Abstract:
A ratcheting driver configured to rotationally drive an item or work piece is provided. The driver includes a handle and pivotal pawls engageable with a driven gear and capable of ratcheting and driving in both rotational directions. The handle and pawls have mating matched surfaces for full and flush overlying contact therebetween. A cap that is rotatable relative to the handle and that has a web for pivoting the pawls out of engagement with the gear is also provided. In addition, a stop is included. The stop is configured to assure that only a correct direction of rotation of the cap is available when assembling. Also, a method of arranging the driver is provided.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims priority to provisional U.S. patent application entitled, RATCHET DRIVER AND METHOD OF MAKING SAME, filed Jul. 19, 2005, having a Ser. No. 60/700,195, the disclosure of which is hereby incorporated by reference in its entirety. 

   Also, this relates to U.S. patent application Ser. No. 10/746,633, filed Dec. 29, 2003 and issued as U.S. Pat. No. 6,997,084 B1. There is common inventorship and a common owner for the present application, the above-referenced application, and the above-referenced patent. The disclosures of the above-referenced application and patent are incorporated into this present disclosure. 
   FIELD OF THE INVENTION 
   Certain embodiments of the present invention relate generally to ratchet drivers and to methods of making ratchet drivers. More particularly, certain embodiments of the present invention relate to ratcheting drivers which have pivotal pawls. The invention is particularly applicable to ratchet screwdrivers and also where there are two pawls which are pivotal between the driving and released positions for respective rotation inducement and free ratcheting movement. 
   BACKGROUND OF THE INVENTION 
   Ratcheting drivers are currently available to those skilled in applying fasteners, and in performing like actions. Such drivers commonly include a handle and an actuator thereon. Such drivers also commonly include a driven gear and pawl assembly, all for maneuvering the actuator for selectively setting the assembly for rotational driving in either direction while allowing ratcheting in the direction opposite the driving direction. 
   SUMMARY OF THE INVENTION 
   At least one embodiment of the present invention improves upon currently-available drivers by presenting a ratcheting driver which firmly transmits an optimum amount of torque through the gear and pawl assembly. In accomplishing this objective, the driver according to this embodiment is relatively easily manufactured, inexpensive, durable, can be miniature, and is reliable. 
   In using a ratcheting driver, torque is typically applied from a user&#39;s hand to the handle, then to the pawl, then to the gear, and then to the driven tool bit and/or to the work piece (e.g., a screw, nut, or bolt). According to certain embodiments of the present invention, it is important to have the assembly arranged for optimum transmission of the applied hand torque. Such optimization is often dependent upon the construction, mounting, and location of the pawls. Certain embodiments of the present invention achieve the optimum arrangement for transmitting that optimum torque, and do so in a reliable and consistent manner. 
   Certain embodiments of the present invention include pivotal pawls which are supported in pockets of the driver handle and, under the force of the rotation torque being applied, the pawls cannot then pivot out of their engaged position with the gear. That is, according to certain embodiments of the present invention, the rotation force applied through the handle serves to secure the pawls in the engaged position. As such, according to these embodiments, there is a relationship between the handle and the pawls to effect the securement of the engaged pawls without any forces tending to tilt the pawl. According to these embodiments, the torquing force, as applied to the pawls themselves, serves to enhance security for the engagement of the teeth which will remain engaged while driving. 
   According to certain embodiments of the present invention, the pawls have a stability with the handle and the gear to always remain aligned therewith and thereby have full and aligned contact with the gear during maximum torque transmission. Also, according to some of these embodiments, in the driving mode, the forces on the pawls from the handle are in a direction to enhance the force of engagement of the pawl with the gear teeth to thereby remain in full and secure driving contact. In fact, according to certain embodiments of the present invention, there can be more than one angular direction of the forces from the handle to the pawl, and thus there can be, for example, two simultaneously applied forces from the handle to the engaged pawl. Those two forces may, for example, be applied to spaced-apart locations, both of which urge the pawl into firm tooth engagement with the gear, as is desired. 
   Another important feature of certain embodiments of the present invention is that, in these embodiments, the pawls are disengaged from the gear by a camming action applied by a control that slidably engages the pawls for pivoting the pawls off the gear to thereby disengage the pawls. In such an arrangement, the control is selectively moved to respective positions relative to the respective pawl to pivot the prawl off of the gear. In that action, the control and the pawl have mutually engaging surfaces for effecting the pivoting action, and that produces the camming action. 
   As will be appreciated by those of skill in the art, that is in contrast to currently available practice of pushing pawls out of the way to free the pawls from gear engagement. As such, currently available pawls are tenuously positioned in their engaged positions. In contrast, according to certain embodiments of the present invention, the disengaging force on the pawl is in a direction of a force-component radially directed relative to the longitudinal axis of the gear. 
   Regarding the foregoing, according to certain embodiments of the present invention, the pawls can extend axially beyond the length of the gear teeth, and an actuator web is arranged for pivoting the pawl off of the gear from underneath the pawl. That is, according to some of these embodiments, the web extends to a location radially inward on the pawl to lift the pawl off the gear. 
   The driver cap according to certain embodiments of the present invention has a web which serves to rotationally release the pawls, so no additional pawl actuator member is required to serve as a pawl release. According to some of these embodiments, release is accomplished with one integral cap with a web which pivots the respective pawls off of the gear. 
   Additionally, according to certain embodiments of the present invention, the pawls are utilized for limiting the rotation of the cap when using the cap for ratcheting and driving adjustments. According to some of these embodiments, the pawls themselves are placed in rotative obstruction so the cap cannot be rotated too far until the cap is intentionally released. 
   According to still other embodiments of the present invention, the gear is rotatably supported at its two ends which flank the gear teeth. Therefore, according to some of these embodiments, the tendency to cock or tilt currently available gears is eliminated because the gear according to certain embodiments of the present invention is held stable against the driving forces. Also, according to certain embodiments of the present invention, the pawls extend beyond the axial length of the gear teeth, and thusly the web which actuates by pivoting the pawls can contact the pawls from underneath at the extending lengths to lift the pawls for pivoting. This is in direct contrast to pushing the pawls off to one side, as is currently done. 
   Further, according to certain embodiments of the present invention, the driver provides for precision and, therefore, firm gear teeth engagement between the handle carrying the two pawls and the driven gear. The gear may be small, at least relative to currently available ratchet drivers. Also, the ratio of gear teeth to base diameter of the gear may be high compared to currently available drivers. Thus, the teeth for engagement between the handle and the gear are, according to certain embodiments of the present invention, relatively numerous and small or fine for quiet, smooth, precise and close engagement, all with a lack of tooth play, while transmitting high torque. 
   The aforementioned are accomplished, according to certain embodiments of the present invention, because of an intimate engagement between the driving handle and each of the two pawls. According to certain embodiments of the present invention, the pawls and the handle have matching surfaces which are in extended contact when a pawl is in the torque driving mode. As such, according to certain embodiments of the present invention, more than a line contact therebetween transmits the torque to the pawls and then to the gear. According to certain embodiments of the present invention, those surfaces face tangentially to the gear at the point of tooth engagement, thereby transmitting torque at the optimum leverage and to the gear. Also, the matching surfaces may be arcuate and have a common center of curvature to produce the extended surface contact therebetween. 
   Also, according to certain embodiments of the present invention, a spring is applied for alternately urging the pawls into engagement with the gear. In some of these embodiments, the spring relates to the pawls in a self-adjusting contact with the pawls by sliding thereon, as needed. When one pawl is mechanically disengaged from the gear, the spring, according to certain embodiments of the present invention, automatically responds and is thus pressed to thereby exert an increased force on the other pawl. In some of these embodiments, the spring slides on both pawls for self-positioning of the spring on the two pawls. 
   Though certain embodiments of the present invention include two pivoting pawls, there is typically a firm stop action effective on the pawls when they are pivoted out of gear release mode. A line abutment, and that is firm, may also be applied between the pivoting pawls and the handle. 
   As will be appreciated by one of skill in the art, certain of the aforementioned embodiments of the present invention permit providing a miniature driver. This miniature driver is typically sensitive, strong, and smooth in its ratcheting action. 
   According to other embodiments of the present invention, a method of arranging one or more drivers according to certain embodiments of the present invention is also provided. Such a method is typically efficient and frequently presents a sturdy driver. Also considered to be part of certain embodiments of the present invention is the control of the parts during assembly so that the pawls and a cap release are properly positioned so that the cap can be released when desired. Further, according to certain embodiments of the present invention, the cap has a restrictor thereon to preclude incorrect rotation of the cap on the handle for assembly of the cap thereon. That is significant because, according to certain embodiments of the present invention, the cap includes a projection or web that is preferably positioned between the two pawls for proper pawl tooth release of the pawls from the gear. 
   There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto. 
   In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting. 
   As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front perspective view of an assembled driver according to one embodiment of the present invention. 
       FIG. 2  is a front end elevational view of  FIG. 1 , on a reduced scale. 
       FIG. 3  is a sectional view taken on a plane designated by the line  3 - 3  in  FIG. 2 . 
       FIG. 4  is a exploded view of the driver illustrated in  FIG. 1 . 
       FIG. 5  is a side elevational view of  FIG. 1 , on a reduced scale. 
       FIG. 6  is an enlarged section view taken on a plane designated by the line  6 - 6  of  FIG. 5 . 
       FIG. 7  is an enlarged perspective view of a part seen in  FIG. 4 . 
       FIG. 8  is an end elevational view of  FIG. 7 . 
       FIG. 9  is perspective view like  FIG. 7 , but with parts added thereto. 
       FIG. 10  is an end elevational view of  FIG. 9 . 
       FIG. 11  is a perspective view like  FIG. 9  but with a part removed. 
       FIGS. 12 and 13  are respectively perspective and end elevational views of the cap part in  FIG. 4 . 
       FIGS. 14 and 15  are respectively perspective and front elevational views of a pawl seen in  FIG. 11 . 
   

   DETAILED DESCRIPTION 
   Certain embodiments of the present invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. 
     FIG. 1  is a front perspective view of an assembled driver  10  (e.g., a screwdriver) according to one embodiment of the present invention.  FIG. 1  illustrates that the driver  10  includes an elongated housing in the form of a handle  11  that is also illustrated in  FIGS. 1-4 .  FIG. 1  also illustrates that the screwdriver  10  includes an attachment  12 , which serves as a pawl positioner or actuator and that the attachment  12 , along with other internal parts of the driver  10 , are all oriented along a longitudinal axis A. 
   According to certain embodiments of the present invention, the driver  10  is a miniature screwdriver. Thus, the handle  11  illustrated in  FIGS. 1-4  has a substantially spherical- or pear-shaped exterior shape to facilitate gripping by the palm of an operator&#39;s hand. The precision and the efficient transmission of rotation torque applied by the operator&#39;s hand allows for the miniature configuration which is shown in the above-discussed figures. However, other shapes and sizes are also within the scope of certain embodiments of the present invention. 
   The attachment  12  included in the handle  11  is illustrated in  FIG. 4  as being threaded and that can thus be screwed into the handle  11 . More specifically, as illustrated in  FIG. 3 , a portion of the attachment  12  includes threads  13  and may be rotated (i.e., screwed) as a unit into the pear-shaped handle portion  11 . The attachment  12  therefore presents an integral and fixed connection as a part of and with the remainder of the handle  11 . As shown in  FIG. 4 , once the handle  11  and attachment  12  are connected to each other, the combination includes an axially extending hollow interior  14  and two pawl pockets  16 . 
   As also illustrated in  FIG. 4 , according to certain embodiments of the present invention, a cylindrical spur gear member  17  that includes spur gear teeth  18  is rotationally snugly assembled with (i.e., screwed into) the handle  11  in the interior  14 . The gear  17  typically has both of its axially extending ends  19  snugly rotationally supported in the interior  14 . 
     FIG. 4  also illustrates a collet member  21  that is suitably rotationally connected to the gear member  17 . The collet member  21  illustrated includes jaws  22  for clamping onto a work piece (not illustrated). The work piece may take the form of, for example, a screw, bolt, nut, or other rotational fastener or member which is to be driven by the driver  10 . 
   The above-discussed handle  11  can rotate or orbit the pawl pockets  16  about the axis A in both directions and relative to the gear member  17 . The pockets  16  are typically disposed radially outwardly of the gear teeth  18  and can rotate therearound. 
   To induce rotation of the gear member  17  and consequent similar rotation of the collet member  21 , two pawls  23  and  24  are pivotally disposed in the respective pockets  16  and are disposed generally radially of the circumference of the gear teeth  18 , as seen in  FIG. 6 . 
   A cylindrical cap  26  that is cup-shaped and that fits over the axial end of the handle  11  is illustrated at least in FIGS.  1 , 4 , and  8 . The cap  26  includes three radially extending tangs  27  which serve as bayonet connectors with the three tangs  28  on the handle  11 . Thus, according to certain embodiments of the present invention, the cap  26  can be moved axially onto the handle portion  12  and then rotated to bayonet-engage the cap  26  onto the handle  11 . The cap  26  typically includes has a rim therearound, and there is typically included a web or projection which is pear-shaped in axial views thereof and that extends inwardly from the rim and to a location between the pawls  23  and  24 . This location is also within the height of the gear teeth  18 , as illustrated in  FIG. 6 . 
   As illustrated in  FIGS. 9 and 11 , the pawls  23  and  24  extend beyond the axial extent of the gear teeth  18  and beyond the planar wall  32  of the handle  11 . Thus, according to certain embodiments of the present invention, the pawls  23 ,  24  present an extension or overhang in their lengths and, upon rotation of the cap  26 , as the cap  26  is rotationally piloted on the housing, the above-discussed web or projection engages those overhanging ends of the pawls  23  and  24  and thereby pivots the pawls  23 ,  24  out of engagement with the gear member  17  and/or gear teeth  18 , as selected. 
   The above-discussed attachment  12  has its two pawl pockets  16  in what is seen as the upper half of the portion  12 , as seen in  FIG. 8 . Those pockets  16  are, according to certain embodiments of the present invention, mirror images of each other, and they both typically include three circular outwardly extending and arcuate pockets  34 ,  36 , and  37 , each one being essentially semi-circular in axial view per  FIG. 8 . The pockets  34 ,  36 , and  37  are typically open to the central opening  14 . 
   The two pawls  23  and  24  are typically identical to each other in shape in axial view, and they substantially match the shape of the pockets  16  in axial view. As illustrated in  FIG. 15 , the pawls  23 ,  24  have a central portion  38  and two opposite end portions  39  and  41 . The central portion  38  is typically a fulcrum or pivot portion and, as shown in  FIG. 15 , can be at least substantially semi-circular and snugly slidable in and conforming to the shape of the semi-circular pocket portion  36 . The two pawl end portions  39  and  41  are respectively disposed in the pockets  34  and  37 . As such, the pockets  16  and the pawls  23  and  24  are, according to certain embodiments of the present invention, substantially T-shaped in the axial view. 
   The pawl portions  39  have spur teeth  42  facing the gear teeth  18 . The locations of gear tooth engagement are typically at the respective 10/11 O&#39;clock and 1/2 O&#39;clock locations, as illustrated in  FIG. 10 , and these engagements are labeled  43  and  44 . Typically, each of these engagements comprehends a circumferential length of several teeth on the gear member  17  and, of course, also with regard to the gear-engaged teeth  42  on the pawls  23 ,  24 . 
   The handle  11  typically has a concave and at least approximately semi-circular surface  46 , as shown herein, defining a pocket  34  and centered about the pawl pivot axis P. Each pawl  23 ,  24  is shown to have a convex at least approximately semi-circular surface  47  of the same size and shape as the surface  46  and fully overlying and fully flush with the housing surface  46 . Therefore, the two surfaces are defined as being matingly matched. Also for each pawl  23 ,  24 , the housing has a concave at least approximately semi-circular surface  48 . Each pawl  23 ,  24  has a convex at least approximately semi-circular surface  49  fully overlying and fully flush with the housing surface  48  in the pawl tooth-engaged mode, and therefore being defined as being matingly matched, as seen in  FIGS. 6 and 10 . 
   Each pocket  16  is defined by an arcuate concave surface  51 , centered on the pivot axis P and which extends contiguous with each pocket  16  surface  48  and presents a sliding surface for sliding contact by the pawl end  52  for approximately ten degrees of pivot sliding of the pawl on the surface  51 . In that sliding action, the pawls swing or pivot about the axis P and between gear tooth engaged mode and gear tooth released mode, as shown respectively with the pawls  24  and  23  in  FIGS. 6 and 10 . 
   With regard to both surfaces  46  and  48 , they face the tooth engaged locations  43  and  44 . One of skill in the art will appreciate that there are imaginary straight lines between each of those surfaces and the respective tooth-engaged locations. One of skill in the art will also appreciate that those lines are respectively at least substantially tangential to the gear teeth  18 . This results in the line of rotation force creating the torque which is applied through the handle  11  and is thus applied at an optimum angle onto the gear  17  for optimum torquing effect. Also, in and during the driving mode, both surfaces  46  and  48  are simultaneous applied to the respective pawl so there is firm and full application of the operator&#39;s hand rotation action applied onto the gear  17 . 
   As discussed above, each pawl  23  and  24  includes at least three portions: the central pivot portion  38 , the engageable end portion  41 , and the opposite end portion  39 . Typically, the two end portions  39 , 41  are swingable in the handle pocket openings  16  and the handle surface  48  extends into the length  51 , which is centered about the pivot axis P. Thus, according to certain embodiments of the present invention, the pawls  23 ,  24  are securely retained in the respective housing pockets  16  while being free to swing toward and away relative to the gear member  17  at the two opposite ends  39  and  41  of each pawl  23 ,  24 . That is, the pawls  23 ,  24  typically have convex tips  52  slidable on the arcuate housing surfaces  51  which are centered on pivot axis P. The housing has surfaces  51  and  53  centered about axis P, and these surfaces  51 ,  53  typically face each other to thereby restrict the pawls from moving out of the handle pockets  16  because the pawls have ends  52  and  50  in respective sliding contact with those surfaces  51  and  53 . 
   Further, when a pawl is in the full gear tooth released mode, as with the pawl  23  illustrated in  FIG. 10 , there is a line contact at  54  on the pawl and a surface  56  defining the pocket  33 . That gives a firm and definite stop point for the pivot of the release pawl. 
   The representative arrangement described above regarding the full surface engagement between the pawls and the handle as at surfaces  46  and  48  of the handle, produces a triangle of force application with the respective tooth-engaged locations. 
   According to certain embodiments of the present invention, the cap  26  is suitably limitedly or restrictively rotatably attached to the handle, and the cap  26  may be in any conventional attachment arrangement, such as the bayonet type attachment arrangement shown where the flanges  27  and  28  interengage in the conventional manner to axially fix the cap  26  relative to the handle but to also allow a slight rotational movement of the cap  26 . Also, according to certain embodiments of the present invention, the cap  26  is releasably retained in any one of three rotated positions for determining the ratcheting and drive directions. Those positions are typically established by a pin  57  which is yieldingly urged axially leftward in  FIG. 1  by spring  58  to sequentially seat the pin  57  into a selected one of the three holes  59  in the cap  12 . That adjustment is simply a self-releasing over-ride arrangement so that the cap can be rotated over the pin  57  to any one of the three positions. 
   The rotation of the cap is typically limited by the pawls  23  and  24  which are axially positioned to interfere with the web  29  in the rotation of the cap. While both pawls  23  and  24  typically extend into the cap  26 , the pawl  23  can be of a shorter length and is urged into the cap  26  by a spring  61  illustrated in  FIG. 1 . In such an arrangement, the pawls  23  and  24  can be of different lengths, and the pawl  24  is shown in  FIG. 2  to be longer. As such, it fully occupies the length, or depth, of its pocket  16  and extends therebeyond, as seen in  FIGS. 9 and 11 . However, the pawl  23  can be of a shorter length. In such arrangements, it does not fully occupy the axial length of its pocket  16  which accommodates the spring  61  and, under the urging of the spring  61 , pawl  23  extends beyond the length of the gear teeth  18 , as does the pawl  24 . Also, according to certain embodiments of the present invention, the pawls extend beyond the handle wall  32 . 
   In assembling the driver  10 , the cap  26  is typically axially moved onto the housing  12  and the cap web  29  is disposed between the pawls. With assembly positioning of the bayonet projections, namely offset from each other, the web  29  is aligned with the forces down on the spring-urged pawl  23  and, upon rotation of the cap out of that positioning, the pawl  23  is released and the web  29  is rotated to a position between the pawls  23  and  24  which are then in the arcuate path of rotation of the web to thereby preclude over-rotation of the cap relative to the handle. 
   According to certain embodiments of the present invention, an access hole  62  in the cap  26  permits the insertion of a pin (not illustrated) into the cap and onto the pawl  23  to push the pawl  23  against the spring  54 , thereby permitting the cap to be rotated beyond the pawl  23  and off of the bayonet connection of the cap  26  with the handle  12  and for disassembly. 
   In assembly, according to certain embodiments of the present invention, there is a fixed projection  63  on the handle  12  extending into the cap  26 . The projection  63  typically provides rotation interference upon rotation of the cap  26  and its web  29  which can abut the projection  63 . Thus, the cap typically cannot be over-rotated in the counterclockwise direction, as viewed in  FIG. 6 . Also, while assembling the driver  10 , the web  29  will, according to certain embodiments of the present invention, always be properly positioned between the pawls and will not rotate therebeyond. 
   According to certain embodiments of the present invention, a spring  64  is coiled and piloted on the pin  57  on the handle. The spring typically has two legs  67  extending respectively into contact with the pawls  23  and  24 . The spring tips  68  are typically angulated and in sliding contact with the pawl concave surfaces  69  and therefore are self-adjusting along those surfaces in response to pivot action of the pawls. The spring  64  illustrated herein has its two legs  67  tensioned for exerting radially outward force on the pawls. Therefore, when one pawl is spring-forced out of gear tooth engagement by the cap web doing so, the spring  64  is placed under tension such that the other spring leg receives an increased force to urge and hold the other pawl into gear tooth engagement, as seen in  FIG. 6 . When such an arrangement with the pawls  23  and  24  is implemented, the spring legs  67  are typically always in sliding contact with the pawl surfaces  69  to pivotally urge the pawls  23  and  24  toward and sometimes into tooth engagement with the gear teeth  18 , as illustrated in  FIGS. 6 and 10 . 
   The web  29  is typically shaped to cam under the pawls  23  and  24  so that, upon rotation of the cap  26 , the pawl is disengaged from the gear  18 , as illustrated in  FIG. 6 . With that maneuver, where the cap  26  has been rotated clockwise from the handle end, the drive is also typically clockwise. 
   According to certain embodiments of the present invention, there are two substantially handle T-shaped pockets  16  with the central portion  34  and the two flanking arm portions  36  and  37 , all forming a substantially right angled relationship of the T-shape upright stem and then to cross bar at right angles to that stem. Likewise, the two pawls are typically at least substantially T-shaped to at least substantially conform to the shape of the handle pockets  16  and be matingly matched therewith. According to certain embodiments of the present invention, there are two rotation drive surfaces  46  and  48  on the handle  12 , and they both apply a drive torque tangential to the gear teeth  18 . In that arrangement, the gear teeth can be small and the drive is firm and precise without lost drive motion between the handle and the gear. With the surfaces  48  and  49 , they are of two dimensional flush and overlying contact with each other, and that is defined as being substantially devoid of only line contact. 
   One representative method of arranging a tool (e.g., the screwdriver  10 ) is disclosed in this description. This method typically includes the arrangement with the pawls and the spring  67  and the cap rotation and the positioning of the web between the pawls for cap rotation restrictions. It also typically includes the release of the cap from its restricted rotation, all as described herein. However, other methods are also within the scope of the present invention. 
   The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.