
In order to achieve the above purposes, the technical scheme adopted by the invention is as follows:
a nozzle structure of ink-jet printer is composed of a nozzle body, a flexible connecting tube with two ends respectively connected to said nozzle body and self-cleaning filter unit, and a self-cleaning filter unit consisting of several end-to-end working units and a connector for connecting said working units to each other or between said working units and said flexible connecting tube,
the pipe fitting comprises a main pipeline and a branch pipeline which are mutually crossed, wherein the main pipeline of the pipe fitting is used for supplying ink into the flexible connecting pipe, and the branch pipeline of the pipe fitting is used for cleaning the inside of the pipe fitting;
the filter element is arranged at the joint of the main pipeline and the branch pipeline of the pipe fitting and is used for filtering ink passing through the pipe fitting;
the dredging device is arranged at the lower end of the branch pipeline of the pipe fitting, the working direction of the working end of the dredging device faces the filter element, the dredging device seals a passage between the filter element and the lower end of the main pipeline of the pipe fitting in a working state, and the dredging device is used for cleaning the filter element;
and the discharging device is arranged at the upper end of the branch pipeline of the pipe fitting, the working end of the discharging device faces the direction of the filter element, and the discharging device is used for discharging sundries generated after the filter element is cleaned out of the pipe fitting.
Preferably, the pipe fitting comprises a first bending pipe and a second bending pipe; the first bending pipe and the second bending pipe are identical in structure and are connected with the two sides of the filter element respectively, the first bending pipe and the second bending pipe are identical in structure and are only symmetrically arranged relative to the filter element, and the first bending pipe and the second bending pipe jointly form a pipe fitting.
Preferably, the first bent pipe comprises a main pipe member and a branch pipe member, wherein the included angle between the main pipe member and the branch pipe member is provided with a butt joint end, and the butt joint end is fixedly connected with one side of the filter element.
Preferably, the filter element is an oval filter plate arranged at the joint of the main pipeline and the branch pipeline of the pipe fitting, filter holes are uniformly formed in the oval filter plate along the axis direction of the branch pipeline of the pipe fitting, and the filter holes are matched with the working end of the dredging device in a plug-in mode in a clean state.
Preferably, the pull through device comprises a pull through pipe,
the first sealing cover is arranged at the lower end port of the branch pipeline of the pipe fitting and used for sealing the lower end of the branch pipeline of the pipe fitting;
the ejection mechanism is arranged at one end, far away from the pipe fitting, of the first sealing cover, the movement direction of the ejection mechanism is collinear with the axis of a branch pipe of the pipe fitting, the ejection mechanism is in clearance fit with the first sealing cover, the ejection mechanism is in plug fit with the filter element in a working state, and the ejection mechanism is used for discharging impurities in the filter element;
the first supporting cylinder is of a cup-shaped structure, one end of an opening of the first supporting cylinder is connected with one end, away from the pipe fitting, of the first sealing cover, the axis of the first supporting cylinder is collinear with the axis of the ejection mechanism, and the cup bottom part of the first supporting cylinder is used for supporting the first linear driver;
the first linear driver is arranged on the cup bottom of the first supporting cylinder, an output shaft of the first linear driver penetrates through the cup bottom of the first supporting cylinder to be connected with the ejection mechanism, and the first linear driver is used for controlling the linear motion of the ejection mechanism.
Preferably, the ejection mechanism comprises an ejector pin and an installation plate; the thimble is equipped with a plurality of and evenly installs perpendicularly on the mounting panel, and the axis of thimble and the axis collineation of the branch pipeline of pipe fitting, mounting panel and first linear actuator's output shaft fixed connection, and the mounting panel is used for installing the thimble and drives the thimble flexible, and thimble operating condition is clearance fit with the filter core down.
Preferably, the discharge means comprises a discharge tube having,
the second sealing cover is arranged at the upper end of the branch pipeline of the pipe fitting, a through hole is formed in the second sealing cover along the axial direction, and the second sealing cover is used for sealing the upper end of the branch pipeline of the pipe fitting;
the sealing plug is in interference fit with the through hole of the second sealing cover and is used for controlling the on-off of the through hole of the second sealing cover;
the opening end of the cup-shaped liquid outlet pipe is fixedly connected with one end, far away from the pipe fitting, of the second sealing cover, the cup bottom of the cup-shaped liquid outlet pipe is in clearance fit with the sealing plug along the axis direction of the through hole of the second sealing cover, and a liquid outlet is formed in one side of the cup-shaped liquid outlet pipe;
the second supporting cylinder is arranged on the cup bottom of the cup-shaped liquid outlet pipe;
and the second linear driver is arranged at one end of the second support cylinder, which is far away from the cup-shaped liquid outlet pipe, the output shaft of the second linear driver is fixedly connected with the tail end of the sealing plug, and the second linear driver is used for controlling the linear motion of the second linear driver.
Preferably, the connecting piece is a double-threaded sleeve, and the peripheral wall of the double-threaded sleeve is uniformly provided with tooth grooves.
Preferably, the feed end of the self-cleaning filtering device is further provided with a switching assembly, and the switching assembly is used for switching the on-off of the self-cleaning filtering device and a water supply pipeline or an ink box.
Preferably, the switching component comprises a three-way pipe, a first electromagnetic valve and a second electromagnetic valve; the three ports of the three-way pipe are respectively an ink inlet end and a water inlet end for feeding ink and water and a material outlet end butted with the self-cleaning filtering device, the first electromagnetic valve and the second electromagnetic valve are respectively arranged on the ink inlet end and the water inlet end of the three-way pipe, and the first electromagnetic valve and the second electromagnetic valve are respectively used for controlling the connection and disconnection of the ink inlet end and the water inlet end of the three-way pipe.
Compared with the prior art, the invention has the beneficial effects that:
1. the filter element cleaning device has the advantages that the filter element can be conveniently cleaned, labor cost is greatly reduced, cleaning efficiency and environmental friendliness are high, specifically, the controller firstly sends a signal to the dredging device, the working end of the dredging device penetrates through the filter element from bottom to top after receiving the signal, so that impurities blocked in the filter element are discharged from the upper end of the filter element, the working end of the dredging device seals the filter element at the moment, the controller sends a signal to the discharging device, the upper end of a branch pipeline of the pipe fitting is opened after the discharging device receives the signal, the controller introduces water or cleaning liquid into the pipe fitting from the feeding end of a main pipeline of the pipe fitting by opening an external water supply pipeline, and the water or cleaning liquid can only be discharged from the upper end of the branch pipeline of the pipe fitting, namely the end where the discharging device is located, and the water or cleaning liquid brings the impurities out of the pipe fitting together, so that the inside of the pipe fitting is cleaned;
2. the plurality of working units are freely combined in a modularized mode through the connecting piece, the operation is convenient, different filtering requirements are met, and particularly, when only one working unit exists, the connecting piece is only used for connecting the lower end of a main pipeline of a pipe fitting of the working unit with the flexible connecting pipe; when the number of the working units is multiple, the connecting piece is also used for connecting the head and the tail of the main pipelines of the plurality of pipe fittings, so that the plurality of working units are connected in series for multi-stage filtration;
3. through setting up the switching module, can conveniently switch supplying ink and wasing two kinds of mode, convenient operation, it is concrete, the ink feed end and the ink horn of three-way pipe are connected, and the end of intaking of three-way pipe is connected with water supply pipeline or washing liquid feed pipe way. When the controller closes the second electromagnetic valve and opens the first electromagnetic valve, the self-cleaning filtering device is in an ink supply mode and supplies ink to the nozzle body through the flexible connecting pipe. When the controller opens the second electromagnetic valve and closes the first electromagnetic valve, the self-cleaning filtering device can be switched to a cleaning mode.
Detailed Description
The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art.
As shown in fig. 1, 2 and 4, a nozzle structure of an ink-jet printer comprises a nozzle body 1, a flexible connecting pipe 2 and a self-cleaning filtering device, wherein two ends of the flexible connecting pipe 2 are respectively connected with the nozzle body 1 and the self-cleaning filtering device, the self-cleaning filtering device comprises a plurality of working units which are connected end to end and a connecting piece 3 which is used for connecting the working units with each other or between the working units and the flexible connecting pipe 2, wherein the working units comprise,
the pipe fitting 4 is composed of a main pipeline and a branch pipeline which are mutually crossed, the main pipeline of the pipe fitting 4 is used for supplying ink into the flexible connecting pipe 2, and the branch pipeline of the pipe fitting 4 is used for cleaning the inside of the pipe fitting 4;
the filter element 5 is arranged at the joint of the main pipeline and the branch pipeline of the pipe fitting 4, and the filter element 5 is used for filtering ink passing through the pipe fitting 4;
the dredging device 6 is arranged at the lower end of the branch pipeline of the pipe fitting 4, the working direction of the working end of the dredging device 6 is arranged towards the filter element 5, the dredging device 6 seals a passage between the filter element 5 and the lower end of the main pipeline of the pipe fitting 4 in the working state, and the dredging device 6 is used for cleaning the filter element 5;
and the discharging device 7 is arranged at the upper end of the branch pipeline of the pipe fitting 4, the working end of the discharging device 7 faces the direction of the filter element 5, and the discharging device 7 is used for discharging sundries generated after the filter element 5 is cleaned out of the pipe fitting 4.
The dredging device 6 and the discharging device 7 are both electrically connected with the controller. The number of the working units can be one, and when only one working unit exists, the connecting piece 3 is only used for connecting the lower end of the main pipeline of the pipe fitting 4 of the working unit with the flexible connecting pipe 2; when the working units are multiple, the connecting piece 3 is also used for connecting the heads and the tails of the main pipelines of the pipe fittings 4, so that the working units are connected in series for multi-stage filtration. Before the work, the staff installs whole nozzle in the inkjet printer main part earlier, the staff installs nozzle body 1 on the mobile device, it is fixed with the frame with automatically cleaning filter equipment, realize automatically cleaning filter equipment's discharge end and nozzle body 1's intercommunication through flexible connection pipe 2, and be connected automatically cleaning filter equipment and ink horn, supply ink to nozzle body 1's stability with guaranteeing automatically cleaning filter equipment, inkjet printer and nozzle main part all adopt common structure, concrete theory of operation does not do the perusal here. When the ink box works, ink is led into the pipe fitting 4 by the ink box, and the ink passes through the filter element 5 when passing through the joint of the main pipeline and the branch pipeline of the pipe fitting 4. The filter element 5 filters the ink passing through, and impurities generated after the filtering are left at the upper end of the filter element 5 or inside the filter element 5. Ink entering the lower end of the main pipeline of the pipe fitting 4 through the filter element 5 enters the nozzle body 1 through the flexible connecting pipe 2 and is sprayed out, and therefore the printing function is achieved. Thereby make a plurality of work units establish ties each other through connecting piece 3 and realize multistage filtration, further improve the filter effect. When the nozzle is used for a long time, the self-cleaning filtering device needs to be controlled to clean by itself. The operator disconnects the feed end of the self-cleaning filter device, i.e. the feed end of the main line of the first tube 4, from the cartridge, and butts it against the water supply line. The controller firstly sends a signal to the dredging device 6, the working end of the dredging device 6 penetrates through the filter element 5 from bottom to top after receiving the signal, so that impurities blocked in the filter element 5 are discharged from the upper end of the filter element 5, and the working end of the dredging device 6 plays a role in sealing the filter element 5. The controller sends a signal to the exhaust device 7, and the exhaust device 7 opens the upper end of the branch pipe of the pipe 4 after receiving the signal. The controller introduces water or cleaning fluid into the pipe fitting 4 from the feed end of the main pipe of the pipe fitting 4 by opening the external water supply pipeline, and because the filter element 5 is closed, the water or cleaning fluid can only be discharged from the upper end of the branch pipeline of the pipe fitting 4, namely, the end where the discharging device 7 is located, and the water or cleaning fluid brings impurities out of the pipe fitting 4 together, so that the inside of the pipe fitting 4 is cleaned. When a plurality of working units are adopted, the cleaning is carried out sequentially from top to bottom.
As shown in fig. 6, the tube member 4 includes a first bent tube 4a and a second bent tube 4 b; the first bent pipe 4a and the second bent pipe 4b are identical in structure and are connected with two sides of the filter element 5 respectively, the first bent pipe 4a and the second bent pipe 4b are identical in structure and are symmetrically arranged only about the filter element 5, and the first bent pipe 4a and the second bent pipe 4b jointly form a pipe fitting 4.
The X-shaped crossed pipe fitting 4 is split into a pair of V-shaped bent pipes, the V-shaped bent pipes can be conveniently butted with the filter element 5, and the V-shaped bent pipes and the filter element 5 can be fixed mutually through welding. The part of the first bent pipe 4a for forming the main pipeline and the part of the second bent pipe 4b for forming the main pipeline are positioned on the same axis; the portion of the first bent tube 4a for forming the branch line and the portion of the second bent tube 4b for forming the branch line are located on the same axis,
as shown in fig. 7, the first bent pipe 4a includes a main pipe member 4a1 and a branch pipe member 4a2, the main pipe member 4a1 and the branch pipe member 4a2 have an abutting end 4a3 at the corner, and the abutting end 4a3 is fixedly connected to one side of the filter element 5.
The main pipe member 4a1 of the first elbow 4a and the main pipe member 4a1 of the second elbow 4b together form a main pipeline of the complete pipe 4, and the branch pipe member 4a2 of the first elbow 4a and the branch pipe member 4a2 of the second elbow 4b together form a branch pipeline of the pipe 4. The assembly is facilitated by welding the abutting ends 4a3 of the first and second bent tubes 4a and 4b to both sides of the filter cartridge 5.
As shown in fig. 7, the filter element 5 is an elliptical filter plate 5a installed at the junction of the main pipeline and the branch pipeline of the pipe 4, filter holes 5b are uniformly formed in the elliptical filter plate 5a along the axial direction of the branch pipeline of the pipe 4, and the filter holes 5b are in plug-in fit with the working end of the dredging device 6 in a clean state.
The upper end surfaces of the filtering holes 5b are positioned in the inner cavity space at the upper ends of the main pipeline and the branch pipeline of the pipe fitting 4. The axial line of the filter hole 5b is not perpendicular to the end surface of the oval filter plate 5a, but is collinear with the branch pipeline axial line of the pipe fitting 4, so that the working end of the dredging device 6 can be inserted into the filter hole 5b along the branch pipeline axial line of the pipe fitting 4, then impurities blocked in the filter hole 5b are pushed out to the upper part of the oval filter plate 5a, namely the inner parts of the upper ends of the main pipeline and the branch pipeline of the pipe fitting 4, and meanwhile, the working end of the dredging device 6 also seals the filter hole 5b, so that the impurities can be discharged through the upper end of the branch pipeline of the pipe fitting 4.
As shown in fig. 4 and 8, the pull through 6 comprises,
the first sealing cover 6a is arranged at the lower end port of the branch pipeline of the pipe fitting 4, and the first sealing cover 6a is used for sealing the lower end of the branch pipeline of the pipe fitting 4;
the ejection mechanism 6b is arranged at one end, far away from the pipe fitting 4, of the first sealing cover 6a, the movement direction of the ejection mechanism 6b is collinear with the axis of a branch pipe of the pipe fitting 4, the ejection mechanism 6b is in clearance fit with the first sealing cover 6a, the ejection mechanism 6b is in splicing fit with the filter element 5 in a working state, and the ejection mechanism 6b is used for discharging impurities in the filter element 5;
the first supporting cylinder 6c is of a cup-shaped structure, one open end of the first supporting cylinder 6c is connected with one end, away from the pipe fitting 4, of the first sealing cover 6a, the axis of the first supporting cylinder 6c is collinear with the axis of the ejection mechanism 6b, and the cup bottom part of the first supporting cylinder 6c is used for supporting the first linear driver 6 d;
the first linear driver 6d is installed on the cup bottom of the first supporting cylinder 6c, an output shaft of the first linear driver 6d penetrates through the cup bottom of the first supporting cylinder 6c to be connected with the ejection mechanism 6b, and the first linear driver 6d is used for controlling the linear motion of the ejection mechanism 6 b.
The first linear driver 6d is electrically connected to the controller. The first linear actuator 6d is an air cylinder or a hydraulic cylinder. The first linear actuator 6d is supported by the first support cylinder 6c, and the controller drives the ejection mechanism 6b to move along the axial direction of the branch pipe of the pipe 4 by the first linear actuator 6 d. When the working end of the ejection mechanism 6b is inserted into the filtering hole 5b of the filter element 5, the impurities blocked in the filtering hole 5b are ejected out, and the filter element 5 is wholly sealed.
As shown in fig. 8, the ejection mechanism 6b includes a thimble 6b1 and a mounting plate 6b 2; the ejector pins 6b1 are uniformly and vertically arranged on the mounting plate 6b2, the axis of the ejector pin 6b1 is collinear with the axis of the branch pipeline of the pipe fitting 4, the mounting plate 6b2 is fixedly connected with the output shaft of the first linear driver 6d, the mounting plate 6b2 is used for mounting the ejector pin 6b1 and driving the ejector pin 6b1 to extend and retract, and the ejector pin 6b1 is in clearance fit with the filter element 5 in a working state.
The first linear actuator 6d drives the plurality of thimble pins 6b1 to move together by driving the mounting plate 6b2, thereby discharging the impurities in the filter element 5, and the mounting plate 6b2 blocks and seals the filter hole 5b of the filter element 5.
As shown in fig. 9, the discharge device 7 includes,
the second sealing cover 7a is installed at the upper end of the branch pipeline of the pipe fitting 4, a through hole is formed in the second sealing cover 7a along the axial direction, and the second sealing cover 7a is used for sealing the upper end of the branch pipeline of the pipe fitting 4;
the sealing plug 7b is in interference fit with the through hole of the second sealing cover 7a, and the sealing plug 7b is used for controlling the on-off of the through hole of the second sealing cover 7 a;
the opening end of the cup-shaped liquid outlet pipe 7c is fixedly connected with one end, far away from the pipe fitting 4, of the second sealing cover 7a, the cup bottom of the cup-shaped liquid outlet pipe 7c is in clearance fit with the sealing plug 7b along the axis direction of the through hole of the second sealing cover 7a, and a liquid outlet is formed in one side of the cup-shaped liquid outlet pipe 7 c;
the second supporting cylinder 7d is arranged on the cup bottom of the cup-shaped liquid outlet pipe 7 c;
and the second linear driver 7e is arranged at one end, away from the cup-shaped liquid outlet pipe 7c, of the second supporting cylinder 7d, an output shaft of the second linear driver 7e is fixedly connected with the tail end of the sealing plug 7b, and the second linear driver 7e is used for controlling the linear motion of the second linear driver 7 e.
The second linear actuator 7e is electrically connected to the controller. The second linear actuator 7e is a pneumatic or hydraulic cylinder. The liquid outlet of the cup-shaped liquid outlet pipe 7c is connected with the collecting device through a flexible drain pipe. The second linear actuator 7e is supported by the second support cylinder 7d while the second linear actuator 7e is spaced apart from the cup-shaped liquid outlet pipe 7c to secure a moving space of the end of the sealing plug 7 b. The controller sends a signal to the second linear driver 7e, and the second linear driver 7e controls the linear motion of the sealing plug 7b to realize the opening and closing of the via hole on the second sealing cover 7a after receiving the signal. When the via hole on the sealed lid 7a of second was opened, water or washing liquid area impurity discharged into cup type drain pipe 7c from the via hole of the sealed lid 7a of second to discharge to the collection device in from the liquid outlet of cup type drain pipe 7c, can effectively avoid causing the pollution, the environmental friendliness is high, has avoided the cleaning work in later stage simultaneously, has reduced the human cost.
As shown in fig. 5, the connecting member 3 is a double-threaded sleeve 3a, and the double-threaded sleeve 3a is provided with splines 3b uniformly on the circumferential wall thereof.
Both ends of the main pipeline of the pipe fitting 4 are provided with threads. Through double-end thread sleeve pipe 3a can conveniently realize the butt joint of a plurality of pipe fittings 4 and dismantle the change, greatly improved and installed convenient degree, can make the work unit conveniently increase and decrease quantity with the modular mode. The friction force of the outer wall of the double-thread sleeve 3a is improved through the tooth grooves 3b, and the convenience degree of operation is further improved.
As shown in fig. 1-3, a switching assembly 8 is further disposed at the feeding end of the self-cleaning filtering device, and the switching assembly 8 is used for switching the self-cleaning filtering device to be connected to or disconnected from the water supply pipeline or the ink cartridge.
The working state of the self-cleaning filtering device can be conveniently and automatically switched by additionally arranging the switching component 8, so that the self-cleaning filtering device can be freely switched between the ink supply state and the cleaning state, the task amount of manual switching is reduced, and the overall convenience of the structure is further improved.
As shown in fig. 10, the switching assembly 8 includes a tee pipe 8a, a first solenoid valve 8b and a second solenoid valve 8 c; the three ports of the three-way pipe 8a are respectively an ink inlet end and a water inlet end for feeding ink and water and a material outlet end butted with the self-cleaning filtering device, the first electromagnetic valve 8b and the second electromagnetic valve 8c are respectively arranged on the ink inlet end and the water inlet end of the three-way pipe 8a, and the first electromagnetic valve 8b and the second electromagnetic valve 8c are respectively used for controlling the connection and disconnection of the ink inlet end and the water inlet end of the three-way pipe 8 a.
The first electromagnetic valve 8b and the second electromagnetic valve 8c are both electric butterfly valves electrically connected with the controller. The ink inlet end of the three-way pipe 8a is connected with the ink box, and the water inlet end of the three-way pipe 8a is connected with the water supply pipeline or the cleaning liquid supply pipeline. When the controller closes the second electromagnetic valve 8c and opens the first electromagnetic valve 8b, the self-cleaning filter apparatus is in the ink supply mode, and ink is supplied to the nozzle body 1 through the flexible connecting tube 2. When the controller opens the second solenoid valve 8c and closes the first solenoid valve 8b, the self-cleaning filtering device is switched to the cleaning mode.
The working principle of the invention is as follows:
the device realizes the functions of the invention through the following steps, thereby solving the technical problems provided by the invention:
firstly, before work, a worker firstly installs the whole nozzle on a main body of an ink-jet printer, installs a nozzle body 1 on a mobile device, fixes a self-cleaning filtering device with a rack, communicates the discharge end of the self-cleaning filtering device with the nozzle body 1 through a flexible connecting pipe 2, and connects the self-cleaning filtering device with an ink box.
And step two, when the ink box works, ink is led into the pipe fitting 4 by the ink box, and the ink passes through the filter element 5 when passing through the joint of the main pipeline and the branch pipeline of the pipe fitting 4. The filter element 5 filters the ink passing through, and impurities generated after the filtering are left at the upper end of the filter element 5 or inside the filter element 5.
And step three, ink entering the lower end of the main pipeline of the pipe fitting 4 through the filter element 5 enters the nozzle body 1 through the flexible connecting pipe 2 and is sprayed out, so that the printing function is realized. Thereby make a plurality of work units establish ties each other through connecting piece 3 and realize multistage filtration, further improve the filter effect.
And step four, when the nozzle is used for a long time, the self-cleaning filtering device needs to be controlled to carry out self-cleaning. The operator disconnects the feed end of the self-cleaning filter device, i.e. the feed end of the main line of the first tube 4, from the cartridge, and butts it against the water supply line.
And step five, the controller firstly sends a signal to the dredging device 6, the working end of the dredging device 6 penetrates through the filter element 5 from bottom to top after receiving the signal, so that impurities blocked in the filter element 5 are discharged from the upper end of the filter element 5, and the working end of the dredging device 6 plays a role in sealing the filter element 5.
And step six, the controller sends a signal to the discharging device 7, and the discharging device 7 opens the upper end of the branch pipeline of the pipe fitting 4 after receiving the signal.
And seventhly, the controller introduces water or cleaning liquid into the pipe fitting 4 from the feed end of the main pipeline of the pipe fitting 4 by opening an external water supply pipeline, the water or the cleaning liquid can only be discharged from the upper end of the branch pipeline of the pipe fitting 4, namely the end where the discharging device 7 is located, and the water or the cleaning liquid brings impurities out of the pipe fitting 4 together due to the fact that the filter element 5 is closed, so that the inside of the pipe fitting 4 is cleaned. When a plurality of working units are adopted, the cleaning is carried out sequentially from top to bottom.
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 merely illustrative of the principles of the invention, but that various changes and modifications may be made without departing from the spirit and scope of the invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.