Abstract:
An apparatus for cutting a plastic blow molded body ejected from a blow mold, the apparatus includes spaced holders rotatable about a common axis. Each holder receives an end of a plastic body. A first drive rotates the holders about the axis. A second drive moves the holders and plastic body against a trim knife to cut the body. The holders start and stop rotation with the body at a predetermined orientation with respect to the common axis.

Description:
[0001]     This application is a division of our co-pending U.S. patent application Ser. No. 10/957,308 filed Oct. 1, 2005. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The invention relates to machines and methods for trimming plastic from blow molded plastic bottles.  
       DESCRIPTION OF THE PRIOR ART  
       [0003]     Blow molded plastic bottles include neck flash formed at the parting lines of the molds adjacent the bottle neck. Blow molded bottles also include a neck ring extending outwardly from the bottle neck. When two bottles are simultaneously blow molded to is form a two-bottle log, neck flash and the neck ring joining the bottle necks must be trimmed away.  
         [0004]     Conventional neck flash trimmers linearly index a lead bottle of a series of bottles to a stationary punching station where the bottle is held stationary while the flash is trimmed away. After trimming, the bottle is released, moved downstream and a new bottle is indexed to the station.  
         [0005]     A neck ring is conventionally trimmed from the neck of a blow molded bottle by rotating the bottle and moving the neck along a cutter which severs the ring from the neck. Alternatively, the ring may be cut away by a guillotine type blade with the top of the neck machined by a rotating spindle to provide a desired finish.  
         [0006]     Conventional neck flash trimming and neck ring or moil trimming are performed slowly. Bottles must be individually captured and oriented before trimming. Guillotine-type trimming with subsequent spindle finishing of the neck creates plastic chips which can be hard to remove from the bottle.  
         [0007]     Conventionally, blow molded logs are trimmed using a first machine for removing neck flash and a second machine for removing neck rings. Auxiliary conveyors move logs to and between the machines. Conventional trimming machines occupy considerable space on the floor of a blow molding facility.  
       SUMMARY OF THE INVENTION  
       [0008]     The invention is an improved compact high-speed bottle trimmer and method for rapidly removing neck flash and neck rings from blow molded plastic bottles. The machine feeds the molded two-bottle logs at a high uniform speed along a path wound around a number of rotating wheels while punching away neck flash and spinning the logs to cut away neck rings between adjacent bottles. Neck flash is punched away by punch assemblies which move down the path with the log during punching.  
         [0009]     The neck rings joining the necks of the two bottles in the log are spin trimmed by spinning the logs as they move along the path and bringing the logs into engagement with two cutters. The logs are spun first in one direction and then in a reverse direction during cutting. The logs are spun around the neck axis which may be located off center, closer to one side of the bottles than the other side of the bottles.  
         [0010]     The continuous path along which the logs are fed winds around a number of rotary wheels cantilevered outwardly from a support wall. Star wheels, having an axial width approximately equal to the length of the logs, transport the logs from an infeed conveyor to a neck flash trim wheel, from the neck flash trim wheel to a spin trim wheel and from the spin trim wheel to a discharge conveyor. All of the wheels move the logs along the path at the same circumferential speed. The logs extend across the path and are moved transversely along the path.  
         [0011]     The position of the logs on the path is controlled during pick up of the logs from the infeed conveyor, rotation around the wheels and transfer between wheels. Accurate location of the logs facilitates accurate punch removal of neck flash and accurate removal of neck rings by spin trimming.  
         [0012]     Continuous feeding of logs along the path permits high-speed trimming of neck flash and neck rings from the logs. The disclosed is machine has a design trim capacity of 200 logs per minute with an output of 400 trimmed bottles per minute. If desired, the throughput of the machine may be doubled without increasing the size of the machine. The machine is compact and takes up less floor space than conventional trimming machines.  
         [0013]     Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings illustrating the invention, of which there are 21 sheets and one embodiment. 
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0014]      FIGS. 1 and 2  are side and top views of a blow molded two-bottle log trimmed by the bottle trimmer;  
         [0015]      FIG. 3  is a top view of the log after removing neck flash;  
         [0016]      FIG. 4  is a top view after trimming of the neck ring to form two trimmed bottles;  
         [0017]      FIG. 5  is a front view of a high-speed bottle trimmer;  
         [0018]      FIG. 6  is a side view along line  6 - 6  of  FIG. 5 ;  
         [0019]      FIG. 7  is a back view of the bottle trimmer shown in the direction of arrow  7  in  FIG. 6 ;  
         [0020]      FIG. 8  is a sectional view taken along line  8 - 8  of  FIG. 5 ;  
         [0021]      FIG. 9  is a view taken along line  9 - 9  of  FIG. 5 ;  
         [0022]      FIG. 10  is a view taken along line  10 - 10  of  FIG. 5 ;  
         [0023]      FIG. 11  is a view taken along line  11 - 11  of  FIG. 10 ;  
         [0024]      FIG. 12  is a sectional view taken along line  12 - 12  of  FIG. 10 ;  
         [0025]      FIG. 13  is a sectional view taken generally along line  13 - 13  of  FIG. 11 ;  
         [0026]      FIG. 14  is a front view of a punch trim assembly;  
         [0027]      FIG. 15  is a view along line  15 - 15  of  FIG. 14 ;  
         [0028]      FIG. 16  is a view like  FIG. 14  showing the punch assembly fully collapsed;  
         [0029]      FIG. 17  is a sectional view along line  17 - 17  of  FIG. 16 ;  
         [0030]      FIG. 18  is a sectional view along line  18 - 18  of  FIG. 17 ;  
         [0031]      FIG. 19  is a top view of a spin trim assembly;  
         [0032]      FIG. 20  is a view taken in the direction of arrow  20  in  FIG. 19 ;  
         [0033]      FIG. 21  is a sectional view taken along line  21 - 21  of  FIG. 19 ;  
         [0034]      FIG. 22  is a view similar to  FIG. 20  with a two-bottle log held in the spin trim assembly;  
         [0035]      FIG. 23  is a sectional view taken generally along line  23 - 23  of  FIG. 22 ;  
         [0036]      FIG. 24  is a sectional view along line  24 - 24  of  FIG. 23 ;  
         [0037]      FIG. 25  is a front view of the spin trim wheel;  
         [0038]      FIG. 26  is a partial sectional view illustrating a control for vacuum seating a bottle in a nest and pressure ejecting the bottle from the nest; and  
         [0039]      FIG. 27  illustrates the path of movement of a log through the trimmer. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0040]     High-speed bottle trimmer  10  accurately and reliably removes neck flash and bottle rings from blow molded two-bottle logs where the neck axes are offset to one side of the center of the log.  
         [0041]      FIGS. 1 and 2  show a two-bottle log A as ejected from a blow molding machine with tail flash removed. The log A includes two blow molded bottled B having necks C located on an axis D offset to one side of the sides of the bottles. Neck ring E extends between the two necks C. Neck flash F extends in the recess between the bottles to one side of the necks and ring. Neck flash G extends between the bottles in the recess to the opposite side of the necks and ring.  
         [0042]      FIG. 3  illustrates log A with neck flash F and G trimmed away.  FIG. 4  illustrates the log with neck ring E trimmed away to separate bottles B and complete the trimming operation.  
         [0043]     High-speed bottle trimmer  10  includes a frame  12  having a base  14  mounted on a workspace floor and a vertical mounting wall  16  extending above one side of the base and running along the length of the base, as illustrated in  FIGS. 5 and 6 . The wall includes a front mounting plate  18  and end and top plates defining a rectangular recess  20  behind plate  18 .  
         [0044]     Infeed star wheel  22 , neck flash trim wheel  24 , intermediate star wheel  26 , spin trim wheel  28  and discharge star wheel  30  are cantilever-mounted on wall  16  and extend outwardly from the wall overlying base  14 . See  FIG. 6 . Infeed screw conveyor  32  is mounted on base  14  under infeed star wheel  22 . Discharge conveyor  34  is mounted on base  14  under star wheel  30 . The conveyors and wheels are driven by electric drive system  36  located principally in recess  20 .  
         [0045]     Infeed conveyor  32  includes a pair of feed screws  38  (only one illustrated) which are rotated to feed spaced flat logs A as shown in  FIGS. 1 and 2  in the direction of arrow  39  for vacuum pick up by infeed star wheel  22 . As illustrated in  FIG. 1 , the offset neck axis D is adjacent the downstream side of the logs.  
         [0046]     Infeed star wheel  22  is illustrated in  FIG. 8  and includes a hub  40  mounted on wall  16  and extending outwardly from the wall over base  14 . Drive shaft  42  is journaled in bearings in the ends of the hub and includes an outer end  44  extending beyond the hub and an inner end  46  extending into recess  20 . Shaft  42  is hollow with the inner end of the shaft supporting a rotary fitting  48  connected to a source of compressed air. The shaft outer end  44  is closed. The shaft supports two spaced radial nest plates  50  and a radial neck support plate  52  located between the nest plates. Each nest plate  50  supports four ninety degree-oriented vacuum nests  54  which engage the bottles of logs A transferred by wheel  22  from conveyor  32  to wheel  24 . The nests  54  on plates  50  are axially aligned so that a nest in each wheel engages one bottle of a log to rotate the log to wheel  24 .  
         [0047]     The position of a log A in a pair of nests  54  is shown in  FIG. 9 . Each nest  54  includes a flat bottom  56  and two sidewalls  58  extending upwardly from the bottom. The sidewalls have a height less than one-half the thickness of the bottles B. A vacuum cup  60  is located in the bottom of each nest plate.  
         [0048]     The nest plates are configured to fit snuggly around the sides and edges of the bottles B in log A. Vacuum applied to cups  60  holds the log in the nest plates. The nest plates hold the logs on wheel  22  and prevent circumferential shifting of the logs. The neck support plate  52  includes a tapered circumferential edge  62  dimensioned to have a snug fit in the shallow recess H between the two ridges on the ends of the neck ring E joining the bottles in each log. Engagement between the edge of plate  52  and the neck ring orients the log A axially when held by the vacuum nests or log holders  54 . Vacuum nests  54  and plate  52  assure the log is accurately located circumferentially and axially on wheel  22  during transport from conveyor  32  to wheel  24 .  
         [0049]      FIG. 26  illustrates a pneumatic circuit for suction cups  60  in each adjacent pair of vacuum nests  54  on wheel  22 . Compressed air from a compressed air source  64  flows through rotary fitting  48  and shaft  42  and through an opening of the shaft to a venturi  66 . The suction port of the venturi is connected to the two suction cups  60  of an aligned pair of vacuum nests  54  through pneumatic lines  68  and  70 . Only one nest  54  is illustrated. The outlet port of the venturi  66  is connected to normally opened discharge opening  72  formed in a surface lying in a radial plate  74  perpendicular to the axis of rotation  76  of wheel  22 .  
         [0050]     When a log A is transferred from conveyor  32  to wheel  22  opening  72  is unobstructed permitting flow of compressed air through venturi  66  and drawing vacuum through the two suction cups in the two vacuum nests  54  receiving the bottles in the log. When the log is seated in the nests the cups  60  engage the sides of the two bottles and vacuum-hold the log with plate edge  62  in recess E in the nest in proper circumferential and longitudinal orientation, as previously described, during rotation of wheel  22 .  
         [0051]     When a log held in nests  54  of wheel  22  is rotated up to the position for transfer to wheel  24  opening  72  is moved over a fixed stop plate  78  to prevent flow of compressed air through the venturi. With opening  72  obstructed, compressed air flows through lines  68  and  70  and to the two vacuum cups  60  to blow the log outwardly from the nests  54  and seat the log on adjacent vacuum nests on wheel  24  to complete transfer of the log to wheel  24 . After the transfer has been completed, continued rotation of wheel  22  moves opening  72  away from plate  78  to permit flow of compressed air through venturi  66  and reapply vacuum to vacuum cups  60  for vacuum capture of another log from conveyor  32 . Plate  78  is illustrated in  FIG. 8 . Air lines associated with the vacuum cups are not illustrated.  
         [0052]     Infeed conveyor  32  is located in trough  80  shown in  FIG. 8  and indicated in  FIG. 5 . Plate  82  is mounted on the piston of an air cylinder  84  attached to the bottom of the outer end of hub  40 . Extension of the piston rod moves plate  82  from a retracted position shown in  FIG. 8  to a work position obstructing discharge opening  72  of the pneumatic circuit shown in  FIG. 26  for the adjacent two vacuum nests  54 . During normal pick up of logs from conveyor  32  by wheel  22  cylinder  84  is retracted and plate  82  does not close discharge opening  72 . Vacuum is then applied to the vacuum cups in the nests so that the nests pick up the logs fed along the conveyor.  
         [0053]     Machine  10  includes sensors (not illustrated) for determining whether tail flash has been trimmed from logs fed along conveyor  32 . In the event a log fed along conveyor  32  contains tail flash and actuates a sensor, cylinder  84  is extended to move plate  82  adjacent the discharge  72  for the pneumatic circuits of the nests which would pick up the log. Vacuum is not applied to the nests and the log is fed past the end of the conveyor and falls into trough  80 .  
         [0054]     Neck flash trim wheel  24  includes a hub  86  mounted on wall  16  and hollow rotary drive shaft  88  journaled bearings in the ends of the hub. A rotary fitting  90  mounted on the inner end of the rotary drive shaft is connected to a source of compressed air which is flowed into the shaft. The outer end of the drive shaft extends outwardly from wall  16  over base  14  and is closed. Three spaced radial support plates  92  are secured to the outer end of shaft  88  above the base and extend radially outwardly from the shaft. Four ninety degree-spaced mounting plates  94  are mounted on plates  92  and extend from plate  92  nearest wall  16  outwardly from the wall and beyond outer most plate  92 . Strengthening ring  96  is mounted on the outer end of plates  94 . Two vacuum nests  98  are mounted on a plate  102  on the free end of each plate  94  in alignment with the nests  54  of wheel  22 . Vacuum nests  98  each include a bottom and sidewalls as in nests  54  and a vacuum cup in the bottom. The adjacent ends of the bottoms of the two nests slope upwardly to provide a tapered ridges  100  conforming to the inwardly sloped upper walls of bottles B in log A transferred to the nests. The nests  98  accurately align logs A circumferentially and longitudinally on wheel  24 . The vacuum cups in each pair of nests  98  are connected to pneumatic systems like the system shown in  FIG. 26  to apply vacuum to the nests when the nests pick up logs from wheel  24  and to remove the vacuum and apply compressed air to the nests when the logs are transferred from the nests in wheel  24  to the nests in intermediate star wheel  26 . A bottle neck and neck ring support  104  shown in  FIG. 18  extends between the two nests under the necks C and bottle ring E of log A held on the nests. The top of support  104  conforms to the ridged shape of the bottle necks and neck ring. The support or anvil  104  has a width equal to the diameter of the neck and ring. Flash discharge openings  106  and  108  are formed through plate  102  to either side of support  104  and are located above discharge opening  110  in plate  94 .  
         [0055]     Wheel  24  includes four sets of flash punch tooling  112  with each set associated with nests  98  on one plate  94 . Each tooling  112  includes a flash punch assembly  114  located above plate  94  and a drive assembly  116  for moving the punch assembly from a retracted position where the punch assembly is away from a log held by the nests  98  and adjacent wall  16  as shown in  FIGS. 11 and 12  to an extended position with the punch assembly located above the log and away from wall  16 . The drive assemblies are moved in and out by fixed cylindrical cam  118  mounted on wall  16 . The punch assemblies are actuated by fixed punch cam  120  mounted on wall  16  by rods  199  and located above the nests and punch assemblies  114  when extended.  
         [0056]     Two slide rails  122  extend along the sides of each plate  94  from the inner most plate  92  to plate  96 . Drive assembly  116  includes a plate  124  located above the inner end of plate  94  and secured to slide rails  122  by suitable bearings for movement along plate  94  in a direction parallel to the axis of rotation of wheel  24 . The inner end of plate  124  carries a cam follower  126  fitted in cam groove  128  of fixed cylindrical cam  118 . The cross shaft for small diameter gear  130  and large diameter gear  132  is journaled in bearings located on the opposite sides of plate  124 . Small diameter gear  130  engages rack  134  on plate  94 . Large diameter gear  132  engages rack  136  on support  138  of punch assembly  114 .  
         [0057]     The flash punch assembly  114  includes a top plate  140  and two like side plates  142  forming U-shaped support  138 . The outer end of each side plate  142  carries a bearing engaging a slide rail  122 . The inner end of each side plate carries a bearing engaging a slide rail  144  mounted on plate  116 . The flash punch assembly  114  includes a punch top plate  146  located above plate  140 , a punch lower plate or platen  148  and four guide posts  150  joining the plates together and extending through bearings in support top plate  140 . Plate  146  extends laterally beyond the sides of support  138  and is connected to two return posts  152  which extend freely through brackets  154  mounted on support side plates  142 . Springs  156  are mounted on posts  152  and confined between the top plate and the brackets. The springs bias the plates  146  and  148  toward an upper position shown in  FIG. 12  with plate  148  engaging plate  140 .  
         [0058]     Flash punches  158  and  160  shown in  FIG. 13  are mounted on the bottom of punch bottom plate or platen  148 . Punch  158  is shaped to punch neck flash F from a log A held on nests  98  and support  104  and punch  160  is shaped to punch neck flash G from the log.  
         [0059]     Top plate  146  supports roller cam follower  162  which is engageable with fixed punch cam  120  for moving the punches from a retracted position through a punch stroke to an extended position and, in cooperation with springs  156 , for returning the punches back to the retracted position above a log A held on the vacuum nests.  
         [0060]     Fixed punch cam  120  is illustrated in  FIGS. 14 and 15 . Rotation of wheel  24  moves successive flash punch tooling  112  in the extended position shown in  FIGS. 17 and 18  past cam  120 . Roller cam follower  162  engages surface  164  of the cam to move punches  158  and  160  inwardly and trim neck flashes F and G from a log held on the vacuum nests and anvil. After the punch stroke has been completed, springs  156  hold the follower against the continuation of cam surface  164  during an outward or return stroke. Stop  166  on support top plate  140  limits downward movement of the punches. Severed neck flash falls into the interior of wheel  24  for gravity delivery through chute  168  to trough  80 . In the event the punch tooling is not returned by the springs rotary follower  170  on top plate  146  engages retraction cam  171  which returns the punches and plates to the retracted position with the punches above the log held on the nests. Additionally, cam  120  is spring loaded in case the tooling  112  jams and prevents lowering of punches  158  and  160  by the cam. In that event, the cam pivots upwardly out of the path of movement of follower  162  and trimmer  10  is shut down.  
         [0061]     During transfer of a log A from wheel  22  to  24 , as shown in  FIG. 2 , the flash punch assembly  114  is retracted adjacent wall  16  out of the path of movement of wheel  22 . After the log has been vacuum transferred from the nests of wheel  22  to the nests of a tooling assembly on wheel  24  the cam follower  126  for the tool assembly is rotated along a rise portion  172  of cam groove  128  to move the punch assembly to the extended position over the log A held on the vacuum nests before engagement with cam  120 . Movement of the punch assembly from the retracted to the extended position is delayed until the assembly has been rotated away from wheel  22 . See  FIG. 6 . As follower  126  moves along rise portion  172  plate  124  is moved outwardly from wall  16 , gear  130  is rotated in rack  134  to rotate large gear  132  and rapidly move rack  136  and support  138  from the retracted to the extended position. Continued rotation of wheel  24  moves follower  126  along dwell portion  174  of groove  128  to hold the punch assembly in the extended position during movement past cam  120  and punching of neck trim from the log. After punching has been completed and assembly  112  has moved away from cam  120  the follower  126  moves down a fall portion of groove  128  to move the punch assembly  114  back to the retracted position.  
         [0062]     Intermediate star wheel  26  transfers flash-trimmed logs A from the flash punch tooling assemblies  112  of wheel  24  to spin trim tooling assemblies  176  on spin trim wheel  28 . Wheel  26  includes four sets of axially spaced vacuum nests  178 , like nests  54  of wheel  22  and is otherwise like wheel  22  as previously described. Both wheels  22  and  26  are rotated in a counterclockwise direction as viewed in  FIG. 5 . Each wheel has four ninety degree-oriented sets of vacuum nests.  
         [0063]     The vacuum nests of wheel  26  are provided with pneumatic circuitry as shown in  FIG. 26  to facilitate vacuum capture of logs from wheel  24  and air jet release of logs to wheel  28 .  
         [0064]     Spin trim wheel  28  includes four ninety degree-spaced spin trim tooling assemblies  176  each mounted on a mounting plate  180 , like plates  94  in wheel  24 , and facing outwardly from the plate. Each plate  180  is mounted on three radially support plates  182 , like plates  92  in wheel  24 , which are in turn supported by a drive shaft mounted for rotation in a hub on wall  16 . A fixed cylindrical cam  184 , like cam  118  in wheel  24 , surrounds the drive shaft for wheel  28  between the inner most plate  182  and wall  16 .  
         [0065]     Each assembly  176  includes two like spin units  190  each having a hollow housing  192  mounted on plate  180  with a slide body  194  located in the housing and extending above the housing. The slide bodies have limited longitudinal movement within the housings in a direction parallel to the axis of rotation of wheel  28 . In  FIGS. 19-21  the bodies are separated. In  FIG. 22  the bodies are moved together to capture a log. The slide bodies are held in the housings on rods  196  extending through the bodies and the ends of the housings.  
         [0066]     Screw nut  198  is mounted on guide rails on the inner end of plate  180 , adjacent wall  16 . A cylindrical cam follower  200  is mounted on the screw nut and is fitted in cam groove  202  extending around cam  184 . The screw nut includes a rotary output shaft  204  which is connected to rotary drive shaft  206  extending through both spin units  190 . A drive gear  208  is mounted on shaft  206  on the outside of each spin unit as shown in  FIG. 21 . Each gear  208  engages an idler gear  210  mounted on shaft  212  extending through assembly  190  and a driven gear  214  mounted on shaft  216  extending through the upper portion of a slide body  194 , above housing  192 . In each spin unit  190 , a bottle retention cup or log holder  218  is mounted on the inner end of each shaft  216  and faces the bottle retention cup  218  on the other spin unit  190 . Each cup  218  includes a rectangular recess  230  dimensioned to be extended over the bottom I of a flash-punched log A positioned by wheel  26  between the cups when retracted as in  FIG. 21 . The cups each include a ledge  232  extending outwardly from the recess to  230  for supporting the log when placed between the open or retracted cups.  
         [0067]     Each assembly  176  includes a bottle neck support  234  for the necks C of the bottles in the log in the assembly. The neck support is mounted on plate  180  and includes a pair of support rollers  236  located under the neck of each bottle in the log held in the assembly so that the bottle necks and the neck ring joining the bottle necks are supported as shown in  FIGS. 23 and 24 . The tops of the necks and the neck ring extend above the rollers to permit spin trimming of the ring away from the necks.  
         [0068]     Shafts  216  rotate bottle retention cups  218 . As shown in  FIG. 19 , the recesses  230  in which the bottoms of the bottles in log A are seated are offset to one side of the shafts  216 . When log A is held in cups  218 , the neck axis D of the log coincides with the axis of shafts  116 . Rotation of the shafts rotates the log about offset axis D for cutting away of neck ring E.  
         [0069]     Trimmer  10  may be used to trim neck flash and neck ring from logs having bottles with the bottle necks located equidistant between the bottle sides, rather than offset. In this case, the anvils and punches of tooling  112  would be located centrally. In assembly  176  the recesses  230  would be located centrally with regard to neck support  234 , rather than offset as shown in  FIG. 19 .  
         [0070]     The screw nut  198 , drive shaft  206 , gears  208 ,  210  and  214  and shaft  216  form a drive  238  for rotating a bottle or log retention cups  210  during trimming away of neck ring E. Drive  238  is actuated by fixed cam  184 .  
         [0071]     Cup opening and closing drive  240  is operated by fixed cams on plate  186 . The drive includes cam follower support  242  located on the end of assembly  186  away from wall  16  and mounted on the outer ends of two shift rods  244 . Each rod is mounted on one end of support  242  and extends longitudinally along the assembly  176  past the outer spin assembly  190  and to inner assembly  190 . See  FIG. 20 . The rods extend through rod supports  246  mounted on plate  180 . A block  248  is attached to the inner end of each rod  244  and supports a link  250  which is connected to the slide body in the inner unit  190  through opening  252  formed in housing  192 . A block  254  is attached to each rod  244  adjacent the outer unit  190  and is connected to the lower end of pivot arm  256  by link  258 . The upper end of the pivot arm is connected to link  260  which in turn is connected to the slide body  194  in housing  192  through opening  262 . The center of the pivot arm  256  is pivotally mounted on housing  192 .  
         [0072]      FIGS. 19-21  show assembly  176  with cups  218  spaced apart in an open position. Cam follower support  242  is located in an inner position. Movement of the support  242  outwardly, away from wall  16 , moves rods  244  outwardly. The slide body  194  in the inner or distal spin unit  190  is pulled outwardly by outward movement of links  250 . The slide body in the outer or proximal spin unit  190  is pushed inwardly the same distance the other slide body is pulled outwardly by rotation of pivot arms  256  and inward movement of links  260 . During movement of the slide bodies toward each other gears  214  slide along idler gears  210  while retaining engagement with the idler gears. The closing movement of the two cups  218  moves recesses  230  onto the ends of a log A supported on ledges  232  to capture the log in assembly  176  with log axis D aligned with the axis of shafts  216  which rotate the cups and log. See  FIGS. 22 and 24 .  
         [0073]     Rotary cam follower  264  is located on the center of support  242  between rods  244  and faces outwardly toward plate  186 . Follower  264  engages a rotary cam  266  on plate  186  to move the cups from the closed, log-engaging position shown in  FIG. 22  to the open position of  FIGS. 19 and 20  permitting placement or removal of logs between the cups.  
         [0074]     Spring  268 , shown in  FIG. 19 , is attached between follower support  242  and support  246  mounted on the outer end of plate  180 . The spring  268  is compressed and biases the support  242  outwardly, away from wall  16  to position cups  218  together in a closed position holding a log in place on assembly  176  with log axis D aligned with the spin axis of shafts  216 .  
         [0075]     Support  242  carries a second follower  270  and plate  186  carries a second fixed cylindrical cam  272  located between follower  270  and plate  180 . During normal operation of assemblies  176  spring  268  moves the cups together to capture logs and cam  272  performs no work. Cam  272  moves the cups together if spring  268  fails to close the cups.  
         [0076]     Two-blade cutter assembly  274  is mounted on wall  16  and partially surrounds wheel  28 , as shown in  FIG. 25 . Logs trimmed with neck flash removed are delivered to assemblies  176  in wheel  28  in the gap  276  between the ends of the cutter assembly. The assembly cuts away the neck rings E of the logs carried by spin trim assemblies  176 . The resultant individual bottles are delivered from assemblies  176  to vacuum nests of takeaway wheel  30 .  
         [0077]      FIG. 24  illustrates the position of a log A, with neck flash previously trimmed away, held between closed cups  218  during spin trimming. Assembly  274  includes circumferential plates  278 ,  280  which extend nearly completely around wheel  28  leaving gap  276 . Each plate  278 ,  280  includes an inner hold down edge  282  which engages the neck C of a bottle B held in assembly  176 . During spin trimming, each bottle B in log A is held in place by a cup  218 , two support rollers  236  and one edge  282 .  
         [0078]     Cutter assembly  274  includes two circumferential cutting blades  284  having sharpened inner edges  286  which engage and spin cut the logs held in assemblies  176  at the junctions between the bottle necks B and neck ring E.  
         [0079]     A log held in vacuum nests on wheel  26  is rotated between open bottle retention cups  218  of one of the rotating assemblies  176  of wheel  28 . When the log is in place, cam follower  264  is rotated to a fall surface on cam  266  and spring  268  moves cups  218  together to seat the ends of the bottles in recesses  230 . At the same time, the vacuum holding the bottles in the nests on wheel  26  is reversed and compressed air is flowed through the suction cups in the nests to release the log from the vacuum nests. Rotation of wheel  28  moves the confined log under hold down surfaces or edges  282  of plates  278 ,  280  to confine the bottle necks between rollers  236  and the plates. Rotation of wheel  28  moves cam follower  200  along a sloped surface in cam groove  202  to drive screw nut  198  outwardly from wall  16  along shaft  204  to rotate the shaft so that the drive shaft  216 , cups  218  and held log A are spun around neck axis D two revolutions in a first direction. The cam follower  200  then is moved along a reverse slope section of cam groove  202  to retract the screw nut and spin the log A on assembly  176  two revolutions in a second, reverse direction.  
         [0080]     Rotation of assembly  176  holding the log and spinning of the log as the log is rotated around wheel  28  moves the neck portions of the spinning log into engagement with cutting edges  286  of blades  284  to trim the neck ring E from the two bottles B.  
         [0081]     In the embodiment disclosed, screw nut  198  spins log A two revolutions in each direction as the log is spun in engagement with blades  284 . The number of rotations per inner and outer stroke of the nut screw may be adjusted as required. Additionally, the shape and lead end of edges  286  may be adjusted as required for optimum cutting away of the neck ring. The blades may be brought into gradual engagement with the sides of the bottle neck for gradual cutting as the bottles are spun along the cutting blades. Alternatively, the blades may include a portion which initially punctures the thickness of the bottle necks and then cuts the entire thickness of the neck is spun around axis D.  
         [0082]     The log is held in a known position in cups  218 . The thickness of the plastic at the part lines extending across the neck ring may vary. The cutting edges  286  may have a geometry selected for optimum cutting of the plastic at the bottle necks dependent upon circumferential variation in thickness of the plastic.  
         [0083]      FIG. 7  illustrates the drive system  36  for trimmer  10 . The system includes an electric motor  288  connected to a transmission  290  mounted on wall  16 . The transmission has an output shaft supporting pulleys adjacent the wall and remote from the wall. Drive belt  292  engages a pulley on the output shaft and pulley  294  mounted on the inner end of drive shaft  88  for wheel  24 . Drive belt  296  engages a second pulley  298  on the inner end of shaft  88  and pulley  299  on the inner end of the drive shaft for wheel  28 .  
         [0084]     Belt  309  is wound around a pulley mounted on the transmission output shaft, drive pulley  302  on drive shaft  42  for wheel  22  and a take off pulley  311  for the infeed screw conveyor drive. Belt  300  is wound around a second pulley  306  on the inner end of the drive shaft  42  and pulley  306  on the inner end of the drive shaft for wheel  26 . Belt  304  is wound around a second pulley on the drive shaft for wheel  26  and small diameter pulley  308  on the drive shaft for wheel  30 .  
         [0085]     Infeed conveyor  32  is driven by belt  309 . Discharge conveyor  34  is driven by belt  310  and rotary shaft drive  314  extending across the back of wall  16  under the motor and transmission.  
         [0086]     The pulleys on the inner ends of the drive shafts for wheels  22 ,  24 ,  26  and  28  are the same diameter. Each of these wheels carries four ninety degree-spaced assemblies or vacuum nests and rotates at the same speed, although as illustrated in  FIG. 5 , wheels  22  and  26  rotate counterclockwise and wheels  24  and  28  rotate clockwise. Wheel  30  carries three sets of vacuum nests. The pulley  308  for rotating wheel  30  is smaller than the pulleys rotating the other wheels and rotates wheel  30  at a speed one-third faster than the speed of rotation of other wheels so that the vacuum nests on wheel  30  capture trimmed bottles delivered from wheel  28  having four spin trim assemblies  176 .  
         [0087]     The operation of bottle trimmer  10  will now be described by describing the operations performed on a log A placed on infeed conveyor  32  after tail flash has been removed from the ends of the two bottles in the log.  
         [0088]     Conveyor  32  conveys log A downstream at a speed which locates the log under a pair of vacuum nests  54  on wheel  22 . The wheel rotates to position the nests over the two bottles in the log as illustrated in  FIG. 1 . Compressed air is flowed through the circuit of  FIG. 26  for the nests to draw vacuum through cups  60  and vacuum-hold the log in the nests. The log is held accurately in place by the nests and edge  62 .  
         [0089]     The infeed conveyor  32  includes sensing means (not illustrated) to detect untrimmed tail flash on log A. In the event tail flash has not been trimmed from the log, air cylinder  84  is shifted to close the discharge opening  72  for the pneumatic system for the nests so that compressed air is flowed through the vacuum cups and the log is not captured in the nests, remains on the infeed conveyor and is discharged into trough  80 .  
         [0090]     A log held in vacuum nests in the wheel  22  is rotated counterclockwise as shown in  FIG. 5  up to wheel  24  and is transferred from nests  54  on wheel  22  to nests  98  on wheel  24 . The two nests are rotated together at the 12 o&#39;clock position for wheel  22  and the 6 o&#39;clock position for wheel  24 . Compressed air is blown through the vacuum cups of nests  54  and vacuum is applied to nests  98  at transfer. As illustrated in  FIG. 8 , the flash punch assembly  114  associated with nests  98  receiving the log is in the retracted position adjacent wall  16  and out of the path of movement of wheel  24  during transfer of the log. After transfer of the log to vacuum nests at the 6 o&#39;clock position on wheel  24 , continued clockwise rotation of the wheel rotates the log and moves cam follower  28  along a rise surface of fixed cam  118  to actuate drive assembly  116  and move flash punch assembly  114  from the retracted position of  FIG. 12  to an extended position where punches  158  and  160  are located above the neck portion of the log. The flash punch assembly is fully extended before the wheel rotates the assembly into engagement with cam  120 .  
         [0091]     As the wheel continues rotation in a clockwise direction, follower  162  engages surface  164  of cam  120  to lower punches  158  and  160  and trim flash F and G from log A. As shown in  FIG. 16 , neck flash is trimmed from the log when the log is located at the upper portion of the path extending partially around wheel  24 . The trimmed flash gravity falls into the hollow interior of wheel  24 . The punches  158  and  160  rotating on wheel  24  and move downstream along the path of movement of the log during punching. Chute  168  extends into the interior of the wheel, receives the trimmed flash and guides the gravity-fall of the flash into trough  80 .  
         [0092]     After punching, continued rotation of wheel  24  moves follower  162  down cam surface  164  to raise the punches above the log. When punch assembly  114  has been rotated clear of the cam a fall surface on cam  128  retracts the flash punch assembly from the extended position to the retracted position before wheel  28  rotates the flash-trimmed log to position for transfer to vacuum nests  178  of wheel  26 . Vacuum is supplied to nests  178  and compressed air is flowed through the vacuum cups of nests  98  to complete the transfer.  
         [0093]     The flash-trimmed log is carried by nests  178  on wheel  26  to gap  276  between the ends of the cutter assembly  274  partially surrounding wheel  28 . When moved into the gap the log is seated between two separated or open bottle retention cups  218  of a spin trim assembly  176 . The log rests on ledges  232 . The neck C of each bottle rests on two rollers  236 . See  FIGS. 19-21 . Immediately after wheel  26  positions the log A on assembly  176  rotation of wheel  28  moves cam follower  264  down a fall surface of cam  266  so that spring  268  moves the bottle retention cups  218  together to capture the ends of the bottle and hold the bottle for spin trimming. Upon continued rotation of wheel  28  neck C of each bottle in the log is held between two rollers  236  and the hold down surface  282  of one of plates  278  and  280 . After the log has been captured as described, follower  200  moves down a surface in cam groove  202  to move screw nut  198  first away from wall  16  and then back toward wall  16  to spin the log first two revolutions about axis D in a first direction and then spin the log back two revolutions about the axis in the opposite direction. Trimming occurs as wheel  28  rotates the log along edges  286  of blades  284  to sever neck ring E from bottle necks C. After the neck ring has been severed, the individual trimmed bottles B are held in place on the spin trim assembly  176  between cups  286  and rollers  236  and plates  278  and  280 .  
         [0094]     After spin trimming continued rotation of wheel  28  moves the trimmed bottles into engagement with vacuum nests  312  on wheel  30 . Follower  264  rides up a rise surface on cam  266  to retract or move apart cups  218  and release the trimmed bottles after the bottle necks have moved past the downstream ends of plates  278  and  280 . The released bottles are vacuum drawn into nests  312  and are rotated by wheel  30  down onto takeaway conveyor  34 . When above the conveyor, vacuum is released and compressed air is blown through the suction cups to transfer the bottles from the nests  312  to the conveyor for takeaway as illustrated.  
         [0095]     Bottle trimming machine is designed to operate at a high production speed of about 200 logs per minute with an output of 400 trimmed bottles per minute. The machine accurately holds the logs and bottles in place on each of the wheels during movement of the logs, and subsequently trimmed bottles, along a continuous arcuate path  320  at a constant speed.  FIG. 27  illustrates the path of movement of log A from infeed conveyor  32  to discharge conveyor  34 .  
         [0096]     Arcuate path  320  extends from infeed end  322  where the log is picked up by wheel  22  from conveyor  32  and extends continuously around arcuate portions  324 ,  326 ,  328 ,  330  and  332  on wheels  22 ,  24 ,  26 ,  28  and  30  respectively to discharge point  324  where the trimmed bottles are placed on discharge conveyor  34 . Wheels  22 ,  24 ,  26  and  30  support the logs and bottles in nests or in spin trim assemblies located a distance r from the axis of rotation of the wheel. Wheels  22 ,  24 ,  26  and  28  are rotated at the same circumferential speed so that the logs are moved along path  320  at the same speed. The radius of wheel  30  is less than r. Accordingly, wheel  30  is rotated more rapidly than the other wheels so that the trimmed bottles carried by wheel  30  are moved along the downstream portion of the path  320  at the same speed the logs are moved along the portion of the path upstream from wheel  30 . The logs are held on the wheels  22 ,  24 ,  26  and  28  with the neck axes D extending transversely to the direction of movement along path  320  and parallel to the rotational axes of the wheels. The neck axes of the bottles carried by wheel  30  parallel the axis of the wheels.  
         [0097]     The punches  158  and  160  in flash punch assembly  112  move along the path with the logs during punching or trimming away of neck flash. In disclosed machine  10 , the flash punch assemblies  114  are retracted away from the logs when the logs are transferred from wheel  22  to wheel  24 . Then, the punch assemblies are extended parallel to the axis of rotation of wheel  24  and perpendicular to the path  320  to a position over the logs where neck flash is trimmed away from the logs.  
         [0098]     If desired, wheel  24  could be modified to have flash punch assemblies which are permanently located in the position of the retracted punch assemblies of machine  10  disclosed herein and the wheel could include drive assemblies which shift the vacuum nests  98  holding the logs in place across the path in a direction parallel to the axis of rotation of the wheel to position the logs under the punch assemblies for trimming. After trimming, the trimmed logs would be shifted back to their original positions for transfer to wheel  26 . During such a punching operation, the logs are moved downstream along path  320  at a continuous speed but are shifted laterally, punched and then shifted back.  
         [0099]     As the logs are rotated along the path on wheel  28  the logs are spun along the neck axis and engage fixed cutting blades to trim away neck rings between the bottles in the log. Spin trimming of the neck rings is preformed without altering the movement of the logs, and then bottles, along the path.  
         [0100]     The vacuum nests on wheels  22 ,  24  and  26  accurately locate the logs on the wheels during continuous movement along the path. Spin trim assemblies  176  accurately locate the logs during movement around wheel  28 . Finally, vacuum nests  312  on wheel  30  accurately locate the trimmed bottles on wheel  30  during transport from wheel  28  to the discharge conveyor  34 .  
         [0101]     A set of four vacuum nests or log holders  54  is provided on wheel  22 . A set of four vacuum nests or log holders  98  is provided on wheel  24 . A set of four vacuum holders or nests  178  is provided on wheel  26 . A set of four pairs of cup holders or log holders  218  is provided on wheel  28 . A set of three vacuum nests or log holders  312  is provided on wheel  30 . During downstream movement of logs along path  320  the log holders on each wheel are repetitively moved downstream along the second of the path defined by the wheel and carry logs downstream along the path. The wheels move the logs continuously downstream along the path during trimming as described. Each wheel  22 ,  24 ,  26 ,  28  and  30  is a feed conveyor which repetitively moves logs downstream along its respective portion of the path. Accurate location of the logs on the wheels assures that flash trimming and spin trimming is performed at proper locations on the logs and improves the quality of the trimmed bottles. Trimmed bottles are discharged at regularly spaced known intervals on discharge conveyor  34  in position for downstream operations.  
         [0102]     The wheels  22 ,  24 ,  26 ,  28  and  30  are cantilevered on wall  16  and extend outwardly from the wall. This arrangement permits the compact machine design and facilitates worker access to the wheels and to drive system  36  during set up and servicing. Path  320  with joined counterclockwise and clockwise sections is compact and reduces the size of the trimmer and auxiliary conveyors.  
         [0103]     Wheels  22 ,  24 ,  26  and  28  have four ninety degree spaced stations. If desired, the throughput of the machine may be increased by doubling the number of stations on each wheel without appreciably increasing the size of the machine. Doubling the stations would increase the throughput from 200 logs per minute to 400 logs per minute and 800 bottles per minute.  
         [0104]     In wheel  24  the punch tooling for removing neck flash moves down along the path  320  with the logs, permitting extension of the tooling for trimming flash without slowing movement of the logs along the path or requiring special alignment of the logs. Spin trim assemblies  176  on wheel  28  rotate around the wheel at the same speed of the logs permitting capture and spinning of the logs for spin trimming without altering downstream movement of the logs along the path.  
         [0105]     Continuous downstream movement of the logs during trimming facilitates high-speed operation of machine  10 . There is no need to stop movement of the logs or reorient the logs in a known position before trimming. Indexing of individual logs is eliminated.  
         [0106]     Machine  10  has been described in connection with trimming of plastic from two bottle logs. If desired, the machine may be used to trim neck flash and neck rings from single body logs using single vacuum nests and tooling for single bottle logs rather than two bottle logs. The single bottle logs trimmed by the machine may have necks located to one side of the bottle, like bottle B, or centrally located necks.  
         [0107]     While we have illustrated and described a preferred embodiment of our invention, it is understood that this is capable of modification, and we therefore do not wish to be limited to the precise details set forth, but desire to avail ourselves of such changes and alterations as fall within the purview of the following claims.