Abstract:
An actuator assembly comprising a piston interconnected to a valve pin, the piston being driven by drive fluid controlled by a restriction valve,
   a pressure sensor adapted to sense pressure of the drive fluid disposed within an upstream drive chamber or within an upstream drive fluid channel connecting the drive chamber and the restriction valve,   the pressure sensor sending and a controller receiving a signal indicative of the sensed pressure, the controller operating to execute a display of a visually recognizable format corresponding to the sensed pressure or an algorithm to control movement of the piston.

Description:
RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of and claims the benefit of priority to U.S. application Ser. No. 15/442,173 filed Feb. 24, 2017 which is in turn a continuation of U.S. application Ser. No. 14/708,533 (7127US1) filed May 11, 2015 which is a continuation of international application PCT/US2013/071667 filed Nov. 25, 2013 the disclosures of both which are incorporated herein by reference in their entirety as if fully set forth herein. 
         [0002]    This application is also a continuation in part of and claims the benefit of priority to U.S. application Ser. No. 14/930,692 filed Nov. 3, 2015 (7117US1) which is a continuation of U.S. application Ser. No. 13/569,464 filed Aug. 8, 2012 (7117U50), the disclosures of all of the foregoing of which are incorporated by reference in their entirety as if fully set forth herein. 
         [0003]    This application is also a continuation in part of and claims the benefit of priority to U.S. application Ser. No. 15/291,721 filed Oct. 12, 2016 (7134US2) which is a continuation of U.S. application Ser. No. 14/311,785 filed Jun. 23, 2014 which is a continuation-in-part of U.S. application Ser. No. 13/484,336 filed May 31, 2012 which is a continuation of PCT/US2011/062099 filed Nov. 23, 2011, the disclosures of all of the foregoing of which are incorporated by reference in their entirety as if fully set forth herein. 
         [0004]    This application is also a continuation in part of and claims the benefit of priority to U.S. application Ser. No. 15/286,917 filed Oct. 6, 2016 (7135US2) which is a continuation of U.S. application Ser. No. 14/325,443 filed Jul. 8, 2014 the disclosures of all of the foregoing of which are incorporated by reference in their entirety as if fully set forth herein. 
         [0005]    This application is also a continuation in part of and claims the benefit of priority to U.S. application Ser. No. 14/567,308 filed Dec. 11, 2014 (7100U54) which is a divisional of U.S. application Ser. No. 13/484,336 filed May 31, 2012 which is a continuation of and claims the benefit of priority of PCT/US11/62099 filed Nov. 23, 2011 which in turn claims the benefit of priority to U.S. Provisional Application Ser. No. 61/475,340 filed Apr. 14, 2011 and to U.S. Provisional Application Ser. No. 61/416,583 filed Nov. 23, 2010, the disclosures of all of the foregoing of which are incorporated by reference herein in their entirety as if fully set forth herein. 
         [0006]    This application is also a continuation in part of and claims the benefit of priority to U.S. application Ser. No. 15/215,774 filed Jul. 21, 2016 (7118US2) which is a continuation of U.S. application Ser. No. 14/834,586 filed Aug. 25, 2015, the disclosures of all of the foregoing of which are incorporated by reference herein in their entirety as if fully set forth herein. 
         [0007]    The disclosures of all of the following are incorporated by reference in their entirety as if fully set forth herein: International Application Publication No. WO2012/074879, U.S. Patent Application Publication No. 2012/0248644, International Application Publication No. 2012/087491, U.S. Patent Application Publication No. 2012/0248652, U.S. Pat. No. 5,894,025, U.S. Pat. No. 6,062,840, U.S. Pat. No. 6,294,122, U.S. Pat. No. 6,309,208, U.S. Pat. No. 6,287,107, U.S. Pat. No. 6,343,921, U.S. Pat. No. 6,343,922, U.S. Pat. No. 6,254,377, U.S. Pat. No. 6,261,075, U.S. Pat. No. 6,361,300 (7006), U.S. Pat. No. 6,419,870, U.S. Pat. No. 6,464,909 (7031), U.S. Pat. No. 6,599,116, U.S. Pat. No. 7,234,929 (7075US1), U.S. Pat. No. 7,419,625 (7075US2), U.S. Pat. No. 7,569,169 (7075US3), U.S. patent application Ser. No. 10/214,118, filed Aug. 8, 2002 (7006), U.S. Pat. No. 7,029,268 (7077US1), U.S. Pat. No. 7,270,537 (7077US2), U.S. Pat. No. 7,597,828 (7077US3), U.S. patent application Ser. No. 09/699,856 filed Oct. 30, 2000 (7056), U.S. patent application Ser. No. 10/269,927 filed Oct. 11, 2002 (7031), U.S. application Ser. No. 09/503,832 filed Feb. 15, 2000 (7053), U.S. application Ser. No. 09/656,846 filed Sep. 7, 2000 (7060), U.S. application Ser. No. 10/006,504 filed Dec. 3, 2001, (7068) and U.S. application Ser. No. 10/101,278 filed Mar., 19, 2002 (7070), U.S. Pat. No. 8,297,836 (7087), U.S. Pat. No. 8,328,549 (7096) and international applications PCT/US2011/062099 (7100) and PCT/US2011/062096 (7100), PCT/US2014/043612, PCT/US2013/075064 filed Dec. 13, 2013, PCT/US2014/019210 filed Feb. 28, 2014, PCT/US2014/031000 and PCT/US2014/032658. 
     
    
     BACKGROUND OF THE INVENTION 
       [0008]    Injection molding systems have been developed having flow control mechanisms that control the movement of a valve pin over the course of an injection cycle based on measuring pressure of injection fluid directly with a pressure sensor disposed with an injection fluid flow channel or the cavity of a mold. 
       SUMMARY OF THE INVENTION 
       [0009]    In accordance with the invention there is provided in an apparatus ( 10 ) for controlling flow of fluid injection material ( 18 ,  100   a,    100   b ) from an injection molding machine to a mold cavity ( 30 ), wherein the apparatus comprises: a manifold ( 40 ) receiving the injected fluid mold material, the manifold having one or more fluid delivery channels ( 42 ,  44 ,  46 ) that delivers the injected fluid material ( 100   a,    100   b ) through a gate ( 32 ,  34 ,  36 ) to the mold cavity ( 30 );
       a pressure sensing assembly comprising:   an actuator ( 20   a,    940 ,  941 ,  942 ) comprising a piston ( 40   p ) interconnected to a valve pin ( 1040 ,  1041 ,  1042 ) drivable along a drive path that extends between a gate closed position ( 40   gc ) where a distal end ( 1155 ) of the valve pin ( 1040 ,  1041 ,  1042 ) ( 1041 ) stops flow through (GC) the gate and an upstream open position where the distal end ( 1155 ) of the valve pin is withdrawn upstream to enable injection fluid material ( 100   a,    100   b ) to flow through the gate ( 32 ,  34 ,  36 ),   the piston ( 40   p ) being housed within a piston housing ( 20   h ) in an arrangement that forms an upstream drive chamber ( 30   u ) and a downstream drive chamber ( 30   d ), the upstream drive chamber having a drive fluid port ( 50 ,  52 ) fluid sealably interconnected via an upstream drive fluid channel ( 704 ) to a restriction valve ( 600 ), the piston ( 40   p ) being drivable upstream and downstream by drive fluid ( 14 ) pumped into and out of the upstream drive chamber ( 30   u ) through the drive fluid port ( 50 ,  52 ), drive fluid channel ( 704 ) and restriction valve ( 600 ),   a pressure sensor ( 603   e,    603   ec ) adapted to sense pressure of the drive fluid ( 14 ) disposed within the upstream drive chamber ( 30   u ) or within the upstream drive fluid channel ( 704 ),   a controller ( 16 ) that includes a program that instructs the restriction valve ( 600 ) to close for a first portion of an injection cycle to prevent flow of the drive fluid ( 14 ) such that the piston ( 40   p ) is held or stopped in a first position where drive fluid (DF) resides and remains within the upstream drive chamber ( 30   u ) or within the upstream drive fluid channel ( 704 ) without flow through the restriction valve ( 600 ) during the first portion of the injection cycle,   the pressure sensor ( 603   e,    603   ec ) sensing pressure of the drive fluid (DF) resident and remaining within either the upstream drive chamber ( 30   u ) or the upstream drive fluid channel ( 704 ) during the first portion of the injection cycle,   the pressure sensor ( 603   e,    603   ec ) sending and the controller ( 16 ) receiving a signal indicative of the sensed pressure, wherein the controller ( 16 ) operates to execute a display ( 1300 ) of a visually recognizable format corresponding to the sensed pressure or uses the received signal in an algorithm to control movement of the piston ( 40   p ).       
 
         [0017]    The controller ( 16 ) preferably includes instructions that operate to display a visually recognizable format of the sensed pressure as either sensed pressure of the drive fluid (DF) or pressure of the injection fluid ( 100   a,    100   b ) that correlates to the sensed pressure (DF) of the drive fluid. 
         [0018]    The controller ( 16 ) can includes instructions that instruct the piston ( 40   p ) to travel to a selected maximum upstream position during the course of the injection cycle that leaves a space or volume ( 30   s ) within which drive fluid (DF) resides during the first portion of the injection cycle. 
         [0019]    The maximum upstream position of the piston ( 40   p ) is typically selected such that an upstream end surface ( 40   e ) of the piston ( 40   p ) is spaced an axial distance of between 0.1 and 2.0 mm from an opposing undersurface ( 20   uws ) of an upstream wall of the upstream drive chamber ( 30   u ). 
         [0020]    The maximum upstream position of the piston ( 40   p ) can be selected such that an upstream end surface ( 40   e ) of the piston ( 40   p ) is spaced an axial distance of between  0 . 25  and 1.0 mm from an opposing undersurface ( 20   uws ) of an upstream wall of the upstream drive chamber ( 30   u ). 
         [0021]    An upstream surface ( 40   e ) of the piston ( 40   p ) typically remains spaced at least a selected axial distance greater than 0.1 mm away from an undersurface ( 20   uws ) of the housing ( 40   h ) or upstream drive chamber ( 30 U) during the entire course of the injection cycle. 
         [0022]    The pressure sensor assembly can include a source of drive fluid ( 14 ) that is drivable into and out of the upper drive chamber ( 30   u ) through the restriction valve ( 600 ) and upstream drive fluid channel ( 704 ), the restriction valve ( 600 ) being controllably openable by the controller ( 16 ) to a selected degree to enable flow of drive fluid (DF, FEX) into and out of the upstream drive chamber ( 30   u ) at a selectable rate of flow to control rate of travel of the piston ( 40   p ), the restriction valve ( 600 ) being controllably closable to controllably stop flow of drive fluid (DF) into and out of the upstream drive chamber ( 30   u ) and to stop movement of the piston ( 40   p ). 
         [0023]    The controller ( 16 ) can includes instructions that instruct the piston ( 40   p ) to travel, subsequent to the first portion of the injection cycle, to a second position for a second portion of the injection cycle where a distal end ( 1155 ) of the valve pin ( 1041 ) is positioned relative to the gate such that flow of injection fluid ( 100   a,    100   b ) is selectively controlled. 
         [0024]    The instructions of the controller ( 16 ) can operate to drive the piston ( 40   p ) to the second position in response to receipt of a first trigger signal from the pressure sensor ( 603   e,    603   ec ) that is indicative of a first selected target pressure. 
         [0025]    The controller ( 16 ) can include instructions that instruct the piston ( 40   p ) to travel, subsequent to the second portion of the injection cycle, to a third position for a third portion of the injection cycle where a distal end ( 1155 ) of the valve pin ( 1041 ) is positioned relative to the gate such that flow of injection fluid ( 100   a,    100   b ) is selectively controlled. 
         [0026]    The instructions of the controller ( 16 ) can operate to drive the piston ( 40   p ) to the third position in response to receipt of a second trigger signal from the pressure sensor ( 603   e,    603   ec ) that is indicative of a second selected target pressure. 
         [0027]    The first position can be a position where a distal end ( 1155 ) of the valve pin ( 1041 ) is positioned relative to the gate ( 32 ,  34 ,  36 ) such that flow of injection fluid ( 100   a ,  100   b ) is not significantly restricted and injection fluid ( 100   a,    100   b ) flows at a maximum speed or a relatively high speed or velocity or pressure at and through the gate and the second position is a position wherein the distal end ( 1155 ) of the valve pin ( 1041 ) is disposed axially intermediate a gate closed ( 40   gc ) and a fully gate open position such that the end ( 1155 ) of the valve pin ( 1041 ) restricts or reduces rate or velocity of flow or pressure of the injection fluid ( 100   a,    100   b ) flowing through or exerted at the gate to a selected reduced velocity or pressure that is less than a maximum rate of flow or pressure. 
         [0028]    The second position can be a position where a distal end ( 1155 ) of the valve pin ( 1041 ) is positioned relative to the gate ( 32 ,  34 ,  36 ) such that flow of injection fluid ( 100   a ,  100   b ) is (a) not significantly restricted and injection fluid ( 100   a,    100   b ) flows at a relatively high speed or velocity or pressure at and through the gate or (b) such that the distal end ( 1155 ) of the valve pin ( 1041 ) is disposed axially intermediate a gate closed ( 40   gc ) and a fully gate open position such that the end ( 1155 ) of the valve pin ( 1041 ) restricts or reduces rate or velocity of flow or pressure of the injection fluid ( 100   a,    100   b ) flowing through or exerted at the gate to a selected reduced velocity or pressure that is less than a maximum velocity or pressure. 
         [0029]    The controller ( 16 ) can include instructions that instruct the actuator ( 40   p ) to drive the valve pin ( 1041 ) upstream beginning from the gate closed position to the first position for the first portion of the injection cycle and subsequently to one or more different subsequent positions for one or more different subsequent portions of the injection cycle in response to receipt by the controller ( 16 )) of one or more trigger signals from the pressure sensor ( 603   ec ,  603   e ) corresponding to one or more selected sensed target pressures. 
         [0030]    One or more of the second and third positions can be positions where a distal end ( 1155 ) of the valve pin ( 1041 ) is positioned relative to the gate such that flow of injection fluid ( 100   a,    100   b ) is not significantly restricted and injection fluid ( 100   a,    100   b ) flows at a relatively high speed or velocity or pressure at and through the gate or such that the distal end ( 1155 ) of the valve pin ( 1041 ) is disposed axially intermediate a gate closed and a fully gate open position such that the end ( 1155 ) of the valve pin ( 1041 ) restricts or reduces rate or velocity of flow or pressure of the injection fluid ( 100   a,    100   b ) flowing through or exerted at the gate to a selected reduced velocity or pressure that is less than a maximum rate of flow or pressure. 
         [0031]    In another aspect of the invention there is provided a method of measuring pressure of an injection fluid material ( 100   a,    100   b ) injected into an apparatus ( 10 ) for controlling rate of flow of the injection fluid material ( 18 ,  100   a,    100   b ) from an injection molding machine to a mold cavity ( 30 ), wherein the apparatus comprises: a manifold ( 40 ) receiving the injected fluid material, the manifold having one or more fluid delivery channels ( 42 ,  44 ,  46 ) that delivers the injected fluid material ( 100   a,    100   b ) through a gate ( 32 ,  34 ,  36 ) to the mold cavity ( 30 ), an actuator ( 20   a,    940 ,  941 ,  942 ) comprising a piston ( 40   p ) interconnected to a valve pin ( 1040 ,  1041 ,  1042 ) drivable along a drive path that extends between a gate closed position where a distal end ( 1155 ) of the valve pin ( 1040 ,  1041 ,  1042 ) ( 1041 ) obstructs (GC) the gate and an upstream open position where the distal end ( 1155 ) of the valve pin is withdrawn upstream to enable injection fluid material ( 100   a,    100   b ) to flow through the gate ( 32 ,  34 ,  36 ), wherein the piston ( 40   p ) is housed within a piston housing ( 20   h ) in an arrangement that forms an upstream drive chamber ( 30   u ) and a downstream drive chamber ( 30   d ), the upstream drive chamber having a drive fluid port ( 50 ,  52 ) fluid sealably interconnected via an upstream drive fluid channel ( 704 ) to a restriction valve ( 600 ), the piston ( 40   p ) being drivable upstream and downstream by drive fluid ( 14 ) pumped into and out of the upstream drive chamber ( 30   u ) through the drive fluid port ( 50 ,  52 ), drive fluid channel ( 704 ) and restriction valve ( 600 ),
       the method being characterized in that:   a pressure sensor ( 603   e,    603   ec ) is adapted to sense pressure of the drive fluid ( 14 ) disposed within the upstream drive chamber ( 30   u ) or within the upstream drive fluid channel ( 704 ),   the restriction valve ( 600 ) is closed for a first portion of an injection cycle to prevent flow of the drive fluid ( 14 ) such that the piston ( 40   p ) is held or stopped in a first fully or partially open position where drive fluid (DF) resides and remains within the upstream drive chamber ( 30   u ) or within the upstream drive fluid channel ( 704 ) without flow through the restriction valve ( 600 ) during the first portion of the injection cycle,   pressure of the drive fluid (DF) resident and remaining within either the upstream drive chamber ( 30   u ) or the upstream drive fluid channel ( 704 ) is sensed via the pressure sensor ( 603   e,    603   ec ) during the first portion of the injection cycle,   the sensed pressure of the drive fluid (DF) is either displayed on a display ( 1300 ) in a visually recognizable format ( 1310 ) corresponding to the sensed pressure or is used as a variable in an algorithm to control movement of the piston ( 40   p ).       
 
         [0037]    In another aspect of the invention there is provided a method of measuring pressure of an injection fluid material ( 100   a,    100   b ) comprising operating a pressure sensing assembly as described above. 
         [0038]    In another aspect of the invention there is provided an apparatus ( 10 ) for controlling the rate of flow of fluid injection material ( 18 ,  100   a,    100   b ) from an injection molding machine to a mold cavity ( 30 ), the apparatus comprising:
       a manifold ( 40 ) receiving the injected fluid mold material, the manifold having one or more fluid delivery channels ( 42 ,  44 ,  46 ) that delivers the injected fluid material ( 100   a ,  100   b ) through a gate ( 32 ,  34 ,  36 ) to the mold cavity ( 30 );   an actuator ( 20   a,    940 ,  941 ,  942 ) comprising a piston ( 40   p ) interconnected to a valve pin ( 1040 ,  1041 ,  1042 ) drivable along a drive path that extends between a gate closed position where a distal end ( 1155 ) of the valve pin ( 1040 ,  1041 ,  1042 ) ( 1041 ) obstructs (GC) the gate and an upstream open position where the distal end ( 1155 ) of the valve pin is withdrawn upstream to enable injection fluid material ( 100   a,    100   b ) to flow through the gate ( 32 ,  34 ,  36 ),   the piston ( 40   p ) being housed within a piston housing ( 20   h ) in an arrangement that forms an upstream drive chamber ( 30   u ) and a downstream drive chamber ( 30   d ), the upstream drive chamber having a drive fluid port ( 50 ,  52 ) fluid sealably interconnected via an upstream drive fluid channel ( 704 ) to a restriction valve ( 600 ), the piston ( 40   p ) being drivable upstream and downstream by drive fluid ( 14 ) pumped into and out of the upstream drive chamber ( 30   u ) through the drive fluid port ( 50 ,  52 ), drive fluid channel ( 704 ) and restriction valve ( 600 ),   a pressure sensor ( 603   e,    603   ec ) adapted to sense pressure of the drive fluid ( 14 ) disposed within the upstream drive chamber ( 30   u ) or within the upstream drive fluid channel ( 704 ),   a controller ( 16 ) that includes a program that instructs the restriction valve ( 600 ) to close for a first portion of an injection cycle to prevent flow of the drive fluid ( 14 ) such that the piston ( 40   p ) is held or stopped in a first fully or partially open position where drive fluid (DF) resides and remains within the upstream drive chamber ( 30   u ) or within the upstream drive fluid channel ( 704 ) without flow through the restriction valve ( 600 ) during the first portion of the injection cycle,   the pressure sensor ( 603   e,    603   ec ) sensing pressure of the drive fluid (DF) resident and remaining within either the upstream drive chamber ( 30   u ) or the upstream drive fluid channel ( 704 ) during the first portion of the injection cycle.       
 
         [0045]    In such an apparatus the controller ( 16 ) preferably includes instructions that operate to execute a display ( 1300 ) of a visually recognizable format corresponding to the sensed pressure or uses the received signal in an algorithm to control movement of the piston ( 40   p ). 
         [0046]    The controller ( 16 ) preferably includes instructions that operate to display a visually recognizable format ( 310 ) of the sensed pressure as either sensed pressure of the drive fluid (DF) or pressure of the injection fluid ( 100   a,    100   b ) that correlates to the sensed pressure (DF) of the drive fluid. 
         [0047]    The controller ( 16 ) can include instructions that instruct the piston ( 40   p ) to travel to a selected maximum upstream position during the course of the injection cycle that leaves a space or volume ( 30   s ) within which drive fluid (DF) resides during the first portion of the injection cycle. 
         [0048]    The maximum upstream position of the piston ( 40   p ) is typically selected such that an upstream end surface ( 40   e ) of the piston ( 40   p ) is spaced an axial distance of between 0.1 and 2.0 mm from an opposing undersurface ( 20   uws ) of an upstream wall of the upstream drive chamber ( 30   u ). 
         [0049]    The maximum upstream position of the piston ( 40   p ) is typically selected such that an upstream end surface ( 40   e ) of the piston ( 40   p ) is spaced an axial distance of between 0.25 and 1.0 mm from an opposing undersurface ( 20   uws ) of an upstream wall of the upstream drive chamber ( 30   u ). 
         [0050]    An upstream surface ( 40   e ) of the piston ( 40   p ) preferably remains spaced at least a selected axial distance of 0.1 mm or greater away from an undersurface ( 20   uws ) of the housing ( 40   h ) or upstream drive chamber ( 30 U) during the entire course of the injection cycle. 
         [0051]    The assembly typically includes a source of drive fluid ( 14 ) that is drivable into and out of the upper drive chamber ( 30   u ) through the restriction valve ( 600 ) and upstream drive fluid channel ( 704 ), the restriction valve ( 600 ) being controllably openable by the controller ( 16 ) to a selected degree to enable flow of drive fluid (DF, FEX) into and out of the upstream drive chamber ( 30   u ) at a selectable rate of flow to control rate of travel of the piston ( 40   p ), the restriction valve ( 600 ) being controllably closable to controllably stop flow of drive fluid (DF) into and out of the upstream drive chamber ( 30   u ) and to stop movement of the piston ( 40   p ). 
         [0052]    The controller ( 16 ) can include instructions that instruct the piston ( 40   p ) to travel, subsequent to the first portion of the injection cycle, to a second position for a second portion of the injection cycle where a distal end ( 1155 ) of the valve pin ( 1041 ) is positioned relative to the gate such that flow of injection fluid ( 100   a,    100   b ) is selectively controlled. 
         [0053]    The instructions of the controller ( 16 ) preferably operate to drive the piston ( 40   p ) to the second position in response to receipt of a first trigger signal from the pressure sensor ( 603   e,    603   ec ) that is indicative of a first selected target pressure. 
         [0054]    The controller ( 16 ) can include instructions that instruct the piston ( 40   p ) to travel, subsequent to the second portion of the injection cycle, to a third position for a third portion of the injection cycle where a distal end ( 1155 ) of the valve pin ( 1041 ) is positioned relative to the gate such that flow of injection fluid ( 100   a,    100   b ) is selectively controlled. 
         [0055]    The instructions can operate to drive the piston ( 40   p ) to the third position in response to receipt of a second trigger signal from the pressure sensor ( 603   e,    603   ec ) that is indicative of a second selected target pressure. 
         [0056]    One or more of the second and third positions are preferably positions where a distal end ( 1155 ) of the valve pin ( 1041 ) is positioned relative to the gate such that flow of injection fluid ( 100   a,    100   b ) is not significantly restricted and injection fluid ( 100   a,    100   b ) flows at a relatively high speed or velocity or pressure at and through the gate or where the distal end ( 1155 ) of the valve pin ( 1041 ) is disposed axially intermediate a gate closed and a fully gate open position such that the end ( 1155 ) of the valve pin ( 1041 ) restricts or reduces rate or velocity of flow or pressure of the injection fluid ( 100   a,    100   b ) flowing through or exerted at the gate to a selected reduced velocity or pressure that is less than a maximum rate of flow or pressure. 
         [0057]    The controller ( 16 ) typically includes instructions that instruct the actuator ( 40   p ) to drive the valve pin ( 1041 ) upstream beginning from the gate closed position to the first position for the first portion of the injection cycle and subsequently to one or more of the second and third positions for the second and third portions of the injection cycle in response to receipt by the controller ( 16 )) of the first and second trigger signals. 
         [0058]    In another aspect of the invention there is provided a method of measuring pressure of an injection fluid material ( 100   a,    100   b ) comprising operating an assembly as described above. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0059]    The above and further advantages of the invention may be better understood by referring to the following description in conjunction with the accompanying drawings in which: 
           [0060]      FIG. 1  is a schematic of one embodiment of the invention showing a pair of sequential gates showing a first gate entering the center of a cavity having been opened and shown closed such that a first shot of fluid material has entered the cavity and traveled past the position of a second sequential gate, the second gate shown being open with its valve pin having traveled along an upstream restricted flow path RP allowing a second sequential shot of fluid material to flow into and merge with the first shot of material within the cavity; 
           [0061]      FIGS. 1A-1E  are schematic cross-sectional close-up views of the center and one of the lateral gates of the  FIG. 1  apparatus showing various stages of the progress of injection; 
           [0062]      FIG. 2A  is a schematic of one embodiment of the invention showing generically a hydraulically actuated valve pin in which at least one port of the actuator is connected to a flow restrictor  600  so as to restrict the flow of hydraulic drive fluid and slow the opening of the valve pin by a selected lessening of pin opening velocity by use of a controller interconnected to the flow restrictor, the controller enabling the user to select a percentage of predetermined full open position velocity that the hydraulic drive supply to the actuator normally operates at full open velocity drive fluid pressure, the controller instructing the restrictor valve to operate at less than full open velocity up until the valve pin reaches a predetermined upstream position at which point a position sensor signals the controller and the controller instructs the restrictor valve to open to a full open full velocity degree of openness position; 
           [0063]      FIG. 2AA  is a schematic cross-sectional view of a hydraulic valve and restrictor configuration used in the system of  FIG. 1  showing a metering restriction valve  600  disposed in the drive fluid flow line that interconnects the directional valve and the upper fluid chamber of the piston, and showing a pressure sensor connected to the controller and disposed in and sensing the pressure of metered hydraulic drive fluid as it exits the metering restrictor valve  600  and flow toward the directional valve during the withdrawal or upstream-cycle of the actuator  941 ; 
           [0064]      FIG. 2B  is a schematic of an alternative embodiment to the  FIG. 2A  system showing generically a hydraulically actuated valve and its interconnection to the hydraulic system and the control system for operating the restrictor valve  600  to cause the valve pin to withdraw at the beginning of a cycle at a predetermined reduced velocity for a predetermined amount of time subsequent to which the control system instructs the restrictor valve to open to a full open full velocity degree of openness position; 
           [0065]      FIGS. 3A-3B  show tapered end valve pin positions at various times and positions between a starting closed position as in  FIG. 3A  and various upstream opened positions, RP representing a selectable path length over which the velocity of withdrawal of the pin upstream from the gate closed position to an open position is reduced (via a controllable flow restrictor) relative to the velocity of upstream movement that the valve pin would normally have over the uncontrolled velocity path FOV when the hydraulic pressure is normally at full pressure and pin velocity is at its maximum; 
           [0066]      FIGS. 4A-4B  show a system having a valve pin that has a cylindrically configured tip end, the tips ends of the pins being positioned at various times and positions between a starting closed position as in  FIG. 4A  and various upstream opened positions, RP wherein RP represents a path of selectable length over which the velocity of withdrawal of the pin upstream from the gate closed position to an open position is reduced (via a controllable flow restrictor or electric actuator) relative to the velocity of upstream movement that the valve pin would normally have over the uncontrolled velocity path FOV when the hydraulic pressure of a hydraulic actuator is normally at full pressure and pin velocity is at its maximum; 
           [0067]      FIGS. 5A-5D  are a series of plots of pin velocity versus position each plot representing a different example of the opening of a gate lateral to a central gate via continuous upstream withdrawal of a valve pin at one rate or set of rates over an initial flow path RP and at another higher rate or set of rates of upstream withdrawal of the valve pin beginning at a pin position of FOP and beyond when the fluid material flow is typically at a maximum unrestricted rate of flow through the open gate without any restriction or obstruction from the tip end of the pin; 
           [0068]      FIG. 5AA  shows a plot corresponding to the velocity versus position plot of  FIG. 5A  of the metered pressure of drive fluid as sensed exiting metering restrictor valve  600  (in a configuration such as shown in  FIG. 2A ) versus upstream position of travel of the valve pin  1041  of actuator  941  beginning from a fully closed position at position zero where the; 
           [0069]    FIG.  5 AAA shows a plot also corresponding to the velocity versus position plot of  FIG. 5A  of the metered pressure of drive fluid as sensed exiting metering restrictor valve  600  (in a configuration such as shown in  FIG. 2A ) versus time of travel of the valve pin  1041  of actuator  941  beginning from a fully closed position at time zero; 
           [0070]      FIG. 5BB  shows a plot corresponding to the velocity versus position plot of  FIG. 5B  of the metered pressure of drive fluid as sensed exiting metering restrictor valve  600  (in a configuration such as shown in  FIG. 2A ) versus upstream position of travel of the valve pin  1041  of actuator  941  beginning from a fully closed position at position zero; 
           [0071]    FIG.  5 BBB shows a plot also corresponding to the velocity versus position plot of  FIG. 5B  of the metered pressure of drive fluid as sensed exiting metering restrictor valve  600  (in a configuration such as shown in  FIG. 2A ) versus time of travel of the valve pin  1041  of actuator  941  beginning from a fully closed position at time zero; 
           [0072]      FIGS. 6A-6B  show various embodiments of position sensors that can be used in a variety of  FIG. 2A  embodiments of the invention, the sensors shown in these figures being mounted so as to measure the position of the piston component of the actuator which is indicative of the position of the valve pin relative to the gate; 
           [0073]      FIGS. 6C-6D  show embodiments using limit switches that detect and signal specific positions of the actuator that can be used in a variety of  FIG. 2A  embodiments of the invention to determine velocity, position and switchover to higher openness of valve restrictor and/or upstream velocity of travel of the actuator and valve pin. 
           [0074]      FIG. 6E  is a schematic sectional view of a fluid driven actuator (hydraulic or pneumatic) showing the piston  40  of the actuator in its fully downstream position and the maximum upstream position MUP of the piston being such that the top upstream surface  40   e  of the piston  40  is spaced a minimum distance X from the inner upstream surface  20   uws  of the upstream wall  20   uw  of the actuator housing  20   h.    
           [0075]      FIGS. 7A-7D  show various examples of downstream velocity protocols for driving a valve pin from a maximum upstream position to a gate closed position. 
           [0076]      FIGS. 7E-7F  show examples of downstream and upstream drive pin position protocols.  FIG. 7E  shows a protocol for driving a pin beginning from a maximum upstream position at a full velocity downstream to a partially gate open position where the tip end of the pin is disposed at about 4 mm from the gate resulting in reduced injection fluid flow and finally driven downstream from the 4 mm position at a reduced velocity to the gate closed position. In the  FIG. 7E  embodiment the tip end of the pin is held or maintained in the partially gate open 4 mm position for a selected period of time from about 0.15 and about 0.26 seconds.  FIG. 7F  shows a protocol for driving a pin from gate closed downstream upstream at a reduced velocity to a partially gate open position where the tip end of the pin is disposed at about 2.5 mm from the gate resulting in reduced injection fluid flow through the gate and finally driven upstream to a maximum upstream position at either a reduced velocity (shown in solid line) or at full velocity (shown in dashed line). 
           [0077]      FIGS. 8A-8D  are a series of graphs representing actual pressure (versus target pressure) measured in four injection nozzles coupled to a manifold, such as in the apparatus of  FIG. 6 ; and 
           [0078]      FIG. 9  shows an interactive screen display of a user interface, such as that shown in  FIG. 1 , which screen is used to display, create, edit and store sensed pressures or target profiles or the like. 
       
    
    
     DETAILED DESCRIPTION 
       [0079]      FIG. 1  shows a system  10  with a central nozzle  22  feeding molten material  100   a ,  100   b  from an injection molding machine through a main inlet  18  to a distribution channel  19  of a manifold  40 . The distribution channel  19  commonly feeds three separate nozzles  20 ,  22 ,  24  which all commonly feed into a common cavity  30  of a mold  42 . One of the nozzles  22  is controlled by actuator  940  and arranged so as to feed into cavity  30  at an entrance point or gate that is disposed at about the center  32  of the cavity. As shown, a pair of lateral nozzles  20 ,  24  feed into the cavity  30  at gate locations that are distal  34 ,  36  to the center gate feed position  32 . 
         [0080]    As shown in  FIGS. 1, 1A  the injection cycle is a cascade process where injection is effected in a sequence from the center nozzle  22  first and at a later predetermined time from the lateral nozzles  20 ,  24 . As shown in  FIG. 1A  the injection cycle is started by first opening the pin  1040  of the center nozzle  22  and allowing the fluid material  100  (typically polymer or plastic material) to flow up to a position the cavity just before  100   b  the distally disposed entrance into the cavity  34 ,  36  of the gates of the lateral nozzles  24 ,  20  as shown in  FIG. 1A . After an injection cycle is begun, the gate of the center injection nozzle  22  and pin  1040  is typically left open only for so long as to allow the fluid material  100   b  to travel to a position just past  100   p  the positions  34 ,  36 . Once the fluid material has travelled just past  100   p  the lateral gate positions  34 ,  36 , the center gate  32  of the center nozzle  22  is typically closed by pin  1040  as shown in  FIGS. 1B, 1C, 1D and 1E . The lateral gates  34 ,  36  are then opened by upstream withdrawal of lateral nozzle pins  1041 ,  1042  as shown in  FIGS. 1B-1E . As described below, the rate of upstream withdrawal or travel velocity of lateral pins  1041 ,  1042  is controlled as described below. 
         [0081]    In alternative embodiments, the center gate  32  and associated actuator  940  and valve pin  1040  can remain open at, during and subsequent to the times that the lateral gates  34 ,  36  are opened such that fluid material flows into cavity  30  through both the center gate  32  and one or both of the lateral gates  34 ,  36  simultaneously. 
         [0082]    When the lateral gates  34 ,  36  are opened and fluid material NM is allowed to first enter the mold cavity into the stream  102   p  that has been injected from center nozzle  22  past gates  34 ,  36 , the two streams NM and  102   p  mix with each other. If the velocity of the fluid material NM is too high, such as often occurs when the flow velocity of injection fluid material through gates  34 ,  36  is at maximum, a visible line or defect in the mixing of the two streams  102   p  and NM will appear in the final cooled molded product at the areas where gates  34 ,  36  inject into the mold cavity. By injecting NM at a reduced flow rate for a relatively short period of time at the beginning when the gate  34 ,  36  is first opened and following the time when NM first enters the flow stream  102   p,  the appearance of a visible line or defect in the final molded product can be reduced or eliminated. 
         [0083]    The rate or velocity of upstream withdrawal of pins  1041 ,  1042  starting from the closed position is controlled via controller  16 ,  FIGS. 1, 2  which controls the rate and direction of flow of hydraulic fluid from the drive system  700  to the actuators  940 ,  941 ,  942 . As discussed in detail below, a predetermined profile of metered drive fluid pressure versus position of the valve pin or actuator piston (examples of which are shown in  FIGS. 5AA, 5BB ) or metered drive fluid pressure versus elapsed time (examples of which are shown in FIGS.  5 AAA,  5 BBB) is input into the controller as the basis for controlling withdrawal of the valve pin(s)  1041  et al. at a reduced velocity relative to one or more selected higher velocities of withdrawal. The higher velocity is typically selected to be the highest velocity at which the system is capable of driving the actuators. The controller  16  receives a signal in real time from a pressure sensor  603  (or  605 ,  607 ) disposed in the drive fluid line communicating with the exit of the metering valve  600 , the signal being indicative of the reduced drive fluid pressure in line  703  (or  705 ,  707 ). The controller  16  instructs the valve  600  to move to a degree of openness that causes the fluid pressure in the line to match the pressure of the predetermined profile at any given point in time or pin position along the pressure versus time profile (e.g. FIG.  5 AAA or  5 BBB) or pressure versus position profile ( FIG. 5AA or 5BB . The pressure in the exit line of the metering valve  600  is proportional and corresponds to the velocity of withdrawal movement of the actuator  941  ( 940 ,  942 ) and associated valve pin  1041  ( 1040 ,  1042 ). 
         [0084]    A “controller,” as used herein, refers to electrical and electronic control apparati that comprise a single box or multiple boxes (typically interconnected and communicating with each other) that contain(s) all of the separate electronic processing, memory and electrical signal generating components that are necessary or desirable for carrying out and constructing the methods, functions and apparatuses described herein. Such electronic and electrical components include programs, microprocessors, computers, PID controllers, voltage regulators, current regulators, circuit boards, motors, batteries and instructions for controlling any variable element discussed herein such as length of time, degree of electrical signal output and the like. For example a component of a controller, as that term is used herein, includes programs, controllers and the like that perform functions such as monitoring, alerting and initiating an injection molding cycle including a control device that is used as a standalone device for performing conventional functions such as signaling and instructing an individual injection valve or a series of interdependent valves to start an injection, namely move an actuator and associated valve pin from a gate closed to a gate open position. In addition, although fluid driven actuators are employed in typical or preferred embodiments of the invention, actuators powered by an electric or electronic motor or drive source can alternatively be used as the actuator component. 
         [0085]    As shown in  FIGS. 2A-2AA, 2B , a supply of hydraulic fluid  14  is fed first through a directional control valve  750  mechanism that switches the hydraulic fluid flow to the actuator cylinders in either of two directions: fluid out to withdraw the pin upstream,  FIG. 2A, 2AA . When a cycle is started, the directional configuration of the directional valve  750  of the hydraulic system  700  is switched by controller  16  to the configuration of  FIG. 2A or 2AA . The hydraulic system includes a flow restriction valve  600  that is controlled by controller  16  to vary the rate of flow of hydraulic fluid to the actuator  941 ,  951  to vary the rate of travel of the actuator  941 /valve pin  1041  upstream according to a predetermined pressure profile (e.g.  FIGS. 5AA ,  5 AAA,  5 BB,  5 BBB) or to drive the actuator  941 /valve pin  1041  downstream. Although not shown in  FIGS. 2A, 2B , the controller  16  and hydraulic system  700  can control the direction and rate of travel of the pistons of actuators  940  and  942  in a manner similar to the manner of control of actuator  941  via the connections shown in  FIG. 1 . 
         [0086]    The user programs controller  16  via data inputs on a user interface to instruct the hydraulic system  700  via control of the degree of openness of the restriction valve  600  to drive pins  1041 ,  1042  at an upstream velocity of travel that is reduced relative to a maximum velocity that the hydraulic system  700  can drive the pins  1041 ,  1042  to travel. The reduced velocity at which the actuator  941  and associated valve pin  1041  are driven is determined by a predetermined profile of reduced drive fluid pressures that is followed by the controller  16  based on the metered pressure exiting valve  600  that is sensed by sensor  603  in line  703  and sent to the controller  16  during an injection cycle, the controller  16  controlling the degree of openness of valve  600  which in turn controls the degree of pressure exiting valve  600  in line  703 . 
         [0087]    As described below, the controller  16  drives the actuator  941 /valve pin  1041  at the profile of reduced pin withdrawal rate or velocity either until a position sensor such as  951 ,  952  detects that an actuator  941 ,  952  or an associated valve pin (or another component), has reached a certain position (e.g. as in  FIGS. 5AA, 5BB ) as sensed by the position sensor  951 ,  952  such as at the end point COP, COP 2 ,  FIGS. 3B, 4B  of a restricted flow path RP, RP 2 , 
         [0088]    In an alternative embodiment, the user can program controller  16  via to instruct the hydraulic system  700  to drive pins  1041 ,  1042  at the profile of reduced velocity of upstream travel for a predetermined amount of time. In such an embodiment, the reduced pin withdrawal rate or velocity is executed for a preselected amount of time that is less than the time of the entire injection cycle, the latter part of the injection cycle being executed with the pins  1041 ,  1042  being withdrawn at a higher velocity typically the highest velocity at which the hydraulic system is capable of driving the pins  1041 ,  1042 . A typical amount of time over which the pins are instructed to withdraw at a reduced velocity is between about 0.25 and about 10 seconds, more typically between about 0.5 and about 5 seconds, the entire injection cycle time typically being between about 4 seconds and about 30 seconds, more typically between about 6 seconds and about 12 seconds. In such an embodiment, the periods of time over which the pins  1041 ,  1042  are withdrawn at reduced velocities are typically determined empirically by trial and error runs. One or more, typically multiple, trial injection cycle runs are carried out to make specimen parts from the mold. Each trial injection cycle run is carried out using a different period or periods of time at which the pins  1041 ,  1042  are withdrawn at one or more reduced velocities over the trial period(s) of time, and the quality of the parts produced from all such trial runs are compared to determine the optimum quality producing time(s) of reduced velocity pin withdrawals. When the optimum time(s) have been determined, the controller is programmed to carry out an injection cycle where the pin withdrawal velocities of pins  1041  are reduced for the predetermined amounts of time at the predetermined reduced withdrawal rates. 
         [0089]      FIG. 1  shows position sensors  950 ,  951 ,  952  for sensing the position of the actuator cylinders  941 ,  942 ,  952  and their associated valve pins (such as  1041 ,  1042 ,  1052 ) and feed such position information to controller  16  for monitoring purposes. As shown, fluid material  18  is injected from an injection machine into a manifold runner  19  and further downstream into the bores  44 ,  46  of the lateral nozzles  24 ,  22  and ultimately downstream through the gates  32 ,  34 ,  36 . When the pins  1041 ,  1042  are withdrawn upstream to a position where the tip end of the pins  1041  are in a fully upstream open position such as shown in  FIG. 1D , the rate of flow of fluid material through the gates  34 ,  36  is at a maximum. However when the pins  1041 ,  1042  are initially withdrawn beginning from the closed gate position,  FIG. 1A , to intermediate upstream positions,  FIGS. 1B, 1C , a gap  1154 ,  1156  that restricts the velocity of fluid material flow is formed between the outer surfaces  1155  of the tip end of the pins  1041 ,  1042  and the inner surfaces  1254 ,  1256  of the gate areas of the nozzles  24 ,  20 . The restricted flow gap  1154 ,  1156  remains small enough to restrict and reduce the rate of flow of fluid material  1153  through gates  34 ,  36  to a rate that is less than maximum flow velocity over a travel distance RP of the tip end of the pins  1041 ,  1042  going from closed to upstream as shown in  FIGS. 1, 1B, 1C, 1E and 3B, 4B . 
         [0090]    The pins  1041  can be controllably withdrawn at one or more reduced velocities (less than maximum) for one or more periods of time over the entirety of the length of the path RP over which flow of mold material  1153  is restricted. Preferably the pins are withdrawn at a reduced velocity over more than about 50% of RP and most preferably over more than about 75% of the length RP. As described below with reference to  FIGS. 3B, 4B , the pins  1041  can be withdrawn at a higher or maximum velocity at the end COP 2  of a less than complete restricted mold material flow path RP 2 . 
         [0091]    The trace or visible lines that appear in the body of a part that is ultimately formed within the cavity of the mold on cooling above can be reduced or eliminated by reducing or controlling the velocity of the pin  1041 ,  1042  opening or upstream withdrawal from the gate closed position to a selected intermediate upstream gate open position that is preferably 75% or more of the length of RP. 
         [0092]    RP can be about 1-8 mm in length and more typically about 2-6 mm and even more typically 2-4 mm in length. As shown in  FIG. 2  in such an embodiment, a control system or controller  16  is preprogrammed to control the sequence and the rates of valve pin  1040 ,  1041 ,  1042  opening and closing. The controller  16  controls the rate of travel, namely velocity of upstream travel, of a valve pin  1041 ,  1042  from its gate closed position for at least the predetermined amount of time that is selected to withdraw the pin at the selected reduced velocity rate. 
         [0093]    The velocity of withdrawal of the valve pins  1041 ,  1042  is determined by regulation of the flow of hydraulic drive fluid that is pumped from a supply  14  to the actuators  941 ,  942  through flow restrictor valve  600 ,  FIGS. 1, 2, 2A, 2B . When the flow restrictor valve  600  is completely open, namely 100% open, allowing maximum flow of the pressurized hydraulic fluid to the actuator cylinders, the valve pins  1041 ,  1042  are driven at a maximum upstream travel velocity. 
         [0094]    According to the invention, the degree of openness of the flow restrictor valve  600  is adjusted in response to sensing with sensors  603 ,  603   e,    603   ec ,  FIGS. 2A-2B ,  FIG. 6E  of the drive fluid pressure of the drive fluid that exits either restrictor valve  600  or that exits the upstream drive fluid chamber  30   u  of the actuator  20   a.  The controller  16  automatically adjusts the degree of openness of flow restrictor valve  600  to less than 100% open to cause the reduced pressure in line  703  to match and follow the predetermined profile of pressure shown for example in  FIGS. 5AA ,  5 AAA,  5 BB,  5 BBB which in turn adjusts rate and volume flow of pressurized hydraulic fluid to the actuator cylinders which in turn adjusts the velocity of upstream travel of the pins  1041 ,  1042  according to the predetermined exit pressure in line  703  for either a selected period of time as in FIG.  5 AAA or  5 BBB or until the actuator/valve pin has travelled upstream to a predetermined position as in  FIGS. 5AA, 5BB , the predetermined upstream position being sensed by a position sensor  951 ,  952 ,  950  and signalling controller  16 . Upon expiration of the predetermined amount of time (FIGS.  5 AAA,  5 BBB) or upon reaching the predetermined upstream position ( FIGS. 5AA, 5BB ), the controller  16  instructs the metering valve to open to a greater degree of openness to drive the actuator  941 /pin  1041  at a higher velocity typically to the highest degree of openness of the valve  600  and thus the highest possible velocity. 
         [0095]    In the  FIGS. 5AA, 5BB  embodiment, the actuator/valve pin travels the predetermined length of the reduced velocity path RP, RP 2 , at the end of which the position sensor signals the controller  16  whereby the controller  16  determines that the end COP, COP 2  has been reached and the valve  600  is opened to a higher velocity, typically to its 100% open position to allow the actuator pistons and the valve pins  1041 ,  1042  to be driven at maximum upstream velocity FOV in order to reduce the cycle time of the injection cycle. 
         [0096]    The valve  600  typically comprises a restrictor valve that is controllably positionable anywhere between completely closed (0% open) and completely open (100% open). Adjustment of the position of the restrictor valve  600  is typically accomplished via a source of electrical power that controllably drives an electromechanical mechanism that causes the valve to rotate such as a rotating spool that reacts to a magnetic or electromagnetic field created by the electrical signal output of the controller  16 , namely an output of electrical energy, electrical power, voltage, current or amperage the degree or amount of which can be readily and controllably varied by conventional electrical output devices. The electro-mechanism is controllably drivable to cause the valve  600  to open or close to a degree of openness that is proportional to the amount or degree of electrical energy that is input to drive the electro-mechanism. The velocity of upstream withdrawal travel of the pins  1041 ,  1042  are in turn proportional to the degree of openness of the valve  600 . Thus the rate of upstream travel of the pins  1041 ,  1042  is proportional to the amount or degree of electrical energy that is input to the electro-mechanism drives valves  600 . The electro-mechanism that is selected for driving the valve  600  establishes in the first instance the maximum amount of electrical energy or power (such as voltage or current) that is required to open the valve to its 100% open position. 
         [0097]    The user can implement a reduced upstream velocity of the pins  1041 ,  1042  over a given upstream length of travel or over a given amount of time by inputting to the controller  16  a profile of reduced exit fluid pressures that are implemented by adjusting the electrical drive mechanism that operates metering valve  600  to less than 100% of the maximum amount of electrical energy or power input (voltage or current) needed to open the valve  600  to 100% open at which setting maximum drive fluid pressure and, a fortiori, maximum actuator/pin velocity occurs. 
         [0098]    In one embodiment, the user can implement reduced actuator/pin withdrawal velocity profiles by inputting reduced exit pressure profiles (or other data corresponding thereto) versus actuator/pin position into the controller  16 . Exit pressure is the pressure of the valve drive fluid that exits either the metering valve  600  or the upstream drive chamber  30   u  of the actuator  20   a  during the upstream withdrawal portion of the injection cycle. In the examples provided, the exit pressure would be the pressure in one of lines  703 ,  705  or  707  as sensed by a respective one of sensors  603 ,  605 ,  607  or as sensed by a sensor  603   ec ,  603   e  in the actuator chamber  30   u,    30   s  or in the drive fluid line interconnecting and between the input port  600   p  of valve  600  and the drive chamber  30   u.  In another embodiment, the user can implement reduced actuator/pin withdrawal velocity profiles by inputting to the controller  16  reduced exit pressure profiles or other data corresponding thereto) versus time of withdrawal beginning from the time at which the gate is closed. 
         [0099]    The user can also preselect the length of the path of travel RP, RP 2  of the valve pin or other end of reduced velocity position of the valve pin or other component over the course of travel of which the material flow through the gate is restricted and input such selections into the controller  16 . In an alternative embodiment the user can preselect the length of time during which the gate is restricted by a valve pin travelling over a restricted path length RP, RP 2  and input such a selection into the controller  16 . 
         [0100]    The controller  16  includes conventional programming or circuitry that receives and executes the user inputs. The controller may include programming or circuitry that enables the user to input as a variable a selected pin velocity rather than a percentage of electrical output, the programming of the controller  16  automatically converting the inputs by the user to appropriate instructions for reduced energy input to the electro-mechanism that drives the valve  600 . 
         [0101]    Typically the user selects a profile of metered exit drive fluid pressures that corresponds to reduced pin withdrawal velocities that are less than about 90% of the maximum velocity (namely the velocity when the valve  600  is fully open), more typically less than about 75% of the maximum velocity and even more typically less than about 50% of the maximum velocity at which the pins  1041 ,  1042  are drivable by the hydraulic system. The actual maximum velocity at which the actuators  941 ,  942  and their associated pins  1041 ,  1042  are driven is predetermined by selection of the size and configuration of the actuators  20   a,    941 ,  942 , the size and configuration of the restriction valve  600  and the degree of pressurization and type of hydraulic drive fluid selected for use by the user. The maximum drive rate of the hydraulic system is predetermined by the manufacturer and the user of the system and is typically selected according to the application, size and nature of the mold and the injection molded part to be fabricated. 
         [0102]    As shown by the series of examples of programs illustrated in  FIGS. 5A, 5B, 5   c ,  5 D one or more profiles of reduced pin withdrawal velocity can be selected and the pin driven by restricted hydraulic fluid flow between the gate closed (X and Y axis zero position) and the final intermediate upstream open gate position (4 mm for example in the  FIG. 5A  example, 5 mm in the  FIG. 5B  example) at which point the controller  16  in response to position sensing instructs the drive system to drive pin  1041 ,  1042  to travel upstream at a higher, typically maximum, upstream travel velocity (as shown, 100 mm/sec in the  FIGS. 5A-5D  examples). In the  FIGS. 5A, 5B  examples, the profile of reduced pin velocity is selected as being about 50, 25 and 75 mm/sec over the initial reduced velocity path length. In practice the velocity of the pin may or may not be precisely known, the Y velocity axis of  FIGS. 5A, 5B  corresponding to the drive fluid pressure profile of  FIGS. 5AA ,  5 AAA,  5 BB,  5 BBB, the degree of precision in control over which depends and may vary slightly with the degree of precision in control over the opening of the flow restriction valve  600 ,  100  mm/sec corresponding to the valve  600  being completely 100% open (and pin being driven at maximum velocity); and 50 mm/sec corresponding to 50% electrical energy input to the electromechanism that drives the restriction valve  600  to one-half of its maximum 100% degree of openness. In the  FIG. 5A  example, the path length RP over which the valve pin  1041 ,  1042  travels at the reduced 50 mm/sec velocity is 4 mm. After the pin  1041 ,  1042  has been driven to the upstream position COP position of about 4 mm from the gate closed GC position, the controller  16  instructs the electro-mechanism that drives the valve  600  (typically a magnetic or electromagnetic field driven device such as a spool) to open the restrictor valve  600  to full 100% open at which time the pin (and its associated actuator piston) are driven by the hydraulic system at the maximum travel rate 100 mm/sec for the predetermined, given pressurized hydraulic system. 
         [0103]      FIGS. 5B-5D  illustrate a variety of alternative profiles for driving the pin  1041 ,  1042  at reduced velocities for various durations of time. For example as shown in  FIG. 5B , the pin is driven for 0.02 seconds at 25 mm/sec, then for 0.06 seconds at 75 mm/sec and then allowed to go to full valve open velocity shown as 100 mm/sec. Full valve open or maximum velocity is typically determined by the nature of hydraulic (or pneumatic) valve or motor drive system that drives the valve pin. In the case of a hydraulic (or pneumatic) system the maximum velocity that the system is capable of implementing is determined by the nature, design and size of the pumps, the fluid delivery channels, the actuator, the drive fluid (liquid or gas), the restrictor valves and the like. The velocity profiles shown in the plots or graphs of  FIGS. 5A, 5B, 5C, 5D  can be calculated, correlated and converted by the controller  16  to and from a corresponding profile of drive fluid pressures that are detected, recorded and monitored with respect to the metered pressure of actuator drive fluid that drives the actuators (hydraulic or pneumatic). 
         [0104]    As shown in  FIGS. 5A-5D , the velocity of the valve pin when the pin reaches the end of the reduced velocity period, the valve  600  can be instructed to assume the full open position essentially instantaneously or alternatively can be instructed to take a more gradual approach up, between 0.08 and 0.12 seconds, to the maximum valve openness as shown in  FIG. 5D . In an alternative pin movement protocol shown in  FIGS. 7E, 7F, 9A-9D, 10 , the tip end of the pin is driven either continuously upstream or continuously downstream with the tip end of the pin being held or maintained in a position intermediate the full open and gate closed positions for some selected period of time during the course of travel between full open and gate closed. In the  FIG. 10  protocol example the pin is held in an intermediate reduced injection flow position (a pack position) for between about 4 seconds and about 15.9 second. In the  FIG. 9A  protocol example the pin is held in an intermediate (pack) reduced injection fluid flow position for between about 3 seconds and about 6.39 seconds. In the  FIG. 7E  example protocol the pin is held in an intermediate reduced flow 4 mm position for between about 0.15 and about 0.26 seconds. In all cases the controller  16  instructs the valve pin  1041 ,  1042 ,  1040  to travel either (a) continuously upstream during the upstream travel portion of the cycle rather than follow a drive fluid pressure, pin position or injection fluid pressure profile where the pin might travel in a downstream direction during the course of the upstream travel portion of the injection cycle, or (b) continuously downstream during the downstream travel portion of the cycle rather than follow a profile where the pin travels upstream during the course of the downstream travel portion of the injection cycle. 
         [0105]    Most preferably, the actuator, valve pin, valves and fluid drive system are adapted to move the valve pin between a gate closed position and a maximum upstream travel position that defines an end of stroke position for the actuator and the valve pin. Most preferably the valve pin is moved at the maximum velocity at one or more times or positions over the course of upstream travel of the valve pin past the upstream gate open position. Alternatively to the hydraulic system depicted and described, a pneumatic or gas driven system can be used and implemented in the same manner as described above for a hydraulic system. 
         [0106]    Preferably, the valve pin and the gate are configured or adapted to cooperate with each other to restrict and vary the rate of flow of fluid material  1153 ,  FIGS. 3A-3B, 4A-4B  over the course of travel of the tip end of the valve pin through the restricted velocity path RP. Most typically as shown in  FIGS. 3A, 3B  the radial tip end surface  1155  of the end  1142  of pin  1041 ,  1042  is conical or tapered and the surface of the gate  1254  with which pin surface  1155  is intended to mate to close the gate  34  is complementary in conical or taper configuration. Alternatively as shown in  FIGS. 4A, 4B , the radial surface  1155  of the tip end  1142  of the pin  1041 ,  1042  can be cylindrical in configuration and the gate can have a complementary cylindrical surface  1254  with which the tip end surface  1155  mates to close the gate  34  when the pin  1041  is in the downstream gate closed position. In any embodiment, the outside radial surface  1155  of the tip end  1142  of the pin  1041  creates restricted a restricted flow channel  1154  over the length of travel of the tip end  1142  through and along restricted flow path RP that restricts or reduces the volume or rate of flow of fluid material  1153  relative to the rate of flow when the pin  1041 ,  1042  is at a full gate open position, namely when the tip end  1142  of the pin  1041  has travelled to or beyond the length of the restricted flow path RP (which is, for example the 4 mm upstream travel position of  FIGS. 5A-5C ). 
         [0107]    In one embodiment, as the tip end  1142  of the pin  1041  continues to travel upstream from the gate closed GC position (as shown for example in  FIGS. 3A, 4A ) through the length of the RP path (namely the path travelled for the predetermined amount of time), the rate of material fluid flow  1153  through restriction gap  1154  through the gate  34  into the cavity  30  continues to increase from 0 at gate closed GC position to a maximum flow rate when the tip end  1142  of the pin reaches a position FOP (full open position),  FIGS. 5A-5D , where the pin is no longer restricting flow of injection mold material through the gate. In such an embodiment, at the expiration of the predetermined amount of time when the pin tip  1142  reaches the FOP (full open) position  FIGS. 5A, 5B , the pin  1041  is immediately driven by the hydraulic system at maximum velocity FOV (full open velocity) typically such that the restriction valve  600  is opened to full 100% open. 
         [0108]    In embodiments, where the tip  1142  has reached the end of restricted flow path RP 2  and the tip  1142  is not necessarily in a position where the fluid flow  1153  is not still being restricted, the fluid flow  1153  can still be restricted to less than maximum flow when the pin has reached the changeover position COP 2  where the pin  1041  is driven at a higher, typically maximum, upstream velocity FOV. In the examples shown in the  FIGS. 3B, 4B  examples, when the pin has travelled the predetermined path length at reduced velocity and the tip end  1142  has reached the changeover point COP, the tip end  1142  of the pin  1041  (and its radial surface  1155 ) no longer restricts the rate of flow of fluid material  1153  through the gap  1154  because the gap  1154  has increased to a size that no longer restricts fluid flow  1153  below the maximum flow rate of material  1153 . Thus in one of the examples shown in  FIG. 3B  the maximum fluid flow rate for injection material  1153  is reached at the upstream position COP of the tip end  1142 . In another example shown in  FIG. 3B   4 B, the pin  1041  can be driven at a reduced velocity over a shorter path RP 2  that is less than the entire length of the restricted mold material flow path RP and switched over at the end COP 2  of the shorter restricted path RP 2  to a higher or maximum velocity FOV. In the  FIGS. 5A, 5B  examples, the upstream FOP position is about 4 mm and 5 mm respectively upstream from the gate closed position. Other alternative upstream FOP positions are shown in  FIGS. 5C, 5D . 
         [0109]    In another alternative embodiment, shown in  FIG. 4B , the pin  1041  can be driven and instructed to be driven at reduced or less than maximum velocity over a longer path length RP 3  having an upstream portion UR where the flow of injection fluid mold material is not restricted but flows at a maximum rate through the gate  34  for the given injection mold system. In this  FIG. 4B  example the velocity or drive rate of the pin  1041  is not changed over until the tip end of the pin  1041  or actuator  941  has reached the changeover position COP 3 . In this embodiment, a position sensor senses either that the valve pin  1041  or an associated component has travelled the path length RP 3  or reached the end COP 3  of the selected path length and the controller receives and processes such information and instructs the drive system to drive the pin  1041  at a higher, typically maximum velocity upstream. In another alternative embodiment, the pin  1041  can be driven at a less than maximum velocity throughout the entirety of the travel path of the pin during an injection cycle from the gate closed position GC up to the end-of-stroke EOS position, the controller  16  being programmed to instruct the drive system for the actuator to be driven at one reduced velocity for an initial path length or period of time and at another less than maximum velocity subsequent to the intial reduced velocity path or period of time for the remainder of the injection cycle whereby the actuator/valve pin travels at a less than maximum velocity for an entire closed GC to fully open EOS cycle. 
         [0110]    In the  FIGS. 5A-5D  examples, FOV is 100 mm/sec. Typically, when the time period or path length for driving the pin  1041  at reduced velocity has expired or been reach and the pin tip  1142  has reached the position COP, COP 2 , the restriction valve  600  is opened to full 100% open velocity FOV position such that the pins  1041 ,  1042  are driven at the maximum velocity or rate of travel that the hydraulic system is capable of driving the actuators  941 ,  942 . Alternatively, the pins  1041 ,  1042  can be driven at a preselected FOV velocity that is less than the maximum velocity at which the pin is capable of being driven when the restriction valve  600  is fully open but is still greater than the selected reduced velocities that the pin is driven over the course of the RP, RP 2  path to the COP, COP 2  position. 
         [0111]    At the expiration of the predetermined reduced velocity drive time, the pins  1041 ,  1042  are typically driven further upstream past the COP, COP 2  position to a maximum end-of-stroke EOS position. The upstream COP, COP 2  position is downstream of the maximum upstream end-of-stroke EOS open position of the tip end  1142  of the pin. The length of the path RP or RP 2  is typically between about 2 and about 8 mm, more typically between about 2 and about 6 mm and most typically between about 2 and about 4 mm. In practice the maximum upstream (end of stroke) open position EOS of the pin  1041 ,  1042  ranges from about 8 mm to about 18 inches upstream from the closed gate position GC. 
         [0112]    The controller  16  includes a processor, memory, user interface and circuitry and/or instructions that receive and execute the user inputs of percentage of maximum valve open or percentage of maximum voltage or current input to the motor drive for opening and closing the restriction valve, time duration for driving the valve pin at the selected valve openings and reduced velocities. 
         [0113]    With regard to embodiments where the use of a position sensor is employed,  FIGS. 6A-6D  show various examples of position sensors  100 ,  114 ,  227 ,  132  the mounting and operation of which are described in U.S. Patent Publication no. 20090061034 the disclosure of which is incorporated herein by reference. As shown the position sensor of  FIGS. 6A and 6B  for example can track and signal the position of the piston of the actuator piston  223  continuously along its entire path of travel from which data pin velocity can be continuously calculated over the length of RP, RP 2 , RP 3  via spring loaded follower  102  that is in constant engagement with flange  104  during the course of travel of piston  223 . Mechanism  100  constantly sends signals to controller  16  in real time to report the position of pin  1041  and its associated actuator.  FIGS. 6C, 6D  show alternative embodiments using position switches that detect position at specific individual positions of the actuator and its associated valve pin  1041 . The  FIG. 6C  embodiment uses a single trip position switch  130   a  with trip mechanism  133  that physically engages with the piston surface  223   a  when the piston  223  reaches the position of the trip mechanism  133 . The  FIG. 6D  embodiment shows the use of two separate position switches  130   a,    130   aa  having sequentially spaced trips  133   aa  and  133   aaa  that report the difference in time or distance between each trip engaging surface  223   a  of the piston, the data from which can be used by controller  16  to calculate velocity of the actuator based on the time of travel of the actuator from tripping one switch  130   a  and then tripping the next  130   aa . In each embodiment the position switch can signal the controller  16  when the valve pin  1041 ,  1042  has travelled to one or more selected intermediate upstream gate open positions between GC and RP, RP 2  or RP 3  so that the velocity of the pin can be adjusted to the selected or predetermined velocities determined by the user. As can be readily imagined other position sensor mechanisms can be used such as optical sensors, sensors that mechanically or electronically detect the movement of the valve pin or actuator or the movement of another component of the apparatus that corresponds to movement of the actuator or valve pin. 
         [0114]      FIG. 6E  illustrates in greater detail in schematic cross section an embodiment where a fluid pressure sensor  603   ec  is disposed such that the sensor  603   ec  measures the pressure of actuator drive fluid disposed in the upstream drive chamber  30   us  of fluid driven actuator. In the  FIG. 6E  embodiment the actuator  20   a  (corresponding to actuators  940 ,  941 ,  942 ) has a pressure sensor  603   ec  that is mounted to the actuator housing  20   h  in an arrangement where the pressure sensing surface  603   ecs  of the sensor  603   ec  extends through the housing  20   h  to make contact with and measure the pressure of drive fluid DF that resides in the interior volume or space  30   s  of the upper drive chamber as well as drive fluid that resides within the fluid flow line  704  that extends and interconnects between the upstream chamber port  50  of the drive chamber  30   u  and the entry port  600   p  to the restriction valve  600 . 
         [0115]    The actuator  20   a  as shown comprises a housing  20   h  and a piston  40  having an O-ring or other fluid seal mechanism  120  mounted in a circumferential groove formed in the circumferential surface of the piston head that extends around the circumference of the piston  40 . The O-ring or fluid seal mechanism  120  is typically comprised of a highly friction resistant polymeric material that is resiliently compressible. The O-ring or seal  120  is formed and adapted to be seated within a complementary groove such that the O-Ring compressibly engages against the inner wall surface  30   w  of chamber  30  to form a circumferential seal surface PS that forms two opposing fluid sealed upstream chamber  30   u  and downstream chamber  30   d  within master chamber  30 . The upstream drive chamber  30   u  is interconnected to and communicates with a source of pressurized fluid  200   f  (typically hydraulic oil or gas such as air) via fluid delivery ports  50 ,  52  which when pumped into chamber  30   u  exerts a downstream force  200  on the upstream end  40   e  of piston  40 . Piston  40  can conversely be driven upstream by pumping pressurized hydraulic fluid  200   f  through ports  60 ,  62  into downstream chamber  30   d  thus exerting upstream drive force  150  on the downstream surface  40   d  of the piston  40 . 
         [0116]    As shown in  FIGS. 2A, 2AA, 2B , a fluid pressure sensor  603   e  can alternatively be mounted such that the sensing surface of the sensor  603   e  is disposed within the drive fluid flow channel  704  that extends between and interconnects the exit  50  of the upper actuator drive chamber  30   u  and the entry port  600   p  of the restrictor valve  600  thus sensing and measuring the pressure of the drive fluid disposed within the upstream drive fluid flow channel  704 , the sensed pressure of the drive fluid DF therein being indicative of the pressure of the injection fluid  100   a,    100   b  resident within the cavity and exerting pressure IFUP on the distal tip end of the valve pin  1041 . In the  FIGS. 2A, 2AA, 2B  embodiment, as in the  FIG. 6E  embodiment, the restriction valve  600  is first closed such the drive fluid DF remains static under pressure within the flow channel  704 , and the sensor  603   e  senses the pressure of the static drive fluid DF which is indicative of the pressure IFUP of the injection fluid  100   a,    100   b  exerted on the tip end  1142  of the valve pin  1041 . 
         [0117]    In the  FIGS. 2A, 2AA, 2B and 6E  embodiments, the pressure sensor  603   e ,  603   ec  senses the pressure of the drive fluid DF that has exited drive fluid chamber  30   u  and is indicative of pressure of drive fluid DF that is resident either within the upstream piston drive chamber  30   u  or at any position within the flow channel  704  between the upstream position drive chamber  30   u  and the inlet port  600   p,    FIG. 6E , of the metering valve  600  to which the piston drive chamber  30   u  is sealably interconnected. 
         [0118]    In these embodiments, the fluid pressure that the sensors  603   e,    603   ec  are sensing is more accurately indicative of the injection fluid pressure IFUP of the injection fluid  100   a,    100   b  that is being exerted on the tip end  1142  of the valve pin  1041  by the injection fluid during the course of the injection fluid. Fluid pressure that is disposed in the exiting drive fluid stream that is upstream of the metering valves  600  that is sensed by the sensors  603 ,  605 ,  705  does not account accurately for the injection fluid pressure IFUP exerted on the drive fluid pressure through the valve pin in the same manner as the sensors  603   e  or  603   ec detect such pressure in the drive fluid that is resident in the upper drive chamber  30   u  or fluid flow channel  704  that is downstream of the port  600   p  to a restrictor valve  600 . 
         [0119]    In the  FIGS. 6E, 2A, 2AA, 2BB  embodiments, the controller  16  is programmed to drive the piston  40   p  of an actuator  940 ,  941  for a preselected portion of the duration of the injection cycle to a preselected maximum upstream position where the upstream surface  40   e ′ of the piston  40  is spaced a minimum axial distance X greater than about 0.05 mm, preferably between about 0.25 mm and about 1.0 mm, most preferably between about 0.25 mm and about 0.5 mm downstream from the inner upstream surface  20   uws  of the upstream wall  20   uw  of the actuator housing  20   h  or chamber  30   u.  In such an embodiment the piston  40   p,    FIG. 6E  is driven upstream from a gate closed position to an axial position that is close to its fully upstream position, the controller  16  being programmed to stop the upstream travel of the piston  40   p  such that the top surface  40   e ′ of the piston  40   p  is always spaced during the entire course or duration of the injection cycle at least a minimum axial distance X away from the inner surface  20   uws  of the top wall  20   uw  such that a relatively small volume of drive fluid DF is maintained resident within an interior volume or space  30   s  of the upper drive chamber  30   u,  typically during the entire course of an injection cycle. In such an embodiment the pressurized drive fluid DF (hydraulic or pneumatic) that resides within the relatively small space  30   s  is static and is not exiting FEX or flowing through the restriction valve  600 . In this embodiment, a fluid pressure is maintained within the space  30   s  during the entire course of the injection cycle such that the sensors  603   e  or  603   ec  are capable of sensing a drive fluid pressure and sending data signal PS to the controller  16  that is indicative of the pressure of drive fluid DF that resides in the upper piston chamber  30   u.    
         [0120]    In the  FIGS. 2A, 2AA, 2B, 6E  embodiments, the piston  40   p  is withdrawn at the start of the cycle from a gate closed position where the distal end  1155  of the valve pin  1041  obstructs flow through the gate upstream to an axial position where the upstream end  40   e ′ is spaced the preselected axial distance X from the inner undersurface  20   uws  of the housing  40   h.  The piston  40   p  is held or maintained stationary in this position as instructed by controller  16  by instructing the valve  600  to close for a preselected portion of the duration of the injection cycle such that the top end surface  40   e ′ of the piston does not engage the undersurface  20   uws  of the housing at any time during the entire course of the duration of the injection cycle. Thus in such an embodiment, the preselected portion of the duration of the injection cycle is selected such that the upper surface  40   e  of the piston never travels fully upstream into engagement with the undersurface  20   uws  of the housing during the entire course of the injection cycle. 
         [0121]    In an alternative embodiment, the controller  16  can instruct the piston  40   p  to travel fully upstream into engagement with the undersurface  20   uws  subsequent to a preselected portion of the duration of the injection cycle where the valve  600  is closed and the piston  40   p  is held stationary in a position where the preselected axial distance X discussed above is maintained between the piston surface  40   e  and the undersurface  20   uws . Thus in such an alternative embodiment, the controller  16  can include instructions that instruct the piston  40   p  to be driven completely upstream at some point during the course of an injection cycle to a position where the top surface  40   e ′ engages the undersurface  20   uws  where all of the drive fluid is driven out FEX of the upper chamber  30   u  and through valve  600  after the piston  40   p  has previously been instructed to remain stationary at a position spaced X distance as described above for a preselected portion of the duration of the injection cycle. 
         [0122]    The program of the controller  16  can include instructions that instruct the piston  40   p  to travel, subsequent to instructing the piston  40   p  to travel to and be held for the selected period of time in the static position where the top surface  40   e ′ is maintained at the distance X from undersurface  20   uws , to another (second) subsequent preselected axial position for another subsequent preselected period of time. Such a subsequent axial position can be selected to be a “fill” position where the distal end  1155  of the valve pin  1041  is positioned relative to the gate such that flow of injection fluid  100   a,    100   b  is not significantly restricted and injection fluid  100   a,    100   b  flows at a relatively high speed or velocity or pressure at and through the gate. Such a fill position can be selected so that injection fluid flows at the maximum velocity or pressure under or to which the drive fluid pump system is capable of pumping the drive fluid. The instructions typically execute the instruction to drive the piston to the second subsequent preselected axial position in response to receipt of a signal from the pressure sensor  603   e,    603   ec  when the sensed signal matches a preselected target or trigger pressure that is typically preselected by a user and stored within a memory of the controller  16 . The controller includes instructions that automatically compare the received pressure sensor  803   e,    603   ec  signal to the stored target or trigger pressure and carry out instruction to drive the piston to the second subsequent preselected axial position. 
         [0123]    Another (second or third) subsequent axial position that the piston can be driven to can be selected to be a “pack position” where the distal end  1155  of the valve pin is disposed axially intermediate the gate closed and fully gate open positions such that the end  1155  of the valve pin  1041  restricts or reduces the rate or velocity of flow or the pressure of the injection fluid  100   a,    100   b  flowing through or exerted at the gate to a “pack rate” or “pack pressure” or some selected reduced velocity or pressure that is less than the fill rate or fill pressure. A pack rate of flow or pack pressure is typically selected such that the flow or pressure of injection fluid at or through the gate operates to prevent the injection fluid  100   a,    100   b  from shrinking after the injection fluid  100   a,    100   b  has travelled through the gate into the cavity and has begun to cool or has cooled down within the cavity. The instructions typically execute the instruction to drive the piston to the second or third subsequent preselected axial position in response to receipt of a signal from the pressure sensor  603   e,    603   ec  when the sensed signal matches another (second or third) preselected target or trigger pressure that is typically preselected by a user and stored within a memory of the controller  16 . The controller includes instructions that automatically compare the received pressure sensor  803   e,    603   ec  signal to the stored (second or third) target or trigger pressure and carry out instruction to drive the piston to the another (second or third) subsequent preselected axial position. 
         [0124]    Control over the withdrawal (upstream) velocity of actuator or pin movement can be accomplished by controlling the degree of fluid pressure that exits the metering valve  600  which in turn is controlled by controlling the degree of openness of the fluid restriction valve  600 . A profile of exit fluid pressures versus time or pin position is determined in advance and input to the controller which includes a program and instructions that automatically adjust the position of valve  600  based on the real time pressure signal received from sensor  603  (or  605  or  607 ) to adjust the exit pressure of the drive fluid in line  703  (or  705  or  707 ) which in turn adjusts the rate or velocity of upstream movement of the actuator  941 /valve pin  1041  (and/or actuators  1040 ,  1042  and valve pins  940 ,  942 ). 
         [0125]    In an alternative embodiment, the actuators can be controlled to cause the valve pins  1041 ,  1042 ,  1043  to travel beginning from an upstream gate open position (such as the maximum upstream position), downstream at a reduced velocity for one or more portions of the downstream path of travel from the gate open to the gate closed position. Controller  16  or  176  can also include an interface that enables the user to input any selected degree of electrical energy or power needed to operate the motors  940 ,  941 ,  942  at less than full speed any portion or all of the downstream portion of an injection cycle as shown and described with reference to  FIGS. 7A-7D . Thus the user can select a reduced downstream velocity of the pins  1041 ,  1042  over any selected portions of the pin path length from fully closed to fully open such as in  FIGS. 5A-5D  and vice versa between fully open and fully closed such as shown in  FIGS. 7A-7D  by inputting to the controller  16  or  176  the necessary data to control the motors. Most preferably the reduced velocity drive of the valve pin  1041 ,  1042 ,  1043  is selected to occur over the course of travel the tip end of the pin through all or a portion of the length of a restricted flow path RP 1 , RP 2 , RP 3 . 
         [0126]    The user inputs such selections into the controller  16  or  176 . Where a position sensor and a protocol for selection of the velocities over selected path lengths is used, the user also selects the length of the path of travel RP, RP 2  of the valve pin or the position of the valve pin or other component over the course of travel of which the valve  600  is to be maintained partially open and inputs such selections into the controller  16  or  176 . The controller  16  or  176  includes conventional programming or circuitry that receives and executes the user inputs. The controller may include programming or circuitry that enables the user to input as a variable a selected pin velocity rather than a degree of electrical energy input to the motors, the programming of the controller  16  automatically converting the inputs by the user to appropriate instructions for reduced energy input to the motors at appropriate times and pin positions as needed to carry out a pin profile such as in  FIGS. 5 a   - 5 D and  7 A- 7 D. 
         [0127]    Typically the user selects one or more reduced pin velocities that are less than about 90% of the maximum velocity at which the motors  940 ,  941 ,  942  can drive the pins, more typically less than about 75% of the maximum velocity and even more typically less than about 50% of the maximum velocity at which the pins  1041 ,  1042  are drivable by the electric motors. The actual maximum velocity at which the actuators  941 ,  942  and their associated pins  1041 ,  1042  are driven is predetermined by selection of the size and configuration of the actuators  941 ,  942 . The maximum drive rate of the motors  940 ,  941 ,  942  is predetermined by the manufacturer and the user of the motors and is typically selected according to the application, size and nature of the mold and the injection molded part to be fabricated. 
         [0128]    In one embodiment, after the pins  1041  have been withdrawn upstream to an upstream position where the flow of injection fluid material is no longer restricted (and thus at maximum flow rate), the pins  1041  can be withdrawn at maximum rate of upstream travel or velocity in order to shorten the injection cycle time. Alternatively, when the pins  1041  have been withdrawn to a position upstream where maximum injection flow rate is occurring, the pins  1041  can continue to be withdrawn at a reduced rate of travel or velocity to ensure that injection fluid does not flow through the gates  34  at a rate that causes a defect in the molded part. 
         [0129]    Similarly, on downstream closure of the pins  1041  after they have reached their maximum upstream withdrawal positions, the rate of travel of the pins is preferably controlled by controller  176  such that the pins  1041  travel downstream to a fully gate closed position at a reduced rate of travel or velocity that is less than the maximum rate of downstream travel or velocity over some portion or all of the stroke length between fully upstream and closed. 
         [0130]    Graphs such as shown in  FIGS. 8A-8D  can be generated on a user interface so that a user can observe the tracking of actual pressure of the injection fluid associated with a nozzle or valve versus a preselected target pressure during the injection cycle in real time, or after the cycle is complete. The injection fluid pressure profiles shown in the plots or graphs of  FIGS. 8A-8D, 10  can be calculated, correlated and converted by the controller  16  to and from a corresponding profile of drive fluid pressures that are detected and recorded with respect to the metered pressures of the actuator drive fluid that drives the actuators (hydraulic or pneumatic). 
         [0131]    The four different graphs of  FIGS. 8A-8D  show four examples of independent target pressure profiles (“desired”) emulated by the injection fluid pressure associated with four individual nozzles (typically injection fluid pressure recorded and detected by a pressure sensor that is disposed to sense pressure within a mold cavity  30  downstream of one or more selected gates  32 ,  34 ,  36  of one or more nozzles or injection fluid pressure as detected and recorded within the flow channel  42 ,  44 ,  46  of a nozzle  20 ,  22 ,  24 . Different target profiles can be desirable to uniformly fill different sized individual cavities associated with each nozzle, or to uniformly fill different sized sections of a single cavity. Graphs such as these can be generated with respect to any of the previous embodiments described herein. 
         [0132]    In the  FIGS. 8A-8D  embodiments, a valve pin  1041 ,  1042 ,  1043  is controllably driven to reside, remain or be disposed for some selected period of time in a single steady position  1235 ,  FIG. 8A, 1237 ,  FIG. 8B, 1239 ,  FIG. 8C, 1241 ,  FIG. 8D  during the course of the injection cycle. The pressure of the injection fluid associated with the particular nozzle (whether recorded within the cavity  30  or within the nozzle channel  42 ,  44 ,  46  or within a manifold channel) can be preselected and programmed to remain steady at a pressure  1235 ,  1237 ,  1239 ,  1241  that is selected to be reduced or less than the maximum or high pressure that occurs when the valve pins are in a fully gate open position FOP. Such reduced pressure  1235 ,  1237 ,  1239 ,  1241  is achieved by programming the controller  16  to move the valve pin  1041 ,  1042 ,  1040  to a position within a path of travel RP 1 , RP 2 , RP 3  where flow of injection fluid through a gate  32 ,  34 ,  36  is reduced as described above. As with all other embodiments, in the embodiments of  FIGS. 8A, 8B, 8C, 8D  the valve pin  1041 ,  1042 ,  1040  is driven continuously either upstream or downstream without ever being driven downstream for any significant period of time during the upstream portion of the cycle and without ever being driven upstream for any significant period of time during the downstream portion of the cycle. 
         [0133]    In the  FIG. 8A  example, the valve pin associated with graph  1235  is opened sequentially at 0.5 seconds after the valves associated with the other three graphs ( 1237 ,  1239  and  1241 ) were opened at 0.00 seconds. At approximately 6.25 seconds, at the end of the injection cycle, all four valve pins are back in the closed position. During injection (for example, 0.00 to 1.0 seconds in  FIG. 8B ) and pack (for example, 1.0 to 6.25 seconds in  FIG. 8B ) portions of the graphs, each valve pin is controlled to a plurality of positions to alter the pressure sensed by the pressure transducer associated therewith to track the target pressure. 
         [0134]    Through a user interface,  FIG. 9 , target profiles can be designed, and changes can be made to any of the target profiles using standard (e.g., windows-based) editing techniques. The profiles are then used by controller  1016  to control the position of the valve pin. For example,  FIG. 9  shows an example of a profile creation and editing screen  1300  generated on a user interface. 
         [0135]    Screen  1300 ,  FIG. 9 , is generated by a windows-based application performed on the user interface, e.g., any of the user interfaces  21  shown in  FIG. 1 . Alternatively, this screen display could be generated on an interface associated with the controller (e.g., display  71  associated with controller  8  in  FIG. 1 ). Interactive screen  1300  provides a user with the ability to create a new target profile or edit an existing target profile for any given nozzle and cavity associated therewith. 
         [0136]    A profile  1310  includes (x, y) data pairs, corresponding to time values  1320  and pressure values  1330  which represent the desired pressure sensed by the pressure transducer for the particular nozzle being profiled. The screen shown in  FIG. 9  is shown in a “basic” mode in which a limited group of parameters are entered to generate a profile. For example, in the foregoing embodiment, the “basic” mode permits a user to input start time displayed at  1340 , maximum fill pressure displayed at  1350  (also known as injection pressure), the start of pack time displayed at  1360 , the pack pressure displayed at  1370 , and the total cycle time displayed at  1380 . 
         [0137]    The screen also allows the user to select the particular valve pin they are controlling displayed at  1390 , and name the part being molded displayed at  1400 . Each of these parameters can be adjusted independently using standard windows-based editing techniques such as using a cursor to actuate up/down arrows  1410 , or by simply typing in values on a keyboard. As these parameters are entered and modified, the profile will be displayed on a graph  1420  according to the parameters selected at that time. 
         [0138]    By clicking on a pull-down menu arrow  1391 , the user can select different nozzle valves in order to create, view or edit a profile for the selected nozzle valve and cavity associated therewith. Also, a part name  1400  can be entered and displayed for each selected nozzle valve. 
         [0139]    The newly edited profile can be saved in computer memory individually, or saved as a group of profiles for a group of nozzles that inject into a particular single or multi-cavity mold. To create a new profile or edit an existing profile, first the user selects a particular nozzle valve of the group of valves being profiled. The valve selection is displayed at  1390 . The user inputs an alpha/numeric name to be associated with the profile being created, for family tool molds this may be called a part name displayed at  1400 . The user then inputs a time displayed at  1340  to specify when injection starts. A delay can be with particular valve pins to sequence the opening of the valve pins and the injection of melt material into different gates of a mold. 
         [0140]    The user then inputs the fill (injection) pressure displayed at  1350 . In the basic mode, the ramp from zero pressure to max fill pressure is a fixed time, for example, 0.3 seconds. The user next inputs the start pack time to indicate when the pack phase of the injection cycle starts. The ramp from the filling phase to the packing phase is also fixed time in the basic mode, for example, 0.3 seconds. 
         [0141]    The final parameter is the cycle time which is displayed at  1380  in which the user specifies when the pack phase (and the injection cycle) ends. The ramp from the pack phase to zero pressure may be instantaneous when a valve pin is used to close the gate, or slower in a thermal gate due to the residual pressure in the cavity which will decay to zero pressure once the part solidifies in the mold cavity. 
         [0142]    User input buttons  1415  through  1455  are provided for purposes of enabling the user to save and load target profiles. Button  1415  permits the user to close the screen. When this button is clicked, the current group of profiles will take effect. Cancel button  1425  is used to ignore current profile changes and revert back to the original profiles and close the screen. Read Trace button  1435  is used to load an existing and saved target profile from memory. The profiles can be stored in memory contained in one or more of the operator interface  21 , in random access or permanent memory contained in the controller. Save trace button  1440  is provided for purposes of enabling a user to save the current profile. Read group button  1445  is provided for purposes of enabling a user to load an existing profile or set of profiles. Save group button  1450  is provided for purposes of enabling a user to save the current group of target profiles for a group of nozzle valve pins. The process tuning button  1455  is provided for purposes of enabling a user to change the settings (for example, the gains) for a particular nozzle valve in a control zone. Also displayed is a pressure range  1465  for the injection molding application. 
         [0143]    In a preferred embodiment, the controller ( 16 ) includes instructions that instruct the actuator piston  40   p,    FIG. 6E , to first drive the valve pin ( 1041 ) upstream beginning from the gate closed position at high velocity to the first position at pressure  1311  (sensed drive fluid pressure or injection fluid pressure correlated to drive fluid pressure),  FIG. 9 , where the top end surface  40   e ′ of the piston  40   p,    FIG. 6E , is disposed close to the undersurface  20   uws  of the housing  20   h,  such as for example a selected axial distance X of between about 0.1 and about 2 mm, at which first position the distal end  1155  of the pin  1041  does not significantly restrict flow of injection fluid  100   a,    100   b  through the gate and the pressure of the injection fluid is at maximum or close to maximum of about 15,000 psi as shown in  FIG. 9 . The X axis pressure scale shown in  FIG. 9  can be recorded and displayed in the interface display shown in  FIG. 9  either as the pressure of the drive fluid DF that is sensed by sensors  603   ec  or  603   e  or as a pressure correlated from the drive fluid pressure to the pressure of the injection fluid  100   a,    100   b.  Thus, use of the sensors  603   ec ,  603   e  to measure pressure of the drive fluid DF can obviate the need for use of separate sensors that sense the pressure of the injection fluid  100   a,    100   b  directly within the injection fluid flow channels  42 ,  44 ,  46  or within the cavity  30 . 
         [0144]    One example of the use of such a pressure detection system is where at the start of the injection cycle when the piston  40   p  is disposed in the fully downstream gate closed position  40   gc ,  FIG. 6E , the restriction valve  600  is fully opened for approximately 0.5 seconds such that the piston  40   p  moves to the upstream (first) position shown in  FIG. 6E  where the top surface  40   e  is moved to a position  40   e ′ that is spaced the selected distance X from the undersurface  20   uws . The precise position of the piston  40   p  at the selected axially spaced distance X can be monitored and detected by a position sensor as described above, or as described in U.S. Pat. No. 9,144,929, the disclosure of which is incorporated by reference in its entirety herein. When the position of the piston  40   p  has reached the first selected axially spaced position, namely the  40   e ′ from  20   uws  by X mm position, the restrictor valve  600  is closed, the drive fluid DF in upper chamber  30  is static, and the piston  40   p  is held stationary while the pressure of the drive fluid DF is monitored by sensor  603   ec  or  603   e.  The piston  40   p  is held stationary for the first period of time, a first portion of the duration of the injection cycle, until the sensor  603   ec  or  603   e  senses a preselected target pressure in the drive fluid DF (shown for example purposes in  FIG. 9  occurring at about 4 seconds from start). Upon detection of the preselected target pressure, the controller  16  is programmed to trigger the restriction valve  600  to open piston and enable the piston  40   p  to be driven to a second or third axial position, such as a downstream position at which the end  1155  of the valve pin  1041  partially obstructs the gate and restricts flow of injection fluid  100   a,    100   b  through the gate such that the pressure  1312  of the injection fluid against the tip end  1142  of the pin  1041  is reduced relative to a gate open position pressure  1311  and thus the recorded pressure  1312  in the drive fluid DF by sensor  603   ec ,  603   e  is reduced (for purposes of example in  FIG. 9  the sensed reduced pressure at the second position is 7500 psi. Once the piston  40   p  is driven to the second or third position, the restrictor valve  600  is again closed and the piston  40   p  and valve pin  1041  remain relatively stationary for a second or third selected period of time. As shown in  FIG. 9 , the piston  40   p  (and associated valve pin  1041 ) is held and maintained in the first position (namely the axially spaced by X position) at an effective injection fluid pressure of 15,000 for about 3 seconds,  FIG. 9 , three (3) seconds being the first portion of the injection cycle. As shown in  FIG. 9 , the piston  40   p  (and associated valve pin  1041 ) is held and maintained in the second position, namely the position where the fluid pressure  1312  is reduced to about 7500 psi, for about twelve (12) seconds. 
         [0145]    In the example just described, the first position ( 1311  pressure of 15,000 psi) could be a “fill” cavity position or a pre-fill position and the second position (at  1312  pressure of 7500 psi) could be a “pack” position. 
         [0146]    As can be readily imagined the first portion of the duration of the injection cycle can be defined or determined by the amount of time that elapses between the time that the piston  40   p  first moves to the first axially spaced X position and the time that the pressure sensor  603   ec ,  603   e  detects the target pressure, opens the valve  600  and drives the piston to the second or third position. Alternatively the first portion of the duration of the injection cycle during with the piston  40   p  resides in the first position can be preselected by the user. In either case, the piston  40   p  is held in the first position for some period of time or portion of the injection cycle with the restriction valve  600  closed and with the sensor(s)  603   ec ,  603   e  acting to sense, detect pressure of the drive fluid and send a signal indicative of sensed pressure to the controller  16 . The same is true with respect to the subsequent second or third positions and the subsequent second or third periods of time or portions of the duration of the injection cycle. 
         [0147]    While specific embodiments of the present invention have been shown and described, it will be apparent that many modifications can be made thereto without departing from the scope of the invention. For example, in one embodiment the controller can be mounted on a hydraulic power unit. 
         [0148]    Thus as described, the control data can comprise a profile of values of a condition of the injected polymer material or a condition or position of a selected component of the injection molding apparatus that is specified to occur at each point in time over the course or duration of an injection cycle when a part is produced in the mold cavity. Thus a profile defines a set of conditions, events or positions to which the injection material or the component of the apparatus is adjusted to attain over the course of a particular injection cycle. Typical injection material conditions that can be specified and controlled are pressure of the injection material at selected positions within a flow channel of the manifold, within an injection nozzle or within the mold cavity. Typical conditions or positions of components of the apparatus that can be controlled and comprise a profile are the position of the valve pin, the position of the screw of the barrel of the injection molding machine and position of an actuator piston. Such profiles are disclosed in detail in for example U.S. Pat. No. 6,464,909 and U.S. Pat. No. 8,016,581 and U.S. Pat. No. 7,597,828, the disclosures of which are incorporated by reference as if fully set forth herein.