Abstract:
Air cleaner including a body forming an exterior, having an first inlet and a second inlet for drawing room air, and an outlet for discharging air having dust or odor removed therefrom, at least more than one dust collecting filters at the first inlet inside of the body, at least more than one deodorizing filters at the second inlet inside of the body, at least more than one discharge fan for providing a suction force so as to draw room air, pass the room air through the filters inside of the body, and discharge the room air through the outlet, and opening/closing means for opening/closing the inlets selectively, thereby operating the air cleaner proper to an environment of use.

Description:
[0001]     This application claims the benefit of the Korean Application No. P2003-0051960 filed on Jul. 28, 2003, which is hereby incorporated by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to air cleaners, and more particularly, to an air cleaner operative proper to a purpose of use or an environment.  
         [0004]     2. Background of the Related Art  
         [0005]     In general, the air cleaner provides a comfortable room environment by carrying out a deodorization function for removing various smells in the room, and a dust collecting function for removing dust from the room.  FIGS. 1 and 2  illustrate related art air cleaners, schematically.  
         [0006]     As shown, the related art air cleaner is provided with a body  10  forming an exterior, various of filters, discharge fan  30 , and a flow guide  40 .  
         [0007]     The body  10  is provided with an air inlet  11  in a lower front part thereof for drawing room air, and an air outlet  12  in a rear upper part thereof for discharging cleaned air.  
         [0008]     The various filters are a plurality of dust collecting filters  21  for removal of various dusts, and a plurality of deodorizing filters  22  for deodorizing various smells, mounted in succession in a part the air inlet  11  is formed.  
         [0009]     The discharge fan  30 , mounted in rear of the filters  21  and  22 , discharges the air drawn through the air inlet  11 , and passed through the filters  21  and  22  to an outside of the body  10 .  
         [0010]     The flow guide  40 , formed in a rear part of the body  10 , guides the air passed through the discharge fan  30  to the air outlet  12  in the body  10 .  
         [0011]     Accordingly, upon putting the air cleaner into operation, the discharge fan  30  is rotated, so that room air is drawn into the body  10  through the air inlet, and passed through the filters  21  and  22  for dust collecting and deodorizing.  
         [0012]     In this instance, the dust collection is made as the air passes through the dust collecting filters  21 , and the deodorizing is made as the air passes the deodorizing filter  22  in rear of the dust collecting filters  21 .  
         [0013]     Cleaning of the room air is made as the air dust collected and deodorized therefrom passes the discharge fan  30 , is guided by the flow guide  40 , and discharged into the room through the air outlet  12 .  
         [0014]     However, the related art air cleaner has the following different problems in a filter mounting structure.  
         [0015]     First, because the related art air cleaner passes air through all the filters in succession regardless of purpose of use or site, a lifetime of the filters is reduced.  
         [0016]     For an example, if the air cleaner is used in a purpose of deodorization in, such as a kitchen, when air containing smell compositions passes the dust collecting filters unnecessarily, the dust collecting filters is contaminated without functioning properly, to shorten a lifetime of the dust collecting filters.  
         [0017]     On the other hand, if the air cleaner is used in a site with much dust for cleaning room air, it is not necessary to pass the air with dust through the deodorizing filters. Despite of this, since the air passes through the deodorizing filter, a lifetime of the deodorizing filters is shortened unnecessarily. Particularly, the deodorizing filter is in general an activated-carbon filter, accumulation of dust makes the deodorizing performance poor, to drop a user&#39;s reliability of the device.  
         [0018]     Second, since the related art air cleaner requires air to pass the plurality of filters, which causes flow resistance at the filters, a load on a fan motor (not shown) for driving the discharge fan increases, to increase a power consumption.  
       SUMMARY OF THE INVENTION  
       [0019]     Accordingly, the present invention is directed to an air cleaner that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.  
         [0020]     An object of the present invention is to provide an air cleaner, in which air passes only a filter required for purpose of use or environment of the air cleaner.  
         [0021]     Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.  
         [0022]     To achieve these objects and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, the air cleaner including a body forming an exterior, having an first inlet and a second inlet for drawing room air, and an outlet for discharging air having dust or odor removed therefrom, at least more than one dust collecting filters at the first inlet inside of the body, at least more than one deodorizing filters at the second inlet inside of the body, at least more than one discharge fan for providing a suction force so as to draw room air, pass the room air through the filters inside of the body, and discharge the room air through the outlet, and opening/closing means for opening/closing the inlets, selectively.  
         [0023]     The inlets are formed in parallel in a front part of the body, and the discharge fan is a centrifugal fan.  
         [0024]     The inlets are formed in opposite sides of the body, and the at least more that one discharge fan includes one pair of centrifugal fans arranged in parallel in a central part of the inlets, respectively.  
         [0025]     The inlets are formed in the front part and a rear part of the body respectively, and the at least more than one discharge fan includes one pair of centrifugal fans arranged in parallel in a central part of the inlets, respectively.  
         [0026]     The air cleaner further includes a baffle plate between the dust collecting filters and the deodorizing filters.  
         [0027]     The opening/closing means includes a first door part for opening/closing the first inlet, a second door part for opening/closing the second inlet, and a first driving part and a second driving part for driving respective door parts.  
         [0028]     The first driving part includes a first driving motor, and a first connection wire connected between the first driving motor and the first door part, and the second driving part includes a second driving motor, and a second connection wire connected between the second driving motor and the second door part.  
         [0029]     The opening/closing means further includes a first guide rail and a second guide rail, and the first guide rail is bent along an edge of an inside of the body so as to guide the first door part to positions at which the first inlet is closed or opened, and the second guide rail is bent along an edge of an inside of the body so as to guide the second door part to positions at which the second inlet is closed or opened.  
         [0030]     The guide rails guide tops or bottoms of the door parts respectively, and the guide rails guide tops and bottoms of the door parts, respectively.  
         [0031]     The door parts are formed of materials, including a flexibly bendable material, and the door part includes a plurality of plates each having a small width, and a flexibly bendable bending part between the plates.  
         [0032]     The opening/closing means includes a third door part movable to close at least any one of the inlets selectively, and a third driving part for moving the third door part in both directions.  
         [0033]     The third driving part includes a third connection wire having one end connected to one side of the third door part, a third driving motor to be driven to wind or unwind the third connection wire, a fourth connection wire having one end connected to the other side of the third door part, and a fourth driving motor to be driven to wind or unwind the fourth connection wire.  
         [0034]     The air cleaner further includes a baffle plate between the dust collecting filters and the deodorizing filters, and pins at both ends of the third door parts to be fastened to the baffle plate.  
         [0035]     The third driving part includes a fifth connection wire having one end connected to one side of the third door part, a sixth connection wire having one end connected to the other side of the third connection part, and a fifth driving motor connected to the other ends of the fifth connection wire and the sixth connection wire to be driven to wind/unwind respective connection wires.  
         [0036]     It is to be understood that both the foregoing description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention claimed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0037]     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings;  
         [0038]      FIG. 1  illustrates a disassembled perspective view of a related art air cleaner, schematically;  
         [0039]      FIG. 2  illustrates a side sectional view of a related art air cleaner, schematically;  
         [0040]      FIG. 3  illustrates a side section showing a part a first inlet of an air cleaner in accordance with a first preferred embodiment of the present invention formed therein, schematically;  
         [0041]      FIG. 4  illustrates a side section showing a part a second inlet of an air cleaner in accordance with a first preferred embodiment of the present invention formed therein, schematically;  
         [0042]      FIG. 5  illustrates a plan view showing a state an air cleaner in accordance with a first preferred embodiment of the present invention is inoperative;  
         [0043]      FIG. 6  illustrates a plan view showing a state an air cleaner in accordance with a first preferred embodiment of the present invention is operative for dust collection;  
         [0044]      FIG. 7  illustrates a plan view showing a state an air cleaner in accordance with a first preferred embodiment of the present invention is operative for deodorization;  
         [0045]      FIG. 8  illustrates a plan view showing a state an air cleaner in accordance with a first preferred embodiment of the present invention is operative both for dust collection and deodorization;  
         [0046]      FIG. 9  illustrates a plan view of an air cleaner in accordance with a second preferred embodiment of the present invention, schematically;  
         [0047]     FIGS.  10 ˜ 12  illustrate plan views each showing operation of an air cleaner in accordance with a third preferred embodiment of the present invention, schematically; and  
         [0048]     FIGS.  13 ˜ 15  illustrate plan views each showing operation of an air cleaner in accordance with a fourth preferred embodiment of the present invention, schematically. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0049]     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings FIGS.  3 ˜ 15 . In describing the embodiments, same parts will be given the same names and reference symbols, and repetitive description of which will be omitted.  
         [0050]      FIG. 3  illustrates a side section showing a part a first inlet of an air cleaner in accordance with a first preferred embodiment of the present invention formed therein, schematically.  
         [0051]     Referring to  FIG. 3 , the air cleaner includes a body  100 , dust collecting filters  210 , deodorizing filters  220 , a discharge fan  300 , and opening/closing means.  
         [0052]     The body  100  includes a first inlet  111  and a second inlet  112  both for drawing room air, and an outlet  120  for discharging air having dust collected, or deodorized therefrom. The first inlet  111  is formed in one side of a front part of the body  100 , the second inlet  112  is formed in the other side of the front part of the body  100 , and the outlet in a top of the body  100 .  
         [0053]     At least one dust collecting filter  210  is mounted in the body  100  in rear of the first inlet  111  for removing various dusts from the air, and the deodorizing filters  220  are mounted in the body  100  in rear of the second inlet  112 .  
         [0054]     That is, the first inlet  110  and the second inlet  112  are formed in parallel to each other, and in correspondence to which the dust collecting filters  210  and the deodorizing filters  220  are also mounted in parallel to each other.  
         [0055]     The discharge fan  300  is mounted in rear of the inlets  111  and  112  in the body, for drawing room air through the inlets  111  and  112 . The discharge fan  300  has a flow guide on an outer circumference thereof, for guiding the air drawn into the discharge fan  300  to be discharged through the outlet  120  in the top of the body  100 .  
         [0056]     The opening/closing means, operative to open/close the inlets  111  and  112  respectively, includes a first door part  510 , a second door part  520 , a first driving part, and a second driving part. The first door part  510  is mounted to open/close the first inlet  111 , and the second door part  520  is mounted to open/close the second inlet  112 .  
         [0057]     The first driving part is positioned in one side of the body  100  for moving the first door part  510 , and the second driving part is positioned in the other side of the body  100  for moving the second door part  520 .  
         [0058]     The first driving part includes a first driving motor  531  mounted in one side of a rear part of inside of the body  100 , and a first connection wire  532 , and the second driving part includes a second driving motor  541  mounted in the other side of the rear part of inside of the body  100 , and a second connection wire  542 .  
         [0059]     Ends of the first connection wire  532  are connected to the first driving motor  531  and the first door part  510  respectively, for moving the first door part  510  as the first connection wire  532  is wound/unwound by the first driving motor  531 . Ends of the second connection wire  542  are connected to the second driving motor  541  and the second door part  520  respectively, for moving the second door part  520  as the second connection wire  542  is wound/unwound by the second driving motor  541 .  
         [0060]     Moreover, the air filter further includes a first guide rail  551  and a second guide rail  552  in the body  100  for guiding moving paths of the first door part  510  and the second door part.  
         [0061]     The first guide rail  551  is formed for guiding a moving path of the first door part  510  from a front part of inside of the body  100  having the first inlet  111  formed therein to one side of a rear part of inside of the body  100  having the first driving motor  531  mounted therein. The second guide rail  552  is formed for guiding a moving path of the second door part  520  from a front part of inside of the body  100  the second inlet  112  is formed therein to the other side of the rear part of inside of the body  100  the second driving motor  541  is mounted therein.  
         [0062]     The guide rails  551  and  552  may be formed to guide a bottom or a top of the door parts  510  and  520  respectively, or to guide both the bottom and the top of the door parts  510  and  520  respectively.  
         [0063]     As shown, since the guide rail  551  or  552  is formed in an “L” along an edge of a space inside of the body  100 , the door parts  510  and  520  have a flexible material able to bend as the door parts  510  and  520  move following the guide rails  551  and  552 , respectively. HHHH.  
         [0064]     Moreover, since the door part  510  or  520  includes a plurality of plates each having a small width, and a bendable part between adjacent plates, in overall, the door parts  510  and  520  can move following the guide rails  551  and  552 , respectively.  
         [0065]     The operation of the first embodiment of the present invention will be described with reference to FIGS.  5  to  8 .  
         [0066]     Referring to  FIG. 5 , when the air cleaner is not in operation, the first inlet is closed with the first door part  510 , and the second inlet  112  is closed with the second door part  520 . In this instance, the room air gives no influence to the dust collecting filters  210  and the deodorizing filters  220  as the door parts  510  and  520  are closed.  
         [0067]     If the air cleaner is used for collecting dust in the room air from above state, (i.e., if the user selects a dust collecting mode), the first driving motor  531  comes into operation to wind the first connection wire  532 .  
         [0068]     In this instance, as shown in  FIG. 6 , since the first connection wire  532  is connected to the first door part  510 , the first door part  510  moves following a winding direction of the first connection wire  532  guided by the first guide rail  551 . Accordingly, only the first inlet  111  for the dust collecting filter  210  are opened, but the second inlet  112  for the deodorizing filters  220  maintains a closed state.  
         [0069]     Since the first door part  510  has a flexible material, the first door part  510  can move following the part bent in the “L” form at a corner part of inside of the body  100  during the first door part  510  moves guided by the first guide rail  551 .  
         [0070]     The operation of the air cleaner in dust collecting mode will be described with reference to  FIG. 6 .  
         [0071]     Room air is drawn into the body  100  through the opened first inlet  111  by a suction force generated as the discharge fan  300  rotates. The room air is introduced into the body  100  only through the first inlet  111 , and involved in removal of various dust as the room air passes through the dust collecting filters  210 . The air having the dust and the like removed therefrom rises along the flow guide  400  to an upper part of the body  100 , and is discharged through the outlet  120  as the discharge fan  300  operates.  
         [0072]     In the meantime, if the air cleaner is used for deodorizing smells in the room air (i.e., if the user selects a deodorizing mode), the second driving motor  541  comes into operation, to wind the second connection wire  542 .  
         [0073]     Referring to  FIG. 7 , since one end of the second connection wire  542  is connected to the second door part  520 , the second door part  520  moves guided by the second guide rail  520  following a direction of winding of the second connection wire  542 . Therefore, only the second inlet  112  for the deodorizing filters  220  are opened, but the first inlet  111  for the dust collecting filters  210  maintains a closed state.  
         [0074]     In this instance, since the second door part  520  has a flexible material, the second door part  520  can move following the part bent in the “L” form at a corner of an inside of the body  100  during the second door part  520  moves guided by the second guide rail  552 .  
         [0075]     The operation of the air cleaner in the deodorizing mode will be described with reference to  FIG. 7 .  
         [0076]     A suction force generated by operating the discharge fan  300  draws the room air into the body  100  through the opened second suction  112 . Therefore, the room air is introduced into the inside of the body  100  only through the second inlet  112 , to remove various odors as the room air passes through the deodorizing filters  220 .  
         [0077]     The air having the odors removed therefrom rises to the upper part of the inside of the body  100  along the flow guide  400 , and discharged to the room through the outlet  120 .  
         [0078]     Thus, by operating the air cleaner only in the dust collecting mode or in the deodorizing mode depending on an environment of the site the air cleaner is installed, an efficiency of the apparatus can be enhanced.  
         [0079]     That is, no air pass through the deodorizing filters  220  is required in the dust collecting mode, and no air pass through the dust collecting filters  220  is required in the deodorizing mode. Therefore, the deodorizing filters  220  and the dust collecting filters  210  are provided separate from, and parallel to, each other in the air cleaner. It is preferable that a baffle plate  600  is provided between the deodorizing filters  220  and the dust collecting filters  210  for preventing the air passing through filters  210  and  220  of different purposes from mixing.  
         [0080]     In the meantime, if the air cleaner is used for carrying out dust collection and deodorizing of the room air at the same time, both the first driving motor  531  and the second driving motor  541  come into operation at the same time, to wind the first connection wire  532  and the second connection wire  542 .  
         [0081]     Referring to  FIG. 8 , since the first connection wire  532  is connected to the first door part  510 , the first door part  510  moves following the first guide rail  551 , and, since the second connection wire  542  is connected to the second door part  520 , the second door part  520  moves following the second guide rail  552 .  
         [0082]     Accordingly, both the first inlet  111  for the dust collecting filters  210  and the second inlet for the deodorizing filters  220  are opened.  
         [0083]     The room air drawn into the inside of the body passes through, and has various dust removed therefrom, at the dust collecting filters  210 , and passes through, and has various odors removed therefrom at the deodorizing filters  220 . The dust collected and deodorized air rises up to the upper part of the body along the flow guide  400 , and is discharged into the room again through the outlet  120  as the discharge fan  300  is driven.  
         [0084]     In this instance, it is preferable that the discharge fan  300  is a centrifugal fan that draws air from a center part and discharges the air in a circumferential direction. The centrifugal fan has advantages of low noise, and high efficiency in comparison to a general blowing fan, and permits an optimal use of an inside space of the fan. Therefore, the flow guide  400  around the discharge fan  300  is provided in a form in conformity with a circumferential surface of the discharge fan  300 , and the air discharged in the circumferential direction by the discharge fan  300  is discharged to room through the outlet  120  guided by the flow guide  400 .  
         [0085]     In the meantime, the inlets  111  and  112  can not be formed only in the front part of the body  100  like the first embodiment of the present invention.  
         [0086]     Referring to  FIG. 9 , in a second embodiment of the present invention, the inlets are formed in opposite sides of the body  100 . Therefore, the discharge fan  300  is mounted in a central part of the inlets  111  and  112  substantially, to draw the room air through the inlets  111  and  112 . If the discharge fan is of a centrifugal type, since it is required to draw air from both sides, one pair of fans, such as a first discharge fan  310  and a second discharge fan  320  having different directions of suction are required. In this instance, the opening/closing means for opening/closing the inlets  111  and  112  can be provided identical to the first embodiment at different positions.  
         [0087]     In the second embodiment too, a baffle plate  430  is provided for separating a space for dust collecting filters  210  and a space for deodorizing filters  220 .  
         [0088]     Moreover, though not shown, the inlets  111  and  112  may be formed in the front part and rear part of the body  100  respectively, with a structure the same with the first or second embodiment.  
         [0089]     In the meantime, the third embodiment of the present invention has a structure in which the door parts of the opening/closing means are integrated.  
         [0090]     Referring to  FIG. 10 , the first inlet  111  and the second inlet  112  are formed in opposite sides of the front part of the body  100 , and one third door part  560  can open/close the inlets  111  and  112  selectively.  
         [0091]     That is, the third door part  560  is formed long enough to open/close the first inlet  111  and the second inlet  112  at the same time, and is movable in both directions inside of the body  100  with a third driving part.  
         [0092]     The third driving part includes a third connection wire  572  having one end connected to one end of the third door part  560 , a third driving motor  571  to be driven for winding/unwinding the third connection wire  572 , a fourth connection wire  582  having one end connected to the other side of the third door part  560 , and a fourth driving motor  581  to be driven for winding/unwinding the fourth connection wire  582 .  
         [0093]     There is a third guide rail  553  for guiding movement of the third door part  560  following an edge of an inside of the body  100 .  
         [0094]     The operation of the air cleaner in accordance with a third preferred embodiment of the present invention will be described, with reference to FIGS.  10 ˜ 12 .  
         [0095]     Referring to  FIG. 10 , in an initial state, the third door part  560  is at a position to close both the first inlet  111  and the second inlet  112 .  
         [0096]     When the user selects a dust collecting mode in the initial state, the third driving motor  571  is driven to unwind the third connection wire  572 , and the fourth driving motor  581  is driven to wind the fourth connection wire  582 .  
         [0097]     Referring to  FIG. 11 , the third door part  560  moves in a direction the second inlet  112  is positioned to open the first inlet  111 , and when the third door part  560  arrives to a position the first inlet  111  is opened fully, operation of the third driving motor  571  and the fourth driving motor  581  are stopped. Thereafter, the discharge fan  300  comes into operation, to introduce room air into the body  100  through the opened first inlet  111 , to remove dust from the air as the air passes through the dust collecting filters  210 .  
         [0098]     In the meantime, if the user selects the deodorizing mode in the initial state, the third driving motor  560  is driven to wind the third connection wire  572 , and the fourth driving motor  581  is driven to unwind the fourth connection wire  582 .  
         [0099]     Referring to  FIG. 12 , the third door part  560  moves in a direction the third inlet  111  is positioned, to open the second inlet  112 , and when the third door part  560  arrives to a position at which the third door part  560  opens the second inlet  112  fully, operation of the third driving motor  571  and the fourth driving motor  581  is stopped. Thereafter, as the discharge fan  300  is operated, the room air is introduced into the body  100  through the opened second inlet  112 , and has odors removed therefrom as the room air passes through the deodorizing filters  220 .  
         [0100]     In the third embodiment too, the baffle plate  430  for separating a space for the dust filters  210  and a space of the deodorizing filters  220  are provided.  
         [0101]     Moreover, it is preferable that the third door part  560  has pins  431  at both ends to be fastened to the baffle plate  430 . For fastening the third door part  560  at an exact position in cases the mode changes from the dust collecting mode to the deodorizing mode, or vice versa, the pins  431  are formed at a preset position inside of the third door part  560 .  
         [0102]     FIGS.  13 ˜ 15  illustrate systems in accordance with a fourth preferred embodiment of the present invention.  
         [0103]     Different from the third embodiment, in the fourth embodiment of the present invention, the third driving part  560  of the opening/closing means includes only one driving motor (fifth driving motor)  591  and one pair of connection wire (a fifth connection wire and a sixth connection wire)  592 , and  593 .  
         [0104]     The fifth driving motor  591  is a dual-axis motor. The fifth connection wire  592  has one end connected to one side of the third door part  560 , and the other side connected to the fifth driving motor  591 . The sixth connection wire  593  has one end connected to the other side of the third door part  560 , and the other end connected to the fifth driving motor  591 .  
         [0105]     Referring to  FIG. 14 , if the air cleaner is used for dust collection, the fifth driving motor  591  is driven to unwind the fifth wire  592  and wind the sixth connection wire  593  in the initial state ( FIG. 13 ), to move the third door part  560  in a direction the second inlet  112  is positioned. Therefore, the room air is drawn into the body  100  only through the opened first inlet  111 , and has various dusts therein removed with the dust collecting filters  210  at the first inlet  111 .  
         [0106]     Referring to  FIG. 15 , if the air cleaner is used for deodorizing, the fifth driving motor  591  is driven to wind the fifth connection wire  592  and to unwind the sixth connection wire  593 , to move the third door part  560  in a direction the first inlet  111  is positioned. Therefore, the room air is drawn into the body  100  only through the opened second inlet  112 , and has the various smell compositions in the room air removed at the deodorizing filters  220  at the second inlet  112 .  
         [0107]     Moreover, in the fourth embodiment too, a baffle plate  430  is provided for separating a space for the dust collecting filters  210  and a space for the deodorizing filters  220 .  
         [0108]     As has been described, the air cleaner of the present invention has an advantage in that reduction of lifetimes of the filters can be prevented by passing room air only to the filters required depending on purpose of use or environment.  
         [0109]     Moreover, since a number of the filters the room air required to pass is reduced, a load on the discharge fan that provides the suction force can be reduced. That is, in comparison to the related art air cleaner, in a case the discharge fan is driven at the same condition (the same speed), a flow rate of the air of the air cleaner of the present invention is significantly higher than the flow rate of the air of the related art air cleaner.  
         [0110]     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.