TECHNICAL FIELD

[001] The present disclosure generally relates to the field of air filtration and circulation systems. More particularly, the present disclosure related to the air filtration and circulation system and method for being worn by a user for filtering and circulating air between a head and face of the user and an external environment to the user.

BACKGROUND

[002] Face masks are worn over a user’s breathing passages for two common purposes: to prevent contaminants from entering the user’s respiratory rack and to protect other users or things from being exposed to pathogens and other contaminants expelled by the wearer. In the first situation, the face mask is worn in an environment where the air contains substances harmful to the wearer. For example, the environment includes factories, construction area within the enclosed building, a smoke filled environment, traffic areas, etc. In the second situation, the face mask is worn in an environment where there is a high risk of infection or contamination to another person or thing, for example, in an operating room.

[003] Conventional face masks with air filtration systems are worn by the users and are deficient in that air purification and sealing from external environment and give sufficient air for the wearer. The air is not distributed completely about the head of the user. Conventional solutions do not provide a respirator mask for filtering breathed air to prevent the user from breathing unfiltered air, a wearable filtration system around the neck and there are no provisions for therapeutic usages and better user experience. [004] In the light of the aforementioned discussion, there exists a need for certain system and method for filtering air between a head and face of the user and the environment external to the user.

BRIEF SUMMARY

[005] The following presents a simplified summary of the disclosure in order to provide a basic understanding to the reader. This summary is not an extensive overview of the disclosure and it does not identify key/critical elements of the invention or delineate the scope of the invention. Its sole purpose is to present some concepts disclosed herein in a simplified form as a prelude to the more detailed description that is presented later.

[006] An objective of the present disclosure is directed towards using the air filtration and circulation system separately without masks for personal indoor use.

[007] Another objective of the present disclosure is directed towards providing aroma or medical or water or any water material chambers or reservoirs for treatment or user experiences purpose.

[008] According to an exemplary embodiment, an air filtration and circulation system comprises a plurality of masks configured to be worn on a user’s face and a plurality of air filtration and circulation devices configured to integrate with the plurality of masks, the plurality of air filtration and circulation devices configured to filter the air inflow from inside the plurality of masks and transmit the filtered air to the plurality of masks from the plurality air filtration and circulation devices. [009] Another exemplary embodiment, the air filtration and circulation system further comprises at least two vacuum sealed cups attached to the user’s ears and are configured to cancel the noise.

[010] Another exemplary embodiment, the air filtration and circulation system further comprises at least one airtight seal filled with a vacuum by using a plurality of components and the at least two airtight seals incorporated with one way valve or pressure release valve and the at least one airtight seal configured to remove exhaled air inside the plurality of masks.

[011] Another exemplary embodiment, the air filtration and circulation system further comprises plurality of air filtration and circulation chambers configured to flow the filtered air inside the plurality of masks by removing exhaled gases and the plurality of air filtration and circulation chambers comprise a plurality of materials.

[012] Another exemplary embodiment, the air filtration and circulation system further comprises at least one thermoelectric module incorporated in the plurality of air filtration and circulation chambers for temperature control inside the plurality of masks.

[013] Another exemplary embodiment, the air filtration and circulation system further comprises a plurality of sensors configured to measure the air quality inside the plurality of masks and the plurality of air filtration and circulation chambers are adjusted based on the measured air quality.

[014] Another exemplary embodiment, the air filtration and circulation system further comprises plurality of modular filters incorporated in the plurality of air filtration and circulation chambers for an air filtration and the plurality of modular filters comprise a plurality of sticky materials.

BRIEF DESCRIPTION OF DRAWINGS

[015] Other objects and advantages of the present invention will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments, in conjunction with the accompanying drawings, wherein like reference numerals have been used to designate like elements, and wherein:

[016] FIG. 1 is a diagram representing an environment in which aspects of the present disclosure may be implemented. Specifically, FIG. 1 depicts a schematic representation of an air filtration and circulation system with a modular mask covering only nose or nose and mouth or a complete face coverage according to an embodiment of the present disclosure.

[017] FIG. 2 is a diagram depicting one exemplary implementation of the air filtration and circulation system, in accordance with one or more embodiments.

[018] FIG. 3 is a diagram depicting another exemplary implementation of the air filtration and circulation system, in accordance with one or more embodiments.

[019] FIG. 4 is a diagram depicting an arrangement of lenses around the air filtration and circulation system, in accordance with one or more embodiments. [020] FIG. 5 is a diagram depicting another variant of arrangement of lens around the air filtration and circulation system, in accordance with one or more embodiments.

[021] FIG. 6 is a diagram depicting another exemplary implementation of the air filtration and circulation system, in accordance with one or more embodiments.

[022] FIG. 7 is a diagram depicting the placement of the air filtration and circulation chambers 602, in accordance with one or more embodiments.

[023] FIG. 8 is a diagram depicting the placement of inhale and exhale chambers on the user’s face 110, in accordance with one or more embodiments.

[024] FIG. 9 is a diagram depicting the depicting the air filtration and circulation chambers 602 as shown in the FIG. 6, in accordance with one or more embodiments.

[025] FIG. 10 is a diagram depicting a communication system, in accordance with one or more embodiments.

[026] FIG. 11 is a diagram depicting masks 102, 104, 106 and 108 with animation effects and graphics, in accordance with one or more embodiments.

[027] FIG. 12 is an example flow diagram depicting the method for air filtration and circulation, in accordance with one or more embodiments.

DETAILED DESCRIPTION [028] It is to be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The present disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[029] The use of “including”,“comprising” or“having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms“a” and“an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. Further, the use of terms“first”,“second”, and “third”, and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.

[030] Referring to FIG. lis a diagram 100 representing an environment in which aspects of the present disclosure may be implemented. Specifically, FIG. 1 depicts a schematic representation of an air filtration and circulation system with a modular mask covering only nose or nose and mouth or a complete face coverage according to an embodiment of the present disclosure. The air filtration and circulation system 100 may be used by a user wearing on or above a neck part. The air filtration and circulation system 100 may be used in traffic, mines, welding, underwater, different areas where the filtration and inhalation of air is required. The air filtration and circulation system 100 may be used to the users in sleep apnea while sleeping CPAP, APAP, BiPAP mechanism where the filters and forced air is required. The air filtration and circulation system 100 comprises a full face covering mask 102, an half face covering mask 104, a nose covering mask 106, and a nose and mouth covering mask 108. The full face covering mask 102 and the half face covering mask 104 may be spaced apart. The full face covering mask 102, the half face covering mask 104, the nose covering mask 106, the nose and mouth covering mask 108are curvilinear. This is a modular arrangement where based on the user requirement some parts of the masks 102, 104, 106 and 108 may be used. The users may include, but are not limited to, pedestrians, workers in mines, traffic police, and people working in polluted areas, patients, doctors, users driving the vehicle, not limited to a two wheeler, and the like.

[031] The full face covering mask 102 worn on a user’s face 110 so the full face covering mask 102 may cover the user’s nose, mouth, eyes, and ears. The half face covering mask 104 may cover the half portion of the user’s face 110. The nose covering mask 106 may cover the nose part and the nose and mouth covering mask 108may cover the nose and mouth. The air filtration and circulation system 100 may further comprise a vacuum sealed cup 112a and 112b (not shown). The vacuum sealed cup 112a and 112b (not shown) may be configured to cancel the noise. The vacuum sealed cup 112a and 112b (not shown) may cover the ear completely or just inserted inside the ear like ear buds. The vacuum sealed cups 112a and 112b may incorporate with audio speakers and mic 114a- 114b inbuilt or near ears. The audio speakers and mic 114a-l 14b may be configured to transfer audio and speech to and from the user.

[032] Referring to FIG. 2 is a diagram 200 depicting one exemplary implementation of the air filtration and circulation system, in accordance with one or more embodiments. The air filtration and circulation system 200 comprises an air filtration and circulation device 202, and an airtight seal 204. The air filtration and circulation device 202 maybe configured to remove exhaled air. The air filtration and circulation device 202 may be incorporated with one way valve or pressure release valve. The air filtration and circulation device 202 may include but is not limited to, an air pump, fan, blower, non-movable blower, movable blower, piezo fan, and the like. The air filtration and circulation system 200 may further depict a cross- sectional view 206 and a top- view of the airtight seal 208.

[033] The airtight seal 204 may be placed around the nose part, nose and mouth part, and complete face part. The airtight seal 204 may be filled with a vacuum by using the air filtration and circulation device 202 (an active mechanism) or by creating vacuum by applying mechanical pressure (a passive mechanism) in places where vacuum may not be used forced air would be sent through the same structure to the airtight seal 204 between the user and the external environment. The cross sectional view 206 of the airtight seal may depict a rectangular shape. Here, the airtight seal may include different shapes without limiting the scope of the present disclosure. The top-view of the airtight seal 208 may depict holes for sucking air or sending pressurized air by the air filtration and circulation device 202. The better airtight seal 204 may be achieved by using a flexible gasket type structure made of silicone or other material shape or structure without limiting scope of the present disclosure. External polluted air may not be entered the internals of masks 102, 104, 106 and 108 because of the airtight seal 204.

[034] Referring to FIG. 3 is a diagram 300 depicting another exemplary implementation of the air filtration and circulation system, in accordance with one or more embodiments. The air filtration and circulation system 300 may include a shield structure 302, projectors 304 and 306, a light 308, cut outs 310 and 312, prism structures 314 and 316. The shield structure 302 may be configured to protect the user’s face 110 from sunlight. The projectors 304 and 306 may be configured to display videos and/or images on the visor. The light 308 may enable the user to view in dark. The cut-outs 310 and 312 may be configured to circulate the air at the eyes part. The prism structures 314 and 316 may be used separately for right side, left side, and rear views. The diagram 300 may further depict a cross-sectional view of bent edges at eye level 318.

[035] Referring to FIG. 4 is a schematic representation 400, of arrangement of lenses around the air filtration and circulation system, in accordance with one or more embodiments. The air filtration and circulation system’s 360 degree view including that of blind spots may be achieved by incorporating fish eye type lenses on 4and/or multiple sides, and transferring the light to the projector and the display through passive light transport mechanism. Also, the displaymay be a passive due to the prism structures314 and 316 mounted near the eye of the user. Two side lenses 402, rear lens 404, and front lens 408 are the four lenses, not limiting to the scope of the disclosure. A light transmitting material 406 interconnects the lenses with a couple of prism structures 314 and 316.The image and/or video which has been recorded is transferred by a passive mechanism using light transmitting material 406 which are tubular and may not be limiting to a fiber optic cable with incorporated lens and mirror structures. An alternative may be the use of projectors 304 and 306 in combination with the cameras.

[036] Referring to FIG. 5 is a schematic representation 500, of another variant of arrangement of lens around the air filtration and circulation system; in accordance with one or more embodiments. In the above mentioned arrangement power may not be needed. Capturing and displaying of images may involve the use of passive components like light transferring using: the lens 502, a tubular light transmitting material 504, and a prism structure 506 (here, the prism structures may also include 314 and 316). The prism structures 506 may be used separately for right side, left side, and rear views. The lights from tubular light transmitting material 504 may be combined at one junction and captured by using the camera and/or cameras for the 360 degree capturing of the image in a single location which can be stored locally and remotely. The light may be projected on to the visor and/or displays an image to reflect on to visor so that the images/videos would be on visor in field of view of user. The viewer’s sight on road or outside may not be affected due to the transparent nature of the visor.

[037] Referring to FIG. 6 is diagram 600 depicting another exemplary implementation of the air filtration and circulation system, in accordance with one or more embodiments. The diagram 600 may include air filtration and circulation chambers 602, and air filtration and circulation devices 202, 604, and 606.The air comes into the mask 102, 104, 106, and 108 using the air filtration and circulation chambers202, 604, 606and the air filtration and circulation chambers 602 which filters the air using the component and sends the air into the mask 102, 104, 106, and 108.The air filtration and circulation devices 202, 604 and 606and the air filtration chambers 602 may be configured to remove the air from the mask 102, 104, 106, and 108 and exhaled air and hot or cold air inside the mask 102, 104, 106, and 108 may be removed which makes user to inhale fresh air every time and makes the user to wear mask 102, 104, 106, and 108 for more time comfortably. The air filtration and circulation system600 may enhance the respiratory experience and also balance humidity, moisture levels inside sealed mask 102, 104, 106, and 108. [038] The air filtration and circulation chambers 602 may be arranged to flow the filtered air for enhancing the user experience to use the mask 102, 104, 106, and 108 for more time and refresh the user regularly by removing exhaled gases. The air filtration and circulation chambers 602 may include, but are not limited to, aroma chamber or reservoir containing materials, exhaust system and diffusion rate controlling structure. The materials may be referred as volatile materials (e.g., scent, aromatic material, medicinal material, vaporized water etc.). The materials may be evaporated and send to the mask 102, 104, 106, and 108 for inhalation. Modular filters may be incorporated in the air filtration and circulation chambers 602 for an air filtration and the modular filters comprise sticky materials.

[039] The air filtration and circulation chambers 602 may be controlled by the user or a device or a software application in process of communication or entertainment purposes. The air filtration and circulation chambers 602 may also be used for medicines for specific treatment purposes. The masks 102, 104, 106, and 108 may include ventilation chambers. The air filtration and circulation system 600 may include a pressure sensor, air quality sensors and bio medical sensors configured to measure and control the air pressure and tracking wearer breath quality inside the mask 102, 104, 106, and 108.

[040] The air filtration and circulation chambers 602 may include an air intake mechanism with active mechanism components (e.g., an air pump, fan, blower, piezo fans, non-movable or movable blower, etc.). The air filtration and circulation chambers 602 may include the active air intake and exhaust mechanism inbuilt. The air filtration and circulation chambers 602 may incorporate pressure release valve or one way valve for controlling pressure in the mask 102, 104, 106, and 108. The air filtration and circulation chambers 602 may include pre-filters, carbon fiber filters, humidifiers, negative ion generators, hydroxyl radicals, ultraviolet light, high efficiency particulate air filter, and the like. The pre-filter may include a sticky material coated mesh configured to trap most of the dust particles (e.g., PM 2.5, PM 10 dust particles) and acts as a dis -infective material which may kill bacteria and viruses when oils or sticky material coated. The oils may include, but are not limited to, clove oil, bee wax, sesame oil, coconut oil, aloe Vera gel, and the like. The carbon fiber filters may include, but are not limited to, pre-activated carbon fiber filters, activated carbon fiber filters, and the like. The carbon fiber filters in the form of a composite used for filtering a variety of contaminants, including organic materials and pathogens, from the air. The humidifiers may be configured to humidify and dehumidify the air inside the mask 102, 104, 106, and 108. The negative ion generators may remove or precipitate dust particles. The hydroxyl radicals may purify the air using materials (e.g., H202, baking soda, vinegar, etc.). The ultraviolet light may remove fungus, pollen. The high efficiency particulate air filter may be configured to remove particles (e.g., PM2.5 and PM3 particles, bacteria, viruses, etc.). The material (e.g., H202) may generate oxygen 02 and nitrogen N2 in case of emergency. The air filtration and circulation chambers 602 may include a silica gel type material configured for absorbing moisture and fight against mold. The air filtration and circulation chamber 602 may include an audio and mic system which may operate based on conducting method to transfer audio and speech to and from the user (e.g., wearer).

[041] Referring to FIG. 7 is a diagram 700 depicting the placement of the air filtration and circulation chambers 602, in accordance with one or more embodiments. The air filtration and circulation chamber 602 may be a modular device which can be placed at different positions. The different positions may include around the neck 702, and around the head 704. Sensors (not shown) may be incorporated inside the mask 102, 104, 106, and 108 for measuring the air quality and based on the amount of gases (e.g., C02/C0/S02/N02 like other environmental gas or Volatile organic compounds/dust/other materials) based on which the working of the air filtration and circulation chambers 602 may be adjusted. The air filtration and circulation chambers 602 may also incorporate pressure controlled valves for controlling pressure inside the mask 102, 104, 106, and 108.

[042] Referring to FIG. 8 is a diagram 800 depicting the placement of inhale and exhale chambers on the user’s face 110, in accordance with one or more embodiments. The diagram 800 may depict an inhale chamber 802, an exhale chamber 804, and a combined inhale and exhale chamber806. The inhale chamber 802, the exhale chamber 804, and the combined inhale and exhale chamber 806may be configured to adjust the inflow and outflow of air. The air filtration and circulation system may include a provision for measuring the exhaled gas contents. The user health conditions may be analyzed and appropriate suggestions may be suggested based on the measured exhaled gas contents. The masks 102, 104, 106, and 108 may be used for breath training of the users by continuously monitoring and adjusting the pressures in the mask to breathe less times per minute which increases user’s absorption (02) capability and in turn increases the lifespan of the user as the number of breaths per minute reduces.

[043] Referring to FIG. 9 is a diagram 900 depicting the depicting the air filtration and circulation chambers 602 as shown in the FIG. 6, in accordance with one or more embodiments. The air filtration and circulation chambers 602may include back lights 902, cut-outs and exhaust vents904a- 904b, a region 906, and power supply connections and a battery908. The back lights 902 may be configured to provide indications (e.g., emergency indications) to the users. The cut-outs and exhaust vents 904a-904b being substantially hollow. The cut-outs and exhaust vents904a-904b may have an extraneous wall extending between a coupled end and free end of the cut outs and exhaust vents 904a-904b. The coupled and free ends of each air intake 904a or 904b being open to allow the air. The region 906may facilitate to place the air filtration and circulation chambers 602, and sensors 910. The battery 912which may work standalone and also provision for taking power from outside in case of extra requirement. The power supply connections 908 may be configured to allow external power supply and provide power supply to and from the external devices (e.g., battery, computing devices).

[044] The air filtration and circulation chambers 602may further include a thermoelectric module 914for heating and cooling mechanism. The thermoelectric module 914may make the mask 102, 104, 106, and 108 as a personal air-conditioned mask. The thermoelectric module 914 may be configured to heat or cool the air before sending the air for inhalation which may be useful in most cold or hot places (locations). The mask 102 or 104 or 106 or 108 may have integrated sensors 910 for measuring temperature, humidity, pollution, exhaled air quality (like C02, CO, S02, N02, Ozone, etc.), pressure both outside and inside mask 102 or 104 or 106 or 108 which may be useful in controlling and adjusting the chambers 802 and 804, the air filtration and circulation chambers 602. The mask 102 or 104 or 106 or 108 may have a wireless speaker, and a microphone. The microphone may be used for audio, calling and user interface works. The mask 102 or 104 or 106 or 108 may have an accelerometer, and a gyrometer. The accelerometer and the gyrometer may be configured to measure the user movements. The air filtration and circulation chambers 602may include the sensor 910(e.g., the brain detection sensor) for identifying the user mental condition. The cut- outs and exhaust vents 904a-904b may be configured for external purified air inlet and power supply.

[045] Referring to FIG. 10 is a diagram 1000 depicting the communication system, in accordance with one or more embodiments. The communication system 1000 may include a personal detachable communication module 1002a- 1002b, a computing device 1004a- 1004b and a wrist watch 1006a- 1006b. The personal detachable communication module 1002a- 1002b may be attached to the vacuum sealed cup 112a and 112b, the air filtration and circulation chambers 602, the mask 102 or 104 or 106 or 108. The personal detachable communication module 1002a- 1002b may be connected to the computing device 1004a- 1004b and the wrist watch 1006a- 1006b through a network 1008. The network 1008 may include, but is not limited to, an Ethernet, a wireless local area network (WLAN), or a wide area network (WAN), a Bluetooth low energy network, a ZigBee network, a NFC/RFID network, a WIFI communication network e.g., the wireless high speed internet, or a combination of networks, a cellular service such as a 4G (e.g., LTE, mobile WiMAX) or 5G cellular data service. The network 1008 may provide a web interface employing transmission control protocol, hypertext transfer protocol, simple object access protocol or any other internet communication protocol. The personal detachable communication module 1002a- 1002b may include a microphone, a speaker for audio recording or outputting. The personal detachable communication module 1002a- 1002b may include a provision for using bone conducting microphone and speaker by using which the user can talk and listen to audio using bone conduction technology so that the user no need to insert speaker in ears and can listen external sounds through ears also. [046] The personal detachable communication module 1002a- 1002b may act as personal communication device for the user which can be attached and detached from the vacuum sealed cup 112a and 112b, the air filtration and circulation chambers 602, the mask 102 or 104 or 106 or 108 separately. The personal detachable communication module 1002a may be connected to other personal detachable communication module 1002b through the network 1008 so that the two or more users can talk to each other without requiring the computing device 1004a-1004bor the wristwatch 1006a- 1006b. Connection may be established when the personal detachable communication modules 1002a- 1002b comes together using the network 1008or by pairing both the detachable communication modules 1002a- 1002b through the computing device 1004a- 1004b or the wrist watch 1006a- 1006b or the network 1008, once this is done the users (e.g., wearers) may talk to each other or with multiple users who are connected to same network 1008 withor without the computing device 1004a- 1004b and the wrist watch 1006a-1006b. The computing device 1004a-1004b may include a device such as a mobile phone, a personal computer, a workstation, a personal digital assistant, a computing tablet, and the like. The computing device 1004a may be configured to establish communications with other computing device 1004b through the network 1008. The detachable communication modules 1002a- 1002b may work stand-alone without use of any other devices like the computing device 1004a- 1004b or the wrist watch 1006a- 1006b for communication (like just intercom). The communications may include, but are not limited to, text messages, voice calls, video calls, and the like. Notifications may be generated with vibration or audio based at the detachable communication module 1002a- 1002b, an LED light or OLED text display of incoming calls, texts, and calendar events. The detachable communication module 1002a- 1002b may be directly connected to the computing device 1004a- 1004b or wrist watch 1006a- 1006b allowing the detachable communication module 1002a- 1002bas "remote control" for home appliances or any other devices via voice and buttons and playing, changing, volume control of music. The detachable communication module 1002a- 1002b may include motion sensors such as accelerometer, magnetometer and gyroscope, together with audio generation device can be used for different user interface applications.

[047] Referring to FIG. 11 is a diagram 1100 depicting masks 102, 104, 106 and 108 with animation effects and graphics, in accordance with one or more embodiments. The masks 102, 104, 106 and 108 may include different lighting mechanisms 1102, 1104, 1106 and 1108 in and around it for emergency indications. The different lighting mechanisms 1102, 1104, 1106 and 1108 may include array of lights (e.g., LED lights) for identifying the user in darkness and making light animation effects and graphics on the masks 102, 104, and 108. The array of lights (e.g., LED lights) may extend through selected portions of the masks 102, 104, 106 and 108, it is also contemplated that the array of lights may be mounted behind the masks 102, 104, 106 and 108 in a manner which enables lighting animation of the imprinted graphics on the masks 102, 104, 106 and 108. The different lighting mechanisms 1102, 1104, 1106 and 1108 may also be configured for displaying animated images on the masks 102, 104, 106, and 108.

[048]" Referring to FIG. 12 is an example flow diagram 1200, depicting the method for air filtration and circulation, inaccordance with one or more embodiments. As an option, the method 1200 may be carried out in the context of the details of FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG. 5, FIG. 6, FIG. 7, FIG. 8, FIG. 9, FIG. 10, and FIG. 11. However, the method 1200 may also be carried out in any desired environment. Further, the aforementioned definitions may equally apply to the description below. [049] The method commences at step 1202 by drawing the air into the cut-outs coupled to the masks. Thereafter, at step 1204, activating the air filtration and circulation devices to filter the air inflow and transmitting the filtered air to the masks. Thereafter, at step 1206, flowing the filtered air into the air filtration and circulation chambers which enhances the user experience to use mask for more time and refresh the user regularly by removing exhaled gases. Thereafter, at step 1208, measuring air quality, air flow rate, inhale and exhaled air contents and pressure inside the masks by the sensors and controlling the air filtration and circulation chambers based on the measured air quality and pressure. Thereafter, at step 1210, analysing the user health conditions based on the measured air quality and pressure.

[050] Although the present disclosure has been described in terms of certain preferred embodiments and illustrations thereof, other embodiments and modifications to preferred embodiments may be possible that are within the principles and spirit of the invention. The above descriptions and figures are therefore to be regarded as illustrative and not restrictive.

[051] Thus, the scope of the present disclosure is defined by the appended claims and includes both combinations and sub combinations of the various features described herein above as well as variations and modifications thereof, which would occur to persons skilled in the art upon reading the foregoing description.