Patent Publication Number: US-2023140803-A1

Title: Method and Apparatus for Controlled Injection Fluid Flow

Description:
RELATED APPLICATIONS 
     The disclosures of all of the following are incorporated by reference in their entirety as if fully set forth herein: U.S. Pat. No. 5,894,025, U.S. Pat. No. 6,062,840, U.S. Pat. No. 6,294,122 (7018), 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. 6062840 (7052), U.S. Pat. No. 6261075 (7052US1), 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. Pat. No. 8297836 (7087) U.S. Pat. Application Serial 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. Pat. Application Serial No. 09/699,856 filed Oct. 30, 2000 (7056), U.S. Pat. Application Serial No. 10/269,927 filed Oct. 11, 2002 (7031), U.S. Application Serial No. 09/503,832 filed Feb. 15, 2000 (7053), U.S. Application Serial No. 09/656,846 filed Sep. 7, 2000 (7060), U.S. Application Serial No. 10/006,504 filed Dec. 3, 2001, (7068), U.S. Application Serial No. 10/101,278 filed March, 19, 2002 (7070) and PCT Application No. PCT/US11/062099 (7100WO0) and PCT Application No. PCT/US11/062096 (7100WO1), U.S. Pat. No. 8,562,336, U.S. Pat. No. 8,091,202 (7097US1) and U.S. Pat. No. 8,282,388 (7097US2), U.S. Pat. No. 9,724,861 (7129US4), U.S. Pat. No. 9662820 (7129US3), Publication No. WO2015006261 (7135WO0), Publication No. WO2014209857 (7134WO0), Publication No. WO2016153632 (7149WO2), International publication no. WO2016153704 (7149WO4), U.S. Pat. No. 9205587 (7117US0), U.S. Application Serial No. 15/432,175 (7117US2) filed Feb. 14, 2017, U.S. Pat. No. 9144929 (7118US0), U.S. Publication No. 20170341283 (7118US3), International Application WO2017214387 (7163WO0), International Application PCT/US17/043029 (7165WO0) filed Jul. 20, 2017, International Application PCT/US17/043100 (7165WO1), filed Jul. 20, 2017 and International Application PCT/US17/036542 (7163WO0) filed Jun. 8, 2017 and International Application WO2018129015 (7169WO0), international application WO2018148407 (7170WO0), international application WO2018183810 (7171WO), international application WO2018175362, international application WO2018194961 (7174WO0), international application WO2018200660 (7176WO0), international application WO2019013868 (7177), international application WO2019100085 (7178WO0), international application WO 2020068285 (7182WO0), international application WO2020176479 (7185WO0). The disclosure of WO2022005 (7192WO0) is incorporated by reference in their entirety as if fully set forth herein. 
    
    
     BACKGROUND 
     Injection molding systems that withdraw valve pins from a gate closed position upstream at multiple or uncontrolled rates of acceleration and up to multiple subsequent intermediate velocities before reaching an end of stroke position and systems that have an internal nozzle channel that have a single taper configuration as shown in  FIG.  1 A  have been employed in sequential gating applications. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention there is provided an injection molding apparatus ( 10 ) comprising an injection molding machine ( 13 ) that injects a flow of injection fluid ( 18 ) to a heated manifold ( 40 ) that distributes the injection fluid ( 18 ) to a distribution channel that delivers the injection fluid to a gate ( 34 ,  36 ,  1000   g ,  3000   gep ) of a mold cavity ( 30 ,  3000 ), the injection molding apparatus ( 10 ) comprising:
     one or more valves each comprised of an actuator ( 941 ,  942 ) interconnected to a valve pin ( 1041 ,  1042 ) having a linear axis (X) of travel in an arrangement wherein the actuator ( 941 ,  942 ) controllably drives an interconnected valve pin ( 1040 ,  1041 ,  1042 ) upstream and downstream through a downstream channel ( 1006 ) that has a downstream channel portion ( 1006   ds ) that has a control surface ( 1008 ),   wherein the control surface ( 1008 ) is sloped or configured, conical, cylindrical, straight or curvilinear and forms a channel or restriction gap (CG,  1006   rg ) of selected size or configuration disposed upstream of the gate ( 34 ,  1000   g ,  3000   gep ) to the mold cavity ( 30 ,  3000 ),   the valve pin ( 1041 ) having a distal axial portion ( 1041   d   1 ) adapted to be controllably driven upstream and downstream through the channel or restriction gap (CG,  1006   rg ), the actuator being adapted to drive the distal axial portion ( 1041   d ) upstream through the channel or restriction gap (CG,  1006   rg ) beginning from a gate closed, zero velocity position up to a selected reduced upstream velocity that is less than a maximum velocity at which the valve pin ( 1041 ) is drivable,   the control surface ( 1008 ) being disposed along an axial length (CT) of the channel or restriction gap (CG,  1006   rg ) of between about 3 mm and about 6 mm, the control surface ( 1008 ) or a portion ( 1006   dsp ) of the control surface ( 1008 ) having a smallest radial diameter (CD) that is greater than a largest radial diameter ( 1041  md) of the distal axial portion ( 1041   d   1 ) by between about 0.1 mm and about 0.8 mm.   

     In such an apparatus, the restriction gap (CG,  1006   rg ) and the valve pin are adapted to cooperate with each other to restrict flow of injection fluid through the downstream channel portion ( 1006   ds ) typically along a selected axial length ( 1006   dsl ) of the channel portion ( 1006   ds ) into the mold cavity ( 30 ,  300 ) at one or more selected reduced rates of injection fluid flow when the distal axial portion ( 1041   d   1 ) is withdrawn upstream through the downstream channel portion ( 1006   ds ), the one or more selected reduced rates being less than a maximum rate at which injection fluid flows when the valve pin is disposed in an end of stroke (EOS) position. 
     In such an apparatus the actuator is adapted to drive the distal axial portion ( 1041   d ) upstream through the channel or restriction gap (CG,  1006   rg ) beginning from a gate closed, zero velocity position at a single selected rate of upstream acceleration up to the selected reduced upstream velocity, 
     the selected size or configuration of the channel or restriction gap (CG,  1006   rg ) and the single selected rate of upstream acceleration being selected in combination with each other to control flow of injection fluid ( 18 ) through the channel gap (CG,  1006   rg ) at a selected rate of flow on driving the distal axial portion ( 1041   d   1 ) upstream at the single selected rate of upstream acceleration beginning from the gate closed, zero velocity position. 
     In such an apparatus the downstream channel portion ( 1006   ds ) preferably includes an interior surface ( 1010 ) extending along a distal end portion (DS) of the downstream channel ( 1006 ) that is disposed immediately downstream of the control surface ( 1008 ) and is adapted to engage or mate with the exterior surface ( 1041   cs ) of the distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) such that the selected gate ( 34 ,  100 G) is closed when the selected valve pin ( 1041 ) is disposed in a position where the distal axial portion ( 1041   d   1 ) is disposed within the distal end portion (DS) of the downstream channel portion ( 1006   ds ). 
     In such an apparatus the downstream channel ( 1006 ) typically includes an upstream channel portion ( 1006   us ) that has a conical or tapered or sloped surface ( 1009 ) disposed upstream relative to the downstream channel portion ( 1006   ds ) and is sloped or angled (UAG) relative to the linear axis (A) or circumferential surface ( 1041   cs ) of the valve pin ( 1041 ) by an angle (UAG) and extends along an axial length (UCT) of the downstream channel ( 1006 ) such that flow of injection fluid ( 18 ) flows without significant restriction through the upstream channel portion ( 1006   us ). 
     The conical or tapered or sloped or configured surface ( 1008 ) is typically disposed along or within a distal interior surface of an insert or extension ( 1003 ) disposed within a distal end of a main nozzle body ( 1004 ). 
     The conical or sloped surface ( 1008 ) can be disposed or formed along or within a distal end interior surface of a main nozzle body ( 1004 ) or disposed or formed within a gate entry portion ( 3000   gep ) of the mold ( 3002 ). 
     In such an apparatus the rate of flow of injection fluid ( 18 ) through the channel gap (CG) is controllable to a selected rate of flow that is less than the maximum rate of flow by controllably driving the selected valve pin upstream at the single selected rate of upstream acceleration. 
     In such an apparatus, the actuator ( 1040 ,  1041 ,  1042 ) typically comprises an electric motor having an electrically driven rotor drivably interconnected to the valve pin in an arrangement that converts rotary motion of the rotor to linear motion of the valve pin ( 1041 ). 
     In such an apparatus, the gate ( 34 ,  36 ) of the one or more valves is disposed downstream of an upstream gate ( 32 ) of an upstream valve through which the injection fluid is injected into the cavity ( 30 ,  300 ) at a first time, the actuator ( 941 ,  942 ) driving the valve pin ( 1041 ,  1042 ) to open the gate ( 34 ,  36 ) at a second time following the first time such that the injection fluid injected through the gate ( 34 ,  36 ) is injected into a stream of injection fluid injected through the upstream gate ( 32 ) and has traveled downstream through the cavity ( 30 ,  300 ) past the gate ( 34 ,  36 ). 
     In such an apparatus, the valve pin is preferably adapted to be driven at the single selected rate of upstream acceleration up to the selected reduced upstream velocity over a path of travel of between about 1 mm and about 5 mm. 
     In such an apparatus the selected reduced upstream velocity is preferably less than about 75% of the maximum velocity. 
     In another aspect of the invention there is provided an injection molding apparatus ( 10 ) comprising an injection molding machine ( 13 ) that injects a flow of injection fluid ( 18 ) to a heated manifold ( 40 ) that distributes the injection fluid ( 18 ) to a distribution channel that delivers the injection fluid to a gate ( 32 ,  34 ,  36 ,  1000   g ,  3000   gep ) of a mold cavity ( 30 ,  3000 ), the injection molding apparatus ( 10 ) comprising:
     one or more valves each comprised of an actuator ( 940 ,  941 ,  942 ) interconnected to a valve pin ( 1040 ,  1041 ,  1042 ) having a linear axis (X) of travel in an arrangement wherein the actuator ( 940 ,  941 ,  942 ) is adapted to controllably drive an interconnected valve pin ( 1040 ,  1041 ,  1042 ) upstream and downstream through a downstream channel ( 1006 ) that has a downstream channel portion ( 1006   ds ) that has a control surface ( 1008 ),   wherein the control surface ( 1008 ) is sloped, conical, cylindrical, straight or curvilinear and forms a channel or restriction gap (CG,  1006   rg ) of selected size or configuration disposed upstream of the gate ( 34 ,  1000   g ,  3000   gep ) to the mold cavity ( 30 ,  3000 ),   the valve pin ( 1041 ) having a distal axial portion ( 1041   d   1 ) adapted to be controllably drivable upstream and downstream through the channel or restriction gap (CG,  1006   rg ), the actuator being adapted to controllably drive the distal axial portion ( 1041   d   1 ) beginning from a gate closed, zero velocity position at a single selected rate of upstream acceleration up to a selected reduced upstream velocity that is less than a maximum velocity at which the valve pin ( 1041 ) is drivable,   wherein the selected size or configuration of the channel or restriction gap (CG,  1006   rg ) and the single selected rate of upstream acceleration are selected in combination with each other to control flow of injection fluid ( 18 ) through the channel gap (CG,  1006   rg ) at a selected rate of flow on driving the distal axial portion ( 1041   d   1 ) upstream at the single selected rate of upstream acceleration beginning from the gate closed, zero velocity position to the selected upstream velocity greater than zero.   

     The size or volume of the channel or restricted gap (CG,  1006   rg ) is selected by selecting one or the other or both of an angle (AG) between the control surface ( 1008 ) and the linear axis (X) of travel of the valve pin ( 1041 ) and by selecting the control surface ( 1008 ) or a portion ( 1006   dsp ) of the control surface ( 1008 ) to have smallest diameter (CD,  1006   dsd ) that is greater than a largest diameter ( 1041   d   1   d ) of the distal axial portion ( 1041   d   1 ) by a selected distance. 
     The downstream channel ( 1006 ) of such an apparatus typically includes an upstream channel portion ( 1006   us ) that has a conical or tapered or sloped surface ( 1009 ) disposed upstream relative to the downstream channel portion ( 1006   ds ) and is sloped or angled (UAG) relative to the linear axis (A) or circumferential surface ( 1041   cs ) of the valve pin ( 1041 ) by an angle (UAG) and extends along an axial length (UCT) of the downstream channel ( 1006 ) such that flow of injection fluid ( 18 ) flows without significant restriction through the upstream channel portion ( 1006   us ). 
     In such an apparatus where the control surface ( 1008 ) is conical or sloped, the control surface is preferably sloped or angled (AG) relative to the linear axis (A) or circumferential surface ( 1041   cs ) of the valve pin ( 1041 ) by an angle (AG) of between about 3 degrees and about 6 degrees. 
     In such an apparatus where the control surface ( 1008 ) is conical or sloped, the angle (UAG) is greater than the angle (AG). 
     In such an apparatus where the control surface ( 1008 ) is conical or sloped, the control surface is typically disposed along an axial length (CT) of between about 3 mm and about 6 mm. 
     In such an apparatus the control surface ( 1008 ) or a portion ( 1006   dsp ) of the control surface ( 1008 ) typically has smallest radial diameter (CD,  1006   dsd ) that is greater than a largest radial diameter ( 1041   md ) of the distal axial portion ( 1041   d   1 ) by between about 0.1 mm and about 0.8 mm. 
     In such an apparatus, the downstream channel portion ( 1006   ds ) preferably includes an interior surface ( 1010 ) extending along a distal end portion (DS) of the downstream channel ( 1006 ) that is disposed immediately downstream of the control surface ( 1008 ) and is adapted to engage or mate with the exterior surface ( 1041   cs ) of the distal axialportion ( 1041   d   1 ) of the selected valve pin ( 1041 ) such that the selected gate ( 34 ,  100 G) is closed when the selected valve pin ( 1041 ) is axially positioned or driven to a position where the distal axial portion ( 1041   d   1 ) is disposed within the distal end portion (DS) of the downstream channel portion ( 1006   ds ). 
     In such an apparatus the single selected rate of upstream acceleration is selected to reduce the rate of flow of injection fluid through the gate ( 32 ,  34 ) to a selected reduced rate of flow that is less than a maximum rate of flow at which the injection fluid ( 18 ) flows at an end of stroke (EOS) position. 
     In such an apparatus the conical or tapered or sloped surface ( 1008 ) is selectively sloped or angled relative to the linear axis (A) by an angle (AG) selected to create a restriction in flow of the injection fluid through the channel gap (CG) into the mold cavity ( 30 ,  1000 ) that enables a controllable acceleration or deceleration in rate of flow of injection fluid ( 1153 ) through the gate relative to acceleration or deceleration that occurs where the channel surface is straight or cylindrical by controllable positioning or driving of a distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) along a path of travel within or through the channel gap (CG) beginning from a closed position downstream of the channel gap (CG) to a position upstream of the channel gap (CG) or beginning from a position upstream of the channel gap (CG) to a closed position downstream of the channel gap. 
     The conical or tapered or sloped or configured surface ( 1008 ) is typically disposed along or within a distal interior surface of an insert or extension ( 1003 ) disposed within a distal end of a main nozzle body ( 1004 ). 
     The conical or tapered or sloped or configured surface ( 1008 ) can be disposed or formed along or within a distal end interior surface of a main nozzle body ( 1004 ) or disposed or formed within a gate entry portion ( 3000   gep ) of the mold ( 3002 ). 
     In such an apparatus the rate of flow of injection fluid ( 18 ) through the channel gap (CG) is controllable to a selected rate of flow that is less than a maximum rate of flow by controllably driving the selected valve pin upstream at the single selected rate of upstream acceleration. 
     In such an apparatus, the actuator ( 1040 ,  1041 ,  1042 ) typically comprises an electric motor having an electrically driven rotor drivably interconnected to the valve pin in an arrangement that converts rotary motion of the rotor to linear motion of the valve pin ( 1041 ). 
     In such an apparatus, the gate ( 34 ,  36 ) of the one or more valves is disposed downstream of an upstream gate ( 32 ) of an upstream valve through which the injection fluid is injected into the cavity ( 30 ,  300 ) at a first time, the actuator ( 941 ,  942 ) driving the valve pin ( 1041 ,  1042 ) to open the gate ( 34 ,  36 ) at a second time following the first time such that the injection fluid injected through the gate ( 34 ,  36 ) is injected into a stream of injection fluid injected through the upstream gate ( 32 ) and has traveled downstream through the cavity ( 30 ,  300 ) past the gate ( 34 ,  36 ). 
     In such an apparatus, the valve pin is preferably adapted to be driven at the single selected rate of upstream acceleration up to the selected reduced upstream velocity over a path of travel of between about 1 mm and about 5 mm. 
     In such an apparatus the selected reduced upstream velocity is preferably less than about 75% of the maximum velocity. 
     In accordance with the invention there is provided an injection molding apparatus ( 10 ) comprising an injection molding machine ( 13 ) that injects a flow of injection fluid ( 18 ) to a heated manifold ( 40 ) that distributes the injection fluid ( 18 ) to a distribution channel that delivers the injection fluid to a gate ( 32 ,  34 ,  36 ,  1000   g ,  3000   gep ) of a mold cavity ( 30 ,  3000 ), the injection molding apparatus ( 10 ) comprising:
     one or more valves each comprised of an actuator ( 940 ,  941 ,  942 ) interconnected to a valve pin ( 1040 ,  1041 ,  1042 ) in an arrangement wherein the actuator ( 940 ,  941 ,  942 ) controllably drives an interconnected valve pin ( 1040 ,  1041 ,  1042 ) upstream and downstream through a downstream channel ( 1006 ) that has a downstream channel portion ( 1006   ds ) that has a conical or tapered or sloped surface ( 1008 ) that is sloped or angled relative to a linear axis (A) along which the selected valve pin ( 1041 ) travels,   wherein the conical or tapered or sloped wall surface ( 1008 ) forms a channel gap (CG) disposed upstream of the gate ( 34 ,  1000   g ,  3000   gep ) to the mold cavity ( 30 ,  3000 ), the selected valve pin ( 1041 ) having a configuration disposed along a distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) that is adapted to be controllably driven upstream beginning from a gate closed, zero velocity position at a single selected rate of upstream acceleration to a selected upstream velocity greater than zero,   wherein the slope or taper of the conical or sloped surface ( 1008 ) is selected to interact with the distal axial portion ( 1041   d ) such that flow of injection fluid ( 18 ) through the channel gap (CG) is controllable to a selected rate of flow by controllably driving the selected valve pin upstream at the single selected rate of upstream acceleration beginning from the gate closed, zero velocity position up to the a selected upstream velocity greater than zero.   

     The downstream channel ( 1006 ) of such an apparatus typically includes an upstream channel portion ( 1006   us ) that has a conical or tapered or sloped surface ( 1009 ) disposed upstream relative to the downstream channel portion ( 1006   ds ) and is sloped or angled (UAG) relative to the linear axis (A) or circumferential surface ( 1041   cs ) of the valve pin ( 1041 ) by an angle (UAG) of greater than about 6 degrees and extends along an axial length (UCT) of the downstream channel ( 1006 ) such that flow of injection fluid ( 18 ) flows without significant restriction through the upstream channel portion ( 1006   us ). 
     In such an apparatus the conical or tapered or sloped wall surface ( 1008 ) is preferably sloped or angled (AG) relative to the linear axis (A) or circumferential surface ( 1041   cs ) of the valve pin ( 1041 ) by an angle (AG) of between about 3 degrees and about 6 degrees. 
     In such an apparatus the conical or tapered or sloped surface ( 1008 ) is typically disposed along an axial length (CT) of between about 3 mm and about 6 mm. 
     In such an apparatus the control surface ( 1008 ) or a portion ( 1006   dsp ) of the control surface ( 1008 ) typically has a smallest radial diameter (CD) that is greater than a radial diameter ( 1041   md ) of the distal axial portion ( 1041   d   1 ) by between about 0.1 mm and about 0.8 mm. 
     In such an apparatus, the downstream channel portion ( 1006   ds ) preferably includes an interior surface ( 1010 ) extending along a distal end portion (DS) of the downstream channel ( 1006 ) that is disposed immediately downstream of the control surface ( 1008 ) and is adapted to engage or mate with the exterior surface ( 1041   cs ) of the distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) such that the selected gate ( 34 ,  100 G) is closed when the selected valve pin ( 1041 ) is axially positioned or driven to a position where the distal axial portion ( 1041   d   1 ) is disposed within the distal end portion (DS) of the downstream channel portion ( 1006   ds ). 
     In such an apparatus the conical or tapered or sloped surface ( 1008 ) is selectively sloped or angled relative to the linear axis (A) by an angle (AG) selected to create a restriction in flow of the injection fluid through the channel gap (CG) into the mold cavity ( 30 ,  1000 ) that enables a controllable acceleration or deceleration in rate of flow of injection fluid ( 1153 ) through the gate relative to acceleration or deceleration that occurs where the channel surface is straight or cylindrical by controllable positioning or driving of a distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) along a path of travel within or through the channel gap (CG) beginning from a closed position downstream of the channel gap (CG) to a position upstream of the channel gap (CG) or beginning from a position upstream of the channel gap (CG) to a closed position downstream of the channel gap. 
     The conical or tapered or sloped surface ( 1008 ) is typically disposed along or within a distal interior surface of an insert or extension ( 1003 ) disposed within a distal end of a main nozzle body ( 1004 ). 
     The conical or tapered or sloped surface ( 1008 ) can be disposed or formed along or within a distal end interior surface of a main nozzle body ( 1004 ) or disposed or formed within a gate entry portion ( 3000   gep ) of the mold ( 3002 ). 
     In such an apparatus the rate of flow of injection fluid ( 18 ) through the channel gap (CG) is controllable to a selected rate of flow that is less than a maximum rate of flow by controllably driving the selected valve pin upstream at the single selected rate of upstream acceleration. 
     In such an apparatus, the actuator ( 1040 ,  1041 ,  1042 ) typically comprises an electric motor having an electrically driven rotor drivably interconnected to the valve pin in an arrangement that converts rotary motion of the rotor to linear motion of the valve pin ( 1041 ). 
     In such an apparatus, the gate ( 34 ,  36 ) of the one or more valves is disposed downstream of an upstream gate ( 32 ) of an upstream valve through which the injection fluid is injected into the cavity ( 30 ,  300 ) at a first time, the actuator ( 941 ,  942 ) driving the valve pin ( 1041 ,  1042 ) to open the gate ( 34 ,  36 ) at a second time following the first time such that the injection fluid injected through the gate ( 34 ,  36 ) is injected into a stream of injection fluid injected through the upstream gate ( 32 ) and has traveled downstream through the cavity ( 30 ,  300 ) past the gate ( 34 ,  36 ). 
     In such an apparatus, the valve pin is preferably adapted to be driven at the single selected rate of upstream acceleration up to the selected reduced upstream velocity over a path of travel of between about 1 mm and about 5 mm. 
     In such an apparatus the selected reduced upstream velocity is preferably less than about 75% of the maximum velocity. 
     In another aspect of the invention there is provided an injection molding apparatus ( 10 ) comprising an injection molding machine ( 13 ) that injects a flow of injection fluid ( 18 ) to a heated manifold ( 40 ) that distributes the injection fluid ( 18 ) to a distribution channel that delivers the injection fluid to a gate ( 32 ,  34 ,  36 ,  1000   g ,  3000   gep ) of a mold cavity ( 30 ,  3000 ), the injection molding apparatus ( 10 ) comprising:
     one or more valves each comprised of an actuator ( 940 ,  941 ,  942 ) interconnected to a valve pin ( 1040 ,  1041 ,  1042 ) in an arrangement wherein the actuator ( 940 ,  941 ,  942 ) controllably drives an interconnected valve pin ( 1040 ,  1041 ,  1042 ) upstream and downstream through a downstream channel ( 1006 ) that has a downstream channel portion ( 1006   ds ) that has a conical or tapered or sloped surface ( 1008 ) that is sloped or angled relative to a linear axis (A) along which the selected valve pin ( 1041 ) travels and an interior surface ( 1010 ) extending along a distal end portion (DS) of the downstream channel ( 1006 ) that is disposed immediately downstream of the control surface ( 1008 ) and is adapted to engage or mate with an exterior surface ( 1041   cs ) of the distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) such that the selected gate ( 34 ,  100 G) is closed when the selected valve pin ( 1041 ) is axially positioned or driven to a position where the distal axial portion ( 1041   d   1 ) is disposed within the distal end portion (DS) of the downstream channel portion ( 1006   ds ),   wherein the conical or tapered or sloped surface ( 1008 ) forms a channel gap (CG) disposed upstream of the gate ( 34 ,  1000 G,  3000   gep ) to the mold cavity ( 30 ,  3000 ), the selected valve pin ( 1041 ) having a configuration disposed along a distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) that is adapted to be controllably driven upstream beginning from a position where the exterior surface ( 1041   cs ) of the distal axial portion ( 1041   d   1 ) is mated with the interior surface ( 1010 ) at a single selected rate of upstream acceleration to a selected upstream velocity greater than zero,   wherein the slope or taper of the conical or sloped surface ( 1008 ) is selected to interact with the distal axial portion ( 1041   d ) such that flow of injection fluid ( 18 ) through the channel gap (CG) is controllable to a selected rate that is less than a maximum rate of flow by controllably driving the selected valve pin ( 1041 ) upstream at the single selected rate of upstream acceleration up to the selected upstream velocity greater than zero beginning with the distal axial portion being disposed at a position where the exterior surface ( 1041   cs ) is mated with the interior surface ( 1010 ).   

     The downstream channel ( 1006 ) of such an apparatus typically includes an upstream channel portion ( 1006   us ) that has a conical or tapered or sloped surface ( 1009 ) disposed upstream relative to the downstream channel portion ( 1006   ds ) and is sloped or angled (UAG) relative to the linear axis (A) or circumferential surface ( 1041   cs ) of the valve pin ( 1041 ) by an angle (UAG) of greater than about 6 degrees and extends along an axial length (UCT) of the downstream channel ( 1006 ) such that flow of injection fluid ( 18 ) flows without significant restriction through the upstream channel portion ( 1006   us ). 
     In such an apparatus, the actuator ( 1040 ,  1041 ,  1042 ) typically comprises an electric motor having an electrically driven rotor drivably interconnected to the valve pin in an arrangement that converts rotary motion of the rotor to linear motion of the valve pin ( 1041 ). 
     In such an apparatus the conical or tapered or sloped surface ( 1008 ) is preferably sloped or angled relative to the linear axis (A) or circumferential surface ( 1041   cs ) of the valve pin ( 1041 ) by an angle of between about 3 degrees and about 6 degrees. 
     In such an apparatus the conical or tapered or sloped surface ( 1008 ) is typically disposed along an axial length (CT) of between about 3 mm and about 6 mm. 
     In such an apparatus the control surface ( 1008 ) or a portion ( 1006   dsp ) of the control surface ( 1008 ) typically has a smallest radial diameter (CD) that is greater than a radial diameter ( 1041   md ) of the distal axial portion ( 1041   d   1 ) by between about 0.1 mm and about 0.8 mm. 
     In such an apparatus, the gate ( 34 ,  36 ) of the one or more valves is disposed downstream of an upstream gate ( 32 ) of an upstream valve through which the injection fluid is injected into the cavity ( 30 ,  300 ) at a first time, the actuator ( 941 ,  942 ) driving the valve pin ( 1041 ,  1042 ) to open the gate ( 34 ,  36 ) at a second time following the first time such that the injection fluid injected through the gate ( 34 ,  36 ) is injected into a stream of injection fluid injected through the upstream gate ( 32 ) and has traveled downstream through the cavity ( 30 ,  300 ) past the gate ( 34 ,  36 ). 
     In such an apparatus, the valve pin is preferably adapted to be driven at the single selected rate of upstream acceleration up to the selected reduced upstream velocity over a path of travel of between about 1 mm and about 5 mm. 
     In such an apparatus the selected reduced upstream velocity is preferably less than about 75% of the maximum velocity. 
     In another aspect of the invention there is provided an injection molding apparatus ( 10 ) comprising an injection molding machine ( 13 ) that injects a flow of injection fluid ( 18 ) to a heated manifold ( 40 ) that distributes the injection fluid ( 18 ) to a distribution channel that delivers the injection fluid to a gate ( 32 ,  34 ,  36 ,  1000   g ,  3000   gep ) of a mold cavity ( 30 ,  3000 ), the injection molding apparatus ( 10 ) comprising:
     one or more valves each comprised of an actuator ( 940 ,  941 ,  942 ) interconnected to a valve pin ( 1040 ,  1041 ,  1042 ) in an arrangement wherein the actuator ( 940 ,  941 ,  942 ) controllably drives an interconnected valve pin ( 1040 ,  1041 ,  1042 ) upstream and downstream through a downstream channel ( 1006 ) that has a downstream channel portion ( 1006   ds ) that has a conical or tapered or sloped surface ( 1008 ) that is sloped or angled relative to a linear axis (A) along which the selected valve pin ( 1041 ) travels,   wherein the conical or tapered or sloped surface ( 1008 ) forms a channel gap (CG) disposed upstream of the gate ( 34 ,  1000   g ,  3000   gep ) to the mold cavity ( 30 ,  3000 ), the selected valve pin ( 1041 ) having a configuration disposed along a distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) that is adapted to be controllably driven downstream beginning from a selected open gate position ( 906   o ) that is upstream of a gate closed position (GC) at a single selected rate of downstream deceleration to the gate closed position (GC),   wherein the slope or taper of the conical or sloped surface ( 1008 ) is selected to interact with the distal axial portion ( 1041   d ) such that flow of injection fluid ( 18 ) through the channel gap (CG) is controllable to a selected rate of flow by controllably driving the selected valve pin downstream at the single selected rate of downstream deceleration beginning from the selected open gate position ( 906   o ) to the gate closed position (GC).   

     The downstream channel ( 1006 ) of such an apparatus typically includes an upstream channel portion ( 1006   us ) that has a conical or tapered or sloped surface ( 1009 ) disposed upstream relative to the downstream channel portion ( 1006   ds ) and is sloped or angled (UAG) relative to the linear axis (A) or circumferential surface ( 1041   cs ) of the valve pin ( 1041 ) by an angle (UAG) of greater than about 6 degrees and extends along an axial length (UCT) of the downstream channel ( 1006 ) such that flow of injection fluid ( 18 ) flows without significant restriction through the upstream channel portion ( 1006   us ). 
     In such an apparatus, the actuator ( 1040 ,  1041 ,  1042 ) typically comprises an electric motor having an electrically driven rotor drivably interconnected to the valve pin in an arrangement that converts rotary motion of the rotor to linear motion of the valve pin ( 1041 ). 
     In such an apparatus the conical or tapered or sloped surface ( 1008 ) is preferably sloped or angled relative to the linear axis (A) or circumferential surface ( 1041   cs ) of the valve pin ( 1041 ) by an angle of between about 3 degrees and about 6 degrees. 
     In such an apparatus the conical or tapered or sloped surface ( 1008 ) is typically disposed along an axial length (CT) of between about 3 mm and about 6 mm. 
     In such an apparatus the conical or tapered or sloped surface ( 1008 ) has a smallest radial diameter (CD) or a portion ( 1006   dsp ) has a smallest radial diameter (CD) that is greater than a radial diameter ( 1041   md ) of the distal axial portion ( 1041   d   1 ) by between about 0.1 mm and about 0.8 mm. 
     In such an apparatus, the downstream channel portion ( 1006   ds ) preferably includes an interior surface ( 1010 ) extending along a distal end portion (DS) of the downstream channel ( 1006 ) that is disposed immediately downstream of the control surface ( 1008 ) and is adapted to engage or mate with the exterior surface ( 1041   cs ) of the distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) such that the selected gate ( 34 ,  100 G) is closed when the selected valve pin ( 1041 ) is axially positioned or driven to a position where the distal axial portion ( 1041   d   1 ) is disposed within the distal end portion (DS) of the downstream channel portion ( 1006   ds ). 
     In another aspect of the invention there is provided an injection molding apparatus ( 10 ) comprising an injection molding machine ( 13 ) that injects a flow of injection fluid ( 18 ) to a heated manifold ( 40 ) that distributes the injection fluid ( 18 ) to a distribution channel that delivers the injection fluid to a gate ( 32 ,  34 ,  36 ,  1000   g ,  3000   gep ) of a mold cavity ( 30 ,  3000 ), the injection molding apparatus ( 10 ) comprising:
     one or more valves each comprised of an actuator ( 940 ,  941 ,  942 ) interconnected to a valve pin ( 1040 ,  1041 ,  1042 ) in an arrangement wherein the actuator ( 940 ,  941 ,  942 ) controllably drives an interconnected valve pin ( 1040 ,  1041 ,  1042 ) upstream and downstream through a downstream channel ( 1006 ) that has a downstream channel portion ( 1006   ds ) that has a conical or tapered or sloped surface ( 1008 ) that is sloped or angled relative to a linear axis (A) along which the selected valve pin ( 1041 ) travels,   wherein the conical or tapered or sloped surface ( 1008 ) forms a channel gap (CG) disposed upstream of the gate ( 34 ,  1000   g ,  3000   gep ) to the mold cavity ( 30 ,  3000 ), the selected valve pin ( 1041 ) having a configuration disposed along a distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) that is adapted to be controllably driven upstream beginning from a selected open gate position ( 904   o ) that is downstream of an open gate end of stroke position (EOS) at a single selected rate of upstream deceleration to the open gate end of stroke position (EOS),   wherein the slope or taper of the conical or sloped surface ( 1008 ) is selected to interact with the distal axial portion ( 1041   d ) such that flow of injection fluid ( 18 ) through the channel gap (CG) is controllable by controllably driving the selected valve pin upstream at the single selected rate of upstream deceleration beginning from the selected open gate position ( 904   o ) to the open gate end of stroke position (EOS).   

     The downstream channel ( 1006 ) of such an apparatus typically includes an upstream channel portion ( 1006   us ) that has a conical or tapered or sloped surface ( 1009 ) disposed upstream relative to the downstream channel portion ( 1006   ds ) and is sloped or angled (UAG) relative to the linear axis (A) or circumferential surface ( 1041   cs ) of the valve pin ( 1041 ) by an angle (UAG) of greater than about 6 degrees and extends along an axial length (UCT) of the downstream channel ( 1006 ) such that flow of injection fluid ( 18 ) flows without significant restriction through the upstream channel portion ( 1006   us ). 
     In such an apparatus, the actuator ( 1040 ,  1041 ,  1042 ) typically comprises an electric motor having an electrically driven rotor drivably interconnected to the valve pin in an arrangement that converts rotary motion of the rotor to linear motion of the valve pin ( 1041 ). 
     In such an apparatus the conical or tapered or sloped surface ( 1008 ) is preferably sloped or angled relative to the linear axis (A) or circumferential surface ( 1041   cs ) of the valve pin ( 1041 ) by an angle of between about 3 degrees and about 6 degrees. 
     In such an apparatus the conical or tapered or sloped surface ( 1008 ) is typically disposed along an axial length (CT) of between about 3 mm and about 6 mm. 
     In such an apparatus the conical or tapered or sloped surface ( 1008 ) has a smallest radial diameter (CD) or a portion ( 1006   dsp ) or the control surface ( 1008 ) has a smallest radial diameter (CD) that is greater than a radial diameter ( 1041   md ) of the distal axial portion ( 1041   d   1 ) by between about 0.1 mm and about 0.8 mm. 
     In such an apparatus, the downstream channel portion ( 1006   ds ) preferably includes an interior surface ( 1010 ) extending along a distal end portion (DS) of the downstream channel ( 1006 ) that is disposed immediately downstream of the control surface ( 1008 ) and is adapted to engage or mate with the exterior surface ( 1041   cs ) of the distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) such that the selected gate ( 34 ,  100 G) is closed when the selected valve pin ( 1041 ) is axially positioned or driven to a position where the distal axial portion ( 1041   d   1 ) is disposed within the distal end portion (DS) of the downstream channel portion ( 1006   ds ). 
     In such an apparatus, the gate ( 34 ,  36 ) of the one or more valves is disposed downstream of an upstream gate ( 32 ) of an upstream valve through which the injection fluid is injected into the cavity ( 30 ,  300 ) at a first time, the actuator ( 941 ,  942 ) driving the valve pin ( 1041 ,  1042 ) to open the gate ( 34 ,  36 ) at a second time following the first time such that the injection fluid injected through the gate ( 34 ,  36 ) is injected into a stream of injection fluid injected through the upstream gate ( 32 ) and has traveled downstream through the cavity ( 30 ,  300 ) past the gate ( 34 ,  36 ). 
     In such an apparatus, the valve pin is preferably adapted to be driven at the single selected rate of upstream acceleration up to the selected reduced upstream velocity over a path of travel of between about 1 mm and about 5 mm. 
     In such an apparatus the selected reduced upstream velocity is preferably less than about 75% of the maximum velocity. 
     In another aspect of the invention there is provided an injection molding apparatus ( 10 ) comprising an injection molding machine ( 13 ) that injects a flow of injection fluid ( 18 ) to a heated manifold ( 40 ) that distributes the injection fluid ( 18 ) to a distribution channel that delivers the injection fluid to a gate ( 32 ,  34 ,  36 ,  1000   g ,  3000   gep ) of a mold cavity ( 30 ,  3000 ), the injection molding apparatus ( 10 ) comprising:
     one or more valves each comprised of an actuator ( 940 ,  941 ,  942 ) interconnected to a valve pin ( 1040 ,  1041 ,  1042 ) that has a distal axial portion ( 1041   d   1 ) having a pin diameter or maximum radial dimension ( 1041   d   1   d ) in an arrangement wherein the actuator ( 940 ,  941 ,  942 ) controllably drives an interconnected valve pin ( 1040 ,  1041 ,  1042 ) upstream and downstream through a downstream channel ( 1006 ) that has a downstream channel portion ( 1006   ds ),   the downstream channel portion ( 1006   ds ) including an interior wall surface ( 1008 ) having a selected interior radial diameter ( 1006   dsd ) and a portion length ( 1006   dsl ) adapted to receive the distal axial portion ( 1041   d   1 ) of the valve pin ( 1041 ) such that the distal axial portion ( 1041   d   1 ) of the valve pin ( 1041 ) is reciprocally drivable upstream and downstream through the portion length ( 1006   dsl ),   the interior surface diameter or selected interior radial dimension ( 1006   dsd ) and the pin diameter or pin maximum radial dimension ( 1041   d   1   d ) being configured to form a flow restriction gap ( 1006   rg ) of selected size and configuration when the distal axial portion ( 1041   d   1 ) is received within the downstream channel portion ( 1006   ds ),   the distal axial portion ( 1041   d   1 ) being adapted to be controllably driven upstream beginning from a gate closed, zero velocity position at a single selected rate of upstream acceleration,   wherein the selected size and configuration of the restriction gap ( 1006   rg ) is selected such that flow of injection fluid ( 18 ) through the restriction gap ( 1006   rg ) is controllable to a selected rate of flow by controllably driving the valve pin ( 1041 ) upstream at the single selected rate of upstream acceleration beginning from the gate closed, zero velocity position.   

     In such an apparatus the distal axial portion ( 1041   d   1 ) is typically adapted to be controllably driven upstream beginning from a gate closed, zero velocity position at a single selected rate of upstream acceleration up to a selected upstream velocity greater than zero, the selected size and configuration of the restriction gap ( 1006   rg ) being selected such that flow of injection fluid ( 18 ) through the restriction gap ( 1006   rg ) is controllable to a selected reduced rate of flow relative to a maximum flow by controllably driving the valve pin ( 1041 ) upstream at the single selected rate of upstream acceleration beginning from the gate closed, zero velocity position up to the selected velocity. 
     In such an apparatus the downstream channel portion ( 1006   ds ) preferably includes an interior surface ( 1010 ) extending along a distal end portion (DS) of the downstream channel ( 1006 ) that is disposed immediately downstream of the portion length ( 1006   dsl ) and is adapted to engage or mate with the exterior surface ( 1041   cs ) of the distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) such that the selected gate ( 34 ,  100 G) is closed when the selected valve pin ( 1041 ) is axially positioned or driven to a gate closed position where the exterior surface ( 1041   cs ) is engaged or mated with the interior surface ( 1010 ). 
     In such an apparatus, the flow restriction gap ( 1006   rg ) is adapted to restrict flow of the injection fluid ( 1153 ) to a flow rate that is reduced relative to a higher flow rate that occurs when the distal axial portion ( 1041   d   1 ) is disposed upstream of the portion length ( 1006   dsl ) of the downstream channel portion ( 1006   ds ). 
     The downstream channel portion ( 1006   ds ) is typically disposed or formed along or within a distal interior channel volume of the main nozzle body ( 1004 ) or of an insert or extension ( 1003 ) that is disposed within a distal end of a main nozzle body ( 1004 ). 
     The downstream channel portion ( 1006   ds ) can be disposed or formed within a gate entry portion ( 3000   gep ) of the mold ( 3002 ), such that the distal axial portion ( 1041   d   1 ) of the valve pin ( 1041 ) is axially drivable through the channel portion ( 1006   ds ) within the gate entry portion ( 3000   gep ) of the mold ( 3002 ). 
     The distal axial portion ( 1041   d   1 ) typically has a portion length ( 1006   dsl ) along an axial path of travel of between about 1 mm and about 18 mm, more typically between about 2 mm and about 10 mm and more typically between about 2 mm and about 8 mm. 
     The exterior or circumferential surface ( 1041   cs ) can be straight, cylindrical, conical or sloped. 
     In such an apparatus, the actuator ( 1040 ,  1041 ,  1042 ) typically comprises an electric motor having an electrically driven rotor drivably interconnected to the valve pin in an arrangement that converts rotary motion of the rotor to linear motion of the valve pin ( 1041 ). 
     In such an apparatus, the gate ( 34 ,  36 ) of the one or more valves is disposed downstream of an upstream gate ( 32 ) of an upstream valve through which the injection fluid is injected into the cavity ( 30 ,  300 ) at a first time, the actuator ( 941 ,  942 ) driving the valve pin ( 1041 ,  1042 ) to open the gate ( 34 ,  36 ) at a second time following the first time such that the injection fluid injected through the gate ( 34 ,  36 ) is injected into a stream of injection fluid injected through the upstream gate ( 32 ) and has traveled downstream through the cavity ( 30 ,  300 ) past the gate ( 34 ,  36 ). 
     In such an apparatus, the valve pin is preferably adapted to be driven at the single selected rate of upstream acceleration up to the selected reduced upstream velocity over a path of travel of between about 1 mm and about 5 mm. 
     In such an apparatus the selected reduced upstream velocity is preferably less than about 75% of the maximum velocity. 
     In another aspect of the invention there is provided an injection molding apparatus ( 10 ) comprising an injection molding machine ( 13 ) that injects a flow of injection fluid ( 18 ) to a heated manifold ( 40 ) that distributes the injection fluid ( 18 ) to a distribution channel that delivers the injection fluid to a gate ( 32 ,  34 ,  36 ,  1000   g ,  3000   gep ) of a mold cavity ( 30 ,  3000 ), the injection molding apparatus ( 10 ) comprising:
     one or more valves each comprised of an actuator ( 940 ,  941 ,  942 ) interconnected to a valve pin ( 1040 ,  1041 ,  1042 ) that has a distal axial portion ( 1041   d   1 ) having a pin diameter or maximum radial dimension ( 1041   d   1   d ) in an arrangement wherein the actuator ( 940 ,  941 ,  942 ) controllably drives an interconnected valve pin ( 1040 ,  1041 ,  1042 ) upstream and downstream through a downstream channel ( 1006 ) that has a downstream channel portion ( 1006   ds ),   the downstream channel portion ( 1006   ds ) including an interior wall surface ( 1008 ) having a selected interior radial diameter ( 1006   dsd ) and a portion length ( 1006   dsl ) adapted to receive the distal axial portion ( 1041   d   1 ) of the valve pin ( 1041 ) such that the distal axial portion ( 1041   d   1 ) of the valve pin ( 1041 ) is reciprocally drivable upstream and downstream through the portion length ( 1006   dsl ),   the interior surface diameter or selected interior radial dimension ( 1006   dsd ) and the pin diameter or pin maximum radial dimension ( 1041   d   1   d ) being configured to form a flow restriction gap ( 1006   rg ) of selected size and configuration when the distal axial portion ( 1041   d   1 ) is received within the downstream channel portion ( 1006   ds ),   the distal axial portion ( 1041   d   1 ) being adapted to be controllably driven downstream beginning from a selected open gate position ( 906   o ) that is upstream of a gate closed position (GC) at a single selected rate of downstream deceleration to the gate closed position (GC),   wherein the selected size and configuration of the restriction gap ( 1006   rg ) is selected such that flow of injection fluid ( 18 ) through the restriction gap ( 1006   rg ) is controllable to a selected rate of flow by controllably driving the selected valve pin downstream at the single selected rate of downstream deceleration beginning from the selected open gate position ( 906   o ) to the gate closed position (GC).   

     In such an apparatus the downstream channel portion ( 1006   ds ) preferably includes an interior surface ( 1010 ) extending along a distal end portion (DS) of the downstream channel ( 1006 ) that is disposed immediately downstream of the portion length ( 1006   dsl ) and is adapted to engage or mate with the exterior surface ( 1041   cs ) of the distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) such that the selected gate ( 34 ,  100 G) is closed when the selected valve pin ( 1041 ) is axially positioned or driven to a gate closed position where the exterior surface ( 1041   cs ) is engaged or mated with the interior surface ( 1010 ). 
     In such an apparatus, the flow restriction gap ( 1006   rg ) is adapted to restrict flow of the injection fluid ( 1153 ) to a flow rate that is reduced relative to a higher flow rate that occurs when the distal axial portion ( 1041   d   1 ) is disposed upstream of the portion length ( 1006   dsl ) of the downstream channel portion ( 1006   ds ). 
     The downstream channel portion ( 1006   ds ) is typically disposed or formed along or within a distal interior channel volume of the main nozzle body ( 1004 ) or of an insert or extension ( 1003 ) that is disposed within a distal end of a main nozzle body ( 1004 ). 
     The downstream channel portion ( 1006   ds ) can be disposed or formed within a gate entry portion ( 3000   gep ) of the mold ( 3002 ), such that the distal axial portion ( 1041   d   1 ) of the valve pin ( 1041 ) is axially drivable through the channel portion ( 1006   ds ) within the gate entry portion ( 3000   gep ) of the mold ( 3002 ). 
     The distal axial portion ( 1041   d   1 ) typically has a portion length ( 1006   dsl ) along an axial path of travel of between about 1 mm and about 18 mm, more typically between about 2 mm and about 10 mm and more typically between about 2 mm and about 8 mm. 
     The exterior or circumferential surface ( 1041   cs ) can be straight, cylindrical, conical or sloped. 
     In such an apparatus, the actuator ( 1040 ,  1041 ,  1042 ) typically comprises an electric motor having an electrically driven rotor drivably interconnected to the valve pin in an arrangement that converts rotary motion of the rotor to linear motion of the valve pin ( 1041 ). 
     In such an apparatus, the gate ( 34 ,  36 ) of the one or more valves is disposed downstream of an upstream gate ( 32 ) of an upstream valve through which the injection fluid is injected into the cavity ( 30 ,  300 ) at a first time, the actuator ( 941 ,  942 ) driving the valve pin ( 1041 ,  1042 ) to open the gate ( 34 ,  36 ) at a second time following the first time such that the injection fluid injected through the gate ( 34 ,  36 ) is injected into a stream of injection fluid injected through the upstream gate ( 32 ) and has traveled downstream through the cavity ( 30 ,  300 ) past the gate ( 34 ,  36 ). 
     In such an apparatus, the valve pin is preferably adapted to be driven at the single selected rate of upstream acceleration up to the selected reduced upstream velocity over a path of travel of between about 1 mm and about 5 mm. 
     In such an apparatus the selected reduced upstream velocity is preferably less than about 75% of the maximum velocity. 
     In another aspect of the invention there is provided an injection molding apparatus ( 10 ) comprising an injection molding machine ( 13 ) that injects a flow of injection fluid ( 18 ) to a heated manifold ( 40 ) that distributes the injection fluid ( 18 ) to a distribution channel that delivers the injection fluid to a gate ( 32 ,  34 ,  36 ,  1000   g ,  3000   gep ) of a mold cavity ( 30 ,  3000 ), the injection molding apparatus ( 10 ) comprising:
     one or more valves each comprised of an actuator ( 940 ,  941 ,  942 ) interconnected to a valve pin ( 1040 ,  1041 ,  1042 ) that has a distal axial portion ( 1041   d   1 ) having a pin diameter or maximum radial dimension ( 1041   d   1   d ) in an arrangement wherein the actuator ( 940 ,  941 ,  942 ) controllably drives an interconnected valve pin ( 1040 ,  1041 ,  1042 ) upstream and downstream through a downstream channel ( 1006 ) that has a downstream channel portion ( 1006   ds ),   the downstream channel portion ( 1006   ds ) including an interior wall surface ( 1008 ) having a selected interior radial diameter ( 1006   dsd ) and a portion length ( 1006   dsl ) adapted to receive the distal axial portion ( 1041   d   1 ) of the valve pin ( 1041 ) such that the distal axial portion ( 1041   d   1 ) of the valve pin ( 1041 ) is reciprocally drivable upstream and downstream through the portion length ( 1006   dsl ),   the interior surface diameter or selected interior radial dimension ( 1006   dsd ) and the pin diameter or pin maximum radial dimension ( 1041   d   1   d ) being configured to form a flow restriction gap ( 1006   rg ) of selected size and configuration along a portion length ( 1006   dsl ) when the distal axial portion ( 1041   d   1 ) is received within the downstream channel portion ( 1006   ds ),   the distal axial portion ( 1041   d   1 ) being adapted to be controllably driven upstream beginning from a selected open gate position ( 904   o ) that is downstream of a gate open end of stroke position (EOS) at a single selected rate of upstream deceleration to the gate open end of stroke position (EOS),   wherein the selected size and configuration of the restriction gap ( 1006   rg ) is selected such that flow of injection fluid ( 18 ) through the restriction gap ( 1006   rg ) is controllable to a selected rate of flow by controllably driving the selected valve pin upstream at the single selected rate of upstream deceleration beginning from the selected open gate position ( 904   o ) to the gate open end of stroke position (EOS).   

     In such an apparatus the downstream channel portion ( 1006   ds ) preferably includes an interior surface ( 1010 ) extending along a distal end portion (DS) of the downstream channel ( 1006 ) that is disposed immediately downstream of the portion length ( 1006   dsl ) and is adapted to engage or mate with the exterior surface ( 1041   cs ) of the distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) such that the selected gate ( 34 ,  100 G) is closed when the selected valve pin ( 1041 ) is axially positioned or driven to a gate closed position where the exterior surface ( 1041   cs ) is engaged or mated with the interior surface ( 1010 ). 
     In such an apparatus, the flow restriction gap ( 1006   rg ) is adapted to restrict flow of the injection fluid ( 1153 ) to a flow rate that is reduced relative to a higher flow rate that occurs when the distal axial portion ( 1041   d   1 ) is disposed upstream of the portion length ( 1006   dsl ) of the downstream channel portion ( 1006   ds ). 
     The downstream channel portion ( 1006   ds ) is typically disposed or formed along or within a distal interior channel volume of the main nozzle body ( 1004 ) or of an insert or extension ( 1003 ) that is disposed within a distal end of a main nozzle body ( 1004 ). 
     The downstream channel portion ( 1006   ds ) can be disposed or formed within a gate entry portion ( 3000   gep ) of the mold ( 3002 ), such that the distal axial portion ( 1041   d   1 ) of the valve pin ( 1041 ) is axially drivable through the channel portion ( 1006   ds ) within the gate entry portion ( 3000   gep ) of the mold ( 3002 ). 
     The distal axial portion ( 1041   d   1 ) typically has a portion length ( 1006   dsl ) along an axial path of travel of between about 1 mm and about 18 mm, more typically between about 2 mm and about 10 mm and more typically between about 2 mm and about 8 mm. 
     The exterior or circumferential surface ( 1041   cs ) can be straight, cylindrical, conical or sloped. 
     In such an apparatus, the actuator ( 1040 ,  1041 ,  1042 ) typically comprises an electric motor having an electrically driven rotor drivably interconnected to the valve pin in an arrangement that converts rotary motion of the rotor to linear motion of the valve pin ( 1041 ). 
     In such an apparatus, the gate ( 34 ,  36 ) of the one or more valves is disposed downstream of an upstream gate ( 32 ) of an upstream valve through which the injection fluid is injected into the cavity ( 30 ,  300 ) at a first time, the actuator ( 941 ,  942 ) driving the valve pin ( 1041 ,  1042 ) to open the gate ( 34 ,  36 ) at a second time following the first time such that the injection fluid injected through the gate ( 34 ,  36 ) is injected into a stream of injection fluid injected through the upstream gate ( 32 ) and has traveled downstream through the cavity ( 30 ,  300 ) past the gate ( 34 ,  36 ). 
     In such an apparatus, the valve pin is preferably adapted to be driven at the single selected rate of upstream acceleration up to the selected reduced upstream velocity over a path of travel of between about 1 mm and about 5 mm. 
     In such an apparatus the selected reduced upstream velocity is preferably less than about 75% of the maximum velocity. 
     In all such apparatuses described herein the apparatus can further comprise a position sensor ( 951 ,  952 ) adapted to sense position of the valve pin ( 141 ) or the actuator ( 941 ,  942 ), the position sensor being interconnected to and adapted to send one or more signals indicative of the position to the controller ( 16 ); 
     the controller including instructions that utilize the one or more signals indicative of the position to control the upstream rate of travel at any one or more of:
     (a) a selected rate of downstream deceleration ( 906 ) beginning from a selected position ( 906   o ) upstream of the gate closed position (GC) to the gate closed (GC) position,   (b) a selected rate of downstream deceleration ( 920 ) beginning from a selected intermediate upstream position ( 920   o ) to an intermediate zero velocity position ( 912 ),   (c) a selected rate of upstream deceleration ( 914 ) beginning from a selected intermediate position ( 914   o ) upstream of the gate closed position (GC) to an intermediate zero velocity position ( 916 ),   (d) a selected rate of downstream acceleration ( 908 ) beginning from an end of stroke (EOS) position or from an intermediate upstream zero velocity position ( 912 ),   (e) a selected rate of downstream deceleration ( 920 ) beginning from a selected intermediate upstream position ( 920   o ) to an intermediate zero velocity position ( 912 ),   (f) a selected constant velocity or rate of travel upstream or downstream over any portion of a duration of an injection cycle,   (g) a selected zero velocity over any portion of a duration of an injection cycle.   

     In another aspect of the invention there is provided a method of performing an injection cycle comprising:
     sensing a position of the valve pin ( 141 ) or the actuator ( 941 ,  942 )   utilizing the one or more signals indicative of the position to control the upstream rate of travel during the course of an injection cycle at any one or more of: 
   (a) a single selected rate of upstream acceleration beginning from a gate closed position (GC) up to a selected upstream position that is downstream of an end of stroke position,   (b) a selected rate of downstream deceleration ( 906 ) beginning from a selected position ( 906   o ) upstream of the gate closed position (GC) to the gate closed (GC) position,   (c) a selected rate of downstream deceleration ( 920 ) beginning from a selected intermediate upstream position ( 920   o ) to an intermediate zero velocity position ( 912 ),   (d) a selected rate of upstream deceleration ( 914 ) beginning from a selected intermediate position ( 914   o ) upstream of the gate closed position (GC) to an intermediate zero velocity position ( 916 ),   (e) a selected rate of downstream acceleration ( 908 ) beginning from an end of stroke (EOS) position or from an intermediate upstream zero velocity position ( 912 ),   (f) a selected rate of downstream deceleration ( 920 ) beginning from a selected intermediate upstream position ( 920   o ) to an intermediate zero velocity position ( 912 ),   (g) a selected constant velocity or rate of travel upstream or downstream over any portion of a duration of an injection cycle,   (h) a selected zero velocity over any portion of a duration of an injection cycle.   
   

     In another aspect of the invention there is provided a method of performing an injection molding cycle in an injection molding apparatus ( 10 ) comprising an injection molding machine ( 13 ) that injects a flow of injection fluid ( 18 ) to a heated manifold ( 40 ) that distributes the injection fluid ( 18 ) to a distribution channel that delivers the injection fluid to a gate ( 34 ,  36 ,  1000   g ,  3000   gep ) of a mold cavity ( 30 ,  3000 ) via one or more valves each comprised of an actuator ( 941 ,  942 ) interconnected to a valve pin ( 1041 ,  1042 ) having a linear axis (X) of travel, the method comprising:
     controlling the actuator ( 941 ,  942 ) to drive an interconnected valve pin ( 1041 ,  1042 ) having a distal axial portion ( 1041   d   1 ) having a selected distal configuration ( 1041   cs ) upstream and downstream through a downstream channel ( 1006 ) that has a downstream channel portion ( 1006   ds ) that has a control surface ( 1008 ) having a selected control surface configuration,   configuring the selected distal configuration ( 1041   cs ) of the valve pin ( 1041 ,  1042 ) and the selected control surface configuration of the control surface ( 1008 ) to interact with each other along a select path of upstream travel ( 1006   dsl ) of the valve pin beginning from a gate closed position (GC) to restrict rate of flow of the injection fluid ( 18 ) through the gate ( 34 ,  36 ) to less than a maximum rate of flow, controllably driving the actuator ( 941 ,  942 ) to drive the distal axial portion ( 1041   d   1 ) beginning from the gate closed, zero velocity position (GC) at a single selected rate of upstream acceleration ( 900 ) through the select path of upstream travel ( 1006   dsl ).   

     In such a method the actuator ( 941 ,  942 ) can be controllably driven to drive the distal axial portion ( 1041   d   1 ) beginning from the gate closed, zero velocity position (GC) at the single selected rate of upstream acceleration ( 900 ) up to a selected constant upstream velocity ( 902 ). 
     The selected constant upstream velocity ( 902 ) is typically less than a maximum velocity at which the valve pin ( 1041 ) is drivable. 
     In such a method the single selected rate of upstream acceleration ( 900 ) beginning from the gate closed, zero velocity position is typically selected to control flow of injection fluid ( 18 ) through the gate ( 34 ,  36 ) at a selected rate of flow of injection fluid ( 18 ) on driving the distal axial portion ( 1041   d   1 ) upstream at the single selected rate of upstream acceleration beginning from the gate closed, zero velocity position. 
     In such a method the single selected rate of upstream acceleration ( 900 ) is typically selected to reduce the rate of flow of injection fluid through a downstream gate ( 34 ,  36 ) to a selected reduced rate of flow of injection fluid that is less than a maximum rate of flow. 
     In such a method the selected distal configuration ( 1041   cs ) and the selected control surface configuration of the control surface ( 1008 ) are preferably selected to control flow of injection fluid ( 18 ) through the gate ( 34 ,  36 ) at a selected rate of flow on driving the distal axial portion ( 1041   d   1 ) upstream at the single selected rate of upstream acceleration beginning from the gate closed, zero velocity position. 
     The selected rate of flow of injection fluid ( 18 ) is preferably less than a maximum rate at which the injection fluid ( 18 ) is injectable through the gate ( 34 ,  36 ). Such a maximum rate of flow typically occurs when the distal axial portion ( 1041   d   1 ) or the valve pin ( 1041 ) is withdrawn to either a maximum upstream axial position to which the valve pin ( 1041 ) can be withdrawn or to an end of stroke (EOS) position. 
     In such a method the valve pin ( 1041 ) or the distal axial portion ( 1041   d   1 ) can be further driven at a selected rate of downstream deceleration ( 906 ) beginning from a selected position ( 906   o ) upstream of the gate closed position (GC) to the gate closed (GC) position. 
     In such a method the valve pin ( 1041 ) or the distal axial portion ( 1041   d   1 ) can be further driven at a selected rate of downstream deceleration ( 920 ) beginning from a selected intermediate upstream position ( 920   o ) to an intermediate zero velocity position ( 912 ). 
     In such a method the valve pin ( 1041 ) or the distal axial portion ( 1041   d   1 ) can be further driven at a selected rate of upstream deceleration ( 914 ) beginning from a selected intermediate position ( 914   o ) upstream of the gate closed position (GC) to an intermediate zero velocity position ( 916 ). 
     In such a method the valve pin ( 1041 ) or the distal axial portion ( 1041   d   1 ) can be further driven at a selected rate of downstream acceleration ( 908 ) beginning from an end of stroke (EOS) position or from an intermediate upstream zero velocity position ( 912 ). 
     In such a method the valve pin ( 1041 ) or the distal axial portion ( 1041   d   1 ) can be further driven at a selected rate of downstream deceleration ( 920 ) beginning from a selected intermediate upstream position ( 920   o ) to an intermediate zero velocity position ( 912 ). 
     Such a method preferably includes forming a sloped or configured, conical, cylindrical, straight or curvilinear channel or restriction gap (CG,  1006   rg ) disposed upstream of the gate ( 34 ,  1000   g ,  3000   gep ) to the mold cavity ( 30 ,  3000 ) having a control surface ( 1008 ) adapted to operate in combination with the distal axial portion ( 1041   d   1 ) and the single selected rate of upstream acceleration ( 900 ) to control flow of injection fluid ( 18 ) through the gate ( 34 ,  36 ) at a controllably selectable rate of flow on driving the distal axial portion ( 1041   d   1 ) upstream at the single selected rate of upstream acceleration beginning from the gate closed, zero velocity position. 
     The controllably selectable rate of flow of injection fluid ( 18 ) through the gate ( 34 ,  36 ) is preferably less than a maximum rate at which the injection fluid ( 18 ) is injectable through the gate ( 34 ,  36 ). 
     Such a method can include one or both of forming the control surface ( 1008 ) into one or both of a configuration disposed at a selected angle (AG) relative to a linear axis (X) of travel of the valve pin ( 1041 ) and forming the control surface ( 1008 ) with a portion ( 1006   dsp ) having a smallest radial diameter (CD,  1006   dsd ) that is greater than a largest diameter ( 1041   d   1   d ) of the distal axial portion ( 1041   d   1 ) by a selected distance or both. 
     Such a method can include forming an upstream channel portion ( 1006   us ) of the downstream channel ( 1006 ) that has a conical or tapered or sloped surface ( 1009 ) disposed upstream relative to the downstream channel portion ( 1006   ds ) and is sloped or angled (UAG) relative to the linear axis (A) or circumferential surface ( 1041   cs ) of the valve pin ( 1041 ) by an angle (UAG) and extends along an axial length (UCT) of the downstream channel ( 1006 ) such that flow of injection fluid ( 18 ) flows without significant restriction through the upstream channel portion ( 1006   us ). 
     Such a method can include selecting the angle (AG) to be between about 3 degrees and about 6 degrees. 
     Such a method can include selecting the angle (UAG) to be greater than the angle (AG). 
     Such a method can include disposing the control surface ( 1008 ) along an axial length (CT) of a path of travel of the valve pin ( 1041 ) of between about 3 mm and about 6 mm. 
     Such a method can include forming the control surface ( 1008 ) to have a smallest radial diameter (CD) or a portion ( 1006   dsp ) having smallest radial diameter (CD,  1006   dsd ) that is greater than a largest radial diameter ( 1041   md ) of the distal axial portion ( 1041   d   1 ) o between about 0.1 mm and about 0.8 mm. 
     Such a method preferably includes extending from the downstream channel portion ( 1006   ds ) an interior surface ( 1010 ) that extends along a distal end portion (DS) of the downstream channel ( 1006 ) that is disposed immediately downstream of the control surface ( 1008 ) and adapting the interior surface ( 1010 ) to engage or mate with the exterior surface ( 1041   cs ) of the distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) such that the selected gate ( 34 ,  100 G) is closed when the selected valve pin ( 1041 ) is axially positioned or driven to a position where the distal axial portion ( 1041   d   1 ) is disposed within the distal end portion (DS) of the downstream channel portion ( 1006   ds ). 
     Such a method preferably includes forming an angle (AG) in the control surface ( 1008 ) relative to the linear axis (A) that is selected to create a restriction in flow of the injection fluid through the channel gap (CG) into the mold cavity ( 30 ,  1000 ) that enables a controllable acceleration or deceleration in rate of flow of injection fluid ( 18 ,  1153 ) through the gate ( 34 ,  36 ) relative to acceleration or deceleration that occurs where the downstream channel ( 1006   ds ) is straight or cylindrical by controllable positioning or driving of a distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) along a path of travel within or through the channel gap (CG) beginning from a closed position downstream of the channel gap (CG) to a position upstream of the channel gap (CG) or beginning from a position upstream of the channel gap (CG) to a closed position downstream of the channel gap. 
     Such a method can include disposing or forming the conical or tapered or sloped or configured surface ( 1008 ) along or within a distal interior surface of an insert or extension ( 1003 ) disposed within a distal end of a main nozzle body ( 1004 ). 
     Such a method can include disposing or forming the control surface ( 1008 ) along or within a distal end interior surface of a main nozzle body ( 1004 ) or within a gate entry portion ( 3000   gep ) of the mold ( 3002 ). 
     Such a method can include controlling the rate of flow of injection fluid ( 18 ) through the channel gap (CG) to a selected rate of flow that is less than a maximum rate of flow by controllably driving a selected valve pin ( 1041 ,  1042 ) upstream at the single selected rate of upstream acceleration. 
     Such a method typically includes selecting the actuator ( 941 ,  942 ) to comprise an electric motor having an electrically driven rotor drivably interconnected to the valve pin in an arrangement that converts rotary motion of the rotor to linear motion of the valve pin ( 1041 ). 
     Such a method preferably includes disposing the gate ( 34 ,  36 ) of one or more of the valves downstream of an upstream gate ( 32 ) of an upstream valve through which the injection fluid is injected into the cavity ( 30 ,  300 ) at a first time, and driving the actuator ( 941 ,  942 ) interconnected to an associated valve pin ( 1041 ,  1042 ) to open the downstream disposed gate ( 34 ,  36 ) at a second time following the first time such that the injection fluid ( 18 ) injected through the gate ( 34 ,  36 ) is injected into a stream of injection fluid injected through the upstream gate ( 32 ) and has traveled downstream through the cavity ( 30 ,  300 ) past the gate ( 34 ,  36 ). 
     Such a method can include driving the valve pin ( 1041 ,  1042 ) at the single selected rate of upstream acceleration ( 900 ) up to the selected upstream velocity ( 902 ) over a path of travel of between about 1 mm and about 5 mm. 
     In such a method the valve pin ( 1041 ,  1042 ) is typically driven at a selected upstream velocity that is less than about 75% of a maximum velocity at which the valve pin is drivable. 
     In another aspect of the invention there is provided an injection molding apparatus ( 10 ) comprising an injection molding machine ( 13 ) that injects a flow of injection fluid ( 18 ) to a heated manifold ( 40 ) that distributes the injection fluid ( 18 ) to a distribution channel that delivers the injection fluid to a gate ( 34 ,  36 ,  1000   g ,  3000   gep ) of a mold cavity ( 30 ,  3000 ) via one or more valves each comprised of an actuator ( 941 ,  942 ) interconnected to a valve pin ( 1041 ,  1042 ) having a linear axis (X) of travel, 
     the apparatus further comprising a controller ( 16 ) interconnected to the actuator ( 941 ,  942 ) that includes instructions that instruct the actuator ( 941 ,  942 ) to drive an interconnected valve pin ( 1041 ,  1042 ) having a distal axial portion ( 1041   d   1 ) having a selected distal configuration ( 1041   cs ) upstream and downstream through a downstream channel ( 1006 ) that has a downstream channel portion ( 1006   ds ) that has a control surface ( 1008 ) having a selected control surface configuration,   wherein the selected distal configuration ( 1041   cs ) of the valve pin ( 1041 ,  1042 ) and the selected control surface configuration of the control surface ( 1008 ) are configured to interact with each other along a select path of upstream travel ( 1006   dsl ) of the valve pin beginning from a gate closed position (GC) to restrict rate of flow of the injection fluid ( 18 ) through the gate ( 34 ,  36 ) to less than a maximum rate of flow, the controller including instructions that instruct the actuator ( 941 ,  942 ) to drive the distal axial portion ( 1041   d   1 ) of the valve pin ( 1041 ,  1042 ) beginning from the gate closed, zero velocity position (GC) at a single selected rate of upstream acceleration ( 900 ) through the select path of upstream travel ( 1006   dsl ).   

     In another aspect of the invention there is provided a method of performing an injection molding cycle in an injection molding apparatus ( 10 ) comprising an injection molding machine ( 13 ) that injects a flow of injection fluid ( 18 ) to a heated manifold ( 40 ) that distributes the injection fluid ( 18 ) to a distribution channel that delivers the injection fluid to a gate ( 34 ,  36 ,  1000   g ,  3000   gep ) of a mold cavity ( 30 ,  3000 ) via one or more valves each comprised of an actuator ( 941 ,  942 ) interconnected to a valve pin ( 1041 ,  1042 ) having a linear axis (X) of travel, the method comprising:
     controlling the actuator ( 941 ,  942 ) to drive an interconnected valve pin ( 1041 ,  1042 ) having a distal axial portion ( 1041   d   1 ) having a selected distal configuration ( 1041   cs ) upstream and downstream through a downstream channel ( 1006 ) that has a downstream channel portion ( 1006   ds ) that has a control surface ( 1008 ) having a selected control surface configuration,   configuring the selected distal configuration ( 1041   cs ) of the valve pin ( 1041 ,  1042 ) and the selected control surface configuration of the control surface ( 1008 ) to interact with each other along a select path of upstream travel ( 1006   dsl ) of the valve pin beginning from a gate closed position (GC) to restrict rate of flow of the injection fluid ( 18 ) through the gate ( 34 ,  36 ) to less than a maximum rate of flow,   controllably driving the actuator ( 941 ,  942 ) to drive the distal axial portion ( 1041   d   1 ) at one or more of: 
   (a) a selected rate of downstream deceleration ( 906 ) beginning from a selected position ( 906   o ) upstream of the gate closed position (GC) to the gate closed (GC) position,   (b) a selected rate of downstream deceleration ( 920 ) beginning from a selected intermediate upstream position ( 920   o ) to an intermediate zero velocity position ( 912 ),   (c) a selected rate of upstream deceleration ( 914 ) beginning from a selected intermediate position ( 914   o ) upstream of the gate closed position (GC) to an intermediate zero velocity position ( 916 ),   (d) a selected rate of downstream acceleration ( 908 ) beginning from an end of stroke (EOS) position or from an intermediate upstream zero velocity position ( 912 ),   
   

     In such a method, the selected rate of downstream deceleration ( 906 ,  920 ), upstream deceleration ( 914 ) and downstream acceleration ( 908 ) is typically selected to control flow of injection fluid ( 18 ) through the gate ( 34 ,  36 ) at or to a selected rate of flow of injection fluid ( 18 ). 
     In another aspect of the invention there is provided an injection molding apparatus ( 10 ) comprising an injection molding machine ( 13 ) that injects a flow of injection fluid ( 18 ) to a heated manifold ( 40 ) that distributes the injection fluid ( 18 ) to a distribution channel that delivers the injection fluid to a gate ( 34 ,  36 ,  1000   g ,  3000   gep ) of a mold cavity ( 30 ,  3000 ) via one or more valves each comprised of an actuator ( 941 ,  942 ) interconnected to a valve pin ( 1041 ,  1042 ) having a linear axis (X) of travel, 
     the apparatus further comprising a controller ( 16 ) interconnected to the actuator ( 941 ,  942 ) that includes instructions that instruct the actuator ( 941 ,  942 ) to drive an interconnected valve pin ( 1041 ,  1042 ) having a distal axial portion ( 1041   d   1 ) having a selected distal configuration ( 1041   cs ) upstream and downstream through a downstream channel ( 1006 ) that has a downstream channel portion ( 1006   ds ) that has a control surface ( 1008 ) having a selected control surface configuration,   wherein the selected distal configuration ( 1041   cs ) of the valve pin ( 1041 ,  1042 ) and the selected control surface configuration of the control surface ( 1008 ) are configured to interact with each other along a select path of upstream travel ( 1006   dsl ) of the valve pin beginning from a gate closed position (GC) to restrict rate of flow of the injection fluid ( 18 ) through the gate ( 34 ,  36 ) to less than a maximum rate of flow,   the controller including instructions that instruct the actuator ( 941 ,  942 ) to drive the distal axial portion ( 1041   d   1 ) at one or more of:
   (a) a selected rate of downstream deceleration ( 906 ) beginning from a selected position ( 906   o ) upstream of the gate closed position (GC) to the gate closed (GC) position,   (b) a selected rate of downstream deceleration ( 920 ) beginning from a selected intermediate upstream position ( 920   o ) to an intermediate zero velocity position ( 912 ),   (c) a selected rate of upstream deceleration ( 914 ) beginning from a selected intermediate position ( 914   o ) upstream of the gate closed position (GC) to an intermediate zero velocity position ( 916 ),   (d) a selected rate of downstream acceleration ( 908 ) beginning from an end of stroke (EOS) position or from an intermediate upstream zero velocity position ( 912 ),   (e) a selected rate of downstream deceleration ( 920 ) beginning from a selected intermediate upstream position ( 920   o ) to an intermediate zero velocity position ( 912 ).   
   

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic side sectional view of an injection molding apparatus according to the invention. 
         FIG.  1 A  is a side schematic sectional view of a known valve with a downstream wide tapered flow channel and cylindrical valve pin configuration. 
         FIG.  2    is a side schematic sectional view of one embodiment of a valve configuration for use in the present invention. 
         FIG.  2 A  is an enlarged view of the downstream end of the  FIG.  3    valve. 
         FIG.  2 B  is an enlarged view similar to  FIG.  2 A  showing a downstream end with the gate disposed in the body of the mold plate. 
         FIG.  3    is a side schematic sectional view of another embodiment of a valve configuration for use in the present invention showing the valve pin in a gate closed position. 
         FIG.  4    is a view of the  FIG.  3    valve showing the valve pin in an upstream partially gate open position. 
         FIG.  5    is a view of the  FIG.  3    valve showing the valve pin in a fully upstream full gate open and end of stroke position (EOS). 
         FIG.  5 A  is a side sectional view of another embodiment of a valve configuration for use in the present invention showing the valve pin in a fully upstream full gate open and end of stroke position (EOS). 
         FIG.  5 B  is a view of the  FIG.  5 A  valve showing the valve pin in an upstream partially gate open position. 
         FIG.  5 C  is a view of the  FIG.  5 A  valve showing the valve pin in a fully gate closed position. 
         FIG.  6 A  is a plot of valve pin position versus time during an injection cycle using a valve configuration according the invention where the valve pin is controllably accelerated on opening and decelerated on approaching the end of stroke position. 
         FIG.  6 B  is a plot of valve pin position versus time during an injection cycle using a valve according the invention where the valve pin is controllably accelerated on opening and decelerated and then accelerated on reaching the end of stroke position and then decelerated on approaching the gate closed position. 
         FIG.  6 C  is a plot of valve pin position versus time during an injection cycle using a valve according the invention where the valve pin is controllably accelerated on opening and decelerated on reaching the end of stroke position and then accelerated on leaving the end of stroke position and then decelerated on approaching a hold position and then accelerated on leaving the hold position and then decelerated on reaching the gate closed position. 
         FIG.  7 A  is a fluid flow, fill or concentration or density map of a sequentially gated mold cavity using a conventional single velocity valve pin opening protocol and valves having conventional configurations that results in a sudden increase in melt or fluid velocity and then a subsequent decrease in melt or fluid velocity in the circled areas of the mold cavity into which the downstream gates labeled 2 and 3 deliver injection fluid from their associated downstream valve channels. 
         FIG.  7 B  is a plot of sprue pressure versus time as measured in the downstream valves labeled 2 and 3 in  FIG.  7 A  using the single pin velocity and conventional valve channel and pin configurations that generated the  FIG.  7 A  concentration or density map. 
         FIG.  8 A  is a fluid flow, fill or concentration map of a sequentially gated mold cavity using a conventional dual velocity, slow then fast valve pin opening protocol and valves having conventional configurations, resulting in a slight reduction relative to the protocol used to generate  FIG.  7 A , in melt or fluid velocity of flow into the cavity in the circled areas of the downstream valves 2 and 3, 
         FIG.  8 B  is a plot of sprue pressure versus time as measured in the downstream valves labeled 2 and 3 in  FIG.  8 A  using the two speed slow then fast pin velocity protocol and conventional valve channel and pin configurations that generated the  FIG.  7 A  fluid concentration or density map. 
         FIG.  9 A  is a fluid flow, fill density or concentration map of a sequentially gated mold cavity as used in the  FIGS.  7 A,  8 A  systems, but instead using a controlled upstream beginning from gate closed single rate of valve pin acceleration protocol according to the invention resulting in a significantly more smooth and uniform distribution and flow of melt fluid delivered from the gates of valves 2 and 3 as well as from the gates of other downstream valves labeled 4, 5, 6 relative to the less uniform melt fluid flow or distribution resulting from use of the pin drive protocols that generates the  FIGS.  7 A and  8 A  distribution maps. 
         FIG.  9 B  is a plot of sprue pressure versus time as measured in the downstream valves labeled 2 and 3 in  FIG.  9 A  using the controlled pin acceleration protocol and the novel valve channel and pin configurations as described herein. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG.  1    shows an injection molding apparatus  10  having a center valve  32  with associated actuator ( 940 ) and two downstream valves  34 ,  36  with associated actuators ( 941 ,  942 ) that are opened to a mold cavity  30  in a predetermined sequence after the center valve is first opened, the actuators ( 940 ,  941 ,  942 ) each comprising an electric motor having an electric drive ( 940   d ,  941   d ,  942   d ). The electric drive ( 940   d ,  941   d ,  942   d ) can be housed within the same housing ( 940   h ,  941   h ,  942   h ) as the driver components of the electric actuator ( 940 ,  941 ,  941 ), or the electric drive ( 940   d ,  941   d ,  942   d ) can be housed within a physically separate thermally conductive housing ( 941   ds ). 
     The electric drive ( 940   d ,  941   d ,  942   d ) is preferably mounted on or to the actuator housing ( 940   h ,  941   h ,  942   h ) in some manner such that the drive components such as a Pulse Width Modulator (PWM) and associated electrical components are disposed in substantial heat communication or contact with the actuator housing ( 940   h ,  941   h ,  942   h ) or the heated manifold ( 40 ). 
     As shown in  FIG.  1    the injection cycle is a cascade process where injection is effected in a sequence from the center nozzle  22  and gate  32  first and at a later predetermined time from the lateral nozzles  20 ,  24  and gates  34 ,  36  typically after the injection fluid  18  has flowed downstream from the center gate  32  past the downstream gates  34 ,  36 . The injection cycle is typically started by first opening the pin  1040  of the center nozzle  22  and allowing the fluid material  18 ,  100  (typically polymer or plastic material) to flow up to a position  100   a  in 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.  1   . 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  100   p  just past the positions  34 ,  36 . Once the fluid material has travelled just past  100   p  of the lateral gate positions  34 ,  36 , the center gate  32  of the center nozzle  22  is typically closed by pin  1040 . The lateral gates  34 ,  36  are then opened by upstream withdrawal of lateral nozzle pins  1041 ,  1042 . As described below, the rate of acceleration or upstream withdrawal or travel velocity of lateral pins  1041 ,  1042  can be controlled to minimize potential problems with the filling of the mold cavity. 
     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 ,  3000  through both the center gate  32  and one or both of the lateral gates  34 ,  36  simultaneously. 
     The rate of acceleration  900 ,  918 ,  908  or deceleration  904 ,  906 ,  920  of pins  1041 ,  1042  starting from any axial position is controlled via controller  16  which controls the rate and direction of drive of the electric actuators  940 ,  941 ,  942 . 
     The single selected rate of upstream acceleration ( 900 ) is typically selected to reduce the rate of flow of injection fluid through a downstream gate ( 34 ,  36 ) to a selected reduced rate of flow that minimizes a reduction in injection fluid flow through an upstream gate ( 32 ) that is opened at a first time prior to a delayed second time during an injection cycle when a downstream gate ( 34 ,  36 ) is opened in a sequential or cascade process. The single selected rate of upstream acceleration ( 900 ) beginning from a gate closed (GC) position is typically selected to reduce the rate of flow of injection fluid through a downstream gate ( 34 ,  36 ) to a selected reduced rate that is less than a maximum rate of flow at which the injection fluid ( 18 ) flows at an end of stroke (EOS) position. 
     The user programs controller  16  via data inputs on a user interface to instruct the electric actuators to drive pins  1041 ,  1042  at an upstream or downstream rate of acceleration from zero to a selected velocity of travel that is selected to minimize potential problems with filing of the mold cavity. 
       FIG.  1    shows position sensors  950 ,  951 ,  952  for sensing the position of the motors  940 ,  941 ,  942  and their associated valve pins (such as  1040 ,  1041 ,  1042 ) 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 first withdrawn upstream beginning in a gate closed GC zero velocity position as shown for example in  FIGS.  3 ,  5 C,  6 A,  6 B,  6 C  the pins are withdrawn at a single selected rate of acceleration  900  beginning from zero velocity to a selected constant upstream velocity  902  that is greater than zero and is typically less than a maximum velocity at which actuator is capable of driving the valve pin  1041 ,  1042 . Similarly, when the pins  1041 ,  1042  have been withdrawn upstream close to a fully upstream end of stroke (EOS) position, the pins can be controllably decelerated at a single selected rate of deceleration  904  typically to zero velocity. Similarly again, the pins  1041 ,  1042  can be driven at a single rate of downstream directed acceleration  908  beginning from the end of stroke position (EOS) toward a selected downstream directed constant velocity  910 . Similarly again, when the pins  1041 ,  1042  approach a fully downstream gate closed position, the pins  1041 ,  1042  can be decelerated at a selected rate of deceleration  906  to zero velocity at which the pins have typically reached the gate closed position GC. 
     The rate of flow of injection fluid through the downstream channel portion ( 1006   ds ) and the gate ( 34 ,  36 ) is typically at a maximum rate for any given injection cycle when the valve pin is disposed in the end of stroke (EOS) position. And, the rate of flow of injection flow is at reduced rate less than the maximum rate when the distal end of the valve pin ( 1041   d   1 ) is disposed within the downstream channel portion ( 1006   ds ). The end of stroke position (EOS) may not necessarily be the furthest upstream position to the which valve pin can be withdrawn. It is possible that the rate of flow of injection fluid could be even higher when the valve pin is withdrawn to a position further upstream than the end of stroke position (EOS). However, where an end of stroke position (EOS) is selected that is downstream of the furthest upstream position to which the valve pin can be withdrawn, the rate of flow of injection fluid will be at a maximum rate for any given injection cycle when the valve pin reaches the end of stroke position (EOS) selected for the given injection cycle even though the valve pin could be withdrawn even further upstream to a maximum upstream position where the rate of injection fluid flow could be at an absolute maximum even higher than the rate of flow when the valve pin is in the end of stroke position. It is also possible that the absolute maximum rate of injection fluid flow is achieved when the valve pin is disposed in the end of stroke (EOS) position even though the valve pin is not disposed in the absolute furthest upstream position to which it could be withdrawn. It is also possible that the end of stroke (EOS) position could be selected to be the absolute furthest upstream position to which the valve pin could be withdrawn. But not necessarily. 
     Movement of the pins  1041 ,  1042  can be further controlled to decelerate the pins at a selected rate of deceleration  914  to a zero velocity position  916  that is downstream of the end of stroke EOS position such that the pins  1041 ,  1042  remain in a selected intermediate, zero velocity position  916  between gate closed GC and end of stroke EOS for a selected period of time,  FIG.  6 A . The pins  1041 ,  1042  can then be again accelerated  918  upstream to an upstream velocity  922 . After having been accelerated  918  to the upstream velocity  922 , the valve pins  1041 ,  1042  can then again be decelerated  918  to terminate in the end of stroke EOS upstream position. 
     As shown in  FIGS.  2 ,  2 A,  2 B,  3 ,  4 ,  5 ,  5 A,  5 B,  5 C , a downstream valve disposed downstream of an upstream center or main valve is comprised of an actuator ( 941 ,  942 ) interconnected to a valve pin ( 1041 ,  1042 ) having a linear axis (X) of travel in an arrangement wherein the actuator ( 941 ,  942 ) is adapted to controllably drive an interconnected valve pin ( 1041 ,  1042 ) upstream and downstream through a downstream channel ( 1006 ) that has a downstream channel portion ( 1006   ds ) that has a control surface ( 1008 ). The control surface ( 1008 ) can be sloped, conical, cylindrical, straight or curvilinear and forms a channel or restriction gap (CG,  1006   rg ). The size or configuration of the channel or restriction gap is pre selected in combination with a single selected rate of acceleration of the pin  1041 ,  1042  beginning from the gate closed position up to a predetermined constant velocity that is preferably less than a maximum velocity at which the actuator is capable of driving the pin  1041 ,  1042 . The channel or restriction gap CG,  1006   rg  is disposed immediately upstream of the gate  34 ,  1000   g ,  3000   gep  to the mold cavity  30 ,  3000 . 
     As shown in  FIGS.  2 ,  2 A,  2 B,  3 ,  4 ,  5 ,  5 A,  5 B,  5 C , the valve pin ( 1041 ) has a distal axial portion ( 1041   d   1 ) that is controllably drivable upstream and downstream via a controller  16  interconnected to the actuator  941 ,  942 . The controller  16  includes a program that contains instructions that instruct the actuator  941 ,  942  to drive the valve pin  1041 ,  1042  through the channel or restriction gap (CG,  1006   rg ) and more particularly to controllably drive a distal axial portion ( 1041   d   1 ) of the valve pin  1041 ,  1042  beginning from a gate closed, zero velocity position at a single selected rate of upstream acceleration up to a selected reduced upstream velocity that is less than a maximum velocity at which the valve pin ( 1041 ) is drivable by the actuator  941 . 
     The size or configuration of the channel or restriction gap (CG,  1006   rg ) and the single selected rate of upstream acceleration are selected in combination with each other to control flow of injection fluid ( 18 ) through the channel gap (CG,  1006   rg ) at a selected rate of flow on driving the distal axial portion ( 1041   d   1 ) upstream at the single selected rate of upstream acceleration beginning from the gate closed, zero velocity position to the selected upstream velocity that is greater than zero and less than a maximum. 
     As shown in  FIGS.  2 ,  2 A,  2 B,  3 ,  4 ,  5 ,  5 A,  5 B,  5 C , the size or volume of the channel or restricted gap (CG,  1006   rg ) is selected by selecting one or the other or both of an angle (AG) between the control surface ( 1008 ) and the linear axis (X) of travel of the valve pin ( 1041 ) and optionally also by further selecting a smallest diameter (CD,  1006   dsd ) of the control surface ( 1008 ) or a portion ( 1006   dsp ) of the control surface that has a smallest radial diameter that is greater than a largest diameter ( 1041   d   1   d ) of the distal axial portion ( 1041   d   1 ) by a selected distance. 
     In the embodiments shown in  FIGS.  2 ,  2 A,  2 B,  3 ,  4 ,  5 ,  5 A,  5 B,  5 C , the downstream channel ( 1006 ) preferably includes an upstream channel portion ( 1006   us ) that has a conical or tapered or sloped surface ( 1009 ) disposed upstream relative to the downstream channel portion ( 1006   ds ) and is sloped or angled (UAG) relative to the linear axis (A) or circumferential surface ( 1041   cs ) of the valve pin ( 1041 ) by an angle (UAG). As shown, the upstream channel portion extends along an axial length (UCT) of the downstream channel ( 1006 ) such that flow of injection fluid ( 18 ) flows without significant restriction through the upstream channel portion ( 1006   us ). 
     In the embodiments shown, the control surface ( 1008 ) is conical or sloped and has a slope or angle (AG) relative to the linear axis (A) or circumferential surface ( 1041  cs) of the valve pin ( 1041 ) of between about 3 degrees and about 6 degrees. The angle (UAG) is greater than the angle (AG). 
     Preferably the control surface ( 1008 ) is conical or sloped and disposed along an axial length (CT) of between about 3 mm and about 6 mm. 
     The control surface ( 1008 ) typically has a smallest radial diameter (CD,  1006   dsd ) or a portion ( 1006   dsp ) that has a smallest radial diameter that is greater than a largest radial diameter ( 1041   md ) of the distal axial portion ( 1041   d   1 ) by between about 0.1 mm and about 0.8 mm. 
     As shown, the downstream channel portion ( 1006   ds ) has an interior surface ( 1010 ) extending along a distal end portion (DS) of the downstream channel ( 1006 ) that is disposed immediately downstream of the control surface ( 1008 ) and is adapted to engage or mate with the exterior surface ( 1041   cs ) of the distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) such that the selected gate ( 34 ,  100 G) is closed when the selected valve pin ( 1041 ) is axially positioned or driven to a position where the distal axial portion ( 1041   d   1 ) is disposed within the distal end portion (DS) of the downstream channel portion ( 1006   ds ). 
     The conical or tapered or sloped surface ( 1008 ) is selectively sloped or angled relative to the linear axis (A) by an angle (AG) selected to create a restriction in flow of the injection fluid through the channel gap (CG) into the mold cavity ( 30 ,  1000 ). The restriction in flow of injection enables a controllable acceleration or deceleration in rate of flow of injection fluid ( 1153 ) through the gate relative to acceleration or deceleration that occurs where the channel surface is straight or cylindrical by controllable positioning or driving of a distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) along a path of travel within or through the channel gap (CG) beginning from a closed position downstream of the channel gap (CG) to a position upstream of the channel gap (CG) or beginning from a position upstream of the channel gap (CG) to a closed position downstream of the channel gap. 
     As shown in  FIGS.  2 ,  2 A,  3 ,  4 ,  5 ,  5 A,  5 B,  5 C  the control surface ( 1008 ) is typically disposed along or within a distal interior surface of an insert or extension ( 1003 ) disposed within a distal end of a main nozzle body ( 1000 ,  1004 ). 
     As shown in  FIG.  2 B  the conical or tapered or sloped surface ( 1008 ) can be disposed or formed along or within a distal end interior surface of a main nozzle body ( 1000 ,  1004 ) or disposed or formed within a gate entry portion ( 3000   gep ) of the mold itself ( 3002 ). 
     The rate of flow of injection fluid ( 18 ) through the channel gap (CG,  1006   rg ) is controllable to a selected rate of flow that is less than a maximum rate of flow by controllably driving the selected valve pin upstream at the single selected rate of upstream acceleration. 
     The actuator ( 1041 ,  1042 ) can comprise an electric motor having an electrically driven rotor drivably interconnected to the valve pin in an arrangement that converts rotary motion of the rotor to linear motion of the valve pin ( 1041 ). 
     In a preferred embodiment, the gate ( 34 ,  36 ) through which fluid is injected by controlled upstream acceleration of a valve pin  1041 ,  1042  is disposed downstream of a main or center upstream gate  32  of an upstream valve through which the injection fluid is first injected into the cavity ( 30 ,  300 ) at a first time. The actuator ( 941 ,  942 ) driving the downstream valve pin ( 1041 ,  1042 ) drives the valve pin  1041 ,  1042  upstream at the controlled single rate of acceleration to open the gate ( 34 ,  36 ) at a second time subsequent to or following the first time such that the injection fluid  18  is injected through the downstream gate ( 34 ,  36 ) after the stream of injection fluid  18  previously injected through the upstream gate  32  has traveled downstream past the downstream gate ( 34 ,  36 ). 
     The controller  16  is typically provided with instructions that instruct the valve pin to be driven at the single selected rate of upstream acceleration up to the selected reduced upstream velocity over a path of travel of between about 1 mm and about 5 mm. 
     The controller  16  is typically provided with instructions that instruct the valve pin to be driven at the selected reduced upstream velocity at preferably less than about 75% of the maximum velocity at which the actuator  941 ,  942  is capable of driving the valve pin. 
     As shown in  FIGS.  6 A,  6 B,  6 C  the controller  16  can include instructions that instruct the actuator  941 ,  942  to controllably drive the valve pin downstream beginning from a selected open gate position ( 906   o ) that is upstream of a gate closed position (GC) at a single selected rate of downstream deceleration ( 906 ) to the gate closed position (GC). In such an embodiment, the configuration of the control surface ( 1008 ) can be selected to interact with the distal axial portion  1041   d  such that flow of injection fluid ( 18 ) through the channel gap (CG) is controllable to a selected rate of flow by controllably driving the selected valve pin  1041 ,  1042  downstream at the single selected rate of downstream deceleration  906  beginning from the selected open gate position ( 906   o ) to the gate closed position (GC). 
     As shown in  FIGS.  6 B,  6 C  the controller  16  can include instructions that instruct the actuator  941 ,  942  to controllably drive the valve pin upstream beginning from a selected open gate position ( 904   o ) that is downstream of an open gate end of stroke position (EOS) at a single selected rate of upstream deceleration ( 904 ) to the open gate end of stroke position (EOS). In such an embodiment, the control surface ( 1008 ) is formed to have a channel gap (CG) configuration in combination with the configuration of the distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) such that the flow of injection fluid ( 18 ) through the channel gap (CG) is controllable as the valve pin  1041  reaches the end of stroke EOS position by controllably driving the selected valve pin  1041  upstream at the single selected rate of upstream deceleration ( 904 ) beginning from the selected open gate position ( 904   o ) to the open gate end of stroke position (EOS). 
     As shown in  FIG.  6 A , the controller  16  can include instructions that instruct the actuator  941 ,  942  to controllably drive the valve pin upstream beginning from a selected open gate position ( 914   o ) that is downstream of a gate open end of stroke position (EOS) at a single selected rate of upstream deceleration to a selected intermediate, zero velocity position ( 916 ) between gate closed GC and end of stroke EOS for a selected period of time. In such an embodiment the selected size and configuration of the restriction gap ( 1006   rg ) is selected in combination with the configuration of the distal end portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) such that the flow of injection fluid ( 18 ) through the restriction gap ( 1006   rg ) is controllable to a selected rate of flow by controllably driving the selected valve pin upstream at the single selected rate of upstream deceleration beginning from the selected open gate position ( 914   o ) to the selected intermediate, zero velocity position ( 916 ) between gate closed GC and end of stroke EOS for a selected period of time. 
     As shown in  FIG.  6 C  the controller  16  can include instructions that instruct the actuator  941 ,  942  to controllably drive the valve pin at a single selected rate of downstream directed acceleration ( 908 ) toward a selected downstream directed constant velocity  910 . In such an embodiment, the control surface ( 1008 ) can be formed to have a channel gap (CG) configuration in combination with the configuration of the distal axial portion ( 1041   d   1 ) of the selected valve pin ( 1041 ) such that flow of injection fluid ( 18 ) through the restriction gap ( 1006   rg ) is controllable to a selected rate of flow by controllably driving the selected valve pin ( 1041 ,  1042 ) at the single rate of downstream directed acceleration ( 908 ) toward the selected downstream directed constant velocity  910 .