Abstract:
An electrical box assembly that is supplied with electricity by an external electrical cord and which in turn supplies electricity to a nearby wall-mounted outlet box. The electrical box assembly includes a cord grip mount that accepts a cord grip fitting for securing the electrical cord to the assembly and sealing around the connected electrical cord. The electrical box assembly may include connecting points for a low voltage scoop to provide a passageway for routing coax cable to the nearby outlet box. The electrical box assembly is especially useful for supplying electrical power to a wall-mounted TV while minimizing disruption of adjacent wall surfaces and underlying studs.

Description:
FIELD OF THE INVENTION 
     This invention relates to the installation of electrical components and specifically to an electrical box assembly that eliminates the need to disturb wall studs in order to provide electrical access to a portion of the wall previously without electrical outlets. 
     BACKGROUND OF THE INVENTION 
     With the advent of lightweight large screen televisions, such as those with LCD and plasma displays, it has become common for homeowners to mount lightweight TVs to the wall to free up floor space and thereby eliminate the need for a stand to obtain the optimum viewing height. 
     Aesthetically, when mounting a TV on a wall, it is desirable to keep the electrical cables out of sight. Thus, even if an existing outlet is available directly under the newly installed TV, it is preferable to route electrical cables within the wall to keep them out of sight. Providing an electrical outlet for the TV by conventional means typically requires locating the closest existing electrical box, installing a new outlet box at the location of the TV, pulling electrical cable between the boxes, and completing the wiring connections to provide line voltage to the new electrical box. 
     Many times the existing electrical outlets are located at some distance horizontally from the desired location of the TV, making it necessary to remove a portion of the drywall, drill holes in the underlying studs, and pull electrical cable through the studs. This is a very time consuming task as the wallboard is disrupted and must be replaced and the wall must be plastered and repainted or re-wallpapered to restore the wall to its original condition. 
     What is needed therefore is a device and method for installing an electrical outlet on a wall that causes no disruption to the visible wall surface below a wall-mounted TV, does not require alteration of the underlying studs, eliminates the pulling of electrical cables through adjacent studs in the wall, and eliminates extensive repairs to the wall surface after the cables are installed. When installed, such a device should provide a clean wall underneath the wall-mounted TV, with no cables running up the wall from a lower electrical outlet to the TV. 
     SUMMARY OF THE INVENTION 
     The invention is an electrical box assembly that is supplied with electricity by an external electrical cord and which in turn supplies electricity to a nearby wall-mounted outlet box. The electrical box assembly includes a cord grip mount that accepts a cord grip fitting for securing the electrical cord to the assembly and sealing around the connected electrical cord. The electrical box assembly may include connecting points for a low voltage scoop to provide a passageway for routing coax cable to the nearby outlet box. The electrical box assembly is especially useful for supplying electrical power to a wall-mounted TV while minimizing disruption of adjacent wall surfaces and underlying studs. 
     OBJECTS AND ADVANTAGES 
     Several advantages are achieved with the electrical box assembly of the present invention, including:
         (1) The electrical box assembly eliminates the disruption of adjacent wall surfaces for the purpose of routing electrical cables through the wall.   (2) The electrical box assembly eliminates the need to alter underlying studs in order to supply electricity to a wall-mounted TV.   (3) The electrical box assembly eliminates the pulling of electrical cables through adjacent studs in the wall.   (4) The electrical box assembly eliminates the need to make extensive repairs to surrounding wall surfaces.   (5) The electrical box assembly provides a clean wall, free of visible cables; underneath any wall-mounted TV it is used in conjunction with.       

     These and other objects and advantages of the present invention will be better understood by reading the following description along with reference to the drawings. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the preferred embodiment of an electrical box assembly according to the present invention depicted in a practical application installed on a wall and supplying electricity to a second electrical box assembly. 
         FIG. 2  is a front perspective view of a first and preferred embodiment of a cord grip mount that forms a portion of the electrical box assembly of  FIG. 1 . 
         FIG. 3  is a rear perspective view of the cord grip mount depicted in  FIG. 2 . 
         FIG. 4  is a front elevation view of the cord grip mount depicted in  FIG. 2 . 
         FIG. 5  is a sectional view of the cord grip mount taken along line  5 - 5  of  FIG. 4 . 
         FIG. 6  is a front perspective view of a second embodiment of a cord grip mount according to the present invention. 
         FIG. 7  is a rear perspective view of the cord grip mount depicted in  FIG. 6 . 
         FIG. 8  is a front elevation view of the cord grip mount depicted in  FIG. 6 . 
         FIG. 9  is a sectional view of the cord grip mount taken along line  9 - 9  of  FIG. 8 . 
         FIG. 10  is an exploded perspective view of a cord grip fitting forms a portion of the electrical box assembly of  FIG. 1 . 
         FIG. 11  is an end view of a cord grip body that forms a portion of the cord grip fitting depicted in  FIG. 10 . 
         FIG. 12  is a sectional view of the cord grip fitting taken along line  12 - 12  of  FIG. 11 . 
         FIG. 13  is a perspective view of a gripper ring that forms a portion of the cord grip fitting depicted in  FIG. 10 . 
         FIG. 14  is a plan view of the gripper ring of  FIG. 13 . 
         FIG. 15  is a sectional view of the gripper ring taken along line  15 - 15  of  FIG. 14 . 
         FIG. 16  is a plan view of a cord locknut that forms a portion of the cord grip fitting depicted in  FIG. 10 . 
         FIG. 17  is a sectional view of the locknut taken along line  17 - 17  of  FIG. 16 . 
         FIG. 18  is a plan view of a compression nut that forms a portion of the cord grip fitting depicted in  FIG. 10 . 
         FIG. 19  is a sectional view of the compression nut taken along line  19 - 19  of  FIG. 18 . 
         FIG. 20  is a plan view of a sealing ring that forms a portion of the cord grip fitting depicted in  FIG. 10 . 
         FIG. 21  is a sectional view of the sealing ring taken along line  21 - 21  of  FIG. 20 . 
         FIG. 22  is a perspective view of an electrical box that forms a portion of the electrical box assembly of  FIG. 1 . 
         FIG. 23  is a front view of the electrical box of  FIG. 22 . 
         FIG. 24  is a front elevation view of a low voltage scoop that may optionally used to form a portion of the electrical box assembly of  FIG. 1 . 
         FIG. 25  is a sectional view of the low voltage scoop taken along line  25 - 25  of  FIG. 24 . 
         FIG. 26  is a perspective view of the preferred embodiment of the electrical box assembly including an electrical cord plugged into an existing electrical outlet. 
         FIG. 27  is a front elevation view of the electrical box assembly depicted in  FIG. 26 . 
         FIG. 28  is a sectional view of the electrical box assembly taken along line  28 - 28  of  FIG. 27 . 
         FIG. 29  is an exploded perspective view of a cord grip fitting and a low voltage scoop in alignment with the preferred embodiment of an electrical box assembly according to the present invention. 
       INDEX TO REFERENCE NUMERALS IN DRAWINGS 
       
           
           
             
                 20  cable holding electrical box assembly 
                 22  electrical box 
                 24  electrical cord 
                 26  plug end of electrical cord 
                 27  free end of electrical cord 
                 28  cord grip fitting 
                 30  outlet box 
                 32  existing duplex outlet 
                 34  electrical outlet 
                 36  cord grip mount, preferred embodiment 
                 38  outward extending nose portion 
                 40  upper surface of nose portion 
                 42  lower surface of nose portion 
                 44  circular opening 
                 46  base portion 
                 48  end portion 
                 50  inner aperture 
                 52  threaded bores 
                 54  cord grip mount, second embodiment 
                 56  flap panel 
                 58  circular opening 
                 60  front side of base portion 
                 62  back side of base portion 
                 64  peripheral wall 
                 66  locknut 
                 68  sealing ring 
                 70  cord grip body 
                 72  gripper ring 
                 74  compression nut 
                 76  grommet 
                 78  first end of cord grip body 
                 80  second end of cord grip body 
                 82  central flange 
                 84  internal bore 
                 86  mount fastening arrangement 
                 88  external threads on cord grip mount 
                 90  cord fastening arrangement 
                 92  external screw threads on cord grip body 
                 94  conical seat 
                 96  waterproof sealing arrangement 
                 98  cavity in gripper ring 
                 100  circular periphery of gripper ring 
                 102  first end of gripper ring 
                 104  second end of gripper ring 
                 106  internal bore 
                 108  finger 
                 110  hex-shaped outer periphery of compression nut 
                 112  central bore 
                 114  internal screw threads 
                 116  box member 
                 118  trim plate 
                 120  divider plate 
                 122  side wall 
                 124  back wall 
                 125  inner cavity 
                 126  front edge 
                 127  rail 
                 128  channel 
                 130  flange 
                 132  aperture in flange 
                 134  fastener 
                 136  tab 
                 138  first mounting arrangement 
                 140  second mounting arrangement 
                 142  rotatable flag 
                 144  mounting fastener 
                 146  aperture 
                 148  head 
                 150  oversize aperture 
                 152  sidewall flange 
                 154  boss 
                 156  mounting screw 
                 158  recessed area 
                 160  connection point 
                 162  flange of trim plate 
                 164  peripheral wall 
                 166  collar 
                 167  recessed wall portion 
                 168  knockout area 
                 170  low voltage scoop 
                 172  base portion 
                 174  ear 
                 176  aperture 
                 178  threaded bore 
                 180  outer wall 
                 182  sidewall 
                 184  conduit or passageway for cable 
                 186  perimeter wall 
                 188  wall 
                 190  quick connect electrical fitting 
                 192  cover plate 
                 194  electrical conductor 
                 196  electrical enclosure 
                 198  fastener for cord grip mount 
                 200  fastener for scoop 
                 202  fastener for cover plate 
                 204  electrical cable 
                 206  coax cable 
                 208  stud 
             
           
         
      
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1  there is shown a preferred embodiment of a cable holding electrical box assembly  20  according to the present invention. The cable holding electrical box assembly  20  includes an electrical box  22 , an electrical cord  24  with a plug end  26 , a free end  27  (see  FIG. 28 ), and a cord grip fitting  28  for securing the electrical cord  24  to the assembly  20 . The cable holding electrical box assembly  20  of the present invention enables a homeowner to provide electrical outlets on a wall for powering a TV or similar electrical component that will later be mounted to the wall over the electrical outlets. Power to the outlet box  30  for the TV, which in the practical application shown in  FIG. 1  is a second cable holding electrical box, is supplied by the electrical cord  24  which is plugged into an existing duplex outlet  32 . The cable holding electrical box assembly  20  enables a homeowner to quickly and easily provide electrical outlets  34  for a TV or similar component at the point where the component will be mounted and in a manner that no electrical cables will be in view. The cable holding electrical box assembly  20  therefore eliminates a significant amount of repair work for the homeowner as compared to the conventional means of powering an electrical box, such as removing drywall, routing electrical cables within the wall and through existing studs as required. The electrical box assembly  20  includes a cord grip mount  36  that is used to attach the cord grip fitting  28  to the electrical box  22 . The electrical box  22  is a two-gang box that can be configured by the homeowner to accept two low voltage components, two high voltage components, or one high and one low voltage component. 
     With reference to  FIGS. 2-5 , the preferred embodiment of the cord grip mount  36  includes an outward extending nose portion  38  with an upper surface  40  and a lower surface  42  and a circular opening  44  in the lower surface  42 . The cord grip mount  36  further includes a substantially planar base portion  46  with end portions  48  having inner apertures  50  and threaded bores  52  therein. 
     Referring to  FIGS. 6-9 , a second embodiment of the cord grip mount  54  includes a flat panel  56  instead of an outward extending nose portion. The flat panel  56  includes a circular opening  58  therein. The second embodiment of the cord grip mount  54 , similar to the preferred embodiment, includes the substantially planar base portion  46 , end portions  48 , and inner apertures  50  and threaded bores  52  in the end portions  48 . The flat panel  56  of the cord grip mount  54  is raised above the front side  60  and recessed away from the back side  62  of the base portion  46 . A peripheral wall  64  extends around the panel  56  on the back side  62 . 
     With reference to  FIG. 10 , the cord grip fitting  28  includes, from left to right in the figure, a locknut  66 , a sealing ring  68 , cord grip body  70 , gripper ring  72 , and a compression nut  74 . A grommet  76 , a lower portion of which is cut away in the figure, may be included in the cord grip fitting  28  as an option if required in a wet environment. As shown in  FIGS. 11-12 , the tubular cord grip body  70  includes a first end  78 , a second end  80 , a central flange  82 , and an internal bore  84  there through. The cord grip fitting  28  includes a mount fastening arrangement  86  for securing the cord grip fitting to the cord grip mount  36  (see  FIG. 2 ). The mount fastening arrangement  86  for securing the cord grip fitting  28  to the cord grip mount  36  includes external threads  88  on the first end  78  of the cord grip body  70 , the sealing ring  68 , and the internally threaded locknut  66  for urging the sealing ring  68  against the central flange  82  of the cord grip body  70 . A detailed view of the locknut  66  is shown in  FIGS. 16-17  and a detailed view of the sealing ring  68  is shown in  FIGS. 20-21 . The cord grip fitting  28  further includes a cord fastening arrangement  90  for securing an electrical cord (not shown) to the second end  80  of the fitting  28 . As shown in  FIG. 12 , the cord fastening arrangement  90  includes external screw threads  92  and a conical seat  94  coaxial with the internal bore  84  on the second end  80  of the cord grip body  70 . The cord fastening arrangement  90  includes an optional waterproof sealing arrangement  96  for sealing the cord grip fitting  28  in a watertight seal against the electrical cord. Tightening the compression nut  74  on threads  92  of cord grip body  70  compresses fingers  108  of gripper ring  72  against the grommet  76  and seals the resilient grommet  76  against the electrical cord (not shown). The material of construction of the cord grip body  70 , gripper ring  72 , and compression nut  74  is preferably nylon. The material of construction of the sealing ring  68  is preferably polyethylene and the grommet  76  is preferably constructed of SANTOPRENE® thermoplastic rubber available from Advanced Elastomer Systems of Akron, Ohio. 
     As shown in  FIGS. 13-15 , the one-piece gripper ring  72  is constructed of resilient material and includes a cavity  98  therein, a circular periphery  100 , a first end  102 , a second end  104 , an internal bore  106 , and a plurality of fingers  108  extending from the periphery of the first end  102 . As shown in  FIG. 10 , tightening of the compression nut  74  on the cord grip body  70  compresses the gripper ring  72  within the conical seat  94  of the cord grip body  70  and thereby causes the fingers  108  to close against and firmly grip an inserted electrical cord (not shown). In case a waterproof seal is required around the cord, a resilient grommet  76  is inserted into the cavity  98  of the gripper ring  72 . The waterproof sealing arrangement  96  includes the cavity  98  in the first end  102  of the gripper ring  72  and the resilient grommet  76  seated within the cavity  98 . Tightening of the compression nut  74  on the cord grip body  70  compresses the gripper ring  72  within the conical seat  94  of the cord grip body  70  and causes the fingers  108  of the gripper ring  72  to compress the resilient grommet  76  against the electrical cord, thereby creating a watertight seal between the grommet  76  and the electrical cord. 
     Referring to  FIGS. 18-19 , the compression nut  74  includes a hex-shaped outer periphery  110 , a central bore  112  therein to accommodate an inserted electrical cord, and internal screw threads  114 . As shown in  FIG. 10 , internal screw threads  114  of compression nut  74  will engage the external screw threads  92  on the cord grip body  70  and continued tightening will tighten the fingers  108  of gripper ring  72  against the surface of the electrical cord thereby securing it with respect to the cord grip fitting  28 . 
     With reference to  FIGS. 22-23 , the electrical box  22  includes a box member  116  a trim plate  118  and an optional divider plate  120 . The box member  116  includes side walls  122 , and a back wall  124  defining an inner cavity  125 . The electrical box  22  further includes a front edge  126 , two rails  127  defining a channel  128  for receipt of the divider plate  120 , and a flange  130  extending from the front edge  126  along the top and bottom of the box member  116 . The flange  130  includes apertures  132  for receipt of fasteners  134  from the trim plate  118 . Tabs  136  are provided on the trim plate  118  to enable the divider plate  120  to securely seat in the channel  128 . The electrical box  22  includes two mounting arrangements  138 ,  140  for mounting the electrical box  22  to a wall. The first mounting arrangement  138  includes rotatable flags  142  secured to the ends of mounting fasteners  144  that pass through apertures  146  in the flange  130  of the box member  116 . After the trim plate  118  is secured to the electrical box  22 , the heads  148  of the mounting fasteners  144  are accessible through oversize apertures  150  in the trim plate  118 , thus the mounting fasteners  144  will be accessible for tightening after the trim plate  118  is secured to the box member  116 . Generally, four mounting fasteners  144  are provided around the periphery of the flange  130  portion of the box member  116  for the purpose of securing the electrical box  22  to a wall. The first mounting arrangement  138  including the rotatable flags  142  is typically used in old work installations for mounting the electrical box  22  to a wall by simply cutting a hole in the drywall and rotating the mounting fasteners  144  until the drywall is clamped between the flags  142  and the trim plate  118 . The box member  116  includes sidewall flanges  152  for stopping rotation of flags  142  thereby causing the flags  142  to be pulled toward trim plate  150  as the mounting fasteners  144  are rotated clockwise. A second mounting arrangement  140  includes a boss  154  within each of the flanges  130  at one end of the box member  116  and mounting screws  156 . The second mounting arrangement  140  is typically used in new work installations to mount the electrical box  22  to a stud (not shown). The box member  116  further includes recessed areas  158  in the side walls  122  and connection points  160  within the box member  116  to enable the connection of electrical components thereto. The divider plate  120  enables the mixing of high voltage and low voltage components within the inner cavity  125  of the electrical box  22 . If either high voltage or low voltage components are used on both sides of the electrical box  22 , there is no need to install the divider plate  120 . If however, the installation requires that both a high voltage component and a low voltage component be installed within the inner cavity  125 , the divider plate  120  must be installed by sliding it into the channel  128  until the tabs  136  lock it securely therein. Divided in this manner, the inner cavity  125  can support a low voltage component side by side with a high voltage component (not shown). Trim plate  118  includes a flange  162  and a rearward extending peripheral wall  164 . It should be noted that box member  116  is preferably molded in one piece of plastic. Although divider plate  120  is shown herein as being a separate member, it is within the scope of the invention that divider plate  120  could also be integral with and molded in one piece with the box member  116 . 
     Electrical box  22  is a recessed electrical box that will recess an electrical component (not shown) within the wall. Electrical box  22  includes a collar  166  that extends rearward from the front edge  126  of the box to a recessed wall portion  167 . Knockout areas  168 , provided in the recessed areas  158  of the sidewalls  122 , can be removed to provide openings for feeding electrical cables into the inner cavity  125 . 
     Referring to  FIGS. 24-25 , there is shown a low voltage scoop  170  which can optionally be used with the cable holding electrical box assembly of the present invention. The low voltage scoop  170  includes a base portion  172 , two ears  174  extending outward from the base portion  172 , an aperture  176 , and a threaded bore  178  in each ear  174 . The low voltage scoop  170  includes an outer wall  180  and sidewalls  182  that define an inner passageway or conduit  184  for the passage of low voltage cables there through. A perimeter wall  186  provides a wide surface for supporting cables thereon. Preferably the low voltage scoop  170  is molded in one-piece of plastic. The low voltage scoop  170  may be secured to the connection points  160  (see  FIG. 1 ) of the cable holding electrical box assembly in order to provide a conduit for passage of a coaxial cable or similar low voltage cable there through to the second electrical box  30 . 
       FIG. 26  is a perspective view of the preferred embodiment of the electrical box assembly  20  of the present invention installed in a wall  188  that is partially cut away in the figure. The electrical box assembly  20  includes an electrical box  22  and an electrical cord  24 . The electrical box  22  is secured to the wall using one of the mounting arrangements such as the rotatable flags  142  which are clamped against the wall  188  by rotating the mounting fasteners  144  until they are tight against the wall. The cord grip fitting  28  secures to the lower surface  42  of the nose portion  38  of the cord grip mount  36 . A quick connect electrical fitting  190  is shown exploded away from one of the knockout areas  168  in the recessed area  158  of the side wall  122 . The recessed areas  158  in the side walls  122  enables the use of electrical fittings or connectors such as the BLACK BUTTONB™ push-in connector  190  for connecting non-metallic cable to the multi-gang electrical box. The BLACK BUTTONB™ push-in connector, available from Arlington Industries of Scranton, Pa., is simply pushed into one of the knockout areas  168  provided in the recessed area  158 . The recessed area  158  prevents the push-in connectors  190  from projecting outward from the sidewalls of the electrical box  22  and thus interfering with placement of the electrical box in locations where space is tightly restricted. A cover plate  192  is secured to the electrical box to seal around the electrical components installed within the box. As shown in  FIG. 23 , electrical box  22  includes two enclosures  196 , including a first enclosure on the left side of the figure and a second enclosure on the right side of the figure. As shown in  FIG. 26 , one of the electrical enclosures  196  can be left open, without a low voltage scoop attached, and still function for the intended purpose of passing a low voltage cable there through enclosure  196  in order to feed low voltage signal to a second electrical box (not shown). As long as electrical box  22  is divided into separate electrical enclosures to separate high and low voltage enclosures, low voltage cable can be passed through the enclosure  196  and routed to a second electrical box. 
     With reference to  FIG. 27  there is shown a completed installation of the cable holding electrical box assembly  20  installed on a wall. A cord grip fitting  28  and a low voltage scoop  170  are mounted side by side in the two-gang electrical box assembly. Electrical power is fed to the left hand side of the electrical box  22  by electrical cord  24 , which is plugged into an existing electrical outlet  32 . The low voltage scoop  170  provides a passageway  184  through which low voltage cable can be routed to supply a second electrical box (not shown). 
     Referring to  FIG. 28 , the cord grip mount  36  is secured to the connection points  160  of the electrical box  22  and a cord grip fitting  28  is secured to the cord grip mount  36 . Electrical cord  24  extends through the cord grip fitting  28  and is held securely therein. After electrical cord  24  is secured to the electrical box  22  by the cord grip fitting  28 , the electrical conductors  194  within the electrical enclosure  196  can be connected to supply line voltage to a separate electrical box (not shown). Locknut  66  secures the cord grip fitting  28  to the cord grip mount  36  and compression nut  74  clamps the electrical cord  24  within the fitting. 
     Reference is made to  FIG. 1  for an understanding of the operation of the present invention. Prior to installing the electrical box assembly  20  on the wall, cables  204 ,  206  are pulled between the lower box assembly  20  and the upper box  30 . The electrical box  22  is then secured to the wall using one of the two mounting arrangements as described hereinabove with reference to  FIG. 22 . With the electrical box  22  secured to the wall, two electrical components are secured to the box, which could be two high voltage components, two low voltage components or one of each depending on the application. Reference is made to  FIG. 29 , which depicts the installation of a high and a low voltage component. For installation of a high and low voltage component, the installer inserts divider plate  120  into the electrical box  22  to provide separate electrical enclosures for each component. The cord grip fitting  28  is secured to cord grip mount  36  and the free end of the electrical cord  24  is fed through the cord grip fitting  28 . Wiring connections completed inside the electrical enclosure  196 , and the cord grip mount  36  is then secured by fasteners  198  to the connection points  160  on the left side of the electrical box  22 . Compression nut  74  of cord grip fitting  28  is then tightened to securely tighten the electrical cord within the fitting  28 . Low voltage cable is then pulled from the box through low voltage scoop  170  and the scoop is secured by fasteners  200  to connection points  160  on the right hand side of the electrical box  22 . Cover plate  192  is then secured with fasteners  202  to threaded bores  52  and  178  in cord grip mount  36  and low voltage scoop  170  respectively to complete the installation. Cover plate  192  includes openings therein to accommodate the nose portion  38  of the cord grip mount  36  and the nose portion  203  of the low voltage scoop  170 . 
     As shown in  FIG. 1 , in order to supply electricity to a TV, the cable holding electrical assembly  20  is installed low on the wall. A second electrical box  30  is installed on the wall in the location at which the TV will be installed. NM electrical cable  204  supplies electricity from cable holding electrical assembly  20  to the outlets  34  in electrical box  30 . Coax cable  206  is routed through the low voltage scoop  170  in box assembly  20  to provide video signal hookup at the upper electrical box  30 . The cable holding electrical assembly  20  thereby provides a means of supplying line voltage and video signal to a TV without the need to tear up existing walls or to pull cables through studs  208 . 
     Although the description above contains many specific descriptions, materials, and dimensions, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.