Patent Abstract:
A steady rest for use on a lathe is formed of a tailstock for mounting on an arbor and including a pair of diametrically opposed channels formed in the tailstock wherein each channel extends a pair of struts each slidably mounted within a different one of said channels, respectively, and securable within the channel to lock the respective strut in position, the struts extending from said tail stock toward the workpiece at an angle with respect to a rotary axis of the workpiece being machined. A pair of wheels each journaled on a different one of said struts are provided for contacting said workpiece.

Full Description:
RELATED APPLICATIONS 
     This application is related to and claims priority to a provisional application entitled “LIVE CENTER STEADY REST” filed Sep. 24, 2013, and assigned Ser. No. 61/881,528. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to woodworking, and more particularly to woodturning apparatus. 
     BACKGROUND OF THE INVENTION 
     When operating a lathe to turn a workpiece, particularly when the workpiece being formed has a large flat or curved surface to be formed, the end of the turning operation on the lathe frequently results in a tenon remaining on the workpiece to be removed after the workpiece has been removed from the lathe. For example, when forming a bowl-shaped surface, the bottom center of the bowl would normally need to be removed from the lathe to remove the remaining tenon. The tenon is typically removed by chiseling, sawing, or simply breaking it off. 
     SUMMARY OF THE INVENTION 
     The present invention permits the removal of any such tenon while the workpiece remains mounted in the lathe. Lathing operations continue using conventional tools to remove the tenon without interference from any other support that may be used such as a live center that heretofore was used to maintain support for the workpiece during turning. The present invention provides retractable wheels contacting the workpiece to continuously support the workpiece and also permit the retraction of the live center&#39;s cone point if a live center is used. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention may more readily be described by reference to the accompanying drawings in which: 
         FIG. 1  is a top view of a steady rest incorporating the teachings of the present invention. 
         FIG. 2  is an exploded enlarged three-quarter front view of the steady rest of  FIG. 1  with the knurled locking screw removed. 
         FIG. 3  is an enlarged three-quarter rear view of the steady rest of  FIG. 1 . 
         FIG. 4  is a perspective view of an alternative embodiment of the present invention. 
         FIG. 5  is an exploded view of a portion of the alternative embodiment of  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 to 3 , the embodiment of the invention incorporating a live center is shown. A tailstock is formed by an internally threaded cylindrical sleeve  10  provided with channels  12  machined diametrically opposed on either side of the sleeve  10 . The channels  12  are rectangular in cross-section with longitudinal axis slightly inclined with respect to the rotary axis of the workpiece being machined and the axis of the cylindrical sleeve. That is, the channels extend to a greater depth in the cylindrical sleeve  10  at one end surface of the cylindrical sleeve to the opposing end of the cylindrical sleeve. These channels receive struts  15  that are slidably contained within the channels and may be moved generally longitudinally of the cylindrical sleeve toward or away from the workpiece. The increasing depth of the channels is best illustrated by the top view of  FIG. 1  where it may be seen that the struts  15  are at an angle with respect to the longitudinal axis  16  of the cylindrical sleeve  10  and thus to the rotary axis of the workpiece being machined. 
     The struts  15  are retained in the corresponding channels by locking screws  18  that extend through holes or slots  20  provided in the struts  15 . Thus, the struts may be positioned longitudinally of the threaded sleeve  10  and fixed in position by tightening the respective locking screws  18 . At one end of each of the struts, a wheel  25  is journaled and is rotatably secured to the corresponding strut. When the struts are secured in their respective channels to the threaded sleeve, and the corresponding wheels are attached to the struts, the distance between the wheels may be adjusted by sliding the corresponding struts in their respective channels; that is, as the struts are extended to the left in  FIG. 1 , the distance between the corresponding wheels increases. Thus, the wheel-to-wheel distance may readily be adjusted by sliding the struts within their corresponding channels. 
     In the embodiment shown in  FIGS. 1 to 3 , a live center  29  is provided with a cone point  30  that is rotatable with respect to the remainder of the live center in a manner well known in the art. The live center includes a threaded cylinder  35  having a pair of opposing flats  37 . The diameter of the cylinder and the pitch of the threads permit the threaded engagement of the cylinder  35  in the threaded sleeve  10 . As the cylinder is threaded into the sleeve, the cone point  30  extends a greater or lesser distance out of the end of the threaded sleeve. The longitudinal position of the cone point may be fixed by a knurled locking screw  40  threadedly extending through locking holes  42  or  44  in the threaded sleeve  10  and engaging one of the flats  37  in the threaded cylinder  35 . 
     In use, when for example a cylindrical tenon is to be removed from the surface of a workpiece, the knurled locking screw is loosened and the threaded cylinder is backed out of the threaded sleeve to permit the cone point to disengage the workpiece. The threaded sleeve, combined with the positioning of the struts thereon, is positioned with the wheels in contact with the workpiece. The wheels force the workpiece to remain engaged with a driving chuck plate or chuck mount while the cone point of the live center is withdrawn. This procedure thus exposes the cylindrical tenon to permit its removal using conventional woodturning tools. It thus becomes unnecessary to remove the workpiece to remove the tenon by sawing, chiseling, etc. 
     Referring to  FIGS. 4 and 5 , an alternative embodiment of the present invention is shown. In this latter embodiment, the live center has been omitted and the tailstock is formed by a cylindrical disk  65  having a center cylindrical passage  67  to receive a chuck arbor  69  in a manner well known in the art. The disc  65  is provided with diametrically opposing pairs of rectangular channels  70 - 72  and  73 - 75 . The channels are machined in the tailstock so that the bottom surface of the respective channel is slightly inclined with respect to the rotary axis  80  of the workpiece being machined. For example, it may be seen that the bottom surface  71  of channel  70  is inclined towards the axis  80  in the direction of a workpiece, while the bottom surface  76  of channel  75  is inclined away from the axis  80  in the direction of a workpiece. Thus, the diametrically opposed channels  70  and  72  incorporate bottom surfaces that are inclined slighted with respect to the axis  80  and are inclined toward the axis  80 ; in contrast, the diametrically opposed channels  73  and  75  have bottom surfaces that are inclined in the opposite direction. The surfaces of the channels  73  and  75  diverge from the axis  80  in the direction of a workpiece while the diametrically opposed channels  70  and  72  are inclined toward the axis  80  in the direction of a workpiece being machined. Thus, a strut  85  may be secured, for example, in the channel  76  by securing the locking screw  86  through the slot  87  into the threaded hole  88  provided in the tailstock which will result in the strut  85  extending upwardly from the tailstock slightly inclined away from the axis  80 . 
     The wheel  92 , secured to the strut  85 , will thus be positioned as shown in  FIG. 4 ; the distances between the wheels  92  and  93  are adjusted by loosening the corresponding locking screw and sliding the respective supporting strut within its corresponding channel and retightening the locking screws. If a shorter range of distances between the wheels  92  and  93  is required, the corresponding struts are moved from the diametrically opposed channels  73  and  76  to alternate opposing channels  70  and  72 . Since their inclined surfaces of channels  70  and  72  are angled toward the axis  80 , the distance between the wheels  92  and  93  will be less but will nevertheless still be adjustable. If it is determined that adjustment is not necessary, and that the selection of the diverging or converging surfaces of the respective channel pairs is sufficient, the slots in each of the struts may be eliminated and replaced by a single hole to receive the corresponding locking screw that will engage a mating threaded hole in the tailstock  65 . 
     The present invention has been described in terms of selected specific embodiments of the apparatus and method incorporating details to facilitate the understanding of the principles of construction and operation of the invention. Such reference herein to a specific embodiment and details thereof is not intended to limit the scope of the claims appended hereto. It will be apparent to those skilled in the art that modifications may be made in the embodiments chosen for illustration without departing from the spirit and scope of the invention.

Technology Classification (CPC): 1