Abstract:
The present invention relates to a connecting device adapted for connecting an electrical cable, which includes wires, to a similar or identical electrical cable. The device includes a housing having a connecting end, which is adapted to be removably connected to a connecting end of an identical connecting device, and an opposite end, which includes a slot for receiving an electrical cable inserted into the housing. The housing also includes a receiving portion at the connecting end for receiving a plurality of connecting blades adapted to engage blades of an identical device and to receive wires of an electrical cable inserted into the housing through an open side thereof. A cover is provided for covering the open side of the housing. The cover is pivotally connected to the housing remote from the opposite end thereof such that the cover is pivotally movable relative to the housing between an open position, in which the open side of the housing is substantially unobstructed by the cover for insertion of electrical wires into the blades, and a closed position, in which the open side of the housing is substantially closed off by the cover. The slot is unobstructed by the cover when the cover is in the open position, whereby an electrical cable inserted into the housing can be laid in the slot while the cover is attached to the housing and then secured to the housing in response to the pivotal movement of the cover from the open position to the closed position.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a §111(a) application relating to U.S. application Ser. No. 60/086,064 filed May 20, 1998. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to electrical connectors and more particularly to a hermaphroditic device for coupling and uncoupling interlinking cables. 
     BACKGROUND OF THE INVENTION 
     Hermaphroditic type electrical connectors are electrical connectors which are mateable with identical electrical connectors. Hermaphroditic type cable connectors are used in the construction of modular housing and recreational vehicles in a factory environment. 
     Existing hermaphroditic cable connectors have certain drawbacks. These drawbacks include connectors which require multiple steps to attach two separate pieces of the connector to a cable. The first step generally involves connecting the cable to one piece of the connector to form a sub-assembly. The second step involves connecting another piece of the connector to the sub-assembly to complete the full assembly. 
     Another drawback of existing hermaphroditic connectors is potentially inefficient insulation displacement contacts resulting in higher resistance and increased voltage drop. Uncoupling of mated hermaphroditic connectors attributable to inadvertent triggering of the unlocking mechanism is also a potential problem. Relatively large size is another drawback of some hermaphroditic connectors. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the disadvantages and shortcomings of the prior art discussed above by providing a new and improved connecting device adapted for connecting an electrical cable, which includes a plurality of wires, to a similar or identical electrical cable. More particularly, the device includes a housing having an open side for insertion of an electrical cable into the housing, a connecting end, which is sized and shaped so as to be removably connected to a connecting end of an identical connecting device, and an opposite end, which includes a receiving slot for receiving at least a portion of an electrical cable inserted into the housing. The housing includes a blade receiving mechanism, located adjacent the connecting end, for receiving a plurality of connecting blades sized and shaped so as to engage connecting blades of an identical connecting device and to receive wires of an electrical cable inserted into the housing. The device also includes a cover for covering the open side of the housing. The cover is pivotally connected to the housing remote from the opposite end thereof such that the cover is pivotally movable relative to the housing between an open position, in which the open side of the housing is substantially unobstructed by the cover for insertion of wires of an electrical cable into the blades, and a closed position, in which the open side of the housing is substantially closed off by the cover. The receiving slot is unobstructed by the cover when the cover is in the open position, whereby an electrical cable inserted into the housing can be laid in the receiving slot while the cover is attached to the housing and then secured to the housing in response to the pivotal movement of the cover from the open position to the closed position. 
     In accordance with one feature of the present invention, the opposite end of the housing includes an end wall. The slot is formed in the end wall and has an open end adjacent the open side of the housing for receiving an electrical cable inserted into said housing when the cover is in the open position. The cover also includes a first end, which is pivotally connected to the connecting end of the housing, and a second end, which is located opposite the first end. The open end of the slot is unobstructed by the second end when the cover is in the open position and abutted by the second end when the cover is in the closed position. The housing also includes a pair of pivot pins, while the cover includes a pair of hinges, each of which is sized and shaped so as to rotatably receive a corresponding one of the pivot pins. 
     Another feature of the present invention involves providing a gripping mechanism for gripping an electrical cable inserted into the housing in a strain-relieving manner in response to pivotal movement of the cover from the open position to the closed position. More particularly, the gripping means includes a gripping member formed on the cover and sized and shaped so as to urge an electrical cable positioned in the slot against the end wall when the cover is pivotally moved from the open position to the closed position. 
     In accordance with yet another feature of the present invention, each of the blades includes a wire receiving mechanism for receiving an end of a wire of an electrical cable inserted into the housing. Each of the wire receiving mechanisms is sized and shaped so as to retain a wire of an electrical cable received therein in proper position relative to the housing while the cover is pivotally moved from the open position to the closed position. Each of the blades also includes a piercing channel, which is formed on a receiving end thereof, and a chamfered edge so as to improve penetration of wire insulation and to insure reliable electrical contact between the blades and wires. 
     In accordance with another feature of the present invention, the blade receiving mechanism includes a plurality of receiving channels formed in the housing adjacent the connecting end thereof. Each of the receiving channels is sized and shaped so as to receive a corresponding one of the blades. The housing is also provided with a retaining mechanism, including notches which are formed in partitions defining the receiving channels, for retaining each of the blades in a corresponding one of the receiving channels. 
     According to yet another feature of the present invention, the device is provided with a locking mechanism for releasably locking the connecting end of the housing to a connecting end of an identical connecting device. More particularly, the locking mechanism includes a first locking member and a second locking member formed on the housing adjacent the connecting end. The first locking member is sized and shaped so as to releasably interlock with a second locking member of an identical connecting device, while the second locking member is sized and shaped so as to releasably interlock with a first locking member of an identical connecting device. The housing includes a base having a depression therein adjacent the connecting end of the housing. The first locking member is formed on the base in such a manner that a second locking member of an identical connecting device interlocked to the first locking member is substantially tucked in the depression, thereby inhibiting inadvertent disengagement of the first locking member from an interlocked second locking member of an identical connecting device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the present invention, reference is made to the following detailed description of exemplary embodiments considered in conjunction with the accompanying drawings, in which: 
     FIG. 1 is a plan view of a cable connector constructed in accordance with a first embodiment of the present invention; 
     FIG. 2 is a side elevational view of the cable connector shown in FIG. 1; 
     FIG. 3 is a plan view of a housing for the connector shown in FIG. 1; 
     FIG. 4 is a side elevational view of the housing shown in FIG. 3; 
     FIG. 5 is a front elevational view of the housing shown in FIG. 3; 
     FIG. 6 is a rear elevational view of the housing shown in FIG. 3; 
     FIG. 7 is a cross-sectional view, taken along section line  7 — 7  in FIG.  3  and looking in the direction of the arrows, of the housing shown in FIG. 3; 
     FIG. 8 is a cross-sectional view, taken along section line  8 — 8  in FIG.  3  and looking in the direction of the arrows, of the housing shown in FIG. 3; 
     FIG. 9 is a cross-sectional view, taken along section line  9 — 9  in FIG.  3  and looking in the direction of the arrows, of the housing shown in FIG. 3; 
     FIG. 10 is a plan view of a blade for the connector shown in FIG. 1; 
     FIG. 11 is a side elevational view of the blade shown in FIG. 10; 
     FIG. 12 is a front elevational view of the blade shown in FIG. 10; 
     FIG. 13 is a rear elevational view of the blade shown in FIG. 10; 
     FIG. 14 is a plan view of a cover for the connector shown in FIG. 1; 
     FIG. 15 is a side elevational view of the cover shown in FIG. 14; 
     FIG. 16 is a front elevational view of the cover shown in FIG. 14; 
     FIG. 17 is a rear elevational view of the cover shown in FIG. 14; 
     FIG. 18 is a cross-sectional view, taken along section line  18 — 18  in FIG.  14  and looking in the direction of the arrows, of the cover shown in FIG. 14; 
     FIG. 19 is a cross-sectional view, taken along section line  19 — 19  in FIG.  14  and looking in the direction of the arrows, of the cover shown in FIG. 14; 
     FIG. 20 is a cross-sectional view, taken along section line  20 — 20  in FIG.  14  and looking in the direction of the arrows, of the cover shown in FIG. 14; 
     FIG. 21 is a cross-sectional view, taken along section line  21 — 21  in FIG.  14  and looking in the direction of the arrows, of the cover shown in FIG. 14; 
     FIG. 22 is a cross-sectional view, taken along section line  22 — 22  in FIG.  14  and looking in the direction of the arrows, of the cover shown in FIG. 14; 
     FIG. 23 is a partial cross-sectional view of the connector shown in FIG. 1 with its cover in a fully open position and an insulated wire of a cable inserted in an initial position; 
     FIG. 24 is a partial cross-sectional view of the connector shown in FIG. 1 with its cover in a fully open position and an insulated wire of a cable bent in an intermediate position; 
     FIG. 25 is a partial cross-sectional view of the connector shown in FIG. 1 with its cover in a partially closed position making contact with the insulated wire of a cable bent in an intermediate position; 
     FIG. 26 is a partial cross-sectional view of the connector shown in FIG. 1 with its cover in a fully closed position after driving the insulated wire of a cable into a final position; 
     FIG. 27 is a partial cross-sectional view of two mated hermaphroditic cable connectors shown interlinking two associated cables; 
     FIG. 28 is a side elevational view of two mated hermaphroditic connectors without associated cables; 
     FIG. 29 is a top plan view of a housing of a cable connector constructed in accordance with a second embodiment of the present invention; and 
     FIG. 30 is a cross-sectional view, taken along section line  30 — 30  and looking in the direction of the arrows, of the housing shown in FIG.  29 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1 and 2, there is shown a hermaphroditic cable connector  10  which includes a housing  12 , a plurality of blades  14 , and a cover  16 . Before discussing each element in detail, it is noted that the exemplary embodiment of the hermaphroditic cable connector  10  is based on a design to interlink three-wire Romex cable. However, it should be noted that the invention is not limited to this particular cable. 
     Referring now to FIGS. 3-9, in general, and FIGS. 3,  4  and  7 , in particular, the housing  12  includes a terminal end  18 , a cable end  20 , a base  22 , and a pair of side walls  24 ,  24 ′. The base  22  is generally rectangular with a topside  26  (see FIG.  7 ), an underside  28 , and two apertures  30  therethrough located toward the cable end  20  in close proximity to the side walls  24 ,  24 ′ (see FIG.  3 ). The underside  28  (see FIG. 7) includes a depression  32  located toward the terminal end  18  and extending, generally, between the side walls  24 ,  24 ′. Near the terminal end  18 , the underside  28  has a wedge-shaped catch  34  located equidistantly between the side walls  24 ,  24 ′ on a recessed surface  36  adjacent to the depression  32 , forming a recess  38  between the catch  34  and the depression  32 . The catch  34  has an inclined surface  40  oriented toward the terminal end  18 . The side walls  24 ,  24 ′ extend perpendicularly from the topside  26  of the base  22  between the cable end  20  and the terminal end  18  of the housing  12 . Each side wall  24 ,  24 ′ includes an interior surface  42  and an exterior surface  44  (see FIG.  8 ). Toward the cable end  20 , the exterior surface  44  of each side wall  24 ,  24 ′ includes a wedge-shaped catch  46  with an inclined surface  48  oriented away from the base  22  (see FIG.  8 ). Toward the terminal end  18 , each side wall  24 ,  24 ′ includes a cylindrical pivot pin  50  oriented generally perpendicular to the exterior surface  42  of the side wall  24 ,  24 ′ (see FIGS.  3  and  4 ). At the terminal end  18 , each side wall  24 ,  24 ′ has a shoulder  52  which is separated from the topside  26  of the base  22  (see FIGS.  4  and  9 ). The exterior side walls  24 ,  24 ′ are generally mirror images of each other. 
     With particular reference to FIGS. 3 and 7, at the cable end  20 , an end wall  54  extends perpendicularly from the topside  26  of the base  22  between the side walls  24 ,  24 ′. The end wall  54  includes a shallow, U-shaped cableway  56  having a groove  58  formed between two ridges  60  which run along the closed end of the cableway  56 . There are also ridges  62  along the sides of the cableway  56 . The topside  26  of the base  22  has a shallow recess  64  parallel to and near the end wall  54 . Two partitions  66 ,  66 ′ (see FIGS. 6 and 7) extend from near the cable end  20  to the terminal end  18 , being normal to the topside  26  and parallel to the side walls  24 ,  24 ′. Each of the partitions  66 ,  66 ′ includes a cable end section  68 ,  68 ′ (see FIG.  3 ), an enclosed section  70 ,  70 ′ and a terminal separator section  72 ,  72 ′ (see FIGS.  7 - 9 ). At the cable end section  68 , the partitions  66 ,  66 ′ include wire guides  74 , which are generally rectangular projections extending somewhat above the side walls  24 ,  24 ′. Notches  76  are located adjacent to the tops of the partitions  66 ,  66 ′ and adjacent the top of a corresponding one of the side walls  24 ,  24 ′. A white wireway  78  is formed between the notched side wall  24 ′ and the cable end section  68 ′ of the partition  66 ′ (see FIG.  3 ). Similarly, a black wireway  80  is formed between the other side wall  24  and the cable end section  68  of the partition  66  (see FIG.  3 ). A ground wireway  82  is formed between the cable end sections  68 ,  68 ′ of the  20  partitions  66  and  66 ′, respectively (see FIG.  3 ). Between each of the wireways  78 ,  80 ,  82 , the topside  26  of the base  22  includes inclined ramps  84  (see FIG. 7) leading to shelves  86  adjacent to the enclosed sections  72 ,  72 ′ of the partitions  66 ,  66 ′. 
     Now, with particular attention to FIGS. 3,  4 ,  5  and  7 , a bridge plate  88  with a centered recess  89  (see FIG. 3) extends between the side walls  24 ,  24 ′ over the enclosed sections  70 ,  70 ′ (see FIG. 7) of the partitions  66 ,  66 ′ forming blade tunnels  90  (see FIG.  5 ). The bridge plate  88  includes a recessed label  92  bearing the legend WHT, a recessed label  94  bearing the legend BLK, and a recessed label  96  bearing the label GRD adjacent to the corresponding white, black and ground wireways  78 ,  80 ,  82  (see FIG.  3 ). A clasp  98  (see FIG. 3) with a raised tab  100  projects from the terminal end  18  of the housing  12 . The raised tab  100  is below the tops of the shoulders  52  of the side walls  24 ,  24 ′ as shown in FIG. 4, thereby inhibiting inadvertent opening of the clasp  98 . 
     The housing  12  is generally molded from a non-conductive polymeric material. Nylon, either clear or colored, is the preferred material. 
     Referring now to FIGS. 10-13, the blade  14  includes a contact end  202  and a wire receiving end  204  and a body  206 . At the contact end  202 , the body  206  has a base contact  208  and a pair of spring contacts  210 . Toward the wire receiving end  204 , the body  206  has a wire locator  212  and another wire locator  214 , which is attached to a support wall  216 . The support wall  216  has a locking tab  218  and a piercing channel  220  with chamfered edges  222 . The blade  14  is fabricated from a flexible conductive material, preferably metal such as brass, bronze, copper, copper alloy, gold plated metal, silver plated metal or other electrically conducting metallic material. The blade  14  is sized and shaped to fit in the housing  12  as indicated in FIGS. 1 and 2. Namely, the body  206  and the wire receiving end  204  of the spring contacts  210  fit snugly within one of the blade tunnels  90 , while the locking tab  218  engages the notch  76  on a side of a corresponding one of the wireways  78 ,  80 ,  82 . 
     Referring now to FIGS. 14-22, in general, and to FIGS. 14-19, in particular, the cover  16  includes a hinge end  300 , a cable end  302 , a cover plate  304 , and a pair of side plates  306 . The cover plate  304  is generally rectangular with an outside  308 , an inside  310 , and two apertures  312  therethrough located toward the cable end  302  near the side plates  306 . At the hinge end  300 , the outside  308  of the cover plate  304  has a chamfered surface  314  and a shallow, U-shaped projection  316 . The side plates  306  extend perpendicularly from the inside  310  of the cover plate  304  between the hinge end  300  and the cable end  302  of the cover  16 . The generally rectangular side plates  306  include hinges  318  near the hinge end  300  and clasps  320  near the cable end  302 . The hinges  318  are sized and shaped to rotatably engage the pivot pins  50  on the housing  12 . The clasps  320  are sized and shaped to lockingly engage the catches  46  on the side walls  24 ,  24 ′ of the housing  12 . 
     Referring particularly to FIGS. 14,  18 ,  19  and  20 , a low, end wall  322  extends perpendicularly from the cable end  302  of the inside  310  of the cover plate  304  between the side plates  306 . A wedge-shaped wire guard  324  is centered in the end wall  322 . Two screw guards  326  partially surround the apertures  312  and project perpendicularly from the inside  310  of the cover plate  304  to shield mounting screws from cable and wires when attached. Another wedge-shaped wire guard  328  extends between the screw guards  326  on the inside  310  of the cover plate  304 . 
     With particular reference to FIGS. 14,  21  and  22 , a cable end ground wire driver  330 , shaped like a pillar with a circular depression at the top, is located at approximately the middle of the inside  310  of the cover plate  304 . Off to one side of the cable end ground wire driver  330  is a similarly shaped cable end black wire driver  332  and a similarly shaped cable end white wire driver  334  is on the opposite side. Oblong recesses  336  in the inside  310  of the cover plate  304  are located between the cable end ground wire driver  330  and both the cable end black wire driver  332  and the cable end white wire driver  334 . Aligned with the cable end ground wire driver  330 , on the hinge end side, is a similarly shaped hinge end ground wire driver  338 . In a like manner, a similarly shaped hinge end black wire driver  340  is aligned with the cable end black wire driver  332  and a hinge end white wire driver  342  is aligned with the cable end white wire driver  334 . 
     The cover  16  is also generally molded from a non-conductive polymeric material. Clear nylon is the preferred material so that the wires in the cable connector  10  can be inspected with the cover  16  in place on the housing  12 . 
     Referring now to FIGS. 1-4,  7 ,  10 ,  11 ,  14  and  15 , when the connector  10  is assembled, three blades  14  are positioned in the white, ground and black wireways  78 ,  80  and  82 , respectively, of the housing  12 . The notches  76  of the housing  12  engage the locking tabs  218  of the blades  14  as the contact ends  202  of the blades  14  are inserted through the blade tunnels  90 . The hinges  318  of the cover  16  are fitted rotatably about the pivot pins  50  on the housing  12 . As the cover  16  is closed, the clasps  320  on the cover  16  lockingly engage the catches  46  on the side walls  24 ,  24 ′ of the housing  12 . When the cover  16  is in its closed position, the piercing channels  220  of the blades  14  lie between the cable end wire drivers  330 ,  332 ,  334  and the hinge end wire drivers  338 ,  340 ,  342 ; the apertures  312  in the cover  16  align with the apertures  30  in the housing  12  to form mounting screw holes for the connector  10 ; the wire guard  324  in the end wall  322  of the cover  16  aligns above the groove  58  in the end wall  54  of the housing  12 ; the wire guard  328  on the cover  16  aligns above the recess  64  in the housing  12 ; and the projection  316  on the cover  16  mates with the recess  89  in the bridge plate  88  of the housing  12 . 
     The operation of the connector  10  is illustrated in FIGS. 23-27 in connection with an electrical cable  402  having three insulated wires  400  (only one of which is shown in FIGS. 23-27) with metallic wires  404  therein. The initial position of the connector  10  is as shown in FIG. 23, with the cover  16  in place in its fully open position. Initial preparation of the cable  402  includes removing the outer sheathing to expose the three individual insulated wires  400  contained therein. The three insulated wires  400  are then separated and the ends of the insulated wires  400  are inserted from the cable end  20  of the housing  12  into the wire locators  214 , as shown in FIG.  23 . Note that the wire guides  74  insure that the individual insulated wires are properly guided to the piercing channels  220  in the blades  14 . As shown in FIG. 24, the insulated wires  400  are bent over the piercing channels  220  as the cable  402  is positioned in the cableway  56  in the end wall  54  of the housing  12 . FIG. 25 shows the cover  16  being lowered so that each of the hinge end wire drivers  338 ,  340 ,  342  contacts one of the insulated wires  400  on one side of one of the piercing channels  220  and each of the cable end wire drivers  330 ,  332 ,  334  contacts one of the insulated wires  400  on the other side of one of the piercing channels  220  to drive the insulated wire  400  into the chamfered edges  222  of the piercing channels  220  to pierce the wire insulation of the insulated wires  400 . In FIG. 26, the cover  16  is in its closed position and each of the insulated wires  400  is seated in a corresponding one of the piercing channels  220  such that each of the metallic wires  404  is in direct contact with the edges of a corresponding one of the piercing channels  220 . Also in FIG. 26, the wire guards  324  and  328  compress the cable  402  into the groove  58  in the cableway  56  and the recess  64 , respectively, to provide strain relief for the insulated wires  400 . 
     FIGS. 27 and 28 illustrate the mating of two hermaphroditic cable connectors  10  and  10 ′. In mating, one connector  10  is in an initial position, while the other connector  10 ′ is flipped over 180 degrees, so that the connectors  10  and  10 ′ can be joined together terminal end  18  to terminal end  18 ′. Note that in the mated position, the clasps  98  and  98 ′ on the terminal ends  18  and  18 ′ of each of the housings  12  and  12 ′ lock on the catches  34 ′ and  34  on the undersides  28 ′ and  28  of the housings  12 ′ and  12 , respectively. In the locked position, the raised tabs  100  and  100 ′ of the clasps  98  and  98 ′ extend into the depressions  32  and  32 ′ on the undersides  28  and  28 ′ of the bases  22  and  22 ′ of the housings  12  and  12 ′ below the edges of the side walls  24 ′,  24 ″, which prevents inadvertent opening of the clasps  98  and  98 ′. Also note that the base contacts  208  of each blade  14  fit between the base contacts  208 ′ and spring contacts  210 ′ of the mating blades  14 ′, while the terminal separator sections  72  of the partitions  66 ,  66 ′ overlap the mating terminal separator sections (not shown) of the connector  10 ′ to provide insulating barriers between adjacent pairs of mating contacts  208 ,  210  and  208 ′,  210 ′. 
     FIGS. 29 and 30 illustrate a hermaphroditic cable connector constructed in accordance with a second embodiment of the present invention. Elements illustrated in FIGS. 29 and 30, which correspond, either identically or substantially, to the elements described above with respect to the embodiment of FIGS. 1-28, have been designated by corresponding reference numerals increased by one thousand. Unless otherwise stated, the hermaphroditic cable connector of FIGS. 29 and 30 is constructed, assembled and operated in the same basic manner as the embodiment of FIGS. 1-28. 
     With reference to FIGS. 29 and 30, the hermaphroditic cable connector includes a housing  1012 . The housing  1012  has a base  1022 , a pair of side walls  1024 ,  1024 ′ and an underside  1028 . The underside  1028  includes a recessed surface  1036 , which has a free end  1410  located at a terminal end  1018  of the housing  1012 , a depression  1032 , which is formed between the side walls  1024 ,  1024 ′ adjacent the terminal end  1018 , and a wedge-shaped catch  1034  which is formed on the recessed surface  1036  and which is located within the depression  1032  between the side walls  1024 ,  1024 ′. Each of the side walls  1024 ,  1024 ′ is provided with a shoulder  1052  extending from a corresponding one of the side walls  1024 ,  1024 ′ and terminating at an end  1412  slightly beyond the free end  1410  of the recessed surface  1036 . A bridge plate  1088  extends between the shoulders  1052 . More particularly, the bridge plate  1088  terminates at an end  1414  which is substantially aligned with the ends  1412  of the shoulders  1052 . The bridge plate  1088  is also integrally connected to the shoulders  1052 . A clasp  1098  projects from the end  1414  of the blade plate  1088 . 
     Still referring to FIGS. 29 and 30, the housing  1012  also includes a pair of partitions  1066 ,  1066 ′ provided with wire guides  1074  at upper ends thereof. Each of the wire guides  1074  extends from an end of a corresponding one of the partitions  1066 ,  1066 ′ towards the terminal end  1018  of the housing  1012  and is sized and shaped so as to be received in a corresponding one of oblong recesses formed in a cover (not shown in FIGS.  29  and  30 ). Each of the partitions  1066 ,  1066 ′ is also provided with a notch  1076  extending downwardly from an upper end of a corresponding one of the wire guides  1074 . 
     It should be noted that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the scope of the invention as defined in the appended claims.