Claims:WE CLAIM
1. A compressed air management system (100) comprising:
• a plurality of compressors (102-1 to 102-n) configured to supply compressed air to a plant (10);
• a plurality of stations (112-1 to 112-s) located in said plant (10), each of said stations in need of compressed air for carrying out an operation;
• pipelines (104, 110-1 to 110-s) carrying compressed air from said compressors (102-1 to 102-n) to said stations (112-1 to 112-s);
• a plurality of valves (108-1 to 108-s) for controlling the flow of compressed air from said compressors (102-1 to 102-n) to said stations (112-1 to 112-s) via said pipelines (110-1 to 110-s); and
• a controller (120) configured to control the operation of said valves (108-1 to 108-s) for selectively supplying compressed air to said stations (112-1 to 112-s), and further configured to selectively control the operation of said compressors (102-1 to 102-n) based on compressed air demand in said plant (10).
2. The system as claimed in claim 1, which includes a controller interface (106) configured to connect said compressors (102-1 to 102-n) with said stations (112-1 to 112-s).
3. The system as claimed in claim 2, wherein said valves (108-1 to 108-s) are located on the pipelines (110-1 to 110-s) between said controller interface (106) and said stations (112-1 to 112-s).
4. The system as claimed in claim 1, wherein each of said compressors (102-1 to 102-n) is configured to compress air at a pre-determined volumetric flow rate capacity and a pre-determined pressure.
5. The system as claimed in claim 1, wherein each of said compressors (102-1 to 102-n) is configured to generate an operational signal indicative of its operating state at pre-defined intervals of time.
6. The system as claimed in claim 2, which includes a main flow meter (114) installed on the pipeline (104) between said compressors (102-1 to 102-n) and said controller interface (106), said main flow meter (114) being configured to determine total compressed air demand of said plant (10).
7. The system as claimed in claim 2, which includes a pressure transducer (116) installed on the pipeline (104) between said compressors (102-1 to 102-n) and said controller interface (106), said pressure transducer (116) being configured to determine the overall pressure demand of compressed air for said plant (10).
8. The system as claimed in claim 2, which includes a branch flow meter (118) installed on each of the pipelines (110-1 to 110-s) between said controller interface (106) and said stations (112-1 to 112-s), said branch flow meter (118) configured to determine the actual consumption of compressed air in said associated station (112).
9. The system as claimed in claim 4, wherein said controller (120) includes:
• a repository (202) configured to store:
i. a first lookup table having a list of said stations (112-1 to 112-s), valve details (108-1 to 108-s) associated with each of said stations (112-1 to 112-s), and a plurality of pre-defined ON times and OFF times for each of said control valves (108-1 to 108-s);
ii. a second lookup table having a list of compressors (102-1 to 102-n), pre-determined volumetric flow rates and pressures of said compressors (102-1 to 102-n), a plurality of groups having pre-defined ON-OFF states of each of said compressors (102-1 to 102-n), and resultant air flow rate and pressure for each of said groups;
iii. a third lookup table having a list of stations (112-1 to 112-s), shifts of operation of each of said stations (112-1 to 112-s), and ideal consumption of compressed air per unit of production for each of said stations (112-1 to 112-s) during each of said shifts; and
iv. a pre-set no load OFF time value.
10. The system as claimed in claims 5, 6, 7 and 9, wherein said controller (120) includes:
• a compressor control module (204) configured to cooperate with said compressors (102-1 to 102-n), said main flow meter (114), and said pressure transducer (116) to receive said operational signals, said total compressed air demand, and said overall pressure demand of compressed air respectively, and further configured to cooperate with said repository (202) to extract the group required for meeting said total compressed air demand and said overall pressure demand; and
• a first interfacing unit (206) configured to cooperate with said compressor control module (204) to generate a switching signal to selectively switch ON/ switch OFF at least one of said compressors (102-1 to 102-n) based on pre-defined ON-OFF states in said extracted group.
11. The system as claimed in claim 9, wherein said controller (120) includes a flow meter module (208), said flow meter module (208) comprising:
• a first input module (208a) configured to facilitate operators of said stations (112-1 to 112-s) to enter the number of units of equipment produced in said stations (112-1 to 112-s) during a shift;
• a computation module (208b) configured to cooperate with said branch flow meters (118-1 to 118-s) to receive said actual consumption of compressed air for said stations (112-1 to 112-s) at the end of said shift, and further configured to crawl through said third lookup table of said repository (202) to extract ideal air consumption of said stations (112-1 to 112-s) per unit of production for said shift; said computation module (208b) configured to cooperate with said first input module (208a) to compute the ideal consumption of compressed air in said stations (112-1 to 112-s) for said number of units; and
• a mapping module (208c) configured to cooperate with said computation module (208b) to generate said comparison chart of ideal consumption of compressed air against actual consumption of compressed air for each of said stations (112-1 to 112-s).

12. The system as claimed in claim 9, wherein said controller (120) includes:
• a timing control module (210) comprising:
i. a second input module (210a) configured to cooperate with said repository (202) to facilitate the operators to define said ON times and said OFF times for each of said control valves (108); and
ii. a timing signal generating module (210b) configured to cooperate with said second input module (210a) to generate an ON control signal at said pre-defined ON times and an OFF control signal at said pre-defined OFF times; and
• a second interfacing unit (212) configured to cooperate with said timing control module (210) to receive said ON/ OFF control signals, and further configured to generate corresponding electrical signals to facilitate selective control of said valves (108-1 to 108-s).

13. The system as claimed in claims 10 and 12, wherein said compressor control module (204) and said timing control module (210) are implemented using programmable logic controllers.
14. The system as claimed in claims 10 and 12, wherein said first and second interfacing units (206, 212) are implemented using relay units.
15. The system as claimed in claim 12, wherein said ON times and OFF times of said valve (108) associated with a station (112-1 to 112-s) are defined based on operator’s meal timings and the time between two shifts when said station (112) is not working.
16. The system as claimed in claim 10, wherein said compressor control module (204) is further configured to cooperate with said repository (202) to generate said turn OFF switching signal to switch OFF a compressor (102-1 to 102-n) when said compressor (102-1 to 102-n) is working under no load condition for a period greater than said pre-set no load OFF time value.
17. The system as claimed in claim 11, wherein said controller (120) includes a display unit configured to cooperate with said mapping module (208c) to receive and display said comparison chart.
, Description:FIELD
The present disclosure relates to field of pneumatic control systems. More particularly, the present disclosure relates to a compressed air management system.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.

Pneumatic systems are extensively used in various industries in departments such as, ventilation, transmission, tractor, paint station, engine assembly, engine testing, crankcase machine station and cylinder head machine station for applications like air tools, pneumatic cylinder press, spray painting, cleaning machines, horizontal machining centre, manipulators, tillites, leak test machines, and the like. Most pneumatic systems rely on a constant supply of compressed air for their operation. This is provided by air compressors which are typically installed in the utility section.
Conventionally, the compressed air is supplied from the utility section to all the stations in a plant through a single line. Each of the stations have different shift timings and require different volumes of air at different instances of time. However, conventional compressed air systems provide no means for controlling the compressors based on the air requirement. Therefore, the compressors keep running even on no load, that is when no parts are being manufactured.
Also, some equipments in plant are very sensitive to the variations in the air pressure. Any variation in pressure and volume can lead to over or under torque and jam their movement. Therefore, there is need to be cautious when lowering the average system header pressure because large or sudden changes in demand can cause the pressure to drop below minimum requirements, which can lead to improper functioning of equipment. To avoid this, the utility team generally ensures continuous running of compressors. However, this calls for higher consumption of energy. The compressed air is fed to the stations even when they are not running, as there is no means of control. Further, efficient load sharing is not possible between the compressors in view of the above problems. Therefore, in many facilities, compressed air systems are the least energy efficient. Further, there is no means of knowing the actual air consumption and the ideal air consumption of the system, leaving no means for the operators to detect wastage of compressed air.
There is, therefore, felt a need for developing a compressed air management system to avoid the above-mentioned drawbacks.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
It is an object of the present disclosure to provide a compressed air management system.
Another object of the present disclosure is to provide a system that automatically manages the supply of compressed air, thereby reducing human dependency.
Still another object of the present disclosure is to provide a compressed air management system that helps in determining daily air loss.
Yet another object of the present disclosure is to provide a compressed air management system that controls the supply of compressed air as per the demand.
Still another object of the present disclosure is to provide a compressed air management system that switches OFF the compressor which is under no load for a pre-set period of time, thereby avoiding wastage of compressed air.
Yet another object of the present disclosure is to provide a compressed air management system that is energy saving.
Still another object of the present disclosure is to provide a compressed air management system that makes identification of air leakages easier.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages a compressed air management system. The system comprises a plurality of compressors, a plurality of stations, pipelines, valves, and a controller. The compressors are configured to supply compressed air to a plant. Each of the stations is located in the plant and is in need of compressed air for carrying out an operation. The pipelines carry the compressed air from the compressors to the stations. The valves control the flow of compressed air from the compressors to the stations via the pipelines. The controller is configured to control the operation of the valves for selectively supplying compressed air to the stations, and is further configured to selectively control the operation of the compressors based on compressed air demand in the plant.
In an embodiment, the system includes a controller interface configured to connect the compressors with the stations. In an embodiment, the valves are located on the pipelines between the controller interface and the stations.
In an embodiment, each of the compressors is configured to compress air at a pre-determined volumetric flow rate capacity and a pre-determined pressure. In another embodiment, each of the compressors is configured to generate an operational signal indicative of its operating state at pre-defined intervals of time.
In an embodiment, a main flow meter and a pressure transducer are installed on the pipeline between the compressors and the controller interface. The main flow meter is configured to determine total compressed air demand of the plant. The pressure transducer is configured to determine the overall pressure demand of compressed air for the plant.
The repository is configured to store:
• a first lookup table having a list of the stations, valve details associated with each of the stations, and a plurality of pre-defined ON times and OFF times for each of the valves;
• a second lookup table having a list of compressors, pre-determined volumetric flow rates and pressures of the compressors, a plurality of groups having pre-defined ON-OFF states of each of the compressors, and resultant air flow rate and pressure for each of the groups;
• a third lookup table having a list of stations, shifts of operation of each of the stations, and ideal consumption of compressed air per unit of production for each of the stations during each of the shifts; and
• a pre-set no load OFF time value.
In an embodiment, the controller includes a compressor control module and a first interfacing unit. The compressor control module is configured to cooperate with the compressors, the main flow meter, and the pressure transducer to receive the operational signals, the total compressed air demand, and the overall pressure demand of compressed air respectively, and is further configured to cooperate with the repository to extract the group required for meeting the total compressed air demand and the overall pressure demand. The first interfacing unit is configured to cooperate with the compressor control module to generate a switching signal to switch ON/ switch OFF at least one of the compressors based on pre-defined ON-OFF states in the extracted group.
The controller further includes a flow meter module. In an embodiment, the flow meter module comprises a first input module, a computation module, and a mapping module. The first input module is configured to facilitate operators of the stations to enter the number of units of equipment produced in the stations during a shift. The computation module is configured to cooperate with the branch flow meters to receive the actual consumption of compressed air for the stations at the end of the shift, and is further configured to crawl through the third lookup table of the repository to extract ideal air consumption of the stations per unit of production for the shift. The computation module is configured to cooperate with the first input module to compute the ideal consumption of compressed air in the stations for the number of units. The mapping module is configured to cooperate with the computation module to generate the comparison chart of ideal consumption of compressed air against actual consumption of compressed air for each of the stations. In an embodiment, the controller includes a display unit configured to cooperate with the mapping module to receive and display the comparison chart.
In an embodiment, the controller includes a timing control module and a second interfacing unit. The timing control module comprises a second input module and a timing signal generating module. The second input module is configured to cooperate with the repository to facilitate the operators to define the ON times and the OFF times for each of the valves. The timing signal generating module is configured to cooperate with the second input module to generate an ON control signal at the pre-defined ON times and an OFF control signal at the pre-defined OFF times. The second interfacing unit is configured to cooperate with the timing control module to receive the ON/ OFF control signals, and is further configured to generate corresponding electrical signals to facilitate actuation of the valves. The ON times and OFF times of the valve associated with a station are defined based on operator’s meal timings and the time between two shifts when the station is not working.

In an embodiment, the compressor control module and the timing control module are implemented using programmable logic controllers.
In an embodiment, the first and second interfacing units are implemented using relay units.
Advantageously, the compressor control module is further configured to cooperate with the repository to generate the turn OFF switching signal to switch OFF a compressor when the compressor is working under no load condition for a period greater than the pre-set no load OFF time value.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A compressed air management system of the present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates a block diagram of a compressed air management system, in accordance with an embodiment of the present disclosure; and
Figure 2 illustrates a block diagram of a central control system of the system of Figure 1.
LIST OF REFERENCE NUMERALS
100 – System
102-1-n – Compressors
104, 110-1-s – Pipelines
106 – Controller interface
108-1-s – Valves
112-1-s – Stations
114 – Main flow meter
116 – Pressure transducer
118-1-s – Branch flow meter
120 – Controller
202 – Repository
204 – Compressor control module
206 – First interfacing unit
208 – Flow meter module
208a – First input module
208b – Computation module
208c – Mapping module
210 – Timing control module
210a – Second input module
210b – Timing signal generating module
212 – Second interfacing unit
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details, are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, elements, components, and/or groups thereof.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element or component from another element or component. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
A compressed air management system (hereinafter referred as “system 100”), of the present disclosure, is now being described with reference to Figure 1 through Figure 2.
Referring to Figure 1, the system 100 comprises a plurality of compressors 102-1 to 102-n, a plurality of stations 112-1 to 112-s, pipelines 104, 110-1 to 110-s, valves 108-1 to 108-s, and a controller 120. The compressors 102-1 to 102-s are configured to supply compressed air to a plant 10. In an embodiment, each of the compressors 102-1 to 102-n is configured to compress air at a pre-determined volumetric flow rate capacity and a pre-determined pressure. In an embodiment, each of the compressors 102-1 to 102-n is configured to generate an operational signal indicative of its operating state at pre-defined intervals of time. The stations are 112-1 to 112-s located in the plant 10. Each of the stations is in need of compressed air for carrying out an operation. The pipelines 104, 110-1 to 110-s carry the compressed air from the compressors 102-1 to 102-n to the stations 112-1 to 112-s. The valves 108-1 to 108-s control the flow of compressed air from the compressors 102-1 to 102-n to the stations 112-1 to 112-s via the pipelines 110-1 to 110-s. In an embodiment, the valves 108-1 to 108-s are solenoid flow control valves. The controller 120 is configured to control the operation of the valves 108-1 to 108-s for selectively supplying compressed air to the stations 112-1 to 112-s, and is further configured to selectively control the operation of the compressors 102-1 to 102-n based on compressed air demand in the plant.
In an embodiment, the system 100 includes a controller interface 106 configured to connect the compressors 102-1 to 102-n with the stations 112-1 to 112-s. The valves 108-1 to 108-s are located on the pipelines 110-1 to 110-s between the controller interface 106 and the stations 112-1 to 112-s.

In an embodiment, the system 100 includes a main flow meter 114 and a pressure transducer 116 installed on the pipeline 104 between the compressors 102-1 to 102-n and the controller interface 106. The main flow meter 114 is configured to determine total compressed air demand of the plant 10. The pressure transducer 116 is configured to determine the overall pressure demand of compressed air for the plant 10.
In an embodiment, the system 100 includes a branch flow meter 118 installed on each of the pipelines 110-1 to 110-s between the controller interface 106 and the stations 112-1 to 112-s. The branch flow meter 118 is configured to determine the actual consumption of compressed air in the associated station.
Referring to Figure 2, the controller 120 comprises a repository 202. The repository 202 is configured to store:
• a first lookup table having a list of the stations 112-1 to 112-s, valve details 108-1 to 108-s associated with each of the stations 112-1 to 112-s, and a plurality of pre-defined ON times and OFF times for each of the valves 108-1 to 108-s;
• a second lookup table having a list of compressors 102-1 to 102-n, pre-determined volumetric flow rates and pressures of the compressors 102-1 to 102-n, a plurality of groups having pre-defined ON-OFF states of each of the compressors 102-1 to 102-n, and resultant air flow rate and pressure for each of the groups;
• a third lookup table having a list of stations 112-1 to 112-s, shifts of operation of each of the stations 112-1 to 112-s, and ideal consumption of compressed air per unit of production for each of the stations 112-1 to 112-s during each of the shifts; and
• a pre-set no load OFF time value.
The valve details may include identifier, location, and electrical and mechanical parameters of the valves 108-1 to 108-s. The ideal consumption of compressed air per unit of production for each of the stations 112 is pre-calculated.
In an embodiment, the controller 120 includes a compressor control module 204 and a first interfacing unit 206. The compressor control module 204 is configured to cooperate with the compressors 102-1 to 102-n, the main flow meter 114, and the pressure transducer 116 to receive the operational signals, the total compressed air demand, and the overall pressure demand of compressed air respectively, and is further configured to cooperate with the repository 202 to extract the group required for meeting the total compressed air demand and the overall pressure demand. The first interfacing unit 206 is configured to cooperate with the compressor control module 204 to generate a switching signal to switch ON/ switch OFF at least one of the compressors 102-1 to 102-n based on pre-defined ON-OFF states in the extracted group.
In an embodiment, the controller 120 includes a flow meter module 208. The flow meter module 208 is configured to obtain the number of units of equipment produced in stations 112-1 to 112-s during a shift from the station operators and actual consumption of compressed air for the stations 112-1 to 112-s during the shift from the branch flow meters 118 to compute the ideal consumption of compressed air in the stations 112-1 to 112-s for the number of units to generate a comparison chart of ideal consumption of compressed air against actual consumption of compressed air for each of the stations 112-1 to 112-s. In an embodiment, the flow meter module 208 comprises a first input module 208a, a computation module 208b, and a mapping module 208c. The first input module 208a is configured to facilitate operators of the stations 112-1 to 112-s to enter the number of units of equipment produced in the stations 112-1 to 112-s during a shift. The computation module 208b is configured to cooperate with the branch flow meters 118-1 to 118-s to receive the actual consumption of compressed air for the stations 112-1 to 112-s at the end of the shift, and is further configured to crawl through the third lookup table of the repository 202 to extract ideal air consumption of the stations 112-1 to 112-s per unit of production for the shift. The computation module 208b is configured to cooperate with the first input module 208a to compute the ideal consumption of compressed air in the stations 112-1 to 112-s for the number of units. In an embodiment, the ideal consumption of compressed air for the number of units produced is calculated using the formula:
Ideal consumption for ‘n’ no. of units produced= n x ideal consumption per unit
The mapping module 208c is configured to cooperate with the computation module 208b to generate the comparison chart of ideal consumption of compressed air against actual consumption of compressed air for each of the stations 112-1 to 112-s. In an embodiment, the controller 120 includes a display unit configured to cooperate with the mapping module 208c to receive and display the comparison chart.
In an embodiment, the controller 120 includes a timing control module 210 and a second interfacing unit 212. The timing control module 210 is configured to generate an ON control signal at a pre-defined ON time and an OFF control signal at a pre-defined OFF time. In an embodiment, the timing control module 210 comprises a second input module 210a and a timing signal generating module 210b. The second input module 210a is configured to cooperate with the repository 202 to facilitate the operators to define the ON times and the OFF times for each of the control valves 108. The ON times and the OFF times of the valve 108 associated with a station 112-1 to 112-s are defined based on operator’s meal timings and the time between two shifts when the station 112 is not working. The timing signal generating module 210b is configured to cooperate with the second input module 210a to generate the ON control signal at the pre-defined ON times and the OFF control signal at the pre-defined OFF times. The second interfacing unit 212 is configured to cooperate with the timing control module 210 to receive the ON/ OFF control signals, and is further configured to generate corresponding electrical signals to facilitate actuation of the control valves 108. In an embodiment, the compressor control module 204 and the timing control module 210 are implemented using programmable logic controllers.
In an embodiment, the compressor control module 204, the flow meter module 208, and the timing control module 210 are implemented using one or more microprocessors.
In an embodiment, the first and second interfacing units 206, 212 are implemented using relay units.
Advantageously, the compressor control module 204 is further configured to cooperate with the repository 202 to generate the turn OFF switching signal to switch OFF a compressor 102-1 to 102-n when the compressor 102-1 to 102-n is working under no load condition for a period greater than the pre-set no load OFF time value.
Thus, the system 100 significantly reduces the power consumption of the plant 10, which ultimately translates into reduced operating cost. As the system 100 is implemented with the help of pre-programmed logic using various modules and relays, it is automatic and operates with minimal human intervention. Further, the system 100 enables the operator to view real-time and ideal air consumption of various stations 112 of the plant 10 in graphical formats. Thus, any leakage or wastage of air can be easily detected. Real-time data monitoring also enables the operators to check if the system design is as per the requirement. This means that the operators can identify pneumatic cylinders working at lower efficiency, and eliminate or replace them with appropriate cylinders to improve the system efficiency.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a compressed air management system that:
• reduces human dependency;
• helps in determining daily air loss;
• controls the supply of compressed air as per the demand;
• switches OFF the compressor which is under no load for a pre-set period of time, thereby avoiding wastage of compressed air;
• is energy saving;
• is cost saving;
• makes identification of air leakages easier; and
• helps in checking if the existing system design is appropriate.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
The numerical values mentioned for the various physical parameters or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.