Patent Publication Number: US-6655811-B2

Title: Theft-proof removable door handle illumination device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. Ser. No. 09/678,011, filed Oct. 3, 2000, now U.S. Pat. No. 6,439,732,which claims the priority under 35 U.S.C. §119( e ) of application Ser. No. 60/157,527 filed Oct. 4, 1999, both of which are hereby incorporated by reference herein 
    
    
     BACKGROUND OF INVENTION 
     1. Field of the Invention 
     The present invention relates generally to entry doors. More particularly, the present invention concerns a theft-proof device that is operable to illuminate hardware (e.g., the handle) of a door and is removable for use as a flashlight. That is to say, the inventive door illumination device illuminates the door hardware and has means to allow the device to be removed from the mounting surface when the door is open—to allow the device to be put to other illumination uses—but prevents the removal of the device from the mounting surface when the door is closed. 
     2. Discussion of Prior Art 
     Those ordinarily skilled in the construction industry will appreciate that door handle illumination devices are commonly used in industry and in many households. However, there are many problems associated with conventional door handle illumination devices. For example, door handle illumination devices are traditionally fixed to the mounting surface so as not to be removable from the mounting surface. That is to say, the only use of traditional door handle illumination devices is to illuminate a door handle associated near the devices permanent, fixed location. This is particularly problematic in household applications, wherein it would be beneficial to have an illumination device that could both illuminate the door handle and be easily removed from the mounting surface to provide other illumination-uses (e.g., a flashlight to illuminate a dark house during a power failure). Removability of door handle illumination devices presents another problem involving ease of theft or vandalism. That is to say, because door handle illumination devices are typically located near an exterior door handle, if the device is easy for the user to remove from the exterior mounting surface, thieves and vandals can easily remove the device as well. 
     SUMMARY OF INVENTION 
     Responsive to these and other problems, an important object of the present invention is to provide a highly effective door hardware illumination device that can also be put to other illumination uses (e.g., a flashlight). That is to say, an important object of the present invention is to provide a door hardware illumination device that is both easily removable from the mounting surface and operable to illuminate when not associated with the mounting surface. Another important object of the present invention is to provide a theft-proof removable door hardware illumination device. That is, it is an important object of the present invention to provide a door hardware illumination device that is both easy for the user to remove from the mounting surface when the user desires to put the device to other illumination uses, and yet virtually impossible to remove from the mounting surface when the user does not desire to put the device to other illumination uses (e.g., when the user is not at home and the door is closed). 
     In accordance with these and other objects evident from the following description of the preferred embodiment, the present invention concerns a theft-proof removable door hardware illumination device comprising a base, operable to mount on a mounting surface, a door hardware illumination assembly operable to provide illumination, and a case supporting the assembly. The case and base are removably interconnected in such a manner that disconnection of the case from the base requires movement of the case in a disconnect direction that is at least substantially parallel to the mounting surface. The case and base cooperate when interconnected to prevent movement of the case in a direction generally perpendicular to the disconnect direction. 
     The device is further presented in combination with a door assembly including a door frame, a door hung on the frame for movement into and out of a closed position, and hardware selectively securing the door to the frame when the door is in a closed position. In the combination, the case and base are removably interconnected in such a manner that, when the door is closed, disconnection of the case from the base is prevented by interengagement of the case and door assembly, and permitted only when the door is open. 
     In this respect, it will be appreciated that the door hardware illumination device is both easy for the user to remove from the mounting surface when the user desires to put the device to uses other than illuminating the door hardware (e.g., as a flashlight once the door is open), and yet virtually impossible for thieves or vandals to remove from the mounting surface when the user does not desire to put the device to other illumination uses (e.g., when the user is not at home and the door is closed). 
     Other aspects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiment and the accompanying drawing figures. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     A preferred embodiment of the invention is described in detail below with reference to the attached drawing figures, wherein: 
     FIG. 1 is a perspective view of a theft-proof removable door hardware illumination device constructed in accordance with the principles of the present invention and mounted on the door of a door assembly, with the door being shown in the closed position; 
     FIG. 2 is a perspective view of the device shown in FIG. 1, particularly illustrating the door in an open position and the case sufficiently moved in the disconnect direction to permit removal from the base; 
     FIG. 3 is a perspective view of the base of the device shown in FIG. 1; 
     FIG. 4 is a perspective view of the back of the case of the device shown in FIG. 1; 
     FIG. 5 is a vertical cross-sectional view of the device shown in FIG. 1, particularly showing the interlocking connection of the case and base; 
     FIG. 6 is a front elevational view of the base of the device shown in FIG. 1, particularly showing the door in the closed position and the case in phantom lines as it rotates in the disconnect direction and is prevented from being removed from the base by engaging the door frame; 
     FIG. 7 is a horizontal cross-sectional view of the depiction of FIG. 6; 
     FIG. 8 is a front elevational view of an alternative embodiment of the present invention, showing the base in solid lines and the case in phantom lines and fully rotated relative to the base in the disconnect direction; 
     FIG. 9 is a perspective view of the base shown in FIG. 8; 
     FIG. 10 is a perspective view of the case shown in phantom in FIG. 8; 
     FIG. 11 is a vertical cross-sectional view of the alternative embodiment, mounted to a door, showing the interlocking connection of the case and base. 
    
    
     DETAILED DESCRIPTION 
     Turning initially to FIG. 1, the theft-proof removable door handle illumination device  10  selected for illustration generally is associated with a door assembly  12 . The door assembly  12  includes a door  14 , a door frame  16  and hardware  18 . The door  14  hangs from the frame  16  by hinges (not shown) that movably support the door  14 . The door  14  closes into and opens out of the frame  16 . The hardware  18  includes a door handle  20 , with handle latch  22 , and a keyhole  24  with keyhole lock  26 . The lock  26  selectively and securely affixes the door  14  to the frame  16 . The handle  20  facilitates opening and closing the door  14  and, as is common, the handle  20  operates the latch  22  that serves to releasably retain the door  14  in the closed position. The frame  16  includes a pair of spaced apart jambs  28  (only one of the jambs being shown in the drawing figures) between which the door  14  is located when in the closed position. The device  10  is shown mounted on the door  14 , illuminating the hardware  18 . As will become clear from the following description, the device  10  could also be mounted to the frame  16 , including on the jamb  26 . In addition, the device  10  could be mounted on a surface in close enough proximity to the door assembly  12  to allow both illumination of the hardware  18  and, as will become apparent, interengagement of the device  10  and the door assembly  12 . The door assembly  12  is preferably a home exterior door assembly, however, the scope of the present invention encompasses use of the device in virtually any door assembly, for example, home interior, building interior and exterior, or vehicle door assemblies (such as door assemblies on recreational vehicles). 
     The device  10  includes a base  30  and a case  32 . The case  32  is removably interconnected to the base  30 . The base  30  (see FIG. 3) is rectangular in shape and includes a front surfaces  34  and a back surface  36 . Extending between the front surface  34  and the back surface  36  are side walls  38  and opposing ends  40 . The base  30  must be sufficiently dimensioned, both with respect to surface area and thickness, to sufficiently support the case  32  when the base  30  is mounted on a mounting surface. The illustrated base  30  is approximately the size of a standard household single outlet cover-plate. The illustrated base  30  and case  32  have roughly equal length and width dimensions. The base  30  is preferably constructed out of molded plastic. To reduce the amount of material used, and to facilitate the molding process, recesses  42  (see FIG. 5) located between the points of contact formed by the back surface  36  and the mounting surface are provided. 
     The base  30  could be any shape and size, so long as it can sufficiently support the case  32 . For aesthetic purposes, a base  30  dimensioned equal to or smaller than the case  32  dimensions would allow the base  30  to be hidden by the case  32  when the case  32  is interconnected with the base  30 . The base  30  could be constructed of any suitable material or combination of materials, e.g. various types of plastics, metals or woods. The base  39  may also be any suitable configuration—e.g. solid, hollow, or a combination so long as the base  30  when mounted on a mounting surface can sufficiently support the case  32 . 
     The base  30  has screw receiving openings  44  that receive screws  46 . The screw receiving openings  44  each have a countersunk configuration whereby the outer edge of the opening  44  located on the front surface  34  are larger than the inner edge of the opening  44  located on the back surface  36 . This countersunk configuration forms a funnel-shape for receiving the complementally shaped head of the screw  46 . The funnel-shape allows the head of the screw  46  to lay flush with the front surface  36  when the base  30  is mounted to a mounting surface. Any type of fastener sufficient to affix the base  30  to a mounting surface and support the weight of the device  10  could be utilized, for example bolts, glue, nails, rivets. 
     The base  30  includes attachment flanges  48  projecting from the front surface  34  on opposite sides of the horizontal centerline of the base  30 . The attachment flanges  48  preferably extend along diametrically opposed arcs of a common imaginary circle having a center point common with the geometrical center of the surface  34 . Each attachment flange  48  extends about approximately one-quarter of the imaginary circle (i.e., an arc of about 90°) Further, each of the illustrated attachment flanges  48  has an inverted L-shaped cross-section relative to the front surface  34  (see FIG.  5 ). The inverted L-shaped flanges  48  each cooperate with a respective grooved projection  49  to define a receiving channel in which a complemental portion of the case  32  is received. The projections  49  are preferably coextensive with the flanges  48 . The projections  49  extend to and define in part the back surface  36 . In this regard, it may be said that the receiving channels project generally inward from the front surface  34 . As will be described, the shape of the flanges  48  may be varied as desired, as long as the flanges  48  cooperate with the corresponding structure of the case  32  to provide the desired interconnection. 
     The base  30  further includes a pair of side cavities  50  recessed below the front surface  34 . Each of the cavities  50  projects from corresponding ends of the receiving channels to the adjacent one of the side walls  38  (see FIG.  3 ). The illustrated cavities  50  each consequently spans the portion of the length of the base  30  extending between the attachment flanges  48 . The cavities are defined by a recessed wall  50   a  that is preferably coplanar with the inner margin of the receiving channels. 
     The case  32  (see FIG. 4) is half-cylindrical in shape and includes an aft surface  52 , an apron  54 , a top plate  56  and a bottom plate  58 . Similar to the base  30 , the case  32  includes attachment flanges  60  projecting from the aft surface  52  on opposite sides of the horizontal centerline of the aft surface  52 . In addition, the attachment flanges  60  similarly extend along diametrically opposed arcs of a common circle, with the arcs each being approximately 90 E in length. It is noted that the radius of the common circles (for both sets of flanges  48  and  60 ) are equal. Yet further, each of the flanges  60  have a shape complemental to the respective receiving channel defined in the base  30 ; that is, the illustrated flanges  60  each present an inverted L-shaped cross-section relative to the aft surface  52 . The case  32  also includes a similar pair of projections  61  that cooperate with the flanges  60  to define receiving channels, each of the channels being configured to receive the respective attachment flange  48  of the base  30 . In other words, the illustrated channels of the case  32  present an L-shaped cross-section complemental to the shape and size of the attachment flanges  48  of the base  30 . 
     Again, it is entirely within the ambit of the present invention to vary the shape, dimension and configuration of the channels and flanges so long as the desired interconnection between the base  30  and case  32  is provided. For example, the principles of the present invention are equally applicable to an alternative device having the upper set of flanges and channels different from the lower set. It will be appreciated that such an alternative configuration ensures that the case is always properly oriented right-side-up on the base (i.e., with the top plate  56  facing upwardly and the bottom plate  58  facing downwardly). It is also entirely possible to configure adjacent flanges (e.g., the upper attachment flanges of the case and base) differently. For example, the upper attachment flange of the base may alternatively have a T-shaped cross-section, while the upper attachment flange of the case may alternatively have a j-shaped cross-section. Of course, such an alternative arrangement requires the receiving channel for each of the flanges to be complementally configured. 
     As is also similar to the base  30 , the case  32  includes a pair of side cavities  62  recessed below the aft surface  52 . Each of the cavities  62  projects from corresponding ends of the receiving channels to the adjacent side edge of the aft surface  52  (see FIG.  4 ). The illustrated cavities  62  each consequently spans the portion of the length of the case  32  extending between the attachment flanges  60 . The cavities are defined by a recessed wall  62   a  that is preferably coplanar with the inner margin of the receiving channels. 
     In the preferred embodiment, the case  32  houses an illumination assembly  74  that is operable to provide selective illumination. The illustrated assembly  74  includes a portable power source  64 , a replaceable lightbulb  66 , and a normally open circuit (not shown) interconnecting the power source  64  and lightbulb  66 . Interposed along the circuit is a push-button type switch  68  that operates to alternatively open and close the circuit when depressed. The configuration of the switch  68  may be varied as desired, with any type of suitable circuit control device being usable. A motion sensor  69  is also suitably provided along the circuit to activate the circuit and thereby turn the lightbulb on when the presence of a person adjacent the door  14  is sensed. It is noted that the switch  68  and sensor  69  are preferably located in suitable openings  78  of the apron  54  so as to face outwardly when the case  32  is supported on the base  30 . A secondary switch (not shown) may also be provided to permit manual control of the sensor  69 , as it will likely be desirable to deactivate the sensor when the case  32  and assembly  74  are being used for portable illumination. 
     The case  32  is generally hollow so that the illumination assembly  74  is essentially contained entirely within the case  32 . However, the principles of the present invention are equally applicable to only partial enclosure or encasement of the illumination assembly by the case  32  (e.g., some or all of the illumination assembly may be supported externally of the case  32 ). As discussed above with respect to the base  30 , the case  32  could be any shape and size, so long as the illumination assembly  74  could be incorporated in the case  32  and the case  32  can be removably interconnected to the base  30 . For aesthetic purposes, a base  30  dimensioned equal to or smaller than the case  32  dimensions would allow the base  30  to be hidden by the case  32  when the case  32  is coupled to the base  30 . In addition, as a practical matter, because the case  32  is designed to be removable and usable for portable illumination, the size and shape of the case  32  should facilitate this portable usage. In fact, it is entirely within the ambit of the present invention to provide an alternative case configuration (e.g., a case with a grip handle) that is more easily held. The case  32  could be constructed of any suitable material or combination of materials, e.g. various types of plastics, metals or woods. The material design could also be any suitable configuration (e.g., solid, hollow, or a combination) subject to the same two limitations discussed above. 
     The lightbulb  66  is oriented at the bottom of the case  32  toward the bottom plate  58  so that when the circuit is closed (i.e., when the button switch  68  is pushed to the on position or the motion sensor senses movement of person or a storm door) a beam of light is emitted. In the illustrated embodiment, the bottom plate  58  is transparent, although the bottom plate  58  could be variously configured to allow the beam of light to penetrate (e.g., the bottom plate  58  could be constructed of opaque material with a light-directing opening configured to direct the beam of light). If desired, the apron  54  and/or the bottom plate  58  may be removably connected to the aft surface  52  so as to allow access to the illumination components housed within the case  32 . It is further noted that a dividing wall  71  is located between the power source  64  and the light  66  and a reflective canopy is fixed adjacent the wall  71  to enhance the directional illumination provided by the device (see FIG.  5 ). 
     The portable power source  64  in the illustrated embodiment is a pair of batteries (e.g., D-size batteries), preferably rechargeable, although other suitable power sources may be used. The power source  64  must supply sufficient power to the lightbulb  66  to generate the desired degree and duration of light. However, it is most preferred to utilize a portable power source  64  (i.e., a power source that is operable when the case  32  is removed from the base  30 ). For example, a single, relatively small battery could be used in combination with a battery charger provided in the base  30 , wherein the charger is activated and charges the battery when the case  32  is coupled to the base  30 . The charger could be directly connected to a normally closed, continuous power supply (e.g., the master circuit of the building or house). A removable cover  72  is provided on the case  32  to facilitate replacement of the preferred power source  64  (see FIG.  4 ). In the illustrated embodiment, the cover  72  comprises a portion of the top plate  56  and is snap fit into place. If desired, the orientation of the cover  72  may be reversed so that it projects from the aft surface  52  and is spaced from the apron  54 . Such an alternative arrangement permits removal of the cover essentially only when the case  32  has been removed from the base  30 , thereby further enhancing the theft-proof nature of the device. 
     The lightbulb  66  can be any suitable, commonly available, replaceable bulb of varying wattage, size, shape and color, subject to the limitation that the bulb  66  provide enough light to sufficiently illuminate the targeted hardware  18 . In this regard, the device  10  must be mounted in close enough proximity to the targeted hardware  18  to sufficiently illuminate the door handle  20  and/or the keyhole  24  so as to facilitate grasping of the handle  20  and unlocking of the lock  26  in low-light conditions (see FIG.  1 ). 
     Turning now specifically to the removable interconnection of the base  30  and case  32 , the attachment flanges  48 , 60  and corresponding receiving channels provide smooth and uncomplicated connection and disconnection of the base  30  and case  32 , while ensuring that the case  32  may be securely locked on the base  30 . That is to say, the device  10  is designed so that the case  32  is easily and quickly removable so that the illumination assembly  74  may be used in various portable applications, but removal of the case  32  is prevented except in certain conditions (e.g., when the door  14  is open). 
     As perhaps best shown in FIG. 2, attachment of the case  32  to the base  30  first requires the door  14  to be open; otherwise, the door frame  16  will obstruct the case  32  from being installed. Once the door  14  is sufficiently open, the case  32  is positioned in a transverse orientation relative to the base  32  and the aft surface  52  thereof is placed against the front surface  34  of the base  30 . It is noted that the geometrical centers of the surfaces  34  and  52  must also be generally aligned. In this orientation, the illustrated attachment flanges  48  and  60  form a continuous circle (so do the receiving channels). The case  32  is then rotated approximately ninety degrees (90°) in a clockwise direction so that the case  32  is generally aligned with the base  30 , with the top plate  56  oriented upwardly and the bottom plate  58  oriented downwardly (see FIG.  1 ). Of course, if the case  32  happened to be facing the opposite direction in FIG. 2 (such that the top of the case  32  projects beyond the adjacent side of the door  14 ), the case  32  would alternatively be turned in a counter-clockwise direction. 
     Those ordinarily skilled in the art will appreciate that placement of the aft surface  52  flatly against the front surface  34  (as shown in FIG. 2) is permitted because the side cavities  50  and  62  receive the flanges  60  and  48 , respectively, without requiring longitudinal movement of the flanges. However, as soon as the base  30  and case  32  are interconnected (i.e., as soon as the flanges  48  and  60  have been received in the respective channels) such non-axial movement of the flanges  48  and  60  is prevented. As perhaps best shown in FIG. 1, the cavities  50  and  62  define a slight gap extending along each side of the device when the case  32  is supported on the base  30 . As will be indicated by the alternative embodiment, such a gap may be eliminated. 
     It is noted that the screw openings  44  are located in the base  30  so that the screws  46  are not exposed once the case  32  is rotated into contact with the door frame  16  (see FIG.  6 ). it is therefore important with the illustrated embodiment that the base  30  is mounted sufficiently close to the frame  16  to ensure that the case  32  is prevented from rotating enough to expose the screws  46 . Of course, the principles of the present invention are equally applicable to other screw opening locations. For example, the openings may alternatively be located between the flanges  48  (i.e., within the imaginary circle), which would ensure that the screws are only exposed once the case  32  is removed. 
     If desired, the base  30  and/or case  32  may be provided with a stop (not shown) that prevents movement of the case  32  beyond the aligned relationship with the base  30 . It may also be desirable and possible to provide a catch (e.g., a detent mechanism) that releasably holds the case  32  in the aligned relationship. In the illustrated embodiment, however, the flanges  48 , 60  and channels are tightly dimensioned so that each flange is snugly received in the respective channel and the frictional interengagement provided thereby prevents inadvertent rotation of the case  32  relative to the base  30 . 
     Once the door  14  is closed as shown in FIGS. 6 and 7, the case  32  can only be rotated only slightly out of the aligned position before engaging the door frame  16 . In this regard, the case  32  is prevented from rotating fully to the transverse position shown in FIG.  2 . This, of course, requires the base  30  to be mounted sufficiently close to the door frame  16 . It also requires the device  10  to be designed so that removal of the case  32  involves movement in a direction that causes such blocking interengagement with the door frame  16 . In other words, because the case  32  is prevented from moving generally perpendicular to this disconnect direction when the flanges  48 , 60  are received in their respective channels, the case  32  cannot simply be pulled away from the base  30 . In view of the foregoing, the case  32  can only be removed when the door  14  has been opened and sufficiently cleared the door frame  16 , such that only a person capable of opening the door  14  (e.g., a homeowner having the key to operate the lock  26 ) can utilize the case  32  and illumination assembly  74  apart from the hardware  18 . It is believed that such a limitation significantly reduces the risk of theft of the case  32  and assembly  74 , while ensuring that the device  10  effectively illuminates the hardware  18 . 
     Preferably, the base  30  is relatively flat and is mounted flush against a flat surface of the door  14  (see FIG.  1 ). Therefore, the case  32  preferably connects and disconnects from the base  30  by movement in a direction that is parallel to both the door  14  and to the base  30 . It is well within the ambit of the present invention that the base  30  could alternatively be mounted to a non-flat surface(s). For example, the device may alternatively be mounted to a door or frame that is somewhat contoured or curved. In addition, it is well within the ambit of the present invention that the base  30  could alternatively be variously shaped and sized (e.g., bowl shaped). It is also possible for the device to be configured so that movement of the case  32  in the disconnect direction is at a slight angle relative to the surface to which the base is mounted. It will be appreciated that such relative angular movement is still sufficiently parallel to the mounting surface that the case  32  will be caused to engage the door frame  16  when the door  14  is closed. Accordingly, movement of the case  32  in the disconnect direction may not be exactly parallel with either or both the mounting surface and the base  30 , although such movement is at least substantially parallel to the mounting surface. An additional alternative embodiment involves limited or slight movement of the case  32  away from the mounting surface (e.g., the base and the case may be threadably interconnected). Such screwing interaction between the base and case is still considered to involve substantially parallel movement of the case relative to the mounting surface. It would also be possible to provide a linear tongue and groove connection between the base and case, such that the case moved in a straight disconnect direction rather than rotate as illustrated. It will be appreciated that such a linear connection would likely be associated with a stop that permits movement of the case in only a single direction (i.e., toward to door frame) out of the fully engaged condition with the base. 
     As noted, the base  30  is preferably mounted to the door  14 . However, the device  10  may alternatively be mounted on any surface close enough to sufficiently illuminate the targeted hardware  18 . For example, the device can alternatively be mounted on the door frame  16  such that the door in its closed position interferes with rotation of the case relative to the base. It is only important that the device provide the desire illumination of the hardware  18 , while permitting the case to be quickly and easily removable only certain conditions (e.g., when the door is closed). 
     An alternative embodiment  100  of the invention is shown in FIGS. 8-11. The device  100  is substantially similar to the embodiment shown in FIGS. 1-7, except that the base  102  and case  104  are removably interconnected by an alternative tongue and groove connection. Particularly, a pair of grooves  106  project inwardly from the front surface  108  of the base  102 . As before, the grooves  106  extend along diametrically opposed arcs of an imaginary circle centered on the front surface  108 . Projecting from the aft surface  110  of the case  104  are a pair of tongues  112 . The tongues are likewise defined along diametrically opposite arcs of an imaginary circle centered on the aft surface  110 . The imaginary circles along which the grooves  106  and tongues  112  extend are equal in size. Furthermore, the common diameter of these imaginary circles is greater than the width of the base  102 . Each of the grooves  106  extend more than ninety degrees (90°) around the imaginary circle and thereby extend from side to side. On the other hand, the tongues  112  each extend only about ninety degrees (90°) around the imaginary circle. It is noted that the base  102  and case  104  do not each include both a tongue and groove (or a flange and channel). 
     In addition, the grooves  106  and tongues  112  have an alternative configuration; that is, they are not L-shaped in cross-section. Instead, each groove  106  has an inverted bulb-shaped cross-section (i.e., a circular opening with a radial projection extending therefrom) relative to the front surface  108  (see particularly FIG.  11 ). The tongues  112  have a cross-sectional shape corresponding to that of the grooves  106 . As best shown in FIG. 8, the ends of each of the grooves are widened (i.e., the portion of the base defining the narrow outer section of the groove is removed) so as to not prevent non-axial movement of the tongue  112  relative thereto. In this regard, the aft surface  110  of the case  104  can be placed flatly against the front surface  108  of the base  102  when the case  104  is oriented in a transverse relationship relative to the base  102 , as shown in FIG.  8 . 
     The preferred forms of the invention described above are to be used as illustration only, and should not be utilized in a limiting sense in interpreting the scope of the present invention. Obvious modifications to the exemplary embodiments, as hereinabove set forth, could be readily made by those skilled in the art without departing from the spirit of the present invention. 
     The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.