Abstract:
A power transfer device adapted for interconnection with the electrical system of a building includes a cabinet, a set of switches mounted to the cabinet, and power input wires interconnected with the switches for supplying power from an auxiliary power source, such as a generator. The switches interconnect with the electrical distribution panel of a building. The power transfer device includes a power input indicating member, such as a watt meter, and a current transformer input arrangement defining an opening through which one or more of the power supply wires extend. The current transformer arrangement is responsive to current in the power supply wires, so as to provide an input to the watt meter as to the amount of power supplied to the power transfer device from the generator.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     This invention relates to a power inlet arrangement for providing power to the electrical system of a building, such as power supplied by a standby generator. 
     Portable generators may be used in certain situations to feed electrical power to residential and commercial load circuits during a utility power outage. These systems frequently include a power inlet box adapted for interconnection with the generator. The power inlet box is typically mounted to the exterior of a building. The power inlet box is connected to a transfer switching mechanism which continues the electrical path through circuit breakers associated with the transfer switching mechanism, to supply power to certain selected circuits of the load center as determined by the transfer switching mechanism circuit breakers. The circuits of the transfer switching mechanism are wired to selected circuits of the load center, through wiring housed within a conduit extending between the load center and the transfer switching mechanism. 
     The present invention relates to a power transfer switching mechanism such as is disclosed in application Ser. No. 09/062,257, filed Apr. 17, 1998, the disclosure of which is hereby incorporated by reference. The &#39;257 application discloses a power input terminal arrangement in the power transfer switching mechanism in combination with a removable cover for preventing access to the power input terminal arrangement. The cover is provided with a power input structure, such as a socket or receptacle, connected to the terminal assembly for selectively receiving a plug connector electrically interconnected with a source of auxiliary power such as a generator. The power transfer switching mechanism in the &#39;257 application provides a selective connection between the remote power inlet box and the switches of the switching mechanism. 
     While the above-described transfer switching mechanisms provide extremely convenient and simple arrangements for establishing direct, hardwired and selective connections with the power inlet box, it is sometimes desirable to provide a power transfer switching mechanism having a power input meter arrangement in its front-panel. With this modification, it is possible to monitor the amount of power provided by a generator during a power outage, so as to prevent overloading of and subsequent damage to the generator or to the building electrical system. Although the broad concept of integrally providing power input meters on a power transfer switching mechanism is well known, it is desirable to modify the power transfer switching mechanisms described in the aforementioned co-pending patent applications to provide an optional meter arrangement in a cover which is selectively engageable with the cabinet of the switching mechanism. 
     One form of a power input meter arrangement for use in connection with a power transfer switching mechanism is disclosed in Flegel U.S. Pat. No. 6,107,701 issued Aug. 22, 2000, the disclosure of which is hereby incorporated by reference. The &#39;701 patent discloses a meter arrangement which is incorporated into the power supply from the remote power inlet box to the power input terminal arrangement of the power transfer switching mechanism. The system disclosed in the &#39;701 patent provides a highly satisfactory system for selectively providing a power input meter arrangement in a power transfer switching mechanism, but requires a number of connections in order to interconnect the power input meters. 
     It is an object of the present invention to provide a transfer switching mechanism having a removable access cover provided with a power input meter arrangement for measuring input power to the transfer switching mechanism from a generator or from a power inlet connected with the generator. It is a further object of the present invention to provide a power input meter arrangement for use in a transfer switching mechanism, which eliminates the numerous connections involved in the prior art system. Another object of the present invention is to provide a transfer switching mechanism which is simple to install and which operates generally similarly to prior art transfer switching mechanisms. It is also an object of the present invention to provide a method for constructing a power transfer device having a power input meter arrangement for monitoring power supplied by a generator so as to prevent overloading thereof. 
     The invention contemplates an improvement in a power transfer arrangement for supplying power from a generator to the electrical system of a building. The power transfer arrangement includes a power inlet arrangement for interconnection with the generator for receiving power therefrom, and a power transfer device separate from the power inlet arrangement adapted for interconnection with the building electrical system. The invention resides in a power input indicating structure for selectively displaying the amount of power provided by the generator. The power transfer device includes a cabinet having a front panel to which is mounted a set of switches for controlling the supply of power from the power transfer device to the building electrical system. The power transfer device further includes a compartment defined by the cabinet at a location spaced from the set of switches. The cabinet defines an opening providing access to the compartment. The cover is positionable over the opening and removably engageable with the cabinet for selectively closing the opening for preventing access to the compartment. The power input indicating structure is fixed to the cover. The power input indicating structure includes at least one meter having a block-like rear portion and a convexly-shaped forward portion projecting through a vertically extending wall of the cover. The forward portion includes a transparent window having a support member for mounting a wattage scale visible through the window, and an indicator mounted for movement along the scale in response to the supplying of power from the generator. 
     The power input indicating structure is preferably in the form of one or more watt meters mounted to the cover. A current transformer input arrangement is interconnected with each watt meter. Each current transformer input arrangement includes a current transformer coil defining an opening through which a power input wire extends. The current transformer coil is located within the compartment defined by the cabinet, and the power input wire extends between the power inlet arrangement and the switches of the power transfer device, for supplying power to the power transfer device from the generator. In a known manner, the current transformer coil cooperates with the meter to form an electrical circuit. Current in the power input wire induces a corresponding current in the current transformer coil, which acts on the watt meter to output a reading indicative of power supplied to the power transfer device. In this manner, a power input meter arrangement can be provided for the power transfer device without the need for making direct connections of the power input meter in the power supply path. 
     The invention further contemplates an improvement in a power transfer device adapted for interconnection with the electrical system of a building and including a cabinet. The invention is in the form of a compartment associated with the cabinet and a cover removably connected to the cabinet for alternately preventing and permitting access to the compartment. The cover is provided with a meter arrangement with a current transformer input arrangement, to selectively measure levels of power provided from a source of auxiliary power connected to the power transfer device. 
     The invention also relates to a method for constructing a power transfer device for supplying power to the electrical system of a building from a generator in electrical communication with a separate power inlet arrangement. The method includes the step of providing a cabinet having a compartment and a plurality of switches interconnected with power supply wires extending through the compartment, for controlling the supply of power from the power transfer device to the building electrical system; providing a first cover member adapted for removable engagement with the cabinet over the compartment for selectively enclosing the power input terminal arrangement; providing a second cover member having a power input meter arrangement with a current transformer input having an opening, which is adapted for removable engagement with the cabinet over the compartment for selectively enclosing the compartment; and mounting either the first cover member or the second cover member to the cabinet over the compartment. The step of mounting the second cover member includes passing the power supply wires through the opening defined by the current transformer input, for providing a current in the current transformer indicative of power supplied to the power transfer device, for providing a visual output from the power input meter arrangement. 
    
    
     Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings illustrate the best mode presently contemplated of carrying out the invention. 
     In the drawings: 
     FIG. 1 is a schematic representation showing the power transfer arrangement constructed according to the invention for interposition between a remote power inlet arrangement fed by a portable power generator and an electrical panel associated with a building; 
     FIG. 2 is a partial, front elevational view showing the bottom portion of the power transfer arrangement of FIG. 1 with the access cover removed; 
     FIG. 3 is a partial, sectional view taken on line  3 — 3  of FIG. 2; 
     FIG. 4 is a partial, front elevational view showing the bottom portion of an alternative power transfer arrangement in which the access cover is provided with a wire connection version of an optional meter arrangement, shown in an installed condition; 
     FIG. 5 is an exploded view of the access cover and bottom portions of the alternative power transfer arrangement shown in FIG. 4; 
     FIG. 6 is a partial, sectional view taken on line  6 — 6  of FIG. 4; 
     FIG. 7 is a view similar to FIG. 4 but showing a part of the access cover broken away to view the components in the bottom portion of the alternative power transfer arrangement; 
     FIG. 8 is a view similar to FIG. 6, showing an alternative power input meter arrangement in accordance with the invention, incorporated into the power transfer arrangement; 
     FIG. 9 is an isometric view showing the cover member incorporated into the alternative power input meter arrangement of FIG. 8; 
     FIG. 10 is a top plan view of the cover member of FIG. 9; 
     FIG. 11 is an enlarged partial top plan view showing one of the power input meters in the cover member of FIGS. 8-10; and 
     FIG. 12 is a side elevation view of the cover member of FIGS.  8 - 11 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows a power inlet arrangement for interconnecting a portable generator  10  with a main electrical panel or load center  12  located in the interior of a building  14 . In the power inlet arrangement of FIG. 1, a manual power transfer switching mechanism  16  constructed in accordance with the invention is mounted adjacent main panel  12  and is interconnected therewith via a series of wires enclosed by a conduit  18  extending between main panel  12  and switching mechanism  16 . 
     A power inlet box  20  is mounted to the wall of building  14 , as shown at  22 . Power inlet box  20  includes an external housing including a series of walls such as  24 , and a recessed power inlet  26  mounted to a front wall of the housing. A cover  28  is mounted to the front wall of the housing via a hinge structure and is movable between an open position, as shown in FIG. 1 and a closed position in which cover  28  encloses recessed power inlet  26  when not in use. A conduit  30  extends between inlet box  20  and switching mechanism  16  and provides a direct electrical connection therebetween. Appropriate wiring and connections are contained within inlet box  20  and conduit  30  for providing an electrical path between inlet box  20  and switching mechanism  16 . 
     A power cord  32  extends between generator  10  and power inlet box  20 . Cord  32  includes a plug  34  at one end, which is engageable with the power outlet of generator  10 . Cord  32  further includes a connector  36  at the end opposite plug  34 . Connector  36  is engageable with recessed power inlet  26  for transferring power generated by generator  10  to power inlet box  20 , which is then supplied through the wiring in conduit  30  to switching mechanism  16 , and from switching mechanism  16  through the wiring in conduit  18  to main panel  12 . In this manner, generator  10  functions to provide power to selected circuits of main panel  12  during a power outage. In this arrangement, the user first connects cord  32  between generator  10  and power inlet  20 , and then commences operation of generator  10 . 
     Switching mechanism  16  is interposed between load center  12  and inlet box  20 . Switching mechanism  16  includes a cabinet defining a pair of side walls  38 ,  40 , a top wall  42  extending between the upper ends of side walls  38  and  40 , a bottom wall  44  extending between and interconnecting the lower ends of side walls  38  and  40 , a partial height front panel  46  and a rear panel  48  (FIG.  3 ). Walls  38 - 44 , in combination with front panel  46  and rear panel  48  define an upper cavity  50  within which a series of circuit breakers or switches  52  are located. Front panel  46  is bent rearwardly at its lower end to form an intermediate transverse wall  54  which defines the lower extent of upper cavity  50 . A terminal compartment  56  is defined by an intermediate transverse wall  54  in combination with bottom wall  44 , the lower portions of side walls  38  and  40  and the lower portion of rear panel  48 . Terminal compartment  56  is accessible through an opening below front panel  46 . A cover  58  (FIG. 1) is sized so as to close the opening of terminal compartment  56 . Cover  58  includes a pair of openings in alignment with openings  60  formed in a pair of tabs  62  mounted to bottom wall  44 , to enable cover  58  to be mounted to bottom wall  44  utilizing threaded fasteners  64 ,  66  (FIG. 1) which extend through the openings in cover  58  and into engagement with the openings  60  in tabs  62 . In this manner, cover  58  is selectively engaged with bottom wall  44  to provide access to terminal compartment  56 , and is connected to bottom wall  44  so as to prevent access to terminal compartment  56 . 
     A terminal assembly  68  is mounted to a terminal plate  70 , which is mounted at its ends to intermediate transverse wall  54  to fix terminal assembly  68  in position relative to intermediate transverse wall  54 . Terminal assembly  68  is of conventional construction, including a series of cylindrical receivers  72 , each of which defines a downwardly facing opening. Each receiver  72  includes an outwardly extending cylindrical member  74  extending perpendicularly to receiver  72 , defining a passage for receiving a threaded member, the head of which is shown at  76  (FIG.  2 ). Receivers  72  are accessible from and in communication with terminal compartment  56 . Terminal assembly  68  further includes a series of upwardly opening cylindrical receivers  78 , which are disposed within upper cavity  50 . Each upper cylindrical receiver  78  includes a cylindrical member  80  which receives a threaded member (not shown). 
     Terminal assembly  68  may illustratively be a terminal assembly such as is available from Atech Corp. of Somerville, N.J., under its Model No. TSF/16, although it is understood that any other satisfactory terminal arrangement could be employed. In a terminal arrangement such as this, receivers  72  and  78  are formed of a molded plastic material integrally with cylindrical member  74  and cylindrical member  80 . These components surround metal contact assemblies with one of the contact assemblies being located in both a cylindrical receiver  72  and a cylindrical receiver  78 . In this manner, an electrical connection to terminal assembly  68  is made by inserting a bare wire into the open lower end of receiver  72  and tightening the threaded member utilizing its head  76 , to establish an electrical connection with the wire via the metal contact enclosed within cylindrical receiver  72 . A similar operation is employed to connect the wire end to the contact enclosed by the opposed cylindrical receiver  78  so as to establish a connection between the wires connected to the terminal assembly in this manner. 
     As shown in FIG. 3, a wire such as  82  is connected to each upper cylindrical receiver  78  at one end. Two of wires  82  feed bus bars (not shown), which in turn are interconnected with switches  52  to provide power to switches  52 . A third one of wires  82  is a neutral wire which is connected to the neutral of load center  12  and a fourth one of wires  82  is a ground wire attached to the frame of transfer switching mechanism  16 . 
     Referring to FIGS. 1 and 2, conduit  30  extends between the power inlet box  20  and switching mechanism  16 . Conduit  30  encloses a series of power input wires  84  (FIG.  2 ), and extends through a knock-out opening formed in the bottom wall  44  via a conventional conduit fitting  86  and lock nut  88 . As can be appreciated, an input wire conduit could also be connected through a knock-out in either side wall  38  or  40 , or in a knock-out opening in the lower portion of rear panel  48 . 
     The ends of power input wires  84  are connected to terminal assembly  68  by placing the bare end of each wire  84  into one of the receivers  72  and tightening the associated threaded member, as explained previously, to establish an electrical connection with a contact member enclosed by one of the cylindrical receivers  72 . In this manner, input power is supplied from remote power inlet  20  to terminal assembly  68 , which is subsequently transferred from terminal assembly  68  to wires  82  and thereby to switches  52 , as explained previously. This arrangement enables a person in installing switching mechanism  16 , such as an electrician or do-it-yourself homeowner, to establish a direct electrical connection between remote power inlet box  20  and switching mechanism  16  without the need for connecting a flexible cord to a power input receptacle, as in the prior art. In this manner, after generator power cord  32  is plugged into remote power inlet box  20 , the only necessary operation in connection with switching mechanism  16  to enable transfer of power from generator  10  to load center  12  is to place switches  52  in the appropriate position so as to transfer power to load center  12  as desired in response to operation of the generator  10 . 
     Output wires from switches  52 , shown at  90 , extend through terminal compartment  56  to a conduit fitting  92  secured to bottom wall  44  by lock nut  94  for routing the wires through conduit  18  to load center  12 . Other wires extend through terminal compartment  56 , such as neutral and ground wires, as well as input wires from load center  12 . 
     It can thus be appreciated that the provision of terminal compartment  56  provides an extremely convenient and simple arrangement for establishing a direct, hardwired connection between power inlet box  20  and power transfer switching mechanism  16 . The user or installer simply must remove cover  58  to gain access to terminal compartment  56  for connecting or disengaging power input wires  84  to or from terminal assembly  68 . Terminal compartment  56  also provides a convenient cavity to provide pulling of wires through conduit  30 . Once the user has completed the necessary operations at terminal compartment  56 , the user simply replaces cover  58 , as described previously, to thereby prevent access to terminal compartment  56 . 
     The above description pertains to a power supply arrangement as disclosed in Flegel U.S. Pat. No. 5,895,981, previously incorporated by reference. 
     FIGS. 4-7 disclose an alternative embodiment as disclosed in Flegel U.S. Pat. No. 6,107,701, previously incorporated by reference. In this embodiment, power transfer arrangement  16 ′ has substantially identical components as previously described in FIGS. 1-3, except for removable access cover plate  58 ′ and power input wires  84 ′ (FIG.  7 ). In this power transfer arrangement  16 ′, cover  58 ′ has a rearwardly extending ledge  96  which is engageable beneath the transverse wall  54  of the front panel  46 , and a vertically extending wall  98  which depends downwardly from ledge  96  and is engage-able against cabinet side walls  38 ,  40  and end wall  44 . As seen in FIG. 5, ledge  96  includes a central recess  100  for accommodating the power input terminals defined by receiver  72  and cylindrical member  74 . It should be appreciated that cover  58  also includes ledge  96 , vertical wall  98 , and central recess  100 . 
     Cover  58 ′ further includes a pair of openings  102 ,  104  in alignment with openings  60  formed in the pair of tabs  62  projecting from bottom wall  44  to enable cover  58 ′ to be secured to bottom wall  44  by threaded fasteners  64 ,  66  which extend through the cover openings  102 ,  104  and into threaded engagement with tab openings  60 . 
     Cover  58 ′ is provided with power input indicating structure in the form of a pair of spaced apart watt meters  106 ,  108  which are connected to the power input terminal arrangement  68  and are selectively used to display the amount of power supplied by the generator  10  during a power outage. Each of the watt meters  106 ,  108  has a convexly-shaped forward portion  110  integrally attached to a T block-shaped rear portion  112 . Each forward portion  110  projects through a respective rectangular opening  114  formed in wall  98 , and is attached to the inside of wall  98  by a pair of spring-biased retainers  116 . Each forward portion  110  defines a transparent window having a convexly-shaped support member  118  for mounting a wattage scale  120  visible through the window, and an indicator  122  mounted for movement along the scale  120  in response to the supplying of generator power. Each rear portion  112  extends rearwardly and perpendicularly to wall  98  and is provided with a pair of upper and lower terminals  124 ,  126 , respectively, for connection with suitable wiring to be further explained below. 
     In order to facilitate connection of the watt meters  106 ,  108  to the power input terminal arrangement  68  the power input indicating structure also includes a one-piece, U-shaped attachment bracket  128  (FIG. 5) positioned on the inside of wall  98  between the watt meters  106 ,  108 . Bracket  128  is fastened by a pair of screws  131 ,  132  which are passed through quibble unthreaded openings in wall  98 , and received in suitably threaded openings in a flat base plate  130  of bracket  128 . Base plate  130  serves as a support for an H-shaped terminal connector  134  which is removably fastened by a single screw  136  (FIG. 7) to a threaded grommet (not shown) retained in the base plate  130 . Bracket  128  also has a pair of parallel side plates  138 ,  140  which extend rearwardly from base plate  130 , and serve as supports for a pair of wire guiding, cylindrical holders  142 ,  144 . 
     Terminal connector  134  has a structure similar to terminal assembly  68  and includes a pair of upwardly opening cylindrical receivers  146 ,  148  and a pair of downwardly opening cylindrical receivers  150 ,  152 . Each receiver  146 - 152  has an inwardly extending cylindrical member  154  (FIG. 6) lying perpendicularly to receivers  146 - 152  and defining a passage for receiving a threaded member (not shown). As seen in FIG. 7, the ends of first and second input wires  84 ′ designated B and R, respectively, are connected to the bottom receivers  150 ,  152  in a manner as previously described in relation to terminal assembly  68 . The third input wire  84 ′ designated N is connected to receiver  72  designated N, and is further connected through conduit  18  to the neutral bar of load center  12 . The fourth input wire  84 ′ designated G is attached to receiver  72  designated G, and is also attached to the frame of transfer switch  16 . A fifth wire  156  interconnects upper terminal  124  of watt meter  106  with upper receiver  146  of connector  134 . A sixth wire  158  showing upper terminal  124  of watt meter  108  with the other upper receiver  148 . A seventh wire  160  passes through holder  142  and connects the bottom terminal  126  of watt meter  106  with receiver  72  designated B. An eighth wire  162  passes through holder  144  and connects the bottom terminal  126  of watt meter  108  with receiver  72  designated R. 
     FIGS. 8-12 illustrate a cover  200  in accordance with the invention, which is adapted for engagement over compartment  56 . Cover  200  has many of the same components as shown and described in connection with cover  58 ′, and like reference characters will be used where possible to facilitate clarity. Generally, the structure of cover  200  is the same as cover  58 ′, including rearwardly extending ledge  96 , vertically extending wall  98 , and spaced apart watt meters  106 ,  108  having forward portions  110  and rear portions  112 . 
     Mirror image bracket members  202 ,  204  extend rearwardly from a transverse mounting wall  205  secured to vertical wall  98 , located behind watt meters  106 ,  108 , respectively. Bracket member  202  defines a rearwardly extending wall  206  and a transverse wall  208 , and bracket member  204  defines a rearwardly extending wall  210  and a transverse wall  212 . Transverse wall  208  is spaced rearwardly from the prong-type contact members of watt meter  106 , and transverse wall  212  is spaced rearwardly from the prong-type contacts of watt meter  108 . 
     A current transformer input arrangement is interconnected with the contacts of watt meters  106 ,  108 , respectively, including current transformers  214 ,  216 , respectively. Current transformer  214  includes a pair of input wires  218  which are interconnected with socket-type engagement members  220 , which are adapted to be pushed onto the prong-type contact members of watt meter  106 . Similarly, current transformer  216  includes a pair of input wires  222  which are interconnected with socket-type engagement members  224 , which are adapted to be pushed onto the prong-type contact members of watt meter  108 . Input wires  218  of current transformer  214  extend through an opening formed in rearwardly extending wall  206 , and a strain relief grommet  226  engages wires  218  within the opening in rearwardly extending wall  206 . Similarly, input wires  222  of current transformer  216  extend through an opening in rearwardly extending wall  210  of bracket member  204 , and a strain relief grommet  228  is engaged with input wires  222  within the opening. Current transformers  214 ,  216  define internal, closed openings  230 ,  232 , respectively. 
     Openings  230 ,  232  of current transformers  214 ,  216 , respectfully, are adapted to receive selected ones of power input wires  84 . In accordance with known current transformer operation, each current transformer  214 ,  216  includes a coil surrounding its respective opening  230 ,  232 . Current in power input wire  84  induces current in the coil of the current transformer  214 ,  216  through which power input wire  84  extends, corresponding to the level of current in power input wire  84 . Each current transformer  214 ,  216  and its associated wires  218 ,  222 , respectively, completes a circuit with its respective watt meter  106 ,  108 , such that the induced current corresponds to the amount of power being supplied to power transfer switching mechanism  16  through power input wire  84 . The current level is converted by watt meters  106 ,  108  into a visual indication of the input power level, to provide the user with an indication as to the power supplied from generator  10  so as to prevent overloading of power transfer switching mechanism  16 . 
     Current transformers  214 ,  216  are coil-type current transformers such as are available from C. R. Magnetics of Fenton, Mo. under its Model No. CR8411-1000, although it is understood that any other type of closed current transformer construction may be employed. 
     In assembly, cover  200  is adapted to be engaged over compartment  56  in the same manner as described previously with respect to covers  58 ,  58 ′. Before making final connections of cover  200 , power input wires  84  are threaded through openings  230 ,  232  of current transformers  214 ,  216 , respectively, prior to engagement with terminals  72 . In this manner, a power input meter arrangement is quickly and easily provided for power transfer switching mechanism  16 , without the need for connecting the power input meters with the power input arrangement and terminals  72 , as in the prior art. 
     It should be understood that current transformers  214 ,  216  may be employed in any type of power supply arrangement, and are not limited to the specific details of the power supply arrangement as shown and described. In particular, power input wires such as  84  may be passed through the openings of current transformers  214 ,  216  and connected directly to switches  52 , thus eliminating the need for power input terminals  72 . However, the presence of power input terminals  72  facilitates relatively quick and easy installation of cover  200 , which is particularly advantageous in a retrofit application. 
     It can thus be appreciated that a manufacturer can provide either a hardwired power transfer switching mechanism  16  or a meter-enhanced power transfer switching mechanism  16 ′ simply by mounting either cover  58 ,  58 ′ or  200  to the cabinet over terminal compartment  56 . With cover  58 ′ or cover  200  in place, an operator is able to read the power being drawn on generator  10  so as to balance the loads and avoid overloading which can stall or slow the generator  10 . The interchangeability of covers  58 , 58 ′ and  200  provides significant efficiencies in manufacturing by providing a large number of common components for different models. It should also be understood that switch mechanism  16  and  16 ′ can be retrofit in the field to provide desired cover  58 ,  58 ′ or  200 . 
     Various alternatives and embodiments are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.