Abstract:
A pinion for mounting rolls thereupon for reducing rod or wire in a rolling mill wherein said pinion has a pair of hydraulic pressure chambers formed therein which cause a threaded plug in a cavity in said pinion to undergo lateral movement to expand the pinion to engage a roll mounted on said pinion, and thence to cause a clamp to laterally clamp a roll against an abutment formed on the pinion to clamp the roll on the pinion once the plug has undergo lateral movement.

Description:
This application claims the benefit of provisional application Ser. No. 60/338,670 filed Dec. 11, 2001. 
    
    
     FIELD OF THE INVENTION 
     This invention is an improvement over U.S. Pat. No. 5,700,233 issued Dec. 23, 1997. 
     In the process of the rolled reduction of steel rod or wire from a billet, the billet or bar is usually passed through a multi stage reduction mill wherein the bar is successively passed between pairs of mill rolls which squeeze the bar to reduce its cross sectional area at each rolling stage. 
     The rolls are mounted on robust cantilevered pinion shafts where slippage between the reducing roll and the pinion cannot be tolerated during a reduction operation. 
     SUMMARY OF THE INVENTION 
     This invention seeks to secure a mill roll on a cantilevered pinion by means of the use of pressurized hydraulic fluid. The roll is placed at a predetermined mounting position on the pinion and hydraulic fluid pressure is then introduced into a cavity provided so as to cause a threaded plug to move laterally from its initial position in the cavity provided within the pinion, and thus increase the diameter of the pinion under the roll mounted on the outer surface of the pinion. As soon as the threaded plug moves a predetermined distance in a lateral direction within the cavity, another set of ports is exposed which allows the introduction of pressurized hydraulic fluid into a second cavity to permit a substantial side thrust to be applied to the roll already located on the pinion so as to clamp it tightly against the shoulder provided on the pinion. 
     PRIOR ART 
     U.S. Pat. No. 5,700,233 issued Dec. 23, 1997. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a sectional view of a pinion assembly of the prior art. 
     FIG. 2 shows a plan view of a roll mounted on the pinion. 
     FIG. 3 shows a sectional view of the pinion of FIG.  2 . 
     FIG. 4 shows an exploded perspective sectionalized view of the hardware illustrated in FIG.  2 . 
     FIG. 5 shows an exploded of the device of FIG.  1 . 
     FIG. 6 shows an alternate form of applicant&#39;s invention in cross section. 
     FIGS. 7 and 8 are exploded views of FIG.  6 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1 which shows a prior art pinion assembly  10  in section. A pinion  12  is shown which is coupled to a driving shaft (not shown). A roll  14  (shown in phantom) is mounted on pinion  12  against shoulder  16  on pinion  12 . 
     Pinion  12  is provided with an internal cavity  18  which is provided with a threaded bore  20  for bolt  22 . A second coaxial bore  24  is provided in cavity  22  which is provided with a buttress thread. A threaded plug  26  having a mating buttress thread  28  is threaded into the thread  24  of cavity  18 . Bolt  22  is provided with head  30  in which a socket receiving receptacle  32  is formed. Bolt head  30  is provided with a thrust shoulder  34  to engage plug  26 . 
     A clamping cap member  36  is threaded onto pinion  12  at threads  38 . Cap  36  contains a bore  40  to provide access to the socket formed in the head  30  of bolt  22 . Plug  42  prevents the ingress of foreign material into bore  40  of cap  36 . 
     A series of pressure screws  44  (only one shown) are threaded into cap  36  to apply pressure to roll  14  to force it against shoulder  16 . 
     The prior art device functions as follows: Plug  26  is threaded into cavity  18  and bolt  30  is threaded into threaded bore  20  in the cavity  18 . No pressure is applied to plug  26  by bolt head  30  at this time. 
     A roll  14  is now mounted on pinion  12  against shoulder  16 . Cap  36  is threaded onto threads  38  of pinion  12  to press roll  14  against shoulder  16 . Next bolt  22  is advanced in threaded bore  20  to push plug  26  further into the cavity  18  to “ramp” threads  28  against threads  24  to expand the part of the pinion  12  located below roll  14 . This expansion is important because it is uniform around the entire circumference of pinion  12  which engages roll  14 . This is important to preserve the concentricity of roll  14  on pinion  12 . Next screws  44  are advanced in cap  36  to apply additional pressure on roll  14  to cause it to forcibly engage shoulder  16  of pinion  12  to increase the friction force between shoulder  16  and roll  14  to prevent slippage between roll  14  and pinion  11  during a rolling operation. 
     Referring to FIG. 2, the pinion-roller combination  110  of the present invention is illustrated. A pinion  112  is driven by a driveshaft (not shown). A roll  114  is mounted on pinion  112  and is clamped in position by pressure ring  116  and end bell  118 . Cap  120  provides protection for the interior elements of end bell  118 . A pair of spacer rings  122  are placed between shoulder  124  and roll  114 . 
     FIG. 3 shows a cross section view of the device of FIG.  2 . FIGS. 4 and 5 are additional views (exploded) to aid in understanding the invention. 
     Pinion  112  is provided with an internal hollow chamber  128  similar to chamber  18  or the prior art device of FIG.  1 . Chamber  128  contains a threaded bore  126  in which bolt  130  is threadably received. 
     Chamber  128  is threaded at  132  in a similar manner to chamber  18  of the prior art device  10  of FIG. 1 with buttress threads. A plug  134  having matching buttress threads  136  is threaded into chamber  128  as shown. Plug  134  is provided with a central clearance bore through which bolt  130  may be passed. Plug  134  is provided with a shoulder  137  and cylindrical thrust collar  138  which is integrally connected to plug  134 . 
     A locking collar  140  is threaded into pinion  112  at threaded bore  142  of the pinion  112 . 
     Locking collar  140  has a series of recesses  142  spaced around the circumference of land  144  and an annular shoulder flange  146  integrally formed therewith. Annular flange  146  is provided with cylindraceous seal surface  148  at the outside of flange  146 . An abutment  150  is formed on face  152  of locking collar  140 . A plurality of ducts  154  are provided in collar  140  to provide a fluid communication passage between pressure chambers  156  and  158 . 
     A pressure piston  160  is provided to slide on bolt  130  and seal against cylindraceous surface  162  of locking collar  140 . Seal  164  is provided in groove  166  of piston  160  for this purpose. A seal ring  168  is located on piston  160  in groove  170  to form a sliding seal with bolt  130 . 
     An annular sealing block  170  is provided to seal with bolt  130  by means of seal ring  172 . Sealing block  170  is threaded into locking collar  140  so that seal ring  174  seals block  170  against cylindraceous surface  176 . Once assembled the sealing block  170  becomes an integral part of locking collar  140 . 
     Pressure chamber  158  is formed by bolt  130 , piston  160 , locking collar  140  and sealing block  170 . 
     Bolt  130  is provided with a central bore  178  which is in communication with cross bore  180 . A hydraulic pressure fitting  182  is threaded into the end of bolt  130  to communicate with bore  178 . Any hydraulic fluid forced into fitting  182  ultimately finds passage to chamber  158  via bores  178  and  180 . 
     A thrust ring  116  is mounted on locking collar  140  to form part of chamber  156 . Ring  116  carries a pair of seal rings  184  and  186  to seal on surfaces  148  and  144  of locking collar  140 . Pressure chamber  156  is formed between locking collar  140  and thrust ring  116 . Duct  154  is shown in communication with chambers  156  and  158  in FIG.  3 . 
     Cap  120  and bell  118  are held in place by threads  190  on bolt  130 . 
     Bell  118  rests against stop  150  in its “rest” position. 
     Thrust ring  116  is provided with a series of locating screws  192  the ends of which are captured in recesses  142  in locking ring  140  to establish a correct position relationship between locking ring  140  and thrust collar  116 . 
     The pinion and roll are assembled as follows: Bolt  130  is threaded into bore  126  until the desired depth of insertion of bolt  130  is reached. Plug  134  is next threaded into cavity  128  to a predetermined depth. Roll  114  and shims  122  are now slid on pinion  112  to engage shoulder  124  of pinion  112 . 
     Thrust collar  116  is next fitted on locking collar  140  by means of locating screws  192  protruding into recesses  142  of locking collar  140  to the desired depth. 
     The locking collar  140  (which includes sealing block  170 ) carrying a loosely mounted thrust collar  116  thereon is threaded into threads  142  of pinion  112 . 
     Piston  160  is slid along bolt  130  until it reaches a “home” position inside locking collar  140  established by the compressible elastic ring  200 . At rest, before any hydraulic pressure is applied to chamber  158 , surface  162  of piston  160  blocks the entrance to duct  154  so that no hydraulic pressure may be applied to chamber  156  until piston  160  has moved to the left to uncover the entrance to duct  154 . 
     Bell  118  is fitted on cap  120  and cap  120  is threaded onto bolt  130  until bell  118  engages stop  150  on locking collar  140 . At this position the bell  118  and thrust ring  116  are in an engaged position in a state ready to have chamber  156  pressurized. 
     At this time elastic ring  200  holds piston  160  at a “rest” position so that surface  162  blocks ducts  154  leading to chamber  156 . 
     Hydraulic fluid pressure is now applied to fitting  182  fitted into the end of bolt  130  to force fluid into channel  178  and channel  180  and thence into chamber  158 . 
     Cap  120  and bell  118  establish a “blocked” position for blocking ring  170  so that any motion of blocking ring  170  is to the right prevented by bell  118 . When the pressure in chamber  158  is sufficient, piston  160  moves to the left causing the external buttress threads on the plug  134  to “ramp” up against the corresponding internal buttress threads on the interior of the cavity  128  of pinion  112 . 
     When piston  160  and plug  134  have moved to the left a distance sufficient to enlarge the diameter of the pinion surface beneath roll  114  and “lock” roll  114  firmly in a concentric position on pinion  112 , the entrance to ducts  154  becomes unblocked by the repositioning of piston  160  to the left, hydraulic pressure now is applied to chamber  156 . This causes ring  116  to move to the left to firmly clamp the roll  114  against shoulder  124  of pinion  112  to provide the final pressure to lock roll  114  in place on pinion  112 . This supplants the force produced by screws  44  of FIG. 1 (prior art). 
     With this scheme chamber  158  can be partially pressurized before significant pressure is applied to chamber  156  so that the concentricity of the roll  114  mounted on the pinion  112  is preserved. 
     FIGS. 7 and 8 show an alternate embodiment of the present invention. Here device  200  is shown in section in FIG. 7, and in exploded format in FIG.  8 . 
     In it driving pinion  212  is provided with a hollow internal chamber  228  which has a threaded bore  226  (similar to threaded bore  126  in FIG.  3 ). Bolt  230  is threaded into bore  226 . 
     Chamber  228  is provided with a shallow ramped thread (modified buttress thread)  232  in a similar manner to chamber  18 , except the slope of the threads is reversed from those shown in FIGS. 1 and 3. 
     A plug  234  having matching threads  236  is threaded into chamber  228  as shown. Plug  234  is provided with a bore  235  through which bolt  230  may easily pass. Plug  234  also has a smaller bore  237  which forms a sliding fit on bolt  230 . 
     Plug  234  is also provided with recesses  239 ,  244  in which seals  250 ,  246  are seated. 
     Plug  234  is provided with a shoulder  251  at the right hand end thereof. Bolt  230  is threaded into threads  226  in the bore provided in pinion  212 . Bolt  230  passes through plug  234  and a seal is formed with plug  234  at seal  250 . Bolt  230  has a shoulder formed thereon  247  to produce an enlarged portion for bolt  230 . Annular groove  236  is formed therein which is in communication with radial spaced ducts  233 . 
     A pair of annular recesses  238  and  239  are provided in bolt  230  for seals  252  and  253  respectively. 
     Bolt  230  is provided with a cylindraceous chamber  290  which is threaded at  292 . Chamber  290  is in communication with radially spaced ducts  233  and central duct  285  of bolt  230  which is in communication with radially extending ducts  287 . 
     A hollow inner locking collar  240  housing a cylindraceous inner cavity  259  is provided with a threaded end  227  to be threaded into threads  242  of pinion  212 . Inner locking collar  240  exhibits a complex exterior surface pattern produced as surfaces of revolution. 
     A groove  229  is provided for housing seal  231 . Raised flange  241  contains a recess  254  housing seal  255 . A bleed passage  243  is closed by bleed plug  245 . 
     A series of radially spaced ducts  249  are formed in the inner locking collar  240  to communicate with annular recess  236  of bolt  230  (in cavity  259  of inner locking collar  240 ). 
     An outer locking collar  216  is provided in device  200  to press against roll  214 . Outer locking collar  216  is slidably mounted on inner locking collar  240  and forms chamber  256  with the inner locking collar  240 . It is chamber  256  in which pressure is subsequently developed to press outer locking collar  216  against roll  214  to hold roll  214  firmly in place against spacers  222  mounted on pinion  212 . 
     Outer locking collar  216  is provided with inner groove  278  for accepting spring clip  280 . 
     A backing plate  220  is threaded on to bolt  230  at threads  291 . 
     A plunger  294  is threaded into bolt cavity  290  at threads  292 . Plunger  294  may be adapted at  295  to be connected to a grease gun to pressurize the interior of device  200 . Alternately plunger  294  may be manually advanced in threads  292  to pressurize the assembly  200 . 
     Device  200  functions as follows: 
     Assume device  200  is pressurized and in an operating condition. Plunger  294  is backed off to remove the internal pressurization of the device  200 . Backing plate  220  is next removed by unscrewing it from threads  291  on bolt  230 . 
     Next the assembly of outer locking collar  216  and inner locking collar  240  are removed together as one assembly by unscrewing inner collar  240  at threads  242  on pinion  212 . 
     Now roll  214  may be slid from pinion  212  and replaced. 
     When a new roll  214  has been fitted to pinion  212  the assembly comprising inner collar  240  and outer collar  216  are mounted on pinion  212  at threads  242 . Backing plate  220  is next replaced on threads  291  and twisted home. 
     Plunger  294  is advanced in threaded bore  292  and a grease gun is applied to adapter  294  at  295 . Pressurized grease is now supplied to passage  296  of plunger  294 . 
     Pressurized grease is now supplied to chamber  290 , ducts  233 , annular groove  236 , ducts  249 , and chamber  256 . 
     Pressurized grease is also supplied to passageway  285  and ducts  287  in bolt  230 . This pressurizes chamber  228  of pinion  212 . 
     As the pressure in chamber  228  increases, plug  234  is forced to move to the right ramping the threads  232  and expanding cavity  228  thus securing roll  214  concentrically on pinion  212 . 
     Pressure is also building up in cavity  256  to press outer locking ring  216  against roll  214  clamp it tightly on pinion  212  against spacers  222 . If occluded air is trapped in the system, backing plate  220  is removed to expose bleed plug  245 . Plug  245  may now removed to allow bleeding of the pressurizing medium to allow the escape of entrapped air.