Patent Application
20220034526
Not Applicable
Not Applicable
Not Applicable
The present invention relates generally to a ventilation system and, more particularly, to a ventilation system that incorporates a systematic ventilation path and ultraviolet light that will kill airborne bacteria, viruses and pathogens that are harmful to humans and animals.
Ventilation systems are used in commercial and residential buildings throughout the United States and the world to circulate air within a building as a means to control indoor air quality, heat and cool buildings and control humidity for human comfort. Ventilation systems help to ensure the air within a building is in constant motion to prevent air from collecting in one area of the building and becoming stale, developing an odor and possibly becoming harmful to humans and animals. Further, ventilation systems will help to clean the air by passing the air through filters to remove particles or pathogens, that may affect the respiratory systems of humans with allergies or cause other sicknesses, from the air prior to recirculating the air back into the building.
Ventilation systems may rely on a mechanical means to circulate the air within a building. That mechanical means may include a supply fan and an exhaust fan. The supply fan pulls air from one area of the building or even outside air into a building. The supply fan may also help to ensure that the air flow is passed through a series of filters to clean the air prior to the air being introduced to an area of the building. The exhaust fan may pull air from one area of a building and send the air to the outside atmosphere. The supply fans and exhaust fans cooperatively work together to maintain a comfortable air flow within a building to ensure comfort for humans and animals. The filters help to filter or clean many, but not all of the harmful particles and pathogens from the air prior to introducing the air into the living or working areas of the building.
While filters help to clean the air of harmful particles and pathogens, there are many harmful particles and pathogens that are too small for the filters to capture. Typical filters can capture particles and pathogens from the air ranging from greater than 10 micros to 0.3 microns in size. The filters that can capture the smallest particles and pathogens begin to limit air flow because the air must be forced through smaller and smaller openings in the filter. Thus, harmful particles and pathogens that are smaller than 0.3 microns, and even larger harmful particles and pathogens if a less efficient filter is used, continue to be recirculated within a building often times causing irritations to allergies or even sickness in humans and animals.
Furthermore, the blower in the HVAC system may not move the air contained in a building in a manner to sufficiently force particles and pathogens that are traveling in aerosols produced by an individual through breathing, talking, yelling, singing, coughing and/or sneezing out of the air intake path of other individuals. In fact, the set-up of present ventilation systems may aid the flow of particles and pathogens in aerosols produced by one individual into the air intake zone, the mouth, nose or eye area, of other individuals, thereby infecting the other individuals with what may be contained in the aerosol produced by the first individual.
The most recent threat to the respiratory systems of humans and animals has been the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus and subsequent Coronavirus Disease (COVID-19). One means of transmitting the SARS-CoV-2 virus is by exposing or passing infectious viral particles in aerosols or water droplets from one individual to other individuals within the same enclosed area. Examples or an enclosed area may be an indoor restaurant, a working manufacturing plant or a conference room in an office building. A single infected individual may transmit the infectious viral particles to other healthy individuals through breathing, talking, yelling, singing, coughing and/or sneezing within the enclosed area. The healthy individuals merely need to have their mouth, nose or eyes in the pathway of the cloud or aerosol of infectious viral particles contained in water droplets produced by the infected individual.
As stated above, the infectious viral particles may be released into the environment by a single infected individual through breathing, talking, yelling, singing, coughing and/or sneezing within the enclosed area. However, the different aspects of expelling the viral particles may be done so in drastically different amounts of the viral particles and at varying speeds of expulsion. A single sneeze releases about 30,000 droplets that may contain the infectious viral particles at about 200 miles per hour. A SARS-CoV-2 virus cloud created by the single sneeze may move about 20 inches in 0.3 seconds. After the initial virus cloud is created by the single sneeze, the cloud will move at the speed of the air flow in the room. If there is little to no air flow in the room, the virus cloud will grow in size and remain infectious for hours. Many droplets are small and may travel great distances, easily across and filling an enclosed room in a few minutes.
A single cough releases about 3,000 droplets that may contain the infectious viral particles at about 50 miles per hour. A SARS-CoV-2 virus cloud created by the single cough may move about 20 inches in 0.3 seconds. After the initial virus cloud is created by the single cough, the cloud will move at the speed of the air flow in the room (see
A single breath releases 50 to 5000 droplets that may contain the infectious viral particles, but they are expelled at a very low velocity and fall to the ground quickly under the force of gravity. Unlike sneezing and coughing which release a large amount of viral material due to the exhalation force of a sneeze or cough, breathing droplets will contain less of the viral material due to a lower exhalation force. Talking increases the release of droplets about ten-fold and singing even more. There is a large amount of infectious viral material that can be introduced into an enclosed area through normal human actions that can easily fill an enclosed area. Traditional building ventilation systems with typical filtering capability merely help to fill an enclosed area with the infectious viral particles faster and may increase the chances of other individuals contracting the infection and causing the exponential spread of the SARS-CoV-2 virus.
To date, means have been developed to interrupt the path of the aerosol of infectious viral particles. Many stores and places of business that deal with the public on a daily basis have installed a plexiglass barrier to prevent any infectious viral particles from passing from an infected person to the individual on the other side of the plexiglass barrier. The plexiglass barrier stops the path of the infectious viral particles from reaching the individual behind the barrier. As the infectious person stands in front of the plexiglass barrier for several minutes, the individual could be creating a large cloud of infectious viral particles though breathing, talking, yelling, singing, coughing and/or sneezing within the enclosed area. As the next person in line moves forward, they will move into the cloud of infectious viral particles and increase their chances of becoming infected. The cloud of viral particles may remain infectious for several hours. If there is little to no air flow to move the cloud, the cloud of infectious viral particles may remain to infect several individuals as they move through the cloud. Further, while the plexiglass barrier stands in the path of the infectious viral particles, the viral particles have been deposited onto the surface of the plexiglass barrier. The plexiglass barrier requires a thorough cleaning with cleaners and disinfectants to adequately kill the virus. Still further, there is nothing to prevent other individuals in line from the pathway of the viral particles or touching the plexiglass surface and then their own mouth, nose or eyes and contracting the infection.
Masks and shields are other means to slow the transmission of the infectious viral particles from person to person. Masks covering the mouth and nose area are an effective means to prevent transmission of the viral particles by mouth or nose, but the mask does not cover the eyes. Shields adequately cover the eyes, nose and mouth, but may not be practical for everyday use. Further, all individuals may not be wearing masks or shields and even if they are being worn, they may not be worn correctly or people may continue to touch their eyes, mouth or nose with hands and fingers that may be infected with the infectious viral particles while adjusting the mask or shield. There have been several reports that a community choir group sang for 2.5 hours in a hall roughly the size of a volley ball court. The participants avoided the usual personal contact (handshakes, hugs, etc.) and they brought their own music to avoid sharing. The participants also social distanced themselves during practice. A single asymptomatic carrier infected 45 of the 60 choir members and two dies. Some of the participants that were infected were approximately 50 feet from the infected person.
Many are practicing social distancing by maintaining a distance of six feet from one another and limiting the number of individuals in an enclosed room. But, as described above, a single infected person may fill a room or even infect a socially distanced person with infectious viral material with a single sneeze.
Others may be shutting down their ventilation systems to limit the flow of aerosols of infectious viral particles in an enclosed room and even opening windows to allow fresh outside air into an enclosed room to dilute the cloud of infectious viral material. However, as the weather changes and heating and air conditioning is required for the comfort of the individuals in the enclosed room, ventilation system will have to be reactivated and windows closed.
Many of the above actions are being put in place in an effort to open restaurants, business and schools. However, as stated above, there are many drawbacks to these efforts to protect individuals from coming into contact with SARS-CoV-2 virus. If one examines the individual protections being proposed for schools as an example, one will quickly determine that the protections have serious drawbacks. All students and faculty will be required to wear masks or face coverings of some type as well as maintain social distancing at the requisite distance. There are several issues with this proposal. First, wearing a mask may greatly interfere with communication between the teacher and students and between the students themselves. If the communication between teacher and students is impacted negatively, both teach and students will become frustrated to a point where learning will be impacted negatively. Even worse, a teacher may remove their mask to communicate better with the students. An unmasked infected teacher may become a super spreader of the disease. An infected teacher speaking loudly for several hours may fill a classroom with many clouds of infectious viral particles in little time. Students wearing masks will still be subject to the infectious viral material contained in the room. Infectious viral particles smaller than 5 microns will pass through any mask that is not N95 certified. Even if N95 masks are required by schools, the exterior surface of the mask or any type of face covering will be contaminated with infectious viral particles. Students may touch the exterior surface when removing the mask (at the end of the day, eating lunch, etc.) or adjusting the mask with their fingers and then touch their eyes, nose or mouth thereby subjecting themselves to potential infection. Further, the cost of replacing the mask every few days is expensive and still further, there may be a shortage of masks to provide to school children and others working in a public business. Prolonged mask usage may cause hypercapnia, a condition arising from too much carbon dioxide in the blood. Symptoms of hypercapnia include dizziness, drowsiness, fatigue, headaches, felling disorientated, flushing of the skin, shortness of breath, increased heart rate and increased blood pressure (N95 masks reduce oxygen intake by approximately 5% to 20%). If one were to wear a mask long enough, it may damage the lungs. For a patient in respiratory distress, wearing a mask for a prolonged period of time may be life threatening. Students wearing face shields may alleviate the breathing issues of wearing a mask, but many of the issues discussed above, will not be improved.
Students and teachers will practice social distancing. A typical desk in a classroom is approximately two feet from a neighboring desk. This allows for a classroom to house approximately 30-35 desks depending on the size of the classroom. Social distancing dictates that there must be at least six feet between individuals. With that requirement, the number of desks and, therefore, students will be reduced to approximately 8-9 in the classroom. The other 22-26 students will have to be relocated into at least three other classrooms thereby requiring more classrooms and teachers.
Another proposal to keep students and faculty safe from the transmission of the SARS-CoV-2 virus is to add transparent plastic or plexiglass barriers between teacher and students and between students. The plastic barriers may greatly interfere with communication between the teacher and students and between the students themselves. If the communication between teacher and students is impacted negatively, both teach and students will become frustrated to a point where learning will be impacted negatively. Further, it will be difficult to move around the classroom for the teacher and the students especially if they all had to exit the classroom quickly due to an emergency. The plastic barriers would be a costly solution and the space required to position the barriers between desks within the classroom would reduce the number of desks and students in the room. As discussed above the plastic barriers may become contaminated with infectious viral particles and would require daily cleaning to remove any particles. Students and teachers may still face the possibility of infection either by existing infectious clouds of viral particles that are in the room or the viral particles present on the plastic barriers.
Still another proposal is to transform a traditional classroom into a clean room much like that of a hospital operating room. A drop ceiling may be installed in each class room with the ceiling including a plurality of high-efficiency particulate absorbing (HEPA) filters to trap the SARS-CoV-2 virus particles. Clean air may be forced downward from the ceiling driving any infectious viral particles out of the ingestion zone of students' mouth, nose and eyes and downward to the floor. The air and infectious viral particles at the floor may be forced to the walls of the clean room and sent through the gap between the walls of the clean room and the classroom back to the drop ceiling and the HEPA filters to filter out the infectious viral particles and return clean air to the room. There are several drawbacks with this proposal. The size of the clean room would still limit the number of desks and therefore students in the room. Creating a clean room will be costly and HEPA filters must be changed on a regular basis which may also be quite expensive. Further, there is a risk that those changing the filters may become infected just by handling the filters and infectious viral particles. Lastly, a continual source of HEPA filters would have to be developed to accommodate all schools and business and it may take several years to outfit and construct clean rooms for all schools and businesses.
Therefore, a need exists for an inexpensive and practical ventilation system capable of driving particles and pathogens that are traveling in aerosols produced by an individual through breathing talking, yelling, singing, coughing and/or sneezing out of the air intake pathway of other individuals in the same enclosed area or building of the infected individual. A need also exists for eliminating and killing harmful viruses and pathogens from the air that passes though the ventilation and filter system of an enclosed room or building.
A ventilation system is provided, the ventilation system comprising at least one air flow generating device, the at least one air flow generating device having a calibrated speed to produce a downward air flow capable of forcing a cloud of infectious bacterial, viral or pathogen particles or droplets out of an ingestion zone of a mouth, a nose and eyes of an individual, at least one ultraviolet C light lamp positioned in a pathway of the air flow, the air flow containing the cloud of infectious bacterial, viral or pathogen particles or droplets, an ultraviolet C radiation field created by the at least one ultraviolet C light lamp, the air flow containing the cloud of infectious bacterial, viral or pathogen particles or droplets passing through the ultraviolet C radiation field, wherein the at least one air flow generating device is positioned to enable an upward air flow return to the at least one air flow generating device to force the air flow and the cloud of infectious bacterial, viral or pathogen particles or droplets out of an area and through the ultraviolet C radiation field to eradicate the infectious bacteria, virus and pathogens from the air flow, and wherein a fresh air flow free of infectious bacteria, viruses and pathogens is reintroduced back into the area by the downward air flow of the at least one air flow generating device.
The features and inventive aspects of the present invention will become more apparent from the following detailed description, claims, and drawings, of which the following is a brief description:
Referring now to the drawings, preferred illustrative embodiments of the present invention are shown in detail. Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated to better illustrate and explain the present invention. Further, the embodiments set forth herein are not intended to be exhaustive or otherwise to limit or restrict the invention to the precise forms and configurations shown in the drawings and disclosed in the following detailed description.
The wearing of masks, other face coverings and shields as well as the use of plexiglass barriers and social distancing all work to limit the transmission of infections and viruses such as influenza and SARS-CoV-2, however, these tools will not kill and eliminate the infectious particles and pathogens. The present invention provides a ventilation system 10 that will force a cloud 12 of infectious viral material and pathogens, such as a cloud of infectious influenza or water droplets of SARS-CoV-2 particles, out of the ingestion zone of the mouth, nose or eye area of an individual (see
According to an embodiment of the present invention, ventilation system 10 includes a plurality of air flow generating devices 20 positioned at or near ceiling 18 of an enclosed room or area of a facility or building as illustrated in
Although an individual may have been exposed to cloud 12 of infectious viral particles, they still not may be infected with influenza or COVID-19. Along with exposure, an individual must also be exposed to the cloud of infectious viral material for a period of time prior to infection becoming present in the individual. Infection is equal to exposure to the infectious viral particles plus a period of exposure time. The amount of exposure time may depend on a number of factors as to whether a person will become infected with influenza, COVID-19 or a myriad of other infections of viruses. Those factors may include the number of infectious viral particles present in the cloud, the distance from the source of the cloud of infectious viral particles, the susceptibility to the infection of the individual and the amount of time the individual spends intaking the infectious viral particles. The present invention will limit the amount of time a particular individual is in contact with the cloud of infectious viral particles. Even if an individual comes into contact with a cloud of infectious viral material, the vertical air flow provided by air flow generating devices 20 will quickly force cloud 12 out of the ingestion zone of the mouth, nose and eyes of the individual, thereby limiting the exposure time to cloud 12 of infectious viral particles.
The Environmental Protection Agency (EPA) recommends a rate of 0.35 air changes per hour (ACH) (about one-third of the air in a typical home being replaced every hour or three hours for a full air change) for health indoor air quality. The average home does have a much higher rate of natural air infiltration than this. A ceiling fan, such as air flow generating device 20, produces an air exchange rate of approximately one air exchange every twenty seconds for air moving at a velocity of 30 inches per second traveling a total distance of 50 feet in a room size of 30 feet by 30 feet by 10 feet. A ceiling fan produces approximately 540 air exchanges for every one air exchange created by a typical heating, ventilation and air conditioning (HVAC) system.
Ventilation system 10 will also include a plurality of ultraviolet C light lamps 22 as the means to disinfect the air by killing and eliminating the infectious viral particles from the air in the room. Ultraviolet C light is most generally referred to as germicidal ultraviolet light capable of killing bacteria, viruses, germs mold and fungus. Ultraviolet C light is a form of electromagnetic radiation with a wavelength from 100 nanometers to 280 nanometers and is invisible to most humans. Ultraviolet C light targets DNA and RNA, the genetic material that makes up all living organisms, controlling growth, development, function and reproduction, of microbes. The electromagnetic radiation produced by ultraviolet C light can destroy the ability of microorganisms to reproduce by causing photo-chemical reactions in nucleic acids. Ultraviolet C light triggers the formation of specific thymine and cytosine dimmers in DNA and uracil dimmers in RNA, which cause inactivation of microbes by causing mutations and/or cell death and failure to reproduce. Products using ultraviolet C light lamps tout pathogen kill rates higher than a 99.9% rate. Ultraviolet C light helps stop the spread of numerous pathogens including, influenza 1, 2, 3, 4, 5, 7 and 9, the cold, the superbug, SARS-CoV-2 and others such as ADENO virus type III, bacteriophage 1, 3, 4, 5, 6 and 9, coxsackie and infectious hepatitis 1, 5, 7 and 8. For a ceiling fan producing approximately 540 air exchanges for every one air exchange created by a typical HVAC system, any pathogens in the air in the room will pass through ultraviolet C light radiation about 540 times meaning there is an extremely high probability the pathogens are dead by the time they are removed by the HVAC system. Further, the chance of spreading live pathogens from one room to another may be eliminated.
Ultraviolet C lamps 22 may be positioned at or near ceiling 18 as depicted in
As stated above, a plurality of air flow generating devices 20 may be positioned on or at the ceiling such that a constant generally vertical air flow is directed downward to the floor.
Ceiling fans 20 will drive air flow and any infectious clouds 12 downward to floor 14 and out to walls 16. As the air flow reaches walls 16, the air flow will be outside of the general force of ceiling fans 20 driving the air flow downward. Air flow and any infectious clouds 12 at walls 16 will be drawn upward to ceiling 18 by the air flow pull from the backside of fans 20. As the air flow and any infectious clouds 12 reach ceiling 18, the air flow and clouds 12 will enter ultraviolet C field 24 produced by ultraviolet C light lamps 22. While the air flow and infectious clouds 12 are within field 24, the ultraviolet radiation will kill the bacteria, viruses and pathogens contained in infectious cloud 12 as fully described above. After passing through field 24, air flow will be free of any infectious clouds 12 and will be driven downward by fans 20 back toward floor 14 to repeat the process.
The arrangement of air flow generating devices 20 depicted in
As the air flow and any infectious clouds 12 reach ceiling 18 either at walls 16 or intake zones B, the air flow and clouds 12 will enter ultraviolet C field 24 produced by ultraviolet C light lamps 22. While the air flow and infectious clouds 12 are within field 24, the ultraviolet radiation will kill the bacteria, viruses and pathogens contained in infectious cloud 12 as fully described above. After passing through field 24, air flow will be free of any infectious clouds 12 and will be driven downward by ceiling fans 20 back toward floor 14 to repeat the process.
As described above, air flow exiting nozzles 30 to create air curtain 32 result in a downward air flow generated by fans 20 being directed to floor 14 through nozzles 30 and outward to walls 16. This arrangement of fans 20 and nozzles 30 to create air curtains 32 may work well in a manufacturing or office scenario where social distancing norms cannot be maintained while work is ongoing. For example, workers in meat processing plants are in close proximity to one another, certainly less than social distancing norms, for communication purposes. A barrier, such as plexiglass, positioned between workers would hinder communication and would lower productivity. Air curtain 32 positioned between workers would allow for communication and the speed of the downward air flow would force any infectious cloud 12 directly to floor 14 prior to entering into the ingestion zone of the mouth, nose or eyes of any workers proximate the worker that produced infectious cloud 12.
Fans 20 and nozzles 30 will drive air flow and any infectious clouds 12 downward to floor 14 and out to walls 16. As the air flow reaches walls 16, the air flow will be outside of the general force of fans 20 and nozzles 30 driving the air flow downward. Air flow and any infectious clouds 12 at walls 16 will be drawn upward to ceiling 18 by the air flow pull from the backside of fans 20. As the air flow and any infectious clouds 12 reach ceiling 18, the air flow and clouds 12 will enter ultraviolet C field 24 produced by ultraviolet C light lamps 22. While the air flow and infectious clouds 12 are within field 24, the ultraviolet radiation will kill the bacteria, viruses and pathogens contained in infectious cloud 12 as fully described above. After passing through field 24, air flow will be free of any infectious clouds 12 and will enter duct 28 be driven downward back toward floor 14 by fans 20 and nozzles 30 to repeat the process.
As the air flow reaches the opposite wall 16′, the air flow will be outside of the general force of ceiling fans 20 driving the air flow downward. Air flow and any infectious clouds 12 at opposite wall 16′ will be drawn upward to ceiling 18 by the air flow pull from the backside of ceiling fans 20. As the air flow and any infectious clouds 12 reach ceiling 18, the air flow and clouds 12 will enter ultraviolet C field 24 produced by ultraviolet C light lamps 22. While the air flow and infectious clouds 12 are within field 24, the ultraviolet radiation will kill the bacteria, viruses and pathogens contained in infectious cloud 12 as fully described above. After passing through field 24, air flow will be free of any infectious clouds 12 and will be driven downward by ceiling fans 20 back toward floor 14 and pulled into duct 38 by fan 20 at ceiling 18 to repeat the process.
As the air flow and any infectious clouds 12 enter duct 38 through intake grate 34, the air flow and clouds 12 will enter ultraviolet C field 24 produced by ultraviolet C light lamps 22. While the air flow and infectious clouds 12 are within field 24, the ultraviolet radiation will kill the bacteria, viruses and pathogens contained in infectious cloud 12 as fully described above. After passing through field 24, air flow will be free of any infectious clouds 12 and will be introduced back into the room at ceiling 18 through exhaust grate 36 to be driven downward by ceiling fans 20 back toward floor 14 and into duct 38 through intake grate 34 to repeat the process.
As the air flow reaches the opposite wall 16′, the air flow will be outside of the general force of nozzles 30 and air curtains 32 driving the air flow downward. Air flow and any infectious clouds 12 at opposite wall 16′ will be drawn upward to ceiling 18 by the air flow pull from the backside of fans 20. As the air flow and any infectious clouds 12 reach ceiling 18, the air flow and clouds 12 will enter ultraviolet C field 24 produced by ultraviolet C light lamps 22. While the air flow and infectious clouds 12 are within field 24, the ultraviolet radiation will kill the bacteria, viruses and pathogens contained in infectious cloud 12 as fully described above. After passing through field 24, air flow will be free of any infectious clouds 12 and will be driven downward by fans 20, nozzles 30 and air curtain 32 back toward floor 14 and into duct 38 through intake grate 34 to repeat the process.
As the air flow and any infectious clouds 12 enter duct 38 through intake grate 34, the air flow and clouds 12 will enter ultraviolet C field 24 produced by ultraviolet C light lamps 22. While the air flow and infectious clouds 12 are within field 24, the ultraviolet radiation will kill the bacteria, viruses and pathogens contained in infectious cloud 12 as fully described above. After passing through field 24, air flow will be free of any infectious clouds 12 and will be introduced back into the room at ceiling 18 through exhaust grate 36 and drawn into duct 28 at intake grate 34 to be driven downward by fans 20, nozzles 30 and air curtain 32 back toward floor 14 and into duct 38 through intake grate 34 to repeat the process.
It is also important to note that ventilation system 10 may use fans of varying sizes speeds and spacing while still accomplishing the main objective of driving cloud 12 of infectious bacterial or viral material out of the ingestion zone of the mouth, nose and eyes of unsuspecting individuals to avoid infection. Along with the use of ultraviolet C light lamps to kill and eradicate the bacterial microbes, viral microbes and any other pathogens, a disinfectant fog may be added to ventilation system 10 to further provide means to disinfect a large area and aid in the killing of any bacteria, viruses and any other pathogens. The disinfectant fog may be added to and disbursed by ventilation system 10 after working hours when the rooms, building and manufacturing plants are empty and free of workers to provide further means of disinfecting the workspaces. The wide distribution of air flow generating devices 20 of ventilation system 10 will help to ensure the disinfectant covers the entire workspace.
In yet another embodiment of the present invention illustrated in
Passengers will be much closer to ventilation system 10 and much closer to one another then in the environments described above in other embodiments. Typical social distancing norms may not be maintained. The passenger environment may resemble the environment depicted in
The present invention has been particularly shown and described with reference to the foregoing embodiments, which are merely illustrative of the best modes presently known for carrying out the invention. It should be understood by those skilled in the art that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention without departing from the spirit and scope of the invention as defined in the following claims. It is intended that the following claims define the scope of the invention and that the method within the scope of these claims and their equivalents be covered thereby. This description of the invention should be understood to include all novel and non-obvious combination of elements described herein, and claims may be presented in this or a later application to any novel non-obvious combination of these elements. Moreover, the foregoing embodiments are illustrative, and no single feature or element is essential to all possible combinations that may be claimed in this or a later application.
