SERVO POUCH KNIFE ASSEMBLY
The invention relates to a servo knife assembly ( 1 ) for cutting web material. The servo knife assembly ( 1 ) comprises a frame assembly ( 2 ) having a fixed blade ( 3 ) and a moveable blade ( 4 ), a base assembly ( 5 ) for linear adjustment of changing pouch lengths, a servo motor and gear box assembly ( 6 ) providing actuation, and a crank and linear bearing assembly ( 7,8 ), the crank and linear bearing assembly ( 7,8 ) drives the moveable blade ( 4 ) for cutting operation, wherein the crank and linear bearing assembly ( 7,8 ) comprises at least a crank arm ( 16 ) and linear bearing means ( 13 f, 13 h ) guiding the moveable blade ( 4 ), wherein the crank motion is transferred to the moveable blade ( 4 ) thru the bearing mounted crank arm ( 16 ), such that the moveable blade ( 4 ) moves in a linear motion relative to the fixed blade ( 3 ). The new servo pouch knife assembly ( 1 ) uses a unique crank method to translate the rotary motion of a servo motor and gearbox, into a high speed and highly accurate linear motion to cycle the knife blades in and out to cut the web material off during the machine swell cycle.
1 . A servo knife assembly comprising
a frame assembly having a fixed blade and a moveable blade,
a base assembly for linear adjustment of changing pouch lengths,
a servo motor and gear box assembly providing actuation, and
a crank and linear bearing assembly, the crank and linear bearing assembly drives the moveable blade for cutting operation, wherein
the crank and linear bearing assembly comprises at least a crank arm and linear bearing means guiding the moveable blade, wherein
the crank motion is transferred to the moveable blade thru the bearing mounted crank arm, such that the moveable blade moves in a linear motion relative to the fixed blade.
2 . The servo knife assembly according to claim 1 , wherein the crank assembly comprises a manual handle.
3 . The servo knife assembly according to claim 1 , wherein the moveable blade is mounted securely on two linear bearing means.
4 . The servo knife assembly according to claim 1 , wherein the moveable blade is spring loaded.
5 . The servo knife assembly according to claim 1 , wherein the fixed blade is presented at an angle to the moveable blade, wherein a toe extends from the moveable blade across the base of the fixed blade face.
6 . The servo knife assembly according to claim 1 , wherein one of the linear bearing means is located at a foot area of the moveable blade, whereby another one of the linear bearing means is space mounted to the foot area mounted one at a head area of the moveable blade.
7 . The servo knife assembly according to claim 1 , wherein the crank of the crank and gear box assembly rotates in a clock-wise rotation.
8 . The servo knife assembly according to claim 1 , wherein the crank of the crank and gear box assembly rotates in a counter clock-wise rotation.
9 . The servo knife assembly according to claim 1 , wherein the fixed blade is presented at an angle to the moveable blade.
10 . The servo knife assembly according to claim 1 , wherein the linear bearing means comprises a first guiding element and a second guiding element, whereby the first guiding element is secured to the moveable blade, and whereby the second guiding element is mounted to a frame element.
11 . The servo knife assembly according to claim 1 , wherein the moveable blade comprises a guiding plate and a knife plate, whereby the knife plate has slotted holes in which threatened bolts, which are mounted to the guiding plate engage, such that the knife plate is adjustable relative to the guiding plate and to the fixed blade.
12 . The servo knife assembly according to claim 10 , wherein the second guiding element has at least one groove engaged by a corresponding nose of the first guiding element.