Abstract:
A device and method for holding a bit for a tool. The holding device, which is secured to a support surface, includes a housing having a base, a first leg and a second leg. A slot is defined between the first and second legs and the shank of the bit is received through one of a plurality of differently dimensioned apertures defined along the slot between the first and second legs. An adjustment assembly is engaged with the first and second legs and is movable to a first position to clamp the shank in the selected aperture; and is movable to a second position to release the shank. When the adjustment assembly is moved from the second position to the first position, a free end of the second leg bends toward the first leg, thereby reducing the diameter of the aperture within which the shank is received.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a Continuation-in-Part of U.S. patent application Ser. No. 12/393,340, filed Feb. 26, 2009, which claimed priority from U.S. Provisional Patent Application Ser. No. 61/031,421, filed Feb. 2, 25008, the disclosures of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to a system and device for holding a bit for a tool so that the bit may be disassembled, re-assembled or cleaned when held. The invention also relates to a method of holding the bit using the holding device. 
         [0004]    2. Background Information 
         [0005]    A router is a tool, especially used in the woodworking industry, used for milling or hollowing out an area in the face of a work piece. Usually the material used in the fabrication of the work piece is wood or metal, but applying the router to other types of materials is also possible. There are several different types of routers. Nowadays, one of the more common types of router is a spindle router where a router bit is mounted onto a rotatable spindle that is rotatably engaged with an electric motor. 
         [0006]    A typical router set-up includes a frame for supporting the router table. The router is mounted to the frame or table in such a way that the router bit will extend through an opening in the table. The work piece to be machined is supported by the table and is positioned so that the router bit will engage the work piece. Different bit sizes and shapes can be used, and the bit is easily exchangeable. The bit is engaged by a collet which is a part of the rotatable spindle that is connected to a motor drive on the router. The router collet and router bit mounted in the mouth of the collet are rotated by the motor drive round an axis perpendicular to the router table. Sometimes the position of the collet may be adjusted relative to the table, in a direction along the axis of rotation. In this case, the shape of the cut that is created by the bit is determined by the size and shape of the bit&#39;s cutter and the height of the bit relative to the upper surface of the router table. 
         [0007]    One of the important variables determining the router&#39;s work is the shape of the router bit, particularly the configuration of the cutting surfaces and spacers that form the bit. A large variety of different router bits are available on the market, allowing an almost indefinite number of shapes to be routed into the work piece. One type of router bit is the so-called “stacked” router bit. Typically, a stacked router bit consists of a central shank which has a threaded top end onto which are mounted one or more removable bit elements. These bit elements include, but are not limited to, disc shaped cutters, ball bearings for guidance and/or various shims or spacers. To keep the stack of cutters and spacers firmly engaged on the shank, an end nut or similar device is tightened on top of the shank. 
         [0008]    Adding or removing bit elements such as spacers or shims in between cutter elements modifies the thickness of wood removed in the routing process or the depth of cut in case of a ball bearing diameter change. The operator can select a variety of differently shaped cutters, or include various other types of bit element to change the overall profile routed into the work piece. In order to change the bit elements, it is necessary for the nut on the stacked router bit to be loosened and then the user may alter the number and type of bit element on the shank. Once the desired stack of bit elements is created, the nut is replaced on the end of the shank and is tightened. The shank is then engaged in the router collet and the router is activated. 
         [0009]    The operation of disassembling and/or re-assembling stacked router bits while keeping the router bits chucked into the router is cumbersome for various reasons. First of all, unless the router itself is securely held, for instance in a base element such as a router table, it will tend to turn when the user applies torque to unscrew or refasten the end nut. While the router can be secured against turning, this tends to prevent the router table from being set up for alternative operations. Moreover, when the operation is performed in case the stacked router bit is clamped by the collet of the router, small parts, such as spacers, washers etc. may fall into the router motor housing. Furthermore, during the time interval wherein the router bit is chucked in the router collet for disassembling or re-assembling it, the router cannot be used for other purposes, such as milling another work piece. A further drawback is that the visibility is less than ideal, because the router collet generally cannot protrude far enough above the router table to allow a full and unencumbered view of the operation. 
         [0010]    Alternatively, the stacked router bit could be held by a clamping element such as a hand plier or a steel bench vise. Generally, however, these clamping elements are less capable of resisting the considerable torque required to unscrew and re-fasten the end nut. Besides, these clamping elements will tend to engage directly on the router bit shank in such a manner that the risk is present to destroy the integrity of the bit&#39;s shank and to render it useless or even dangerous for further usage. 
         [0011]    One device proposed in the prior art is that disclosed in a copending and allowed U.S. patent application to the present inventor, namely, U.S. patent application Ser. No. 12/393,340, the entire specification of which is incorporated herein by reference. This application describes the use of a holding device which includes a housing to be secured to a stationary base, such as the router table, and a clamping mechanism for releasably clamping the shank of the bit to the housing so that the bit may be disassembled, reassembled or simply held in a suitable position so that the cutter elements may be cleaned. In particular, the housing disclosed in this application defines a recess that is spaced from the peripheral edges of the housing. A movable element and stationary element are arranged inside the recess. The stationary gripping element includes a gripping area that is configured to engage the bit&#39;s shank. The movable element is rotated in a first direction within the recess to clamp the bit&#39;s shank in the gripping area. When the movable element is rotated in a second direction, the bit&#39;s shank is no longer clamped in the gripping area and is free to be withdrawn from the recess. 
         [0012]    While the above holding device works well, there is still a need in the art for a device that is configured to engage a shank of a stacked router bit and tightly hold the shank against rotation during disassembly, reassembly or cleaning of the router bit. 
       BRIEF SUMMARY OF THE INVENTION 
       [0013]    A device and method for holding a bit for a tool. The holding device, which is secured to a support surface, includes a housing having a base, a first leg and a second leg. A slot is defined between the first and second legs and the shank of the bit is received through one of a plurality of differently dimensioned apertures defined along the slot between the first and second legs. An adjustment assembly is engaged with the first and second legs and is movable to a first position to clamp the shank in the selected aperture; and is movable to a second position to release the shank. When the adjustment assembly is moved from the second position to the first position, a free end of the second leg bends toward the first leg, thereby reducing the diameter of the aperture within which the shank is received. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0014]    A preferred embodiment of the invention, illustrated of the best mode in which Applicant contemplates applying the principles, is set forth in the following description and is shown in the drawings and is particularly and distinctly pointed out and set forth in the appended claims. 
           [0015]      FIG. 1  is a partially exploded perspective view of a holding device in accordance with the present invention shown positioned on a support surface; 
           [0016]      FIG. 2  is a top view of the holding device; 
           [0017]      FIG. 3  is a top view of the holding device showing a router bit shank engaged in the first aperture defined in the holding device with the holding device in a first, at-rest position; 
           [0018]      FIG. 4  is a front cross-section of the holding device taken along line  4 - 4  of  FIG. 3 ; 
           [0019]      FIG. 5  is a top view of the holding device showing the router bit shank engaged and clamped in the first aperture, and showing the holding device in a second, clamping position; and 
           [0020]      FIG. 6  is a front cross-section of the holding device taken along line  6 - 6  of  FIG. 5 . 
       
    
    
       [0021]    Similar numbers refer to similar parts throughout the drawings. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0022]    Referring to  FIGS. 1-6  there is shown a holding device in accordance with the present invention, generally indicated at  10 . Holding device  10  is configured to receive and retain a rotary device, such as a router bit  12  therein and to restrain the same against movement. Router bit  12  includes cutter and/or spacer elements  12   a  (hereinafter cutter elements  12   a ) and a shank  12   b . Particularly, holding device  10  is configured to receive and retain the shank  12   b  of router bit  12  therein, as will be further described herein. More specifically, holding device  10  is configured to clampingly engage shank  12   b  and substantially prevent it from rotating as cutter elements  12   a  are assembled on shank  12   a  or are disassembled therefrom, or bit  12  is simply held in an upright position so that particulate material removed by cutter elements  12  during a routing operation are cleaned from bit  12 . 
         [0023]    Holding device  10  comprises a generally U-shaped housing fabricated out of a strong durable material, such as stainless steel. Holding device  10  has a top surface  10   a , a bottom surface  10   b  ( FIG. 4 ), a first end  10   c , a second end  10   d , a first side  10   e , and a second side  10   f . Preferably, top surface  10   a  and bottom surface  10   b  are spaced a distance apart and are disposed substantially parallel to each other. First and second ends  10   c ,  10   d  are spaced a distance apart and are disposed substantially parallel to each other. Finally, first and second sides  10   e ,  10   f  are spaced a distance apart and are disposed substantially parallel to each other. Holding device  10  has a length “L” ( FIG. 2 ) as measured between first and second ends  10   c ,  10   d  and has a longitudinal axis “Y” extending therebetween. Preferably, length “L” is around 130 mm and the thickness of holding device  10  as measured between top and bottom surfaces  10   a ,  10   b  is approximately 22 mm. In accordance with a specific feature of the present invention, the U-shaped housing includes a base  14  and first and second legs  16 ,  18  which originate in base  14  and extend longitudinally outwardly away therefrom. Base  14  extends longitudinally from second end  10   d  of holding device  10  for a length “L 1 ” inwardly away therefrom and toward first end  10   c . Base  14  furthermore extends laterally between first and second sides  10   e ,  10   f . The size of length “L 1 ” is only a fraction of the entire length “L” of holding device  10 . 
         [0024]    First leg  16  originates in a first end at base  14  and extends longitudinally therefrom, terminating in a free end  16   a  proximate first end  10   c  of holding device. Second leg  18  originates in a first end at base  14  and extends longitudinally therefrom, terminating in a free end  18   a  proximate first side  10   c  of holding device. First side  10   e  includes an exterior surface of first leg  16 . First leg  16  further includes an interior surface  16   b  which is disposed substantially parallel to first side  10   e . Substantially the entire length of first side  10   e  is substantially flat. Second side  10   f  includes an exterior surface of second leg  18 . Second leg  18  further includes an interior surface  18   b  which is disposed substantially parallel to second side  10   f . Second side  10   f  is flat along most of its length but is curved for a region proximate first end  18   a  of second leg  18 . The curved region is indicated by the reference character  18   c . Curved region  18   c  includes two indentations which flank a central convex region. 
         [0025]    A slot  20  is defined between interior surfaces  16   b ,  18   b  of first and second legs  16 ,  18 . Slot  20  originates in an innermost end  20   a  defined in base  14  and extends to the free ends  16   a ,  18   a  of first and second legs  16 ,  18 , terminating at first end  10   c .  FIGS. 2 and 3  show holding device  10  in a first at-rest position. In this first position, slot  20  is of a width “W” ( FIG. 2 ) for substantially the entire length of first and second legs  16 ,  18 , with the exception of one or two regions, as will be described hereafter. Preferably, width “W” is approximately 6 mm in size and the length of each of the first and second legs  16 ,  18  is approximately 114 mm. The region of base  14  between innermost end  20   a  of slot  20  and second end  10   d  of holding device  10  acts as somewhat of a hinge region between first and second legs  16 ,  18 . This hinge region permits the free end  16   a ,  18   a  of one or both of first and second legs  16 ,  18  to move toward and away from the other free end  16   a ,  18   a  thereof as will be described herein. 
         [0026]    In accordance with a specific feature of the present invention, holding device  10  defines at least one aperture therein which extends between top and bottom surfaces  10   a ,  10   b . In the preferred embodiment of the present invention shown in the attached figures, holding device  10  defines a first aperture  22  therein and a second aperture  24  therein. (It will be understood that holding device  10  may define only one or the other of first and second apertures  22 ,  24  or may define more than two apertures therein, without departing from the scope of the present invention.) First and second apertures  22 ,  24  are centered along the midline of slot  20  as shown in  FIG. 2 . 
         [0027]    In particular, interior surface  16   b  of first leg  16  defines two recessed regions  22   b ,  24   b  which extend from top surface  10   a  of holding device  10  to bottom surface  10   b  thereof. Recessed regions  22   b ,  24   b  preferably are semi-circular or concave when viewed from the top. The portion of interior surface  16   b  which defines recessed region  22   b ,  24   b  preferably is disposed at right angles to top and bottom surfaces  10   a ,  10   b . Similarly, interior surface  18   b  of second leg  18  defines two recessed regions  22   c ,  24   c  which are disposed opposite recessed regions  22   b ,  24   b , respectively. Recessed regions  22   c ,  24   c  extend from top surface  10  to bottom surface  10   b  and are disposed generally at right angles relative thereto. Recessed regions  22   c ,  24   c  preferably are semi-circular or concave when viewed from the top. First aperture  22  is therefore defined by recessed regions  22   b ,  22   c  and a portion of slot  20 . Second aperture  24  is defined by recessed regions  24   b ,  24   c  and a portion of slot  20 . The center of first aperture  22  is disposed a distance “L 2 ” from first end  10   c  and the center of second aperture  24  is disposed a distance “L 3 ” from first end  10   c . Distance “L 2 ” preferably is around 32 mm and distance “L 3 ” preferably is around 46 mm. First aperture  22  has a chamfered upper region  22   a  and second aperture  24  has a chamfered upper region  24   a . Chamfered regions  22   a ,  24   a  are angled so that the shank  12   b  of router bit  12  is directed thereby into the respective selected one of the first and second apertures  22 ,  24 . 
         [0028]    In accordance with yet another specific feature of the present invention, first and second apertures  22 ,  24  are of different diameters. As illustrated in  FIG. 2 , the diameter “D 1 ” of first aperture  22  is larger than the diameter “D 2 ” of second aperture  24 . (It will be understood that first aperture  22  may instead be of a smaller diameter than second aperture  24  but this different configuration is not illustrated in the attached figures.) The diameters “D 1 ” and “D 2 ” are both larger than the width “W” of slot  20 . By way of example only, diameter “D 1 ” is around ½″ and diameter “D 2 ” is around 12 mm. In other words, first aperture  22  is sized to be suitable for engagement of a shank  12   b  that is fabricated in accordance with imperial measurements and second apertures  24  is sized to be suitable for engagement of shanks that are fabricated in accordance with metric measurements. The difference in diameter between the first and second apertures  22 ,  24  in the preferred embodiment is almost imperceptible to the human eye. 
         [0029]    In accordance with yet another feature of the present invention, first leg  16  defines a first hole  26  ( FIG. 3 ) which originates in first side  10   e  and terminates in interior surface  16   b  which defines a portion of slot  20 . Second leg defines a second hole  28  which originates in curved region  18   c  of second side  10   f . Second hole  28  terminates in interior surface  18   b  which defines a portion of slot  20 . First and second holes  26 ,  28  preferably are oriented at right angles to longitudinal axis “Y” and are aligned with each other. 
         [0030]    In accordance with a specific feature of the present invention, the portion of first leg  16  which defines first hole  26  preferably is threaded so that first hole is internally threaded. The portion of second leg  18  which defines second hole  28  preferably is smooth. Holding device  10  further includes a fastener  30  and a washer  32 . Preferably fastener  30  is a bolt which has a terminal region with external threads  30   a  thereon. Fastener  30  is inserted through hole  32   a  ( FIG. 3 ) of a washer  32 , through second hole  28  in second leg  18 , and into first hole  26  of first leg  16  where threads  30   a  engage threads in first hole  26 . 
         [0031]    In accordance with yet another feature of the present invention, holding device  10  defines a plurality of apertures  36  ( FIG. 2 ) therein. Preferably, holding device  10  defines three apertures  36  and each aperture  36  extends from top surface  10   a  through to bottom surface  10   b  of holding device  10 . Preferably, a pair of the apertures  36  is defined in base  14  and the third aperture  36  is defined in free end  16   a  of first leg  16  in a location where the third aperture does not intersect first hole  26  ( FIGS. 2 and 4 ). The apertures  36  in base  14  are located proximate the corners thereof i.e., in the regions adjacent where second end  10   d  intersects each of the first and second sides  10   e ,  10   f . Each of the three apertures  36  is configured to receive a fastener  38  therethrough. Fasteners  38  are used to fixedly secure holding device  10  to a support surface  40 , such as the upper surface of a router table or work bench, for example. 
         [0032]    Holding device  10  further preferably defines one or more recesses  42  in top surface  10   a  thereof. Recesses  42  may be of any configuration but as illustrated are longitudinally extending rectangular recesses. Recesses  42  provide a convenient place on holding device  10  for the user to place small component parts, such as cutter sections  12   a , which are to be incorporated into the router bit  12  when it is assembled, or which are removed from router bit  12  when it is disassembled. Each recess  42  is bounded by a beveled peripheral wall  42   a  that extends upwardly away from the bottom surface of the recess  42  and connects to top surface  10   a  of holding device  10 . Peripheral wall  42   a  directs the small component parts toward the bottom surface of recess  42 , thereby making the parts readily available to the user during assembly, and preventing the parts from rolling off top surface  10   a  of holding device  10 . 
         [0033]    Holding device  10  is used in the following way. Holding device  10  is placed on a support surface  40  as shown in  FIG. 1 , and fasteners  38  are inserted through the three apertures  36  to secure holding device  10  to support surface  40 . This ensures that holding device  10  will not move on support surface  40  in response to torque applied to a router bit  12  retained within holding device  10 . If the router bit  12  is fully assembled and the user desires to change the configuration of the cutter sections  12   a , for instance, shank  12   b  of the fully assembly router bit  12  is inserted into one or the other of the first and second apertures  22 ,  24 . (It will be understood that the user will select only one of these two apertures  22 ,  24  as both apertures cannot receive a shank of a bit therein at the same time or the device will cease to function in the manner contemplated by the inventor.) The user will select which of the first and second apertures  22 ,  24  to use based on the diameter of the shank  12   b . In particular, the user will select that one of the two apertures  22 ,  24  that is closest in diameter to the diameter “D” of shank  12   b.    
         [0034]    In the figures attached hereto, the aperture selected by the user is the first aperture  22  as the diameter “D 1 ” thereof more closely approximates the diameter “D” of shank  12   b  ( FIG. 4 ).  FIGS. 3 and 4  show shank  12   b  of router bit  12  inserted into first aperture  22  so that shank  12   b  is disposed generally at right angles to top surface  10   a  of holding device  10 . Holding device  10  is in a first, at rest position. In this first position, shank  12   b  is loosely received within first aperture  22  but is not clampingly locked into the same, and shank  12   b  may therefore be easily and readily removed from first aperture  22 . 
         [0035]    In order to secure shank  12   b  within holding device  10  against rotation so that bit  12  will not rotate when torque is applied thereto, the user rotates fastener  30  in the direction of arrow “A” ( FIG. 6 ). This rotational motion causes the threaded free end of fastener  30  to advance further into first hole  26  in first leg  16  ( FIG. 6 ). When this occurs, free end  18   a  of second leg  18  is drawn toward first leg  16  in the direction indicated by arrow “B”. Free end  18   a  of second leg  18  tends to move laterally toward free end  16   a  of first leg  16  because free end  16   a  of first leg  16  is fixedly secured to support surface  40  but free end  18   a  of second leg  18  is not secured thereto. The movement of second leg  18  tends not to be movement that is substantially parallel to first leg  16  but is instead at an angle relative thereto. The overall effect is that second leg  18  tends to bend along its length toward first leg  16 . This bending movement is not necessarily visible to the naked eye but can be felt by the user as they rotate fastener  30 , as will be described later herein. The bending of second leg  18  is illustrated in  FIG. 5  in a slightly exaggerated fashion for the sake of explanation only.  FIG. 5  shows that the width of slot  20  between the first ends of first and second legs  16 ,  18  (i.e., the regions adjacent base  14 ) is of a size “W” but the width of slot  20  between free ends  16   a ,  18   a  is smaller and is of a size “W 1 ”. In other words, the size of the space between first and second legs  16 ,  18  narrows from the base region  14  of holding device  10  toward the first end  10   c  thereof. The relative movement between free ends  16   a  and  18   a  may be quite small, in the order of approximately 0.5-2 mm, particularly if holding device is fabricated from stainless steel. 
         [0036]    It will be understood that the degree of bending of second leg  18  toward first leg  16  is sufficient to cause a change in the diameter of each of first and second apertures  22 ,  24 . Thus, when fastener  30  is rotated in a first direction “A”, it causes free end  18   a  of second leg  18  to bend slightly toward first leg  26 , thereby reducing the width “W” of slot  20  in this region to a width “W 1 ”, and simultaneously reducing the diameters “D 1 ” and “D 2 ” of first and second apertures  22 ,  24 . Specifically, because shank  12   b  is in first aperture  22 , the rotation of fastener  30  is continued until the diameter “D 1 ” of first aperture  22  is reduced to be substantially identical to diameter “D”, i.e., to the diameter of shank  12   b , thus clampingly locking shank  12   b  within first aperture  22 . This second, locking position of holding device  10  is illustrated in  FIG. 5 . 
         [0037]    It will be understood that if shank  12   b  is inserted into second aperture  24  instead of first aperture  22 , the rotation of fastener  30  would be continued until the diameter “D 2 ” of second aperture  24  approximates the diameter “D”. Thus, shank  12   b  would be clampingly locked into second aperture  24 . Obviously if this is the case, the diameter of first aperture  22  would simultaneously be reduced to a diameter of less than “D”. 
         [0038]    Once shank  12   b  is secured by second leg  18  within holding device  10 , the user can perform the desired action on bit  12 . So, for example, if is desired action is to change the overall stacked configuration of the cutter elements  12   a  of bit  12 , the user will rotate the lock nut  12   c  at the top end of bit  12  and add or remove cutter elements  12   a  until the desired configuration is attained. Lock nut  12   c  will then be reengaged and rotated in the opposite direction to secure the various cutter elements  12   a  in place. During the disassembly and re-assembly of bit  12 , shank  12   b  is tightly retained within holding device  10  and is prevented from rotating within first aperture  22  as bit  12  is torqued to disengage or re-engage lock nut  12   c.    
         [0039]    When the user wishes to disengage bit  12  from holding device  10  and thereby move holding device from the second locked position ( FIG. 5 ) to the first, at rest position ( FIG. 3 ), fastener  30  is rotated in a second direction opposite to that indicated by arrow “A”. This rotation causes a length of fastener  30  to be withdrawn from first hole  26  and permits second leg  18  to move in the opposite direction to arrow “B”, thereby returning second leg  18  to its original, at rest position. When second leg  18  moves away from first leg  16 , the width of slot  20  defined between free ends  16   a  and  18   a  increases in size from width “W 1 ” to width “W”. Simultaneously, the movement causes diameter of first aperture  22  to increase from around “D” in size to around “D 1 ”. Because the diameter “D 1 ” of first aperture  22  is greater than the diameter “D” of shank  12   b , shank  12   b  is released from its engagement with holding device  10  and the user is then able to remove bit  12  from first aperture  22  and re-engage it with a rotary tool (not shown). 
         [0040]    The retention of router bit  12  within holding device  10  makes it possible for changes to be made to bit  12  quickly and easily without damaging the various component parts, particularly shank  12   b.    
         [0041]    It will be understood that while the preferred embodiment of the invention is described and illustrated as being fixedly secured to the support surface  40  by way of three fasteners  38  which are inserted through three apertures  36 , one or two fasteners  38  could be used instead. For instance, a single fastener inserted through an aperture somewhere around the mid-section of first leg  16  (i.e., somewhere mid-way between base  14  and first end  10   c ) could be sufficient to enable holding device  10  to function in the manner described above. Alternatively, a single fastener could be inserted through an aperture defined in the mid-section of base  14  and another fastener could be inserted through an aperture defined around the mid-section of first leg  16  or in the location identified herein in free end  16   a  of first leg  16 . It will of course be understood that additional fasteners could be utilized to secure even the first end  18   a  of second leg  18  to support surface  40 . However holding device  10  is configured, the free end  18   a  of second leg  18  must be able to move toward and away from free end  16   a  of first leg  16  in an arcuate fashion. Preferably, this means that free end  18   a  of second leg  18  must be free of attachments to support surface  40  but it is conceived that some type of guided, interlocking, arcuately configured track and groove system between free end  18   a  and support surface  40  could be utilized. Furthermore, it is contemplated that instead of using fasteners  38  to secure holding device  10  to support surface  40 , an adhesive or other securement means could be utilized to fixedly secure base  14  and first leg  16  to support surface  40 . 
         [0042]    In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. 
         [0043]    Moreover, the description and illustration of the invention are an example and the invention is not limited to the exact details shown or described.