Packer machine

Abstract

A wrapping wheel forming part of a cigarette packer is equipped with at least one conveying head that presents a pocket and is carried by the wheel along a feed path, passing through a first station at which a product is directed into the pocket, then through a second station at which a leaf of wrapping material is laid over the pocket and pinned in a predetermined position by pivoted grippers, and finally through an outfeed station where the product is ejected from the pocket, paired with the wrapping leaf and transferred together with the leaf to a further wrapping wheel; the grippers are operated by direct interaction with suitable transmission and shifter components positioned outside the peripheral compass of the wrapping wheel.

1 ) A packer machine comprising: 
 a conveying wheel affording at least one pocket internally of which to accommodate a product and at least one predetermined placement area in which to accommodate a leaf of wrapping material destined to envelop the product, set in rotation about a center axis in such a way as to advance the product and the leaf of wrapping material along a feed path;    a first infeed station located along the feed path, at which a product is directed into the pocket; a second infeed station located along the feed path, at which a single leaf of wrapping material is directed into the predetermined placement area, and means by which a product is ejected from the conveying wheel and transferred together with a relative leaf of wrapping material to external conveying means;    retaining means by which the single leaves of wrapping material can be held in the at least one predetermined placement area, comprising at least one gripper capable of movement between a first stable position, in which a leaf of wrapping material is retained and held in contact with the predetermined placement area, and a second stable position in which the leaf of material is released.    
   
   
       2 ) A packer as in  claim 1 , wherein the gripper is positioned on the wheel and fulcrumed to a respective axis in such a way as to pivot between the first stable retaining position and the second stable release position.  
   
   
       3 ) A packer as in  claim 1 , wherein the retaining means comprise holding means designed to ensure the gripper is maintained in the stable positions.  
   
   
       4 ) A packer as in  claim 3 , wherein the holding means comprise at least a first portion of ferromagnetic material associated with the gripper and a second portion of ferromagnetic material associated rigidly with the wheel, the first portion and second portion of ferromagnetic material being attractable one to another.  
   
   
       5 ) A packer as in  claim 4 , wherein the first portion and the second portion of ferromagnetic material are disposed substantially in contact one with another when the gripper occupies the first stable retaining position, separated only by an interposed leaf of wrapping material.  
   
   
       6 ) A packer as in  claim 3 , wherein the holding means further comprise a third portion of ferro-magnetic material associated with the gripper and a fourth portion of ferromagnetic material associated rigidly with the wheel, the third portion and fourth portion of ferromagnetic material being attractable one to another.  
   
   
       7 ) A packer as in  claim 6 , wherein the third portion and fourth portion of ferromagnetic material are disposed substantially in contact one with another when the gripper occupies the second stable release position.  
   
   
       8 ) A packer as in  claim 1 , comprising actuator means by which the gripper is caused to alternate between the first stable retaining position and the second stable release position.  
   
   
       9 ) A packer as in  claim 8 , wherein actuator means comprise a transmission component positioned outside the dimensional compass of the conveying wheel and in such a way as to intercept the movable gripper when occupying the second stable position, substantially at the moment when the leaf of wrapping material is directed into the predetermined placement area.  
   
   
       10 ) A packer as in  claim 9 , wherein the transmission component is a roller freely rotatable about an axis substantially parallel to the center axis of the wheel.  
   
   
       11 ) A packer as in  claim 8 , wherein actuator means comprise a shifter component such as will engage the movable gripper when occupying the first stable position and force it to assume the second stable position in which the leaf of wrapping material is released.  
   
   
       12 ) A packer as in  claim 11 , wherein the shifter component comprises a lever operated by a respective motor.  
   
   
       13 ) A packer as in  claim 11 , wherein the shifter component comprises a pneumatic or hydraulic actuator.  
   
   
       14 ) A packer as in  claim 11 , wherein the shifter component comprises magnetic repulsion means.  
   
   
       15 ) A packer as in  claim 14 , wherein magnetic repulsion means comprise at least one electromagnet installed on a part of the machine outside the dimensional compass of the conveying wheel, fixed relative to the selfsame wheel in a position facing the second arm of the gripper and designed to exert a magnetic repulsion force on the selfsame arm.  
   
   
       16 ) A packer as in  claim 1 , wherein the gripper is carried by a respective mounting, and the conveying wheel comprises means by which to house the mounting, located on a peripheral area of the selfsame wheel and designed to establish a plurality of different angular positions assumable by the mounting relative to the axis of the wheel, each such position allowing the predetermined placement area to accommodate a different size of wrapping leaf.  
   
   
       17 ) A packer as in  claim 16 , wherein housing means comprise a plurality of holes arranged in succession along a circumferential segment of the conveying wheel, such as will accept respective fastening elements designed to engage the mounting.  
   
   
       18 ) A packer as in  claim 17 , wherein the mounting affords an area engageable by the fastening means.  
   
   
       19 ) A packer as in  claim 18 , wherein the engageable area comprises at least one clearance opening through which the fastening means are insertable.  
   
   
       20 ) A packer as in  claim 18 , wherein at least one clearance opening is fashioned as a slot allowing fine adjustment of the position of the mounting relative to the wheel.  
   
   
       21 ) A packer as in  claim 1 , wherein the conveying wheel is driven intermittently in rotation about the center axis and equipped with a plurality of grippers equispaced around its developable peripheral and circumferential length.