Patent Publication Number: US-2007119488-A1

Title: Dish washer with disc type passage control valve

Description:
This application claims the benefit of Korean Patent Application No. 10-2005-0096390 filed on Oct. 13, 2005, which is hereby incorporated by reference as if fully set forth herein.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a dish washer for washing dishes, and more particularly, to a dish washer which includes a disc type passage control valve formed to have a simple disc structure, thereby being capable of smoothly supplying wash water to a washing arm.  
      2. Discussion of the Related Art  
      Generally, dish washers are adapted to wash dishes by injecting wash water onto the dishes, and to dry and/or sterilize the washed dishes.  
      Hereinafter, a conventional dish washer will be described with reference to the annexed drawings.  
       FIG. 1  is a schematic view illustrating a configuration of a conventional dish washer.  FIG. 2  is an exploded perspective view illustrating a driver of the dish washer shown in  FIG. 1 .  FIG. 3  is a plan view illustrating a passage structure of a filter housing shown in  FIG. 2 .  FIG. 4  is a sectional view illustrating a flow of wash water during a washing operation of the driver shown in  FIG. 2 .  FIG. 5  is a plan view illustrating a flow of wash water in the filter housing OF  FIG. 2  during the washing operation.  FIG. 6  is a plan view illustrating a flow of wash water in the filter housing of  FIG. 2  during a draining operation.  
      The configuration of the conventional dish washer will be described in outline with reference to  FIG. 1 . The dish washer includes a tub  1 . Installed in the tub  1  are upper and lower washing arms  4  and  5 , upper and lower racks  6  and  7 , and a driver  10 .  
      Upper and lower connecting tubes  2  and  3  are connected to the driver  10 , in order to pump wash water. A draining hose  9  is also connected to the driver  10 , in order to drain wash water. The upper and lower washing arms  4  and  5  are connected to the upper and lower connecting tubes  2  and  3 , respectively. The upper rack  6  is arranged over the upper washing arm  4 , whereas the lower rack  7  is arranged over the lower washing arm  5 .  
      The upper and lower washing arms  4  and  5  are rotatably mounted above the driver  10 . Each of the upper and lower washing arms  4  and  5  are provided with injection holes for injecting wash water. Additional injection holes are also provided at the lower washing arm  5 , in order to remove garbage from a filter of the driver  10 , and thus, to prevent the filter from being closed by the garbage.  
      Hereinafter, the driver will be described in detail with reference to  FIG. 2 . The driver  10  includes a sump  20  for receiving wash water, a heater  30  mounted in the sump  20 , to heat the wash water, a washing pump (including elements  41  and  42 ) mounted to the sump  20 , to pump the wash water, a draining pump (including elements  51  and  52 ) mounted to the sump  20 , to drain the wash water, and filtering means for guiding a part of the pumped wash water to the washing arms  4  and  5 , and filtering the remaining wash water.  
      A space for receiving wash water, namely, a wash water receiver  21 , is defined in the sump  20 . A draining chamber  22  is also defined in the sump  20 . The draining chamber  22  is partitioned from the wash water receiver  21 . A passage control device  25  is disposed outside the wash water receiver  21 . A passage control valve  26  is axially coupled to the passage control device  25 .  
      The washing pump includes a washing motor  41  mounted to the bottom of the sump  20 , and adapted to generate a drive force, and an impeller  42  mounted to the filtering means, and adapted to pump wash water, using the drive force of the washing motor  41 . A disposer  45  is axially coupled to a shaft of the washing pump. The disposer  45  functions to finely chop garbage as it rotates. A screen  46  having a certain mesh size is arranged over the disposer  45 , in order to separate garbage having a large grain size.  
      The draining pump is mounted to the draining chamber  22  of the sump  20 . The draining pump includes a draining motor  51  and an impeller  52 .  
      The filtering means includes a pump housing  60  formed with a space for receiving the impeller  42  therein, a filter housing  70  arranged to cover the top of the pump housing  60 , and a cover  80  arranged to cover the top of the filter housing  70  and the top of the sump  20 . The pump housing  60  is mounted to the bottom of the filter housing  70 . The cover  80  is mounted to the top of the filter housing  70 .  
      A garbage chamber  75  is defined in the filter housing  70 . The garbage chamber  75  is provided with a draining member  75   a  communicating with the draining chamber  22 . The draining member  75   a  is downwardly protruded from the garbage chamber  75  by a certain length such that the draining member  75   a  is inserted into the draining chamber  22 . Details of the filter housing  70  will be described later.  
      A filter  81  is mounted in the cover  80  such that the filter  81  faces the garbage chamber  75 . A plurality of recovering holes  82  are formed at the cover  80  outside the filter  81 . The recovering holes  82  communicate with the sump  20 .  
      The filter housing  70  will now be described with reference to  FIG. 3 .  
      The filter housing  70  includes a wash water inlet  72  for receiving wash water pumped by the impeller  42 , main passages  73   a  and  73   b  connected to the wash water inlet  72 , a sampling passage  74  connected to the wash water inlet  72 , and a garbage chamber  75  connected to the sampling passage  74 . An opening/closing valve is arranged in the draining member  75   a  of the garbage chamber  75 , in order to discharge wash water and garbage from the garbage chamber  75  to the draining chamber  22  ( FIG. 2 ) during a draining operation.  
      The passage control valve  26  is rotatably seated in the wash water inlet  72  of the filter housing  70 , to selectively open and close the main passages  73   a  and  73   b . The passage control valve  26  is axially coupled to the passage control device  25  ( FIG. 2 ) installed in the sump  20 . An opening/closing lip  26   a  is formed at the periphery of the passage control valve  26 , to selectively open and close the main passages  73   a  and  73   b.    
      Hereinafter, operation of the dish washer having the above-mentioned configuration will be described.  
      The dish washer washes dishes while sequentially or selectively performing pre-washing, main washing, rinsing, hot rinsing, and drying operations. A draining operation is carried out between adjacent ones of the above-mentioned operations. The main washing operation and draining operation will be described hereinafter.  
      When the main washing operation is begun, the washing motor  41  rotates, thereby causing the impeller  42  to rotate. As a result, the impeller  42  pumps wash water (containing a detergent) from the sump  20  to the wash water inlet  72  ( FIG. 3 ) of the pump housing  60 .  
      In this case, in accordance with rotation of the passage control device  25 , the passage control valve  26  can simultaneously open the two main passages  73   a  and  73   b , as shown in  FIG. 3 , or can selectively open one of the main passages  73   a  and  73   b , as shown in FIGS.  5  or  6 . Accordingly, a part of the wash water received in the wash water inlet  72  is introduced into the upper washing arm  4  and/or the lower washing arm  5  via the main passage  73   a  and/or main passage  73   b . The remaining wash water is introduced into the garbage chamber  75  via the sampling passage  74 .  
      In this case, the passage control valve  26  simultaneously or alternately opens the main passages  73   a  and  73   b , to supply wash water to both the upper and lower washing arms  4  and  5 . At the same time, a part of the wash water is always introduced into the sampling passage  74 , irrespective of which main passage is opened by the passage control valve  26 .  
      The wash water introduced in the sampling passage  74  is directly introduced into the garbage chamber  75 . This wash water then overflows the filter  81  ( FIG. 2 ) arranged over the garbage chamber  75 . At this time, the filter  81  filters the wash water to remove foreign matter from the wash water. The filter wash water is returned to the sump  20  via the recovering holes  82  of the cover  80 , together with wash water discharged from the upper and lower washing arms  4  and  5 .  
      Although the wash water seems to be partially filtered in the above procedure carried out for a short period of time, most wash water is, in practical, filtered during the main washing operation. After completion of the washing operation, the draining operation is begun.  
      When the draining operation is begun, the draining pump operates. At this time, the wash water and garbage in the sump  20  are introduced into the draining pump by virtue of a suction force generated by the draining pump. At the same time, the wash water and garbage in the garbage chamber  75  are also introduced into the draining pump via the draining member  75   a , as shown in  FIG. 6 . The wash water and garbage introduced in the draining pump are then outwardly discharged through the draining hose  9  ( FIG. 1 ).  
      In the above-mentioned conventional dish washer, however, it is impossible to smoothly supply wash water to the washing arms because the passage control valve has a complex structure. In order to eliminate this problem, it is necessary to increase the capacity of the washing pump.  
      Furthermore, although the passage control valve is rotated using a motor, to perform a passage control operation, this operation is carried out in a state in which wash water is filled in the passage control valve. As a result, a large load is applied to the motor. For this reason, the motor must have an increased capacity, in order to smoothly rotate the passage control valve.  
      In addition, the conventional passage control valve is expensive because its structure is complex. As a result, the manufacturing costs of the dish washer are increased.  
     SUMMARY OF THE INVENTION  
      Accordingly, the present invention is directed to a dish washer with a disc type passage control valve that substantially obviates one or more problems due to limitations and disadvantages of the related art.  
      An object of the present invention is to provide a disc type passage control valve capable of smoothly supplying wash water to a washing arm, and a dish washer provided with the disc type passage control valve.  
      Another object of the present invention is to provide a disc type passage control valve which is efficiently rotatable, using a motor having a small capacity, and a dish washer provided with the disc type passage control valve.  
      Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become 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 may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.  
      To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a dish washer comprises: an upper washing arm; a lower washing arm; a sump for receiving wash water; a washing pump for pumping the wash water; and a passage control valve including a passage opening/closing plate having a plate shape and functioning to open/close a passage guiding the wash water to the upper washing arm or to the lower washing arm.  
      Preferably, the passage opening/closing plate has a disc shape.  
      Preferably, the passage control valve has a rotating shaft. The rotating shaft connects the passage opening/closing plate to a motor. When the motor rotates, the passage opening/closing plate is rotated, thereby opening or closing the passage.  
      The passage opening/closing plate may comprise an upper washing arm opening portion for opening a passage communicating with the upper washing arm, a lower washing arm opening portion for opening a passage communicating with the lower washing arm, and a passage closing portion for selectively closing the passage communicating with the upper washing arm or the passage communicating with the lower washing arm.  
      The dish washer may further comprise a pumping chamber where an impeller of the washing pump is arranged, and a housing assembly having a passage control chamber communicating with the upper washing arm and the lower washing arm.  
      Preferably, the passage opening/closing plate is arranged in a passage defined in the passage control chamber to communicate with the upper washing arm and the lower washing arm.  
      In accordance with the present invention, when wash water is guided to the washing arms, the flow of the wash water can be smoothly carried out. Accordingly, the supply of the wash water can be smoothly achieved. As a result, it is possible not only to achieve an enhancement in washing performance, but also to relatively reduce the capacity of the washing pump. Also, there is no problem associated with the supply of wash water to the washing arms, even when the washing pump exhibits a degraded performance after being used for a prolonged period of time.  
      Since no load caused by wash water is applied to the passage control valve when passage control is carried out by rotating the passage control valve using a control motor, in accordance with the present invention, differently from the conventional case, it is possible to extend the life span of the motor, and thus, to more efficiently use the motor.  
      The passage control valve of the present invention is simple, and thus, inexpensive, as compared to the conventional passage control valve. Accordingly, it is possible to reduce the manufacturing costs of the dish washer.  
      It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      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:  
       FIG. 1  is a schematic view illustrating a configuration of a conventional dish washer;  
       FIG. 2  is an exploded perspective view illustrating a driver of the dish washer shown in  FIG. 1 ;  
       FIG. 3  is a plan view illustrating a passage structure of a filter housing shown in  FIG. 2 ;  
       FIG. 4  is a sectional view illustrating a flow of wash water during a washing operation of the driver shown in  FIG. 2 ;  
       FIG. 5  is a plan view illustrating a flow of wash water in the filter housing of  FIG. 2  during the washing operation;  
       FIG. 6  is a plan view illustrating a flow of wash water in the filter housing of  FIG. 2  during a draining operation;  
       FIG. 7  is a schematic view illustrating a disc type passage control valve for a dish washer according to a preferred embodiment of the present invention;  
       FIG. 8  is an exploded perspective view illustrating a configuration of a dish washer according to the present invention;  
       FIG. 9  is a sectional view illustrating a flow of wash water during a washing operation of the dish washer of  FIG. 8 ; and  
       FIG. 10  is a sectional view illustrating a flow of wash water during a draining operation of the dish washer of  FIG. 8 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.  
       FIG. 7  is a schematic view illustrating a disc type passage control valve for a dish washer according to the present invention.  FIG. 8  is an exploded perspective view illustrating a configuration of a dish washer to which the passage control valve of  FIG. 7  is applied.  FIG. 9  is a sectional view illustrating a flow of wash water during a washing operation of the dish washer of  FIG. 8 .  FIG. 10  is a sectional view illustrating a flow of wash water during a draining operation of the dish washer of  FIG. 8 .  
      The passage control valve  190  shown in  FIG. 7  includes a passage opening/closing plate  192  having a disc shape, and a rotating shaft  191  coupled to a shaft of a control motor  200 . The passage opening/closing plate  192  has an upper washing arm opening portion  192   a  for opening a passage communicating with an upper washing arm, a lower washing arm opening portion  192   b  for opening a passage communicating with a lower washing arm, and a passage closing portion  192   c  for selectively closing the passage communicating with the upper washing arm or the passage communicating with the lower washing arm.  
      As the control motor  200  rotates, the passage control valve  190  is rotated to open only the passage communicating with the upper washing arm or the passage communicating with the lower washing arm. The passage control valve  190  may also open both the passage communicating with the upper washing arm and the passage communicating with the lower washing arm.  
      The dish washer shown in  FIG. 8  includes the passage control valve shown in  FIG. 6 . In detail, the dish washer includes a sump  110  for receiving wash water, a washing pump  120  for pumping the wash water from the sump  110 , and a housing assembly (including elements  130 ,  140 , and  150 ) formed with passages  141  and  142  for guiding the pumped wash water to washing arms. The dish washer also includes a cover  160  arranged to cover the top of the sump  110 , a filtering device  170  extending downwardly from the cover  160  such that it is arranged in the sump  110 , to guide wash water falling onto the cover  160  to the sump  110  after filtering the wash water, and a draining pump  180  communicating with the filtering device  170 , and functioning to outwardly discharge garbage separated in the filtering device, along with the wash water present in the sump  110 .  
      Preferably, a heater for heating wash water is arranged in the sump  110 . The illustration of the heater is omitted from  FIG. 8 . It will also be appreciated that the heater may be installed on the bottom of the sump.  
      The sump  110  is defined with a garbage receiving chamber  111  for storing garbage separated by the filtering device  170 . The garbage receiving chamber  111  communicates with the draining pump  180 . Preferably, the garbage receiving chamber  111  is arranged in the bottom of the sump  110 . More preferably, the garbage receiving chamber  111  is inclined toward the draining pump  180  by a predetermined angle α. In accordance with this inclination, it is possible to easily discharge garbage collected in the garbage receiving chamber  111  to the draining pump  180 .  
      A draining passage  112  is also provided to communicate the garbage receiving chamber  111  and the draining pump  180 . Preferably, the garbage receiving chamber  111  is communicated with a draining chamber  113  via the draining passage  112 .  
      The draining chamber  113  is defined in the sump  110 , to receive the draining pump  180 . The draining chamber  113  has a space for receiving an impeller, and a space for receiving garbage.  
      The washing pump  120  includes a washing motor  121  for generating a drive force, and an impeller  122  axially coupled to the washing motor  121 . The washing motor  121  is of a vertical drive type in which the shaft of the washing motor  121  extends vertically. The draining pump  180  includes a draining motor (not shown), and an impeller (not shown). The draining pump  180  is of a horizontal drive type in which the shaft of the draining motor extends horizontally.  
      Meanwhile, the housing assembly is provided with a pumping chamber  131  where the impeller  122  of the washing pump  120  is arranged, and a passage control chamber  132  communicating with the pumping chamber  131 . The passage control valve  190  is arranged in the passage control chamber  132 . The housing assembly is also provided with main passages  141  and  142  for guiding wash water from the passage control chamber  132  to respective washing arms.  
      Preferably, the pumping chamber  131  and the passage control chamber  132  are flush with each other, in order to increase the internal space of the sump  110  while reducing the height of the housing assembly (including elements  130 ,  140 , and  150 ). Also, the main passages  141  and  142  are preferably arranged over the pumping chamber  131  and passage control chamber  132 , respectively, in order to reduce the width of the housing assembly.  
      An example of the housing assembly will be described.  
      The housing assembly includes a lower housing  130  defined with the pumping chamber  131  and flow control chamber  132 , and an upper housing  140  coupled to the lower housing  130  such that the upper housing  140  covers the top of the lower housing  130 , and defined with the main passages  141  and  142 . In the case of  FIG. 7 , the lower housing  130  and upper housing  140  are separate from each other. Although not shown, the lower housing and upper housing  140  may be integrated with each other.  
      Preferably, the housing assembly further includes a connecting housing  150  coupled to the upper housing  140  such that the connecting housing  150  covers the top of the upper housing  140 . The connecting housing  150  is also coupled to a connecting tube (not shown) connected to the washing arms. The connecting housing  150  has a coupling portion for coupling the connecting housing  150  to the connecting tube.  
      Preferably, the cover  160 , which covers the sump  110 , is arranged to be inclined toward the filtering device  170  by a predetermined angle β ( FIG. 8 ), in order to enable wash water and garbage falling onto the cover  160  to flow easily toward the filtering device  170 .  
      Preferably, a plurality of filtering holes  161  is formed through the cover  160 , in order to enable a part of the wash water falling onto the cover  160  to be directly introduced into the sump after being filtered. More preferably, the filtering holes  161  are arranged in a region outside the housing assembly, in order to minimize contamination of the outer surface of the housing assembly by the contaminated wash water.  
      Meanwhile, the filtering device  170  has an opened lower end. The opened lower end of the filtering device  170  is coupled to the garbage receiving chamber  111 . Preferably, the lower end of the filtering device  170  is vertically spaced apart from the bottom of the garbage receiving chamber  111  by a predetermined distance. To this end, a step  111   a  may be formed at the top of the garbage receiving chamber  11  such that the opened lower end of the filtering device  170  is supported by the step  111   a . The draining passage  112  is arranged beneath the step  111   a  of the garbage receiving chamber  111 . Accordingly, garbage received in the garbage receiving chamber  111  can be discharged to the draining chamber  113  via the draining passage  112  without being obstructed by the filtering device  170 .  
      The filtering device  170  includes an upper filter  176  mounted to the cover  160  such that the upper filter  176  communicates with the cover  160 , and adapted to primarily filter wash water and garbage falling onto the cover  160 , and a lower filter  171  connected to the upper filter  176  and garbage receiving chamber  111 , and adapted to secondarily filter the wash water, and thus, to separate garbage from the wash water. The lower filter  171  has an opened lower end.  
      Preferably, the upper filter  176  is detachably mounted to the cover  160 . Also, the lower filter  171  is detachably coupled to the upper filter  176 . The upper filter  176  performs a filtering function for separating garbage having a large grain size, whereas the lower filter  171  performs a filtering function for separating garbage having a small grain size not separated by the upper filter  176 .  
      Preferably, the upper filter  176  is protruded from the upper surface of the cover  160  by a predetermined height, in order to enable the user to easily grip and pull the upper filter  176 . Of course, it is unnecessary for the upper filter  176  to be upwardly protruded from the cover  160 , as long as the user can easily grip and pull the upper filter  176 .  
      As described above, the rotating shaft  191  of the passage control valve  190  is coupled to the shaft of the control motor  200 . The passage opening/closing plate  192 , which is also included in the passage control valve  190 , is arranged at an upper end of the rotating shaft  191 , and has a disc shape. The passage opening/closing plate  192  opens or closes the main passages  141  and  142  in accordance with rotation thereof.  
      The passage control valve  190  is structured such that it receives a pumping pressure from the washing pump  120  at the upper surface of the passage control valve  190 . Accordingly, when the pumping pressure is applied, the passage control valve  190  is pressed against the upper housing  140 . As a result, the passage control valve  190  is stably supported by the upper housing  140  without rocking laterally.  
      Hereinafter, operation of the dish washer having the above-described configuration will be described.  
      The dish washer washes dishes while sequentially or selectively performing pre-washing, main washing, rinsing, hot rinsing, and drying operations. A draining operation is carried out between adjacent ones of the above-mentioned operations. The main washing operation and draining operation will be described hereinafter.  
      The washing operation of the dish washer will be described with reference to  FIG. 9 .  
      When the impeller  122  rotates in accordance with operation of the washing motor  121 , wash water present in the sump  110  flows to the pumping chamber  131  and passage control chamber  132 .  
      At this time, in accordance with rotation of the passage control valve  190 , the main passages  141  and  142  are communicated with the passage control chamber  132 . In this case, the passage control valve  190  may selectively open one of the main passages  141  and  142 , or may simultaneously open both the main passages  141  and  142 . Alternatively, the passage control valve  190  may alternately open the main passages  141  and  142 .  
      When the main passages  141  and  142  are opened, the wash water in the passage control chamber  132  is supplied to the washing arms via the main passages  141  and  142 , respectively, so that the wash water can be injected from the washing arms.  
      In accordance with the present invention, the pumped wash water is completely supplied to the washing arms because there is no sampling passage, as compared to the conventional case. Accordingly, the amount of wash water injected onto dishes to be washed is increased. Practically, the pumped wash water is completely used only to wash the dishes. Thus, it is possible to use a washing pump having a reduced capacity, as the washing pump  120 , as compared to the conventional case. The amount of wash water used can be considerably reduced. In addition, the wash water passages are simple, as compared to the conventional case. Accordingly, it is possible to reduce the flow resistance of wash water, and thus, to achieve an enhancement in pumping ability even when the washing pump  120  has the same capacity as that of the conventional case.  
      The wash water injected from the washing arms falls onto the cover  160  after washing the dishes. Since the cover  160  is inclined toward the filtering device  170 , the wash water falling onto the cover  160  and garbage falling onto the cover after being separated from the dishes by the wash water are introduced into the upper filter  176 . The wash water is partially directly introduced into the sump  110  via the filtering holes  161 .  
      Garbage having a large grain size is separated by the upper filter  176 . The lower filter  171  separates the remaining garbage not separated by the upper filter  176 . Accordingly, only the filtered wash water is introduced into the sump  110 .  
      In accordance with the present invention, it is unnecessary to periodically wash the filtering device  170  during the washing operation. Accordingly, even when a reduced amount of wash water is pumped, as compared to the conventional case, it is possible to obtain the same amount of injected wash water as that of the conventional case. It is also possible to reduce the amount of used wash water.  
      As the above-described washing operation is continued for a predetermined time, the wash water used to wash the dishes is filtered, and re-used to wash the dishes. As the washing operation is continued, the amount of the garbage collected in the filtering device  170  is gradually increased. After completion of the washing operation, a draining operation is begun.  
      The draining operation of the dish washer will be described hereinafter with reference to  FIG. 10 .  
      When the draining pump  180  operates, the wash water present in the sump  110  is introduced into the garbage receiving chamber  111  via the lower filter  171  in accordance with a suction force generated by the draining pump  180 . The wash water is then introduced into the draining chamber  113 , together with garbage collected in the garbage receiving chamber  111 . Since the garbage receiving chamber  111  is inclined toward the draining chamber  113 , the introduction of garbage into the draining chamber  113  can be smoothly achieved. Thereafter, the garbage and wash water present in the draining chamber  113  is outwardly discharged via a draining hole of the draining chamber  113  and a draining hose connected to the draining hole.  
      In this case, the draining path (the passage between the garbage receiving chamber  111  and the draining chamber  113 ) is very short. Accordingly, there is little or no garbage in the draining path. In accordance with the above-described operation, the garbage collected in the garbage receiving chamber  111  during the draining operation is completely outwardly discharged.  
      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 inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.