Patent Publication Number: US-2023158580-A1

Title: Chuck jaw

Description:
FIELD 
     The invention concerns a chuck jaw. In one particular but non-exclusive aspect the invention concerns a chuck jaw for use in securing a workpiece with irregular contours to a lathe chuck. 
     BACKGROUND 
     A lathe is a machine tool that rotates a workpiece about an axis of rotation to perform machining operations such as cutting and turning to the workpiece. A lathe typically includes a horizontal beam which supports a headstock. The headstock includes spinning bearings which support a horizontal axle referred to as a spindle. The spindle is driven by a power source such as an integral electric motor. Many lathes employ CNC (computer numerical control) to process a piece of material. CNC is the automated control of machining tools by means of a computer and without the need of a manual operator. 
     A lathe further includes a chuck which is mounted to the spindle and rotates with the spindle. A chuck is a type of clamp which is adapted to hold the rotating workpiece during a machining operation. Many lathe chucks employ jaws, at times referred as dogs, that are arranged within a chuck body in a radially symmetrical pattern. The jaws are tightened, typically with the use of a chuck key, to secure a workpiece to the chuck. Once machining of the workpiece has been completed the workpiece can be removed from the chuck once the jaws have been loosened. 
     At times it may be required to hold a workpiece which potentially may be crushed by the jaws of the chuck. At other times it may be necessary to hold a workpiece with an irregular circumference or irregular contours. For such applications a tradesperson may employ tools which are referred to as soft jaws. The term “soft” is employed as soft jaws are produced from materials of lesser hardness than that of master chuck jaws. In one arrangement the soft jaws are adapted to be secured to the master chuck jaws. 
     Certain drawbacks are associated with soft jaws. One drawback includes that a tradesperson may require a large number of soft jaws to be stored to cater for workpieces having different circumferences/contours and the consequential cost implications. In other instances a tradesperson may be required to machine soft jaws having a specific shape suited to accommodate the unique contours of a particular workpiece. This may be a time-consuming process and result in a delay before machining of the workpiece can commence. 
     OBJECT 
     It is an object of the present invention to provide a chuck jaw which addresses or ameliorates one of more or the above disadvantages associated with existing soft jaws or at least to provide a useful alternative. 
     SUMMARY 
     According to a first aspect there is disclosed herein a chuck jaw for securing a workpiece to a lathe chuck, the chuck jaw including: 
     a jaw body adapted for operative mounting to the lathe chuck; 
     at least one holding element operatively associated with the jaw body and adapted to engage the workpiece, the at least one holding element being moveable between (i) a release condition in which the holding element is released from the workpiece, and (ii) an engaged position in which the holding element engages a surface of the workpiece; and 
     a clamping assembly operatively adapted to secure the at least one holding element in the engaged position. 
     Preferably the at least one holding element is a first holding element and the chuck jaw includes a plurality of holding elements each operatively adapted to engage the workpiece. 
     Preferably each respective holding element is moveable between (i) a release condition in which the respective holding element is released from the workpiece, and (ii) an engaged position in which the respective holding element engages a surface of the workpiece. 
     Preferably each holding element includes a holding element body and two holding element legs outwardly extending for the holding element body. 
     Preferably the two holding element legs define a holding slot between them. 
     Preferably the jaw body includes at least one jaw body bore for receiving a fastener to secure the jaw body to the lathe chuck. 
     Preferably the one jaw body bore is a first jaw body bore and the jaw body includes a second jaw body bore to receive a second fastener to secure the jaw body to the lathe chuck. 
     Preferably the clamping assembly includes a jaw body clamping member outwardly extending from the jaw body and a clamping element operatively associated with the jaw body clamping member, in use the at least one holding element being clamped between the jaw body clamping member and the clamping element. 
     Preferably the jaw body clamping member includes a clamping member hole operatively adapted to be located in register with a corresponding clamping element hole of the clamping element. 
     Preferably the holding slot of the at least one holding element is adapted to permit a clamp fastener to pass through the clamping member hole, through the holding slot and through the corresponding clamping element hole. 
     Preferably the jaw body clamping member includes a plurality of clamping member holes operatively adapted to be located in register with corresponding clamping element holes of the clamping element. 
     Preferably the holding slot of each of the plurality of holding elements is adapted to permit a clamp fastener to pass through the clamping member hole, through the holding slot and through the corresponding clamping element. 
     Preferably the jaw body defines a jaw body guide formation which is operatively adapted to couple with a complemental clamping element guide formation of the clamping element. 
     Preferably the jaw body guide formation is a jaw body slot and the clamping element guide formation is clamping element adapted to be received and held within the jaw body slot. 
     Preferably the jaw body defines a jaw body recess operatively adapted to receive a chuck fastener secured to a master jaw of the chuck. 
     Preferably the jaw body recess is adapted to receive a T-shaped nut coupled to the master jaw. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred embodiments of the invention will be described hereinafter, by way of examples only, with reference to the accompany drawings, wherein: 
         FIG.  1    is front view of a lathe chuck having three embodiment chuck jaws mounted thereto; 
         FIG.  2    is a front perspective view of the lathe chuck of  FIG.  1    showing a partial exploded view of one of the embodiment chuck jaws; 
         FIG.  3    is a perspective view of a jaw body of the chuck jaw shown partially exploded in  FIG.  2   ; 
         FIG.  4    is a top view of the jaw body of  FIG.  3   ; 
         FIG.  5    is an end view of the jaw body of  FIG.  3   ; 
         FIG.  6    is a perspective view of a holding element of the chuck jaw shown partially exploded in  FIG.  2   ; 
         FIG.  7    is a side view of the holding element of  FIG.  6   ; and 
         FIG.  8    is a perspective view of a clamping element of the chuck jaw shown partially exploded in  FIG.  2   . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
       FIG.  1    shows three embodiment chuck jaws, generally indicated with the reference numerals  10 . 1 ,  10 . 2 ,  10 . 3 , employed to secure a workpiece  12  to a lathe chuck  14 . It is pointed out that the workpiece  12  has irregular contours and that the chuck jaws  10 . 1 ,  10 . 2 ,  10 . 3  are adapted to secure the workpiece  12  to the lathe chuck  14  as will become apparent from the below description. 
       FIG.  2    shows a partially exploded view of the chuck jaw  10 . 1 . Although the description below will focus on the chuck jaw  10 . 1 , the chuck jaws  10 . 2  and  10 . 3  are identical to the chuck jaw  10 . 1  and accordingly include the same components and operate in a manner corresponding to the chuck jaw  10 . 1 . 
     The chuck jaw  10 . 1  first includes a jaw body  16  which is adapted for operative mounting to the lathe chuck  14 . The chuck jaw  10 . 1  further includes a plurality of holding elements  18  operatively associated with the jaw body  16  and adapted to engage the workpiece  12 . Each holding element  18  is moveable between (i) a release condition in which the respective holding element  18  is released from the workpiece  12 , and (ii) an engaged position in which the respective holding element  18  engages a surface of the workpiece  12 . In effect the holding elements  18  can be adjusted longitudinally relative to each other and the jaw body  16  so as to engage the outer contours of the irregular circumference of the workpiece  12 . A skilled person will accordingly appreciate that the embodiment chuck jaws  10 . 1 ,  10 . 2 ,  10 . 3  can be employed to secure a range of differently configured workpieces by adjusting the holding elements  18  between release and engaged positions to accommodate a particular workpiece. 
     The embodiment chuck jaw  10 . 1  includes a clamping assembly, generally indicated with the reference numeral  20 , operatively adapted to secure the holding elements  18  in their respective engaged positions. With the holding elements  18  secured in the engaged positions the workpiece  12  is secured to the lathe chuck  14  in order to undergo a machining process. 
     The embodiment clamping assembly  20  includes an oblong jaw body clamping member  22 , shown in Figurers  2  and  3 , outwardly extending from the jaw body  16 . The clamping assembly  20  further includes an oblong clamping element  24 , shown in  FIGS.  2  and  8   , operatively associated with the jaw body clamping member  22 . In use the holding elements  18  are clamped between the jaw body clamping member  22  and the clamping element  24 . 
     The jaw body clamping member  22  includes a plurality of clamping member holes  26  operatively adapted to be located in register with corresponding clamping element holes  28  of the clamping element  24 . 
     Referring to  FIGS.  6  and  7   , each holding element  18  includes a holding element body  30  and two holding element legs  32  outwardly extending for the holding element body  30 . The two holding element legs  32  define a holding slot  34  between them. The holding slot  34  of each holding element  18  is adapted to permit clamp fasteners  36  to pass through clamping member holes  26 , through the holding slot  34  and through corresponding clamping element holes  28 . In this embodiment the clamp fasteners  36  are bolts which are secured in position with mating nuts  38 . 
     Referring to  FIGS.  3  and  8   , the jaw body  16  defines a jaw body guide formation  39  operatively adapted to couple with a complemental clamping element guide formation  40  of the clamping element  24 . In this embodiment the jaw body guide formation  39  is a T-shaped jaw body slot and the clamping element guide formation  40  is a T-shaped clamping element adapted to be received and held within the jaw body slot  39 . 
     The jaw body  16  includes two countersunk jaw body bores  42  adapted to receive non-illustrated chuck fasteners to secure the jaw body  10 . 1  to the lathe chuck  14 . In this embodiment the non-illustrated chuck fasteners are operatively adapted to secure the jaw body  16  to a corresponding non-illustrated master jaw of the lathe chuck  14 . In this regard it is pointed out that the jaw body  16  defines a jaw body recess  44 , shown in  FIG.  5   , which is operatively adapted to receive a non-illustrated chuck fastener secured to a master jaw of the lathe chuck  14 . In this embodiment the jaw body recess  44  is adapted to receive a non-illustrated T-shaped nut coupled to the master jaw. 
     Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms. 
     KEY TO REFERENCE NUMERALS 
     
         
           10 . 1  Chuck jaw 
           10 . 2  Chuck jaw 
           10 . 3  Chuck jaw 
           12  Workpiece 
           14  Lathe chuck 
           16  Jaw body 
           18  Holding element 
           20  Clamping assembly 
           22  Jaw body clamping member 
           24  Clamping element 
           26  Clamping member holes 
           28  Clamping element holes 
           30  Holding element body 
           32  Holding element legs 
           34  Holding slot 
           36  Clamp fastener 
           38  Nuts 
           39  Jaw body guide formation 
           40  Clamping element guide formation 
           42  Jaw body bore 
           44  Jaw body recess