End effector with multiple pick-up members

Abstract

An end effector for use with a moving device has a frame and a plurality of operational members mounted for movement on the frame. The effector also has an actuation mechanism directly connected to a first operational member and is operable to move the first operational member from a first position to a second position, and from the second position to the first position. A linking apparatus is provided for linking the first operational member to a second operational member. The actuation mechanism moves the first operational member from the first position to the second position, and results in the second operational member being moved by the linking apparatus from a third position to a fourth position. The operational members can be pick up members for picking up items at one pitch and releasing them at a second pitch.

We claim: 
     
         1 . An end effector for use with a moving device, said end effector comprising:
 a) a frame;   b) a plurality of operational members mounted for longitudinal movement on said frame;   c) an actuation mechanism directly connected to a first operational member of said plurality of operational members and operable to move said first operational member from a first position to a second position in,   d) a linking apparatus for linking said first operational member to a second operational member of said plurality of operational members said second operational member not directly connected to said actuation mechanism;   wherein when said actuation mechanism moves said first operational member from said first position to said second position, said second operational member is moved by said linking apparatus from a third position to a fourth position;   and wherein said actuation mechanism comprises:
 i) at least one cam block having a cam slot in an upper surface of said cam block said cam slot extending in a generally transverse direction that is generally orthogonal to the direction of longitudinal movement and across said upper surface of said cam block, said cam block also being mounted for longitudinal movement relative to said frame; 
 ii) a generally longitudinally oriented member attached to said cam block and to said first operational member; 
 iii) a rotary cam mounted and operable for rotation about an axis that is generally orthogonal to said direction of longitudinal movement and said transverse direction, said rotary cam having at least one cam follower protruding from said rotary cam, wherein said at least one cam follower is positioned to move transversely inside said cam slot of said cam block and move said cam block in a longitudinal direction during rotation of said rotary cam. 
   
     
     
         2 . An end effector as claimed in  claim 1  wherein said actuation mechanism is directly connected to a third operational member of said plurality of operational members and is operable to move said third operational member from a fifth position to a sixth position, and from said sixth position to said fifth position, said linking apparatus also for linking said third operational member to a fourth operational member of said plurality of operational members;
 and wherein when said actuation mechanism moves said third operational member from said fifth position to said sixth position, said fourth operational member is moved by said linking apparatus from a seventh position to an eighth position; 
 and wherein said at least one cam block comprises: 
 a) a first cam block having a first cam slot in an upper surface of said first cam block extending generally in said transverse direction across said upper surface of said first cam block, said first cam block being mounted for longitudinal movement relative to said frame; 
 b) a second cam block having a second cam slot in an upper surface of said second cam block extending generally in said transverse direction across said upper surface of said second cam block, said second cam block being positioned in parallel longitudinal relation to said first cam block and being mounted for longitudinal movement relative to said frame; 
 and wherein said actuation mechanism further comprises:
 i) a first rod attached to said first cam block and to said first operational member; 
 ii) a second rod attached to said second cam block and said third operational member; 
 iii) and wherein said rotary cam has a first cam follower protruding from said rotary cam and wherein said first cam follower is positioned to move transversely inside said first cam slot of said first cam block and push said first cam block in a first direction during rotation of said rotary cam in a first rotational direction, and said rotary cam having a second cam follower protruding from said rotary cam, wherein said second cam follower is positioned to move transversely inside said second cam slot of said second cam block and push said second cam block in a direction opposite to said first direction during rotation of said rotary cam in said first rotational direction about said axis. 
 
 
     
     
         3 . An end effector as claimed in  claim 2  further comprising a rotatable shaft for driving said rotary cam about said vertical axis, and wherein said rotatable shaft is driven by a motor associated with said moving device. 
     
     
         4 . An end effector as claimed in  claim 3  further comprising a controller for controlling the motor and thus the rotation of said rotatable shaft. 
     
     
         5 . An end effector as claimed in  claim 2  wherein when said actuation mechanism moves said first operational member from said second position to said first position, said second operational member is moved by said linking apparatus from said fourth position to said third position. 
     
     
         6 . An end effector as claimed in  claim 2  wherein said linking apparatus is configured such that when said first operational member is at said first position and said second operational member is at said third position, the spacing between said first and second operational members is less than said spacing when said first operational member is at said second position and said second operational member is at said fourth position. 
     
     
         7 . An end effector as claimed in  claim 6  further comprising a fifth operational member, said fifth operational member not directly connected to said actuation mechanism, said fifth operational member linked by said linking apparatus to said second operational member, wherein when said actuation mechanism moves said first operational member from said first position to said second position, said second operational member is moved by said linking apparatus from a third position to a fourth position, and said fifth operational member is moved by said linking apparatus from a ninth position to a tenth position, and when said actuation mechanism moves said first operational member from said second position to said first position, said second operational member is moved from said fourth position to said third position, and said fifth operational member is moved from said tenth position to said ninth position. 
     
     
         8 . An end effector as claimed in  claim 2  wherein said first, second, third, and fourth operational members are pick up members adapted to pick up and release at least one item. 
     
     
         9 . An end effector as claimed in  claim 8  further comprising a vacuum source that is interconnected to provide vacuum to said first, second third and fourth pick-up members, wherein said vacuum source creates a suction force at a suction location on each of said first, second, third and fourth pick-up members, to lift and hold said at least one item. 
     
     
         10 . A method for carrying out a first operation on a plurality of items delivered at a first pitch and carrying out a second operation on said plurality of items at a second pitch using an end effector connected to a robot, said method comprising:
 a) actuating a first of a plurality of operational members mounted for longitudinal movement on a body of said end effector and causing one or more operational members connected to said first operational member to be pulled in a first direction to a pre-determined end position of each said operational member, wherein at said first end position of each said operational member, said plurality of operational members are spaced at said first pitch and wherein said plurality of operational members are each in fully diverged positions;   b) performing a first operation on said plurality of items;   c) actuating said first operational member and causing the said one or more operational members connected to said first operational member to be moved in a direction opposite to said first direction to a second pre-determined end position, wherein at said second end position, said plurality of operational members is at said second pitch and wherein said plurality of operational members are in fully converged positions;   d) performing said second operation on said plurality of items.   
     
     
         11 . The method of  claim 10  wherein said one or more operational members are located at arbitrary positions with non-uniform spacing during moving between said fully diverged position and said fully converged position. 
     
     
         12 . The method of  claim 10  wherein said first operation comprises picking up an item. 
     
     
         13 . The method of  claim 12  wherein said second operation comprises releasing an item. 
     
     
         14 . A method for lifting and transferring items from a first location to a receptacle using an end effector attached to a robot, said method comprising:
 a) moving said robot to position said end effector above a first batch of said items;   b) moving a first operational member of said end effector that is movable longitudinally to a position directly above a first item of said first batch of said items, and using a linking apparatus connecting a second operational member to said one operational member to move said second operational member to a position directly above a second item of said first batch of said items, wherein said first and second operational members are in fully diverged positions;   c) lowering said end effector so that said operational members can pick up said first and second items;   d) raising said end effector;   e) moving said robot to reposition said end effector above a receptacle;   f) moving said first operational member with said actuation apparatus and causing said second operational member connected by said linking apparatus to move said first and second operational members into fully converged positions;   g) lowering said end effector toward said receptacles so that said first batch of said items are placed inside said receptacle;   h) releasing said first batch of said items from said operational members;   i) raising said end effector from above said receptacle;   wherein said first and second operational members are at arbitrary positions during movement between said fully diverged positions and said fully converged positions.   
     
     
         15 . The method of  claim 13  wherein said first batch of said items is held by said operational members using suction force created by a vacuum force interconnected to said operational members. 
     
     
         16 . An end effector for use with a moving device, said end effector comprising:
 a) a frame;   b) first, second and third operational members mounted in series on said frame for longitudinal movement along said frame;   c) a first and second link protrusion extending from said second and third operational members;   d) at least one tie link for linking said first, second and third operational members;   e) an actuation mechanism directly connected to said first operational member and operable to move with reciprocating movement said first operational member, in a first longitudinal direction from a first position to a second position, and in a second direction opposite to said first direction, from said second position to said first position, said actuation mechanism not directly connected to said second and third operational members;   wherein said at least one tie link has at least two longitudinally extending apertures each for receiving said first and second link protrusions respectively   and wherein each aperture in said tie link is adapted to allow longitudinal reciprocating movement within said aperture, said end effector being operable such that when said actuation mechanism moves said first operational member from said first position to said second position, said first operational member is moved away from said second and said third operational member, and said first link protrusion and said second link protrusion in said at least two apertures of said tie link moves in said apertures to a respective outer edge of said at least two apertures, and wherein said second and third operational members are pulled in said first direction by said at least one tie link.   
     
     
         17 . An apparatus as claimed in  claim 16  wherein when said actuation mechanism moves said first operational member from said second position to said first position, said first operational member is moved towards said second operational member and moves said second operational member which in turn moves said third operational member and said first link protrusion and said second link protrusion in said at least two apertures of said first tie link moves in said aperture towards respective inner edges of said at least two apertures. 
     
     
         18 . An apparatus for moving a plurality of items comprising:
 a) a frame;   b) a plurality of operational members mounted to said frame for longitudinal movement on said frame;   c) an actuation mechanism mounted to said frame and directly connected to a first operational member of said plurality of operational members and operable to move said first operational member longitudinally from a first position to a second position, and from said second position to said first position;   d) a linking apparatus for linking longitudinally said first operational member to a second operational member of said plurality of operational members, said second operational member being not directly connected to said actuation mechanism;   e) a rotary actuator connected to said actuation mechanism, said rotary actuator having at least a portion rotatable about an axis that is generally orthogonal to said direction of longitudinal movement;   wherein rotation of said rotary actuator causes movement of said actuation mechanism and wherein when said actuation mechanism moves said first operational member longitudinally from said first position to said second position, said second operational member is moved in said direction of longitudinal movement by said linking apparatus from a third position to a fourth position.   
     
     
         19 . The apparatus of  claim 18  further comprising a robot having a robot arm, wherein said robot arm comprises a drive mechanism proximate to a distal end of said robot arm, said drive mechanism for driving said rotary actuator.