Abstract:
A coffee maker includes a housing, the housing of the coffee maker shaped and configured to fit within a wall cavity inside a wall and attach to one or more wall structures, the housing including an integral mounting structure having engagement structures to engage the one or more wall structures. The coffee maker unit further includes an in-line water heater located within the housing to receive a supply of water from plumbing that is external to the housing and a brewing area located within the housing to contain a supply of coffee grounds and to receive water from the water heater. The coffee maker farther includes a coffee pot receptacle configured to support a coffee pot at least partially within the wall cavity such that the coffee pot is located to receive coffee from the brewing area.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation of copending U.S. patent application Ser. No. 10/891,223, filed on 12 Jul. 2004, which is a continuation of U.S. patent application Ser. No. 10/239,973, filed on 25 Sep. 2002, now U.S. Pat. No. 6,892,626, which claims priority from PCT/US01/09630, filed 26 Mar. 2001, which is a continuation-in-part of U.S. patent application Ser. No. 09/537,973, filed 28 Mar. 2000, now U.S. Pat. No. 6,253,663. 
     
    
     BACKGROUND  
       [0002]     This invention relates generally to automatic coffee makers. More specifically, this invention relates to coffee makers that are built into a wall of a dwelling, recreational structure, or vehicle. This invention also relates to self-filling home coffee makers.  
         [0003]     Prior art coffee makers suffer from several drawbacks. First of all, most traditional coffee makers require a user to fill a reservoir of the coffee maker with water before operating the coffee maker. This is inconvenient because it generally requires the user to fill a separate container with water and transport it from the water source to the coffee maker. This can also be messy. Water is frequently spilled either when transporting the water to the coffee maker or when pouring the water from the separate container into the coffee maker&#39;s water reservoir. Commercial-sized coffee makers are permanently plumbed but have other drawbacks, such as size, that make them undesirable for home use.  
         [0004]     An additional problem with prior art coffee makers is that they take Up valuable counter space. Coffee drinkers generally prefer to have coffee on a daily basis and, consequently, coffee makers are generally left out on the counter to allow frequent use without the hassle of repeated setup. Unfortunately, this means that the coffee maker is permanently taking up counter space that might be needed for other things. This is particularly troubling in homes, apartments, hotels, offices, motor homes, and boats where counter space is limited or non-existent. Smaller coffee makers have been manufactured to take up less room, but they still take up counter space. Other coffee makers have been mounted under cabinets to free up counter space, but these are generally positioned over the counter and therefore continue to limit the free space above the counter for use in food preparation or for placement of other kitchen devices. Some prior art coffee makers have even been mounted inside cabinets. Although cabinet-mounted coffee makers do not occupy counter space, they instead take tip valuable storage space.  
         [0005]     The industry has been unable to supply a coffee maker that is ideally space conservative. What is needed, therefore, is a coffee maker that avoids taking up valuable countertop, cabinet, or above-counter space. The industry would also be benefited by a self-filling home coffee maker.  
       SUMMARY  
       [0006]     An object of the present invention is to enable a coffee maker that takes up little or no counter or above-counter space and is not cabinet mounted.  
         [0007]     Another object of the present invention is to enable a space conservative coffee maker that is self-filling.  
         [0008]     This invention provides a significant improvement in the art by enabling a coffee maker that is mounted within the wall of a house, apartment, hotel room, office, motor home, boat, recreational vehicle (RV), or the like. An in-wall coffee maker according to the present invention includes a mounting structure for mounting a coffee maker unit within a wall. The mounting structure includes engagement structures to enable engagement between the mounting structure and one or more wall structures, and also includes attachment members to enable attachment with a coffee maker unit. The coffee maker unit mounts to or within the mounting structure. The coffee maker unit can include a water meter configured to provide a regulated supply of water from an incoming water line to a water reservoir. An electrical junction box can also be provided to supply electrical power from a power source to the coffee maker.  
         [0009]     An in-wall coffee maker according to this invention is ideally space conservative because it occupies space not generally used. By placing the in-wall coffee maker of this invention within a wall cavity, no countertop space and little or no above-counter space is required. Furthermore, cabinet space is also not required. Also, by providing a self-filling capability through the use of a water meter, the in-wall coffee maker of this invention becomes extremely convenient to use.  
         [0010]     The foregoing and other objects, features and advantages of the invention will become more readily apparent from the following detailed description of a preferred embodiment of the invention that proceeds with reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a perspective view of an in-wall coffee maker according to a preferred embodiment of the present invention, shown mounted within a wall cavity of a building.  
         [0012]      FIG. 2  is a perspective view of the in-wall coffee maker of  FIG. 1 , shown removed from the wall cavity.  
         [0013]      FIG. 3  is a side elevation view of the in-wall coffee maker of  FIG. 2  with dashed lines indicating a location of a wall panel when the in-wall coffee maker is mounted within the wall cavity.  
         [0014]      FIG. 4  is a top plan view of the in-wall coffee maker of  FIG. 2 , also with dashed lines indicating the location of the wall panel when mounted.  
         [0015]      FIG. 5  is a schematic diagram illustrating the components of the coffee maker of  FIG. 1  for providing a self-filling capability.  
         [0016]      FIG. 6  is a perspective view of a mounting box configured to secure the coffee maker unit of  FIG. 2  within the wall cavity, as shown in  FIG. 1 .  
         [0017]      FIG. 7  is an exploded perspective view of the coffee maker unit of  FIG. 2  removed from the mounting box of  FIG. 6 .  
         [0018]      FIG. 8  is an illustration of a wall installation area set up for mounting the in-wall coffee maker shown in  FIG. 1 .  
     
    
     DETAILED DESCRIPTION  
       [0019]      FIG. 1  is a perspective view of an in-wall coffee maker  10  mounted within a wall cavity in a kitchen area according to one embodiment of the present invention. The basic advantages of this invention are evident from  FIG. 1 . Particularly, as illustrated, the in-wall coffee maker  10  does not occupy any space on top of the counter  13 . Furthermore, the amount of above-counter space it occupies is minimal or none. In the embodiment shown, only a small semicircular projection  14  protrudes into the room from the wall panel  12 . In an alternative embodiment, the face  17  can be configured to lie flush with the wall  12 . In that embodiment, no above-counter space is occupied by the in-wall coffee maker  10 . Also according to this invention, no cabinet space is occupied by the in-wall coffee maker  10 . Accordingly, the in-wall coffee maker  10  of this invention leaves counter, above-counter, and cabinet space available for activities or other kitchen appliances. The specific features of the in-wall coffee maker  10  will now be more fully discussed with reference to  FIGS. 2-4 .  
         [0020]      FIG. 2  is a perspective view, and  FIGS. 3 and 4  are a side elevation and a top plan view, respectively, of the in-wall coffee maker  10  of the present invention according to the embodiment of  FIG. 1 . Referring to  FIGS. 2-4 , according to one embodiment, the in-wall coffee maker  10  includes a mounting structure, such as a mounting box  20 , that receives a coffee maker unit  15 . The coffee maker unit  15  is attached to the mounting box  20  using attachment structures. In this embodiment, the attachment structures include flanges  60  (see  FIG. 6 ) in the mounting box  20  having holes  16 A that allow fasteners, such as screws, to be threaded through mating holes  16  in the face  17  of the coffee maker unit  15  into the wall panel  2 . Of course, it should be evident that any type of attachment between the coffee maker unit  15  and the mounting box  20  is within the contemplation of this invention, including, but not limited to, mechanical attachment via screws, rivets, bolts, nails, clips, latches, snap engagement, hook and eye material (i.e., VELCRO®), etc., or chemical attachment via glue or other adhesives.  
         [0021]     Referring specifically to  FIGS. 3 and 4 , dashed lines represent the position of the wall panel  12  when the coffee maker  10  is mounted within a wall cavity. As illustrated by  FIGS. 3 and 4 , when mounted, most of the coffee maker  10  is retained within the wall cavity. Specifically, the coffee maker  10  of this preferred embodiment extends approximately four inches into the wall cavity while protruding only about two and one-half inches from the wall  12  at the center of its semicircular projection  14 . Only a small portion of the coffee maker  10 , therefore, protrudes from an outside face of the wall  12  after installation. As noted previously, another embodiment has a front face that lies flush with the wall. In-wall mounting is therefore extremely advantageous because it frees up countertop and above-counter space for other things.  
         [0022]     Unlike conventional home coffee makers, the coffee maker unit  15  of this invention also preferably includes a self-filling capability.  FIG. 5  is a schematic diagram showing the components of the coffee maker of  FIG. 1  for providing the self-filling capability. Self-filling coffee makers having various cup capacities are within the contemplation of this invention, including, for example, four, ten, and twelve cup embodiments. In the self-filling coffee maker, the user actuates a fill selector  71  to select the desired amount of coffee to be brewed, up to the maximum amount for that particular embodiment. After a user selects the desired cup amount for the coffee maker to produce, a water meter  75  (such as a solenoid valve connected to a timer) operates to regulate a supply of water from an incoming water line  70 , generally from a cold water source, to provide the selected amount of water to the coffee maker unit  15 . Specifically, a water metering system  75  is provided that can be controlled by a program on an electronic circuit or directly by a user. The water metering system  75  can be used in combination with a traditional heated water reservoir  72  or it can be used in an in-line heating system (not shown). In a water reservoir system, the meter  75  regulates a supply of water into the water reservoir  72 . The water reservoir  72  typically contains a heating element  76  for heating the water to the desired temperature for brewing the coffee in the drip cone  74 . In an in-line system, however, an in-line heating system (rather than a heated water reservoir  72 ) is used to heat water in route from the metering system  75  to a brewing area such as a drip cone  74  for brewing the coffee. A preferred water metering system is electric, but a water pressure-driven meter could also be used.  
         [0023]     Another feature of this embodiment is the provision of electrical power outlets  26  located on the face  17  of the coffee maker unit  15 . The outlets  26  are wired to an electrical power source through an electrical junction box  50  (see  FIG. 6 ) in the mounting box  20 . These outlets  26  allow other electrical appliances to be plugged in and receive electrical power through the coffee maker unit  15 .  
         [0024]     The coffee maker unit  15  also preferably includes conventional coffee maker features known in the art. Some of these features include a programming control  21  for an on/off timer, a manual on/off switch  22 , a  24 -hour digital clock  24 , and a power indicator  25  all located on the face  17 . Also, a coffee pot  35  can be removably supported within a coffee pot cavity  30  on a warming plate  32 . The on/off timer of the coffee maker unit  15  is preferably fully programmable to allow automatic starting at any desired time. Another preferable feature is a two-hour automatic shutoff. The specific details regarding the provision of these and other electronic features is known to those of skill in the art.  
         [0025]      FIG. 6  is a front perspective view of one embodiment of the mounting box  20 , into which the in-wall coffee maker unit  15  is installed, according to this invention. Referring to  FIG. 6 , the mounting box  20  is preferably a rough-in sheet metal box that includes a top wall  40 , a bottom wall  42 , two side walls  44 ,  46 , and a rear wall  48 . Preferred dimensions for the mounting box  20  for a ten-twelve cup coffee maker  10  are approximately 27.9 cm wide×27.9 cm tall by 10.16 cm deep. For a four cup embodiment, the preferred dimensions are approximately 20.32 cm wide by 20.32 cm tall by 7.62 deep. Flanges  60  or tabs are provided along a front portion of each of the top, bottom, and side walls  40 ,  42 ,  44 ,  46  of the mounting box  20 . The flanges  60  provide attachment members for attaching the mounting box  20  to the coffee maker unit  15 . Fasteners can be used to secure the coffee maker unit  15  to the mounting box  20  via the flanges  60 . If screws are used as the fasteners, each of the flanges  60  preferably contains one or more holes  16 A for receiving the screws from mating holes  16  in the coffee maker unit  15 . As noted previously, the attachment members according to this invention are not limited to the flanges  60  with screw holes  16 A of this embodiment. Rather, any type of attachment that is sufficient to secure the coffee maker unit  15  to the mounting structure  20  is within the scope of this invention. The attachment, however, is preferably non-permanent, such that the coffee maker unit  15  can be easily removed from the mounting box  20  for maintenance, repair, or replacement. Furthermore, in some embodiments, no attachment members are required at all. For instance, the coffee maker unit  15  can rest within the mounting box  20  (or on a mounting shelf) without being secured thereto and still satisfy the requirements of this invention.  
         [0026]     The mounting box  20  also preferably includes engagement members in the form of tabs  54  formed from cut out portions of the top  42 , bottom  44  and side walls  46 ,  48 . The tabs  54  are cut from the sheet metal box  20  in such a way that they can be bent outwardly from the box  20  to engage a wall panel  12  (see  FIG. 1 ), such as sheet rock, wood paneling, etc. Specifically, the tabs  54  can be rectangular-shapes cut out along three edges or triangular shapes cut out along two edges, among others. Redundant or alternative securing can be provided by engagement members in one of the side walls  44 ,  46  used to fasten the mounting box  20  to a wall stud  84  (see  FIG. 8 ). For example, mechanical fasteners such as nails, screws, bolts, etc.,  85  can be applied through holes  56  to secure the mounting box  20  to the wall stud  84 . A chemical engagement member, such as an adhesive strip, or any of a number of other types of engagement members could also be used to secure the mounting box to the stud  84 , obviating the need for holes  56 .  
         [0027]     Still referring to  FIG. 6 , an electrical junction box  50  is provided along one of the side walls  44  of the mounting box  20 . The junction box  50  can be formed along any of the walls  40 ,  42 ,  44 ,  46 ,  48 . The electrical junction box  50  can be a conventional single gang outlet box configured to allow hardwiring between the in-wall coffee maker  10  and power supply lines of the building or vehicle in which the coffee maker  10  is installed. The power supply lines may provide AC (i.e., 110V or 220V) or DC (i.e., 12V) power, depending on the power available. For situations where hardwiring is impracticable or undesirable, the electrical junction box can comprise a power cord that allows the coffee maker  10  to be plugged into an existing power outlet. The coffee maker unit  15  is electrically connected to power connections in the junction box  50 . The electrical connection between the coffee maker unit  15  and the junction box  20  can be established through hardwiring or a power cord can be provided on the coffee maker unit  15  that plugs into a conventional-type outlet in the junction box  50 . Yet another possible embodiment would include having a simple male/female interface between a power connector on the coffee maker unit  15  and a power connector in the electrical junction box  50 . In this way, the coffee maker unit  15  could simply be inserted into the mounting box  20  such that its power connector (e.g., a plug) slides into engagement with the power connector (e.g., a receptacle) of the junction box  50 , without the need for additional wiring. Besides receiving power for the coffee maker unit  15  itself, the in-wall coffee maker  10  can include power lines routed from the junction box  50  to electrical outlets  26  on the front face  17  of the coffee maker unit  15  to provide electrical power to external devices. Yet another alternative embodiment is provided by extending an edge of face  17  of the coffee maker unit  15  beyond the side wall  44  of the mounting box  20  and by providing a slidable plug on the face  17  which can be plugged directly into an electrical wall socket located proximal with the coffee maker  10 .  
         [0028]     In a self-filling embodiment, described again with reference to  FIG. 6 , an incoming water line  70  enters the mounting box  20  through a hole  52  in one of the walls  40 ,  42 ,  44 ,  46 ,  48  thereof. As with the junction box  50 , the hole  52  can be located within any one of the walls  40 ,  42 ,  44 ,  46 ,  48 , although, in this embodiment, it is located in the same side wall  44  as the junction box  50 . The hole  52  for receiving the incoming water line  70  is provided with a rubber grommet  53  to protect the water line  70  from being damaged by the sharp edges of the sheet metal mounting box  20 . Alternatively, a plumbing fixture, such as an “I” connector, could be used in the hole  52  to allow the incoming water source line  70  to be connected to an outside end of the connector and a water reservoir line to be connected to an opposite end of the connector on the inside of the mounting box  20 . The water reservoir line receives water from the incoming water source line  70  through the connector and supplies water to the water reservoir through a metering system  75 . Yet another embodiment that can further simplify installation includes male/female plumbing connectors on the coffee maker unit  15  and the mounting box  20 . The male/female plumbing connectors allow the coffee maker unit  15  to be connected directly to the incoming water supply line  70  without requiring tubing between the mounting box  20  and the coffee maker unit  15 .  
         [0029]     Although the preferred material for the mounting box  20  is sheet metal because of its ease of manufacture and adaptability, other materials, such as plastic, wood, etc., could also be used for the mounting box  20 . The use of other materials would require only minor modifications to the mounting box  20 . Tabs  54  of the sheet metal box, for instance, in a plastic or wood box, could be replaced by other types of engagement structures such as clips or other fasteners. Also, although the mounting structure of the foregoing embodiments was a mounting box  20 , it should be noted that any mounting structure that is capable of supporting the coffee maker unit  15  in place within the wall cavity is within the contemplation of this invention. For instance, a mounting bracket, a mounting shelf, a mounting hook(s), etc., could all be used for this purpose. A sheet rock screw can also be used to secure the box from either a side, top, or bottom location. Metal bars (i.e., “T”, “L”, or “I” bars) could also be added behind the box to secure it.  
         [0030]      FIG. 7  is an exploded perspective view of the coffee maker unit  15  and the mounting box  20  illustrating an interface between them. As illustrated by  FIG. 7 , the mounting box  20  receives and supports the coffee maker unit  15  within a wall cavity and provides the necessary water  52  and power  50  interconnections. Specifically, an incoming water line  70 A provides water to the mounting box  20  through hole (or plumbing fixture)  52 . An internal water line  70 B (either the same as line  70 A or connected thereto via a plumbing fixture) supplies water to a water meter  75  of the coffee maker unit  15 . Also, electrical power is provided to the junction box  50  of the mounting box  20  by an external power cable  99 A. Power from the junction box  50  to the coffee maker unit  15  is supplied via an internal power cable  99 B. Although the embodiments described so far have included a separate mounting structure, it should be noted that one embodiment of this invention can include a coffee maker unit provided with an integral mounting structure to mount with a wall structure that has the necessary water and power interconnections provided directly thereon. In such an embodiment, a separate mounting structure would be unnecessary.  
         [0031]     A method for installing the in-wall coffee maker of  FIGS. 1-7  will now be described in detail with reference to  FIGS. 6, 7 , and  8 . It should be noted, however, that most of the following steps need not be performed in the order in which they are described. The first step is to locate an area for installation. The installation area for a self-filling coffee maker should be near a water source  90 , such as is typically found near a sink, dishwasher, or refrigerator (if plumbed for ice/water), to facilitate easy routing of the incoming water line  70 . The installation area should also be located near a power source  92 . The width between wall studs  84  at the installation area should be checked to make sure that the coffee maker  10  will fit between them. Specifically, the opening between studs  84 , or cavity width, should not be less than 27.9 cm wide for the ten-twelve cup embodiment and not less than 20.32 cm wide for the four cup embodiment. Also, the power outlet area  92  should not be within the cavity width.  
         [0032]     Once a suitable location has been selected, a template corresponding to the desired size of the wall cut out is used to properly mark a cut out area on the wall panel  12 . The cut out area should be above the typical 10.16 cm back splash  82 . If the back splash  82  is higher than typical and is noticeably in the way, the installation location may have to be altered, or a professional may need to be hired, to install the unit. Otherwise, the back splash  82  can be modified by cutting around the necessary areas to facilitate installation. Once the cut out area is marked, the marked area of the wall panel  12  can be cut out using any suitable cutting tool, such as a saw, and then removed. At this point, an area directly below counter  13  height from the cut out area should be located, and a 1.27 cm hole should be drilled through the wall at this location. Holes adjacent to this hole should also be drilled along the wall  12  in the direction of the water source  90 . These holes should be spaced a few inches apart to enable the person installing the unit to run the water line  70  (preferably 0.635 cm) to the installation area. Once all the holes are finished, the water line  70  is routed from the water source  90  to the installation location. Plenty of line length should be left at both ends to make sure that a proper connection can be made. No excess line should be cut off at this point.  
         [0033]     A cold water valve at the cold water source  90  is now turned off. An “I” connection (preferably either 0.952 cm by 0.635 cm or 0.635 cm by 0.635 cm) can be used to tie in the water line  70  to the mounting box  20 . Alternatively, the water line  70  can be run through the hole  52  in the mounting box  20  and connected to the coffee maker unit  15  using an “I” connection. The water should not be turned back on yet. The electrical junction box  50  should next be connected to the power source  92 , either with a power cord connection or hardwire integration. Hardwire integration may require a professional electrician and is described in further detail below.  
         [0034]     In the case of a hardwire connection, a nearby power source  92  (i.e., an electrical outlet) is found. This outlet  92  should be located within one stud cavity away from the installation area. The power to this outlet  92  is then turned off to prevent the risk of electrocution. Any necessary holes in the studs  84  should then be drilled in order to route a power cable  99 A from the power source  92  to the junction box  50 . Next, the necessary cable length is cut and fed into the outlet box. The outlet  92  is disconnected so the wire can be safely pulled into the outlet box. The power cable  99 A can then be routed into the mounting box  20  and the power lines tied to the junction box  50 .  
         [0035]     Referring still to  FIGS. 6, 7 , and  8 , once the power lines and water line  70  are connected to the mounting box  20 , the mounting box  20  is placed in the wall cavity so that the opening of the mounting box  20  is flush with the wall panel  12 . When the entrance to the mounting box  20  is flush against the outside of the wall panel, the tabs  54  are bent outwardly to secure the box  20  to the wall panel  12 . If necessary, a side wall of the mounting box  20  can be further fastened to a wall stud  84  with fasteners such as nails  85 . Of course, any other type of fastener such as screws, glue, etc., may be used. Next, the coffee maker unit  15  is installed into the mounting box  20 . To do this, the coffee maker unit  15  is electrically connected to the power source at the junction box  50  and also connected to the incoming water line  70 A. The electrical connection between the coffee maker unit  15  and the junction box  50  can be a plug-in connection or a hardwire connection, among others. The connection to the water line can be through a separate internal water line  70 B and a plumbing fixture or directly between the unit  15  and the external line  70 A, among others.  
         [0036]     The coffee maker unit  15  should not be fully secured within the mounting box  20  until the water is checked and verified to be running properly. The cold water source  90  should therefore be turned on and the connections should be checked for leaks. If any leaks appear, they should be fixed. If there are no leaks, the unit  15  is then attached to the mounting box  20  via mating screw holes  16  in the unit  15  and flanges  60 . Other types of attachment between the box  20  and the unit  15  are also acceptable. Also alternatively, the coffee maker unit  15  can have an integral mounting structure to allow it to be directly fastened to the wall panel  12  and be directly supplied with power and water without the need for a separate mounting box  20 . In any event, once the coffee maker  10  is completely installed, the power can be turned on and the coffee maker unit  15  can be operated.  
         [0037]     Installation of the in-wall coffee maker  10  of this invention in boats and motor homes is relatively the same as for buildings such as houses, hotels, offices, and apartments. Because tabs  54  are provided in the rough-in box  20  that can be bent over to engage a wall panel  12 , a wall opening of sufficient size to house the unit is the only requirement for installation. The tabs  54  will generally provide enough strength to hold the coffee maker  10  in place. Furthermore, additional holes  56  are available for securing the mounting box  20  to other wall structures if alternative or additional securing is needed.  
         [0038]     A few of the many other possible embodiments of this invention will now be described in general terms. At the outset, it should be noted that ease of installation and maintenance are important considerations for designing a system according to this invention. It is desirable to have the installation as easy as possible and to have the ability to change out the unit quickly and easily if problems occur (such as a water leak or a malfunction with the unit itself). It is also important to make the face flush (or substantially flush) with the wall to provide the advantage of freeing countertop space. Other important considerations include avoiding problems associated with the water supply or power supply issues through reliable connections.  
         [0039]     Although the primary embodiment includes a rough-in sheet metal box with hardwired power and water connections, there are numerous other possible ways to accomplish the objects of this invention. For instance, an enclosure made of plastic, wood, or other material can be built inside a wall cavity and provided with a water metering system. A conventional countertop coffee maker can then be fitted within the enclosure, connected to a power source, and receive water into its water reservoir from the water metering system. A slide-in unit is also contemplated where the water and power sources are supplied through male to female connectors that engage each other as the unit is slid into place.  
         [0040]     Yet another alternative is to frame-in and sheet rock an alcove area and place a water dispenser and outlet inside this area. A conventional coffee maker could then be placed within the alcove. Another alternative includes providing a frame, similar to a picture frame, to an existing coffee pot to support it within a wall cavity. The coffee pot is connected to a water supply and a power supply and placed within the wall cavity, using the frame to support it in place. Furthermore, a mounting bracket or a shelf could be used instead of a mounting box to support the in-wall coffee maker within the wall cavity according to this invention. Still other embodiments are possible which are not described here but are within the spirit of the invention and should be considered to be within the scope of the claims.  
         [0041]     Having described and illustrated the principles of the invention in various embodiments thereof, it should be apparent that the invention can be modified in arrangement and detail without departing from such principles. I claim all modifications and variations coming within the spirit and scope of the following claims.