Patent Publication Number: US-6708426-B2

Title: Torsion management outsoles and shoes including such outsoles

Description:
TECHNICAL FIELD 
     The present invention is directed to an outsole. More particularly, the present invention is directed to a golf shoe having an improved outsole that enables greater torsional movement and flexibility of the shoe. 
     BACKGROUND OF THE INVENTION 
     Historically, people first wore shoes to protect their feet. Over the centuries, footwear evolved into many different types that were specific to particular activities. Thus, the protection offered by a cold-weather work boot is highly different from that offered by a running shoe. In addition to protecting the feet, athletic footwear has further developed to offer specific functions dependent on the particular sport. Soccer shoes, for instance, have spikes for traction, whereas cycling shoes have very stiff soles with mounting plates for cleats to engage the pedal. In this manner, golf shoes have evolved to provide the wearer with good traction on grass, comfort while walking, and a stable platform for hitting the ball. Typical golf shoes thus have a relatively stiff sole with metal spikes or plastic cleats. 
     A stiff sole, while providing a stable platform, can nonetheless cause discomfort because there is a balance between how the foot should be allowed to move versus how it should be supported. An example of this is the fact that during walking and at the start and finish of the golf swing, the foot bends at the metatarsal joints (the ball). Aside from the physical effort needed to flex a very stiff sole (which would tend to cause a ‘clunky’ gait as when wearing clogs), sole stiffness tends to cause the heel of the foot to slide up and down in the heel cup, potentially causing blisters. Thus, golf shoes have evolved to have soles that flex across the ball area to allow this movement without compromising the lateral stability of a good hitting platform. 
     Relatively recent studies in biomechanics have sought to better quantify how the 26 bones of the foot move relative to each other during human movements. One particular motion that has been identified is a torsional movement about the long axis of the foot. In effect, the forefoot and rearfoot twist relative to each other. It is thought that this movement smooths the contact between foot and ground, decreasing impacts with the ground as well as providing better ground contact. This observation has led to the development of a golf shoe sole to allow this natural movement. 
     U.S. Pat. No. Re. 33,194, reissued from U.S. Pat. No. 4,608,970, to Marck et al. discloses an orthopedic device for correcting infants&#39; feet. The device includes a posterior part, an anterior part, and a ball-and-socket for allowing three degrees of freedom between the posterior and anterior parts during set-up. These parts are immobilized in a particular position, when the device is in use. As a result, this device does not assist with the natural torsional-like action of the foot in walking where such action is missing. 
     U.S. Pat. No. 3,550,597 discloses a device that facilitates the natural rolling action of the foot during movement by providing a flat construction with front and rear main lifting sections rigidly connected to a resilient intermediate section that is twisted into the form of a flat torsion spring. The device applies a yieldable torsional action during use that is applied to the foot by the lifting sections, whereby the heel of the foot is urged upwardly at the inner side and the forefoot is raised upwardly at the outer side, producing a torsional action similar to the natural torsion action of the foot. 
     Another construction intended to provide greater support to the wearer of the shoe is disclosed in U.S. Pat. No. 5,243,776 to Zelinko. The Zelinko golf shoe has a sole having a forward end, a heel end and an intermediate portion joining the two ends. A spike support plate is journaled to a post extending from the forward end of the shoe. The spike support plate is so mounted to the forward end for rotation about a vertical axis. A biasing means, such as tension springs, is provided to connect the spike support plate to the heel end and for constantly biasing the spike support plate to a neutral (i.e., non-rotated) position and returning the support to that position after the support has been rotated. A cover is provided to protect the biasing means. The Zelinko golf shoe is constructed to allow the forward end of a golfer&#39;s foot to remain fixed during a golf swing while the heel rotates. 
     There remains a need for an improved outsole for a shoe that enables individuals movements of the foot, particularly, the rotation between the rearfoot and the forefoot. By allowing and controlling these rotations, the outsole would resists torsional instability during play, provides independent traction suspension, and increases the flexibility of the shoe to accommodate the movement of the wearer. 
     SUMMARY OF THE INVENTION 
     The present invention is directed toward an outsole for a shoe construction having a forward portion, and a rearward portion, coupled together at a pivot point. The forward and rearward portions are operatively connected to freely allow independent and relative movement of the forward and rearward portions about the pivot point. This relative movement may occur during a user walking with the outsole or swinging a golf club. 
     In another embodiment, the outsole further comprises a first axis extending substantially longitudinally across the outsole and through the pivot point and the forward and rearward portions are moveable about the first axis. In yet another embodiment, the outsole further includes a second axis extending through the pivot point and offset with respect to the first axis and the forward and rearward portions are moveable about the second axis. In one embodiment, the second axis is offset at an angle between about 5° and about 30° and in another embodiment the pivot point is positioned adjacent the exterior of the outsole. 
     In one embodiment, the forward and rearward portions may be operatively connected discrete pieces. In another embodiment, the outsole may include a ball-and-socket connection configured to allow relative movement of the forward and rearward portions. 
     In yet another embodiment, the present invention is directed to a shoe comprising an outsole and an upper generally configured to accommodate a foot connected to the outsole. The outsole includes a forward portion for supporting the forefoot of a foot and a rearward portion for supporting the heel of the foot. The forward portion defines a chamber. The rearward portion includes a protrusion. The forward and rearward portions are operatively connected when the protrusion is received in the chamber. 
     In another embodiment, the present invention includes an outsole comprising a first piece, a second piece separate from the first piece, and a flexible member joining the first piece to the second piece. The flexible member includes a length that is less than the length of each of the first and second pieces. Furthermore, the material of the flexible member is substantially softer than the first and second piece materials. 
     In such an outsole, the first and second piece materials may have a Shore A greater than about 75 and the flexible member material may have a Shore A less than about 85. In addition, in such an outsole the first and second piece materials may have a Shore A greater than about 85 and the flexible member material may have a Shore A of about 70. 
     The present invention is also directed to a sole construction comprising an outsole having a transparent window member on the upper surface thereof, a midsole for connected to the outsole, and a gel cushion between the outsole and the midsole. At least a portion of the gel cushion may be aligned with the window member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     To facilitate the understanding of the characteristics of the invention, the following drawings have been provided wherein: 
     FIG. 1 is a top, perspective view of a golf shoe of the present invention with a portion broken away to expose a midsole; 
     FIG. 2 is an exploded, bottom view of a first embodiment of an outsole of the golf shoe of FIG. 1, wherein a non-metal spike is disassembled therefrom; 
     FIG. 3 is an enlarged, bottom view of a portion of the outsole of FIG. 2; 
     FIG. 4 is a bottom view of the outsole of FIG. 2 according to the present invention, wherein the outsole is assembled and the spike is disassembled therefrom; 
     FIG. 5 is a top view of the outsole of FIG. 4; 
     FIG. 6 is a side view of the outsole of FIG. 4 showing the forward portion rotated with respect to the rearward portion; 
     FIG. 7 is an enlarged, partial, perspective view of the rearward portion of outsole of FIG. 4 with a gel cushion and a heel cushion disassembled therefrom; 
     FIG. 8 is a bottom view of the outsole of FIG. 4, with the spikes disassembled therefrom, joined to a midsole of the golf shoe of FIG. 1; 
     FIG. 9 is a cross-sectional view of the outsole and midsole of FIG. 8 taken along the line I—I; 
     FIG. 10 is a bottom view of a second embodiment of an outsole of the present invention joined to a midsole; 
     FIG. 11 is a side view of another embodiment of a gel cushion joined to an outsole and midsole of the present invention; 
     FIG. 12 is a cross-sectional view of the gel cushion, outsole and midsole along line II—II of FIG. 11; and 
     FIG. 13 is a top view of the gel cushion, outsole and midsole of FIG.  11 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An embodiment of a golf shoe  10  constructed according to the present invention is shown in FIG.  1 . The shoe  10  includes an upper  12 , a midsole  14  joined to the upper  12 , and an outsole  16  joined to the midsole  14 . The upper  12  has a generally conventional shape and is formed from a suitable upper material, such as leather or the like. An opening  18  is formed by the top portion of the upper  12  for receiving a user&#39;s foot. Upper  12  is preferably secured to midsole  14  with cement or other adhesives using an insole board and conventional techniques, as known by those of ordinary skill in the art. 
     The midsole  14  provides cushioning to the wearer, and is formed of a material such as an ethylene vinyl acetate copolymer (EVA). Preferably, the midsole  14  is formed on and about the outsole  16 . Alternatively, the midsole can be formed separately from the outsole and joined thereto such as by adhesive. Once the midsole and outsole are joined, the outsole  16  forms a substantial portion of the bottom of shoe  10 . 
     Referring to FIG. 2, the outsole  16  includes a forward portion  20  coupled to a separate rearward or shank-heel portion  22 . The forward and shank-heel portions  20  and  22  are discrete pieces connected to permit relative movement therebetween. The outsole  16  has a top surface  24  and a bottom surface  26 . Midsole  14  is joined to top surface  24 . The bottom surface  26  is configured to contact the turf or ground during use. 
     Referring to FIGS. 2 and 3, one preferred mechanism used to couple forward portion  20  to shank-heel portion  22  includes a connector  30  and a male member  38 . Connector  30  is positioned at the rearward edge of forward portion  20 , and is received in a recess  28  formed in forward portion  20 . Preferably, connector  30  has a substantially spherical, interior chamber  32  with an opening  34  and an inner ridge  36 . Ridge  36  is preferably spaced from and near the opening  34  within the chamber  32 . 
     Male member  38  extends from the forward edge of shank-heel portion  22  and includes a projection portion  38   a  extending from a base portion  38   b  that is embedded in shank-heel portion  22 . In one preferred embodiment, base portion  38   b  is wider than projection  38   a  and may optionally include holes for assuring good molding or adhesion of the male member  38  to shank-heel portion  22 . 
     The projection portion  38   a  is configured and dimensioned to be received within chamber  32  of connector  30 , as shown in FIG.  4 . In a preferred embodiment, connector  30  and projection portion  38   a  form a ball-and-socket joint. In this regard, the projection portion  38   a  preferably has a ball  40  at the free end and the spherical chamber  32  serves as the socket. The connector  30  is dimensioned and flexible enough to allow entry of the ball  40  into chamber  32 , but also retains the ball  40  within the chamber  32 . 
     The chamber  32 , preferably, has an inner diameter Di. The ball  40  preferably has an outer diameter Do. The chamber  32  inner diameter Di is slightly larger than the ball  40  outer diameter Do such that there is sufficient clearance to allow the ball  40  to rotate in the socket  32 . In a preferred embodiment, the outer diameter Do of the ball  40  is between about 5 mm and about 6 mm, and most preferably is about 5.5 mm. The inner diameter Di of the chamber  32  is preferably no more than 0.1 mm greater than the diameter of the outer diameter Do to allow movement between the two pieces without excessive free play. 
     In a preferred embodiment, the connector  30  may be formed of flexible plastic material. A suitable material for the connector  30  is an ester-based thermoplastic polyurethane manufactured by URE-TECH CO., Ltd. located in Taiwan under the name Utechllan UTY-85A. This material is desirable because it is available as a transparent material so that the ball-and-socket connection is visible from the top and bottom surfaces  24 ,  26  of the outsole  16 . The connector  30  and male member  38  preferably have a hardness of about 90 Shore A. 
     Referring to FIG. 4, the outsole  16  further includes a longitudinal axis L that extends longitudinally along the center of shank-heel portion  22  through the ball-and-socket connection to the forefoot portion  20  of the outsole  16 . A transverse axis T extends transversely across the outsole  16  and through the ball-and-socket connection and is aligned substantially perpendicular to the longitudinal axis L. Referring to FIG. 6, a vertical axis Z extends through the ball-and-socket connection and substantially perpendicular to the bottom surface  26  of the outsole  16  and the longitudinal and transverse axes L and T. Projection portion  38   a  of male member  38  preferably extends along an axis of rotation R that is configured to align with an axis about which the foot naturally rotates or torques during walking and during a golf swing. Projection portion  38   a  and axis R are preferably offset at an angle α of between about 5° and about 30°, most preferably about 15°, with respect to longitudinal axis L. 
     The ball-and-socket connection defines a pivot point P that is positioned to allow natural rotation between the forefoot and rearfoot during walking and during a golf swing. In a preferred embodiment, the pivot point P is located between the midfoot and forefoot, preferably just behind the transverse arch (TA) of a user at the intersection of the subtalar joint axis and the midtarsal. Pivot point P is also preferably located adjacent the exterior of the outsole. The ball-and-socket connection allows the forward and rearward portions  20  and  22  to move independently, pivotally, and relatively with respect to each other about pivot point P. Also, this connection permits relative movement with three degrees of freedom, i.e. rotation about the axes R, T, and Z, while providing a stable connection therebetween. For example, the forward and rearward portions can rotate about axis R (twist) as indicated by arrow  41 , rotate about axis T (move upward and downward) as indicated by arrow  42 , and rotate about axis Z (move sideways) as indicated by arrow  43  in FIG.  6 . Accordingly, torsional management of the outsole  16  is achieved by allowing the shank-heel portion  22  to move independently of the forefoot portion  20  and thereby minimizing any strain that may be caused when the rolling motion of the wearer&#39;s foot is constrained by the shoe while walking or swinging a club. Additionally, the coupled connection provided by the ball-and-socket supports the wearer&#39;s foot, further providing comfort thereto. Advantageously, a golfer can keep more shoe sole on the ground during a golf swing by not having the heel portion of the shoe torque or lift the forefoot up off the turf. 
     Referring to FIGS. 5 and 7, the shank-heel piece  22  includes a shank section  78  and a heel section  80 . As can be seen in FIG. 9, shank section  78  includes a stiff member  79 , preferably embedded within shank section  78 , which is positioned to cover a substantial portion of the midfoot. Siff member  79  is preferably made from a kevlar or titanium material, however other stiff material can alternatively be used to have a desirably rigid shank that preferably resists bending. Stiff member  79  does not extend longitudinally into the heel section  80  and allows for the heel to collapse and cushion the wearer&#39;s heel during walking. In a preferred embodiment, shank section  78  is trapezoidal in shape having a larger width towards the heel section  80  and narrowing towards the forefoot. During walking and or swinging, the trapezoidal shape of the shank advantageously focuses the torsional forces exerted upon the shank-heel piece  22  toward the ball-and-socket joint and pivot point P. Also, because stiff member  79  is difficult to bend, both transversely and rotationally, shank section  78  preferably transmits substantially all of the torsional forces toward the ball-and-socket joint so that a maximum amount of rotation and bending occurs at a single pivot point P. In alternate embodiments shank sections can be curved, or have other shapes. 
     Referring to FIG. 2, in one preferred embodiment, the forward portion  20  includes a toe piece  46  and a separate forefoot piece  48 . The toe piece  46  and the forefoot piece  48  are connected together by a flexible member  50 . The flexible member  50  has a length less than the length of either of the toe piece  46  or the heel piece  48 . The shank-heel portion  22  in this embodiment is a single piece. However, the present invention is not limited to this construction and alternative embodiments, the forefoot portion  20  can be formed by a single piece. 
     It is recommended that the flexible member  50  is located such that it will be substantially below the user&#39;s metatarsal bones. The middle of the flexible member  50  is preferably located directly under the metatarsal heads. This optimally allows for variability of the location of the metatarsal heads by being wider than the flexion axis of the metatarsal heads. As a result, the flexible member  50  forms a hinge and the outsole  16  has good longitudinal flexibility for comfort. 
     Referring to FIG. 5, the flexible connector  50  that couples the toe piece  46  to the forefoot piece  48  includes a central portion  66 , a forward portion  68  and a rearward portion  70 . The central portion  66  is formed to arch upward (as best seen in FIG.  6 ). Preferably, the arched shape of the central portion  66  is formed during molding of the central portion  66 . In addition, the central portion  66  may be preferably wider at a lateral edge  67  than at a medial edge  69 . The central portion may narrow from each edge  67  and  69  toward the center  71  of the outsole. 
     The forward portion  68  of the connector  50  overlaps a rear section of the toe piece  46  and is joined thereto preferably during molding. The rearward portion  70  overlaps a front section of the forefoot piece  48  and is joined thereto preferably during molding. In this embodiment, projections  72  formed on the toe and forefoot pieces  46  and  48  extend through the forward and rearward portions  68  and  70  of the connector  50  to insure good adhesion between the connector and the pieces  46  and  48 . 
     Referring to FIGS. 5 and 6, the toe piece  46 , forefoot piece  48 , and shank-heel portion  22  have similar constructions and preferably include a first or base layer  52  and a second layer formed of discrete exterior or second layer pieces  54   a-c  for toe piece  46 . In alternate embodiment, these components may also be a single-layer construction. 
     The base layer  52  of the outsole  16  forms the inner layer of the outsole and is preferably formed from material that is soft for flexibility in the longitudinal direction. Preferably, the exterior or second layer pieces  54   a-c  form the outer layer of the outsole that primarily contacts the ground. Preferably, the second layer material is firm for lateral stability. The first or base layer material may be softer than or equal to the exterior or second layer material in hardness. 
     The outsole  16  of the present invention may be formed by various conventional methods. For example, one recommended method is disclosed in U.S. Pat. No. 5,979,083 to Robinson et al., which is hereby incorporated by reference in its entirety. According to this method, the first and second layers are molded together. 
     In the embodiment shown in FIG. 5, sockets  58  retain cleat receptacles  60  (best shown in FIG. 4) therein. The receptacles  60  releasably retain cleats  61  therein. The toe and forefoot pieces  46 ,  48  and shank-heel portion  22  preferably all include cleat receptacles  60 . 
     Referring again to FIG. 4, the first layer (not shown) further forms sets of projections  62  and  64  that extend therefrom. Sets of projections  62  and  64  are commonly referred to as “spikes” or “cleats,” and protrude from the bottom surface of the outsole. These projections  62  and  64  provide traction when the outsole  16  interacts with the ground thereby provide stable support to the golfer especially when the golfer executes a golf shot. These projections  62  and  64  are preferably non-metallic as most golf courses now require that non-metallic spikes or cleats be used with golf shoes. 
     The set of projections  62  extend from the layer  52  without contacting another layer, while the set of projections  64  extend from the layer  52  and extend through the second layer pieces  54   a-c . In this embodiment, the projections in the set of projections  64  are interconnected with one another. Similarly projections  74  formed on the second layer pieces  54   a-c  extend through the first layer  52  to insure good adhesion of these components together. 
     Preferably first or base layer  52  and second layer pieces  54   a-c  materials of the toe piece  46 , and forefoot piece  48  and the heel section  80  have a Shore A durometer greater than about 75, more preferably greater than about 85 Shore A, and most preferably of about 95 Shore A±3 Shore A. The preferred first layer and second layer materials for the above components are an ester thermoplastic urethane manufactured by URE-TECH CO., Ltd. located in Taiwan under the name U-95A. Other materials like other thermoplastic polyurethane can also be used including Desmopan® manufactured by Bayer and PEBAX® manufactured by Elf Atochem S.A. 
     The flexible member  50  may be formed of a thermoplastic urethane that is substantially softer than the first and second layer material for additional flexibility of the forefoot portion  20  (as shown in FIG.  2 ). Preferably, the flexible member  50  has a hardness of less than about 85 Shore A and more preferably about 70 Shore A. One recommended material is manufactured by URE-TECH CO., Ltd. under the name U-70AP which has a Shore A of about 70±3. 
     Referring to FIG. 7, the heel section  80  includes a bottom wall  82  and a front wall  84  and side wall  86  extending upwardly therefrom. The walls  82 ,  84 , and  86  of heel section  80  define a recess  81 . The side wall  86  has an arcuate shape and a height  83 . An arcuate window member  88  is joined to the upper surface of the side wall  86 . The height of the arcuate window member  88  is designated as  85 . The arcuate window member  88  in this embodiment has a cross-section that is C-shaped, however, the present invention is not limited to this shape. 
     A heel cushion  90  is configured and dimensioned to fit within the recess  81  and has a thickness  87  substantially equal to the side wall height  83 . When assembled, the heel cushion  90  is disposed within the recess  81 . A gel cushion  92  is configured and dimensioned to fit within the arcuate window member  88  and has a thickness  89  substantially equal to the window member height  85 . 
     Preferably, the heel cushion  90  is formed of a cushioning material such as EVA, but is not limited thereto and other materials or constructions such as foam, air cushions, and the like can be used. In the preferred embodiment, the window member  88  is formed of clear thermoplastic urethane and the components are configured and dimensioned so that when assembled, the gel cushion  92  is disposed on the heel cushion  90  and the gel cushion  92  is visible through the window member  88 . In a preferred embodiment, window member  88  is made from the UTY-90A material mentioned above. 
     In an alternative embodiment, the heel cushion  90  can be omitted and the gel cushion can have a thickness substantially equal to the side wall height  83  combined with the window member height H WM . As a result, the cushions  90  and  92  are disposed substantially below the user&#39;s calcaneus bone  94  (as shown in FIG.  6 ). 
     Referring to FIGS. 8 and 9, the outsole  16  can be joined to the midsole  14  via a cementing process or molding process. The midsole  14  has a section  14   a  adjacent the shank section  78  that must be formed sufficiently bendable to allow the portions  20  and  22  to move with respect to one another. This can be done by varying the thickness of the midsole. The portion of the midsole  14  that is adjacent the front portion  20  has a first thickness  97 . The portion of the midsole  14  that is adjacent the shank section  78  has a second thickness  98 . The portion of the midsole  14  that is adjacent the heel section  80  has a third thickness  99 . Preferably, the first and third thickness  97  and  99  are substantially greater than the second thickness  98 . More preferably, the first thickness  97  is about 12-14 mm, the second thickness  98  is about 5-7 mm and the third thickness  99  is about 9-11 mm. The midsole  14  when joined to the outsole  16  overlies the top surface  24  (as shown in FIG. 5) and the upper surface of the gel cushion  92  (as shown in FIG.  7 ). Alternatively, the midsole can be bendable adjacent the shank due to selecting a material for the midsole with the proper characteristics. 
     Referring to FIG. 10, an alternative embodiment of an outsole  116  is shown connected to midsole  14 . Outsole  116  is similar to outsole  16  previously discussed and operates similarly. Outsole  116  is formed with a forward portion  120  and rearward portion  122  connected similarly to outsole  16 . Forward portion  120  however is formed of three first layer pieces  154   a-c  that are connected to one another by a second layer  156 . Portions of the second layer  156  extend through the pieces  154   a-c  to form projections  162 . 
     A logo assembly  158  is positioned along a portion of outsole  116  and includes a transparent layer material to protect the logo when the outsole contacts the ground and permit visibility of the logo. One preferred material for the logo assembly  56  is an ester-based thermoplastic polyurethane manufactured by URE-TECH CO., Ltd. under the name UTY-90A, which has a Shore A of about 90. 
     Referring to FIGS. 11-13, an alternative construction of an outsole  216  is shown. Outsole  216  can include the ball-and-socket feature of outsoles  16  or  116  discussed above and operates similarly. Outsole  216  includes a gel cushion  292 . Cushion  292  includes a central portion  292   a  (best seen in FIG. 13) that is configured and dimensioned so that it is disposed within the recess  86  (as shown in FIG. 5) under the midsole portion  214   a.    
     The gel cushion  292  further includes extensions  292   b  that extend from the central portion  292   a  beyond the midsole  214  and outsole  216  (as best seen in FIG. 12) so that they are visible from the exterior of the shoe and contactable by a user. Although four extensions  292   b  are shown, the number and geometry of the extensions can vary in another embodiment. 
     The gel cushion  292  further includes three apertures  292   c  in the main body portion  292   a . In addition, the number and geometry of the apertures  292   c  can vary in another embodiment. As shown in FIG. 12, when the midsole  214  is molded to the outsole  216  and gel cushion  292 , the midsole portion  214   b  extends through the apertures  292   c  of the cushion and portion  214   a  of the midsole is above the gel cushion  292 , and portion  214   c  is below the gel cushion  292 . The gel for the cushion is this embodiment is not covered by a membrane, however, in another embodiment the cushion can be disposed within a membrane of material, such as plastic. 
     While it is apparent that the invention herein disclosed is well calculated to fulfill the objects above stated, it will be appreciated that modifications and embodiments may be devised by those skilled in the art. For example, other types of connections, such as latches or clamps may also be used in place of the ball-and-socket connection to provide independent and relative movement of the forefoot and shank-heel portions. The outsoles  16 ,  116  and  216 , and features thereof discussed above may be used with other types of shoes, not just golf shoes. The flexible member can be used with shoes with other constructions and particularly golf shoes with or without the ball-and-socket connection. In addition, the gel cushions can be used with shoes with other constructions and particularly golf shoes with or without the ball-and-socket connection. The appended claims cover all such modifications and embodiments as fall within the true spirit and scope of the present invention.