Patent Publication Number: US-11648701-B1

Title: Orbital knife

Description:
CLAIM OF PRIORITY 
     This application is a divisional application of and claims the benefit of and priority to Non-Provisional patent application Ser. No. 17/945,924 filed Sep. 15, 2022, now pending, which in turn claims the benefit of and priority to Provisional Patent Application No. 63/330,109 filed Apr. 12, 2022, with the entirety of each of the foregoing applications incorporated herein by this reference. 
    
    
     FIELD OF THE INVENTION 
     The invention is an apparatus for the repeated and accurate cutting a moving extended length of material into discrete pieces of predetermined length. 
     BACKGROUND OF THE INVENTION 
     A variety of manufacturing processes, such as, by way of inclusion and not of limitation, production of disposable personal hygiene products, require that an extended, continuous length of material, referred to herein as a web of material or simply as a web, having a longitudinal (i.e., lengthwise) dimension significantly greater than the other two dimensions (i.e., the axial [width-wise] direction and vertical dimension which defines the thickness of such material and is smaller than the axial direction), be divided, or cut, into discrete pieces of predetermined length with separations commonly perpendicular to the longitudinal dimension. There are a variety of technologies used to accomplish this task, with burst cutting being one of the fundamental processes employed. 
     With reference to  FIGS.  1 ( a ) and  1 ( b ) , a prior art cutting apparatus P for use in burst cutting is depicted. The cutting assembly P is comprised of a support structure  5  to which is rotatably attached a knife roll  20  which has an axis of rotation  26 . Rotation of the knife roll  20  is effectuated by a knife roll motor  25 . Removably attached to the knife roll  20  is a blade  80  comprising an upper end proximal and clamped to the knife roll  20  (i.e., upper end is fixed) and a (free) lower end comprising a cutting element  88  positioned parallel to the longitudinal axis of the knife roll  20 . The blade  80 , which generally has a rectangular cross section, is defined by four length edges, four thickness edges, and four width edges. The cutting element  88  is generally characterized as a narrow sharp edge which extends axially and generally perpendicular to the longitudinal dimension of the web  100  (longest/lengthwise dimension of the web). In general practice, the any one or more of the length edges of blade  80  can comprise a cutting element  88  such that, potentially, blade  80  can have up to four cutting elements  88  so that blade  80  has an effective service life four times that of a blade  80  with only one edge formed into a cutting element  88 . The length of the cutting element  88  is generally longer than the width of the web  100  (e.g., the axial dimension of the web  100 ). 
     Also rotatably attached to the support structure  5  is an anvil roll  50  with axis of rotation  56  wherein rotation of the anvil roll  50  is effectuated by an anvil roll motor  55 . Removably attached to anvil roll  50  is an adjustable anvil  53  which is adjustable spatially in a direction radial proximally and distally from the center of anvil roll  50 . The blade  80  upper edge is proximal and attached to the knife roll  20  and the blade lower end with cutting element  88  is proximal the anvil roll  50  so as to effectuate a cut of web  100  when web  100  passes between knife roll  20  and anvil roll  50  as further described herein. Anvil roll  50  of orbital knife  1 , amongst its multiple attributes, serves the anvil  53  function of prior art cutting apparatus P in that it provides a surface against which the cutting element  88  presses to effect a cut of web  100 . 
     As indicated above, the lower end of blade  80  is free (unclamped) to deflect, enabling the cutting element  88  to be positioned proximally anvil  53  to effectuate the cutting operation of web  100  disposed on a conveyor comprised of an infeed conveyor  104  positioned to the posterior of cutting apparatus P and spaced apart from a discharge conveyor  105  positioned to the anterior of cutting apparatus P. Given the spaced-apart nature of infeed conveyor  104  and discharge conveyor  105 , a small gap exists between these structures and it is in this gap where cutting element  88  contacts web  100 , which is disposed on anvil  53  in the gap, to effectuate a cut of web  100  resulting in individual cut web pieces  101 . 
     The longitudinal axis of the anvil roll  50  is parallel to the longitudinal axis of the knife roll  20 . The anvil roll  50  of the cutting apparatus P generally has a curved smooth continuous surface with an axis of curvature parallel to the cutting element  88  of the blade  80 . Further, the longitudinal axes of the two rolls are separated by a distance such that when the knife roll  20  is rotated about its longitudinal axis, it cannot pass the parallel surface of the anvil roll  50  (i.e., the surface parallel the cutting element positioned at the lower end of the blade  80 ) without displacing or deflecting the lower (free) end of the blade  80  on which cutting element  88  is disposed toward the longitudinal axis of knife roll  20 . The distance between the location of the cutting element  88  on a deflected blade  80  in a state of maximum working deflection and the position of that same cutting element  88  on that same blade  80  in the undeflected condition is hereinafter referred to as interference or blade deflection and hereinafter the two terms “interference” and “blade deflection” are used interchangeable and have the same meaning. Web  100  passes through cutting apparatus P on the conveyor and is cut, resulting in individual cut web pieces  101 , as a result of a load (force) imposed on anvil roll  50  by knife roll  20 , causing the pushing of cutting element  88  against anvil  53 , with web  100  passing between the cutting element  88  and anvil  53  with which it is in contact. The load (force) required to displace the cutting element  88  on blade  80  away from the undeflected state increases as the interference increases and it is this load (force) that effects the cut in the web  100 . 
     During operation with both rolls  20  and  50  rotating about their respective axes of rotation  26  and  56 , web  100  passes between the knife roll  20  and anvil roll  50 , with the longitudinal axis (lengthwise or long dimension) of the web  100  ( i ) passing between the rolls  20  and  50  and in contact anvil  53 , and (ii) perpendicular to the rolls&#39; longitudinal axes. The cutting element  88  of the blade  80  is proximal the anvil roll  50  and, in the gap between infeed and discharge conveyors  104  and  105 , contacts web  100  disposed on the anvil on the conveyor and positioned between knife roll  20  and anvil roll  50 . As web  100  passes between the anvil roll  50  and knife roll  20 , the force of the cutting element  88  imparted on the anvil  53  results in the application of a compressive load to the web  100 . As the compressive load increases, the tensile stress in the longitudinal dimension of the web  100  and perpendicular to the direction of loading increases according to the Poisson effect until that tensile stress exceeds the level tolerable by the web and the material fractures, resulting in a generally axial cut in the web  100 . 
     In some prior art embodiments, inserted between adjustable anvil  53  and anvil roll  50  is an adjustment member  57  which is attached to anvil roll  50  and is in contact with anvil  53 . The positioning of adjustment member  57  between anvil  53  and anvil roll  50  increases or decreases the effective radius of anvil roll  50 , thereby increasing or decreasing the interference (overlap) between anvil  53  and blade  80 . 
     In practice, the amount of the referenced blade  80  deflection, referred to as interference, is small. Establishing the correct amount of blade  80  deflection is critical to effectively cutting the web  100 . If there is too little deflection, operation results in the web  100  not being fully separated, and too much deflection results in the blade material wearing away at an accelerated rate or fracturing. It is typical in the prior art cutting apparatuses P that operation must be stopped in order to adjust the interference and said adjustment is frequently a tedious trial and error process requiring multiple time-consuming attempts before reaching a suitable outcome. Further, changes in temperature of the equipment during operation can result in detrimental changes to the interference (i.e., as the temperature of the support structure  5  increases due to normal operating conditions the material comprising the support structure  5  expands and the distance between the knife roll  20  center of rotation and the anvil roll  50  center of rotation increases thereby reducing the cutting element  88 -to-anvil  53  interference). As such, there exists a need in the prior art to overcome this operational challenge of establishing the correct amount of blade deflection without needing to stop the machine and go through the tedious, time-consuming trial-and-error process of adjusting the cutting apparatus to establish the ideal interference. The present invention provides a means of adjusting the cutting element-to-anvil roll interference while the machine is in operation. 
     SUMMARY OF THE INVENTION 
     A first aspect of the invention comprises an orbital knife comprising (a) a support structure; (b) a yoke rotatably attached to the support structure having a yoke axis of rotation, wherein the yoke comprises a yoke hub and a plurality of yoke arms; (c) one or more rotatable knife rolls radially displaced from and parallel to the yoke hub and securely connected to at least one of the plurality of yoke arms wherein each knife roll has an axis of rotation; (d) one or more blades attached to each of the one or more knife rolls and comprising a cutting element parallel to the knife roll to which the blade of such cutting element is attached; (e) one or more sun gears rotatably attached to the support structure wherein each sun gear has (1) an axis of rotation concentric with the yoke axis of rotation, (2) associated therewith a sun gear pitch radius, and (3) attached thereto a phasing arm; (f) an anvil roll rotatably attached to the support structure and having an axis of rotation parallel to the yoke axis of rotation; and (g) one or more planet gears each with a planet gear axis of rotation and a planet gear pitch radius, wherein (1) each knife roll has rotatably attached thereto at least one planet gear, (2) each planet gear is mated with one of the one or more sun gears forming a gear train wherein the sun gear drives the planet gear and in each such gear train the planet gear pitch radius is substantially tangential to the sun gear pitch radius, and (3) the planet gear axis of rotation of each planet gear is concentric with the axis of rotation of the knife roll to which the planet gear is attached. 
     A second aspect of the invention comprises an orbital knife comprising (a) a support structure; (b) a yoke rotatably attached to the support structure having a yoke axis of rotation, wherein the yoke comprises a yoke hub and a plurality of yoke arms; (c) one or more rotatable knife rolls radially displaced from and parallel to the yoke hub and securely connected to at least one of the plurality of yoke arms wherein each knife roll has an axis of rotation; (d) one or more blades attached to each of the one or more knife rolls and comprising a cutting element parallel to the knife roll to which the blade of such cutting element is attached; (e) one or more sun pulleys rotatably attached to the support structure wherein each sun pulley has (1) an axis of rotation concentric with the yoke axis of rotation, (2) associated therewith a sun pulley pitch radius, and (3) attached thereto a phasing arm; (f) an anvil roll rotatably attached to the support structure and having an axis of rotation parallel to the yoke axis of rotation; and (g) one or more planet pulleys each with a planet pulley axis of rotation and a planet pulley pitch radius, wherein (1) each knife roll has attached thereto at least one planet pulley, (2) each planet pulley is joined via a drive belt with one of the one or more sun pulleys wherein rotation of the sun pulley causes rotation of the planet pulley effectuated by the force imparted by the drive belt, and (3) the planet pulley axis of rotation of each planet pulley is concentric with the axis of rotation of the knife roll to which the planet pulley is attached. 
     A third aspect of the invention comprises an orbital knife comprising (a) a support structure; (b) a yoke rotatably attached to the support structure having a yoke axis of rotation, wherein the yoke comprises a yoke hub and a plurality of yoke arms; (c) one or more rotatable knife rolls radially displaced from and parallel to the yoke hub and securely connected to at least two of the plurality of yoke arms wherein each knife roll has an axis of rotation; (d) one or more blades attached to each of the one or more knife rolls and comprising a cutting element parallel to the knife roll to which the blade of such cutting element is attached; (e) one or more sun gears rotatably attached to the support structure wherein each sun gear has (1) an axis of rotation concentric with the yoke axis of rotation, (2) associated therewith a sun gear pitch radius, and (3) attached thereto a phasing arm; (f) an anvil roll rotatably attached to the support structure and having an axis of rotation parallel to the yoke axis of rotation; (g) one or more idler gears wherein each such idler gear is mated with one of the one or more sun gears; and (h) one or more planet gears each with a planet gear axis of rotation and a planet gear pitch radius, wherein (1) each knife roll has attached thereto at least one planet gear, (2) each planet gear is mated with one of the one or more idler gears that, together with one of the one or more sun gears, forms a gear train wherein the sun gear drives the idler gear which in turn drives the planet gear, and (3) the planet gear axis of rotation of each planet gear is concentric with the axis of rotation of the knife roll to which the planet gear is attached. 
     By way of example only, specific embodiments of the invention will now be described, with reference to the accompanying drawings. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG.  1 ( a )  is a perspective view of an embodiment of a prior art cutting assembly; 
         FIG.  1 ( b )  is an elevation view of an embodiment of a prior art cutting assembly wherein the support structure  5  is omitted for clarity; 
         FIG.  2    is a perspective view of an embodiment of the present invention; 
         FIG.  3 ( a )  is a perspective view of an embodiment of the present invention; 
         FIG.  3 ( b )  is a perspective view of an embodiment of the present invention; 
         FIG.  4 ( a )  is an elevation view of an embodiment of the present invention; 
         FIG.  4 ( b )  is an elevation view of an embodiment of the present invention; 
         FIG.  5 ( a )  is an anterior perspective view of an embodiment of the present invention; 
         FIG.  5 ( b )  is a posterior perspective view of an embodiment of the present invention; 
         FIG.  6 ( a )  is a perspective view of an embodiment of the present invention; 
         FIG.  6 ( b )  is an elevation view of an embodiment of the present invention; 
         FIG.  7    is a perspective view of an embodiment of the present invention; 
         FIG.  8 ( a )  is an elevation view of an embodiment of the present invention; 
         FIG.  8 ( b )  is an elevation view of an embodiment of the present invention; 
         FIG.  8 ( c )  is an elevation view of an embodiment of the present invention; and 
         FIG.  9    is a perspective view of an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to  FIGS.  2 ,  3   ( a ), and  3 ( b ), an embodiment of the present invention comprises an orbital knife  1  comprising (a) a support structure  5 , and (b) a yoke  10  rotatably attached to the support structure  5  with a yoke axis of rotation  16  and having a yoke hub  11  substantially concentric with yoke axis of rotation  16  and one or more yoke arms  12  positioned laterally with respect to and attached to the yoke hub  11 . 
     Orbital knife  1  further comprises one or more knife rolls  20  radially displaced from and parallel to yoke hub  11 , each of the one or more knife rolls  20  having its own axis of rotation  26 . Each of the one or more knife rolls  20  is securely connected to a plurality of yoke arms  12  of yoke  10  using means known in the art, such as a protrusion extending from each end of a knife roll  20  extending through an aperture in yoke arm  12  of yoke  10 . In preferred embodiments, orbital knife  1  comprises a plurality of knife rolls  20 , more preferably plurality of knife rolls  20  comprises (a) a first knife roll  20 ( a ) securely connected to yoke  10  via first knife roll first yoke arm  12 ( a   1 ) and first knife roll second yoke arm  12 ( a   2 ) spaced apart from first knife roll first yoke arm  12 ( a   1 ) and (b) a second knife roll  20 ( b ) securely connected to yoke  10  via second knife roll first yoke arm  12 ( b   1 ) and second knife roll second yoke arm  12 ( b   2 ) spaced apart from second knife roll first yoke arm  12 ( b   1 ). First knife roll first yoke arm  12 ( a   1 ) can be attached to, integral with, or separate from second knife roll first yoke arm  12 ( b   1 ) and first knife roll second yoke arm  12 ( a   2 ) can be attached to, integral with, or separate from second knife roll second yoke arm  12 ( b   2 ). Yoke arms  12  are positioned so that the knife roll axis of rotation  26  is parallel to the yoke axis of rotation  16 . 
     Further with reference to  FIGS.  2 ,  3   ( a ), and  3 ( b ), a preferred embodiment of the present invention comprising orbital knife  1  further comprises one or more sun gears  30  rotatably attached to support structure  5  and having an axis of rotation concentric with the yoke rotational axis  16  and having a pitch radius (often referred to as a pitch circle, and which is equal to the distance from the center of the gear to the pitch point, the pitch point in turn being the point of tangency of the pitch circles of a pair of mating gears) such that the sun gear  30  pitch diameter (i.e., the diameter of the pitch circle) of each of the one or more sun gears  30  is concentric with rotational axis  16  of yoke  10 . In preferred embodiments, orbital knife  1  comprises a plurality of sun gears  30 , more preferably a pair of sun gears  30  comprising a first sun gear  30 ( a ) and a second sun gear  30 ( b ). 
     Further with reference to  FIGS.  2 ,  3   ( a ), and  3 ( b ), an embodiment of the present invention of orbital knife  1  further comprises one or more blades  80  with an upper end and a lower end wherein blade  80  is separably attached to each of the one or more knife rolls  20  at its upper end. Each blade  80  comprises a cutting element  88  formed on lower end of blade  80  and positioned parallel to the knife roll  20  to which the blade  80  is separably attached. 
     An embodiment of the present invention of orbital knife  1  further comprises an anvil roll  50  rotatably connected to support structure  5 , wherein anvil roll  50  has an axis of rotation  56  parallel to rotational axis  16  of yoke  10 . In preferred embodiments of the present invention, orbital knife  1  further comprises one or more oiler rolls  70 , wherein each oiler roll  70  (1) is preferably comprised of an absorbent material and (2) receives a slow feed of oil or other lubricating liquid from an oil or liquid reservoir. When a knife roll  20  is proximal the one or more oiler roll  70  by virtue of rotation of yoke  10 , the cutting element  88  of blade  80  attached to knife roll  20  contacts oiler roll  70  and a thin coating of oil or other lubricating liquid from oiler roll  70  transfers to cutting element  88  each time knife roll  20  passes oiler roll  70 . The lubrication of cutting element  88  of blade  80  improves long-term operation and lifespan of such structures buy reducing wear of the cutting element  88  of blade  80  when it contacts anvil roll  50 . 
     In preferred embodiments of orbital knife  1  comprising a plurality of knife rolls  20 ( a ) and  20 ( b ), first knife roll  20 ( a ) has separably attached thereto first blade  80 ( a ) comprising first blade cutting element  88 ( a ) and second knife roll  20 ( b ) has separably attached thereto second blade  80 ( b ) comprising second blade cutting element  88 ( b ). In preferred embodiments of orbital knife  1  comprising a plurality of knife rolls  20 ( a ) and  20 ( b ) and a rotating yoke  10 , web  100  is compressed alternatively between knife rolls  20 ( a ) and  20 ( b ) depending on the rotational position of yoke  10 , and anvil roll  50 , with web  100  cut into individual cut web pieces  101  alternatively by blade  80 ( a ) attached to knife roll  20 ( a ) when rotation of yoke  10  results in the positioning of knife roll  20 ( a ) proximal anvil roll  50  and blade  80 ( b ) attached to knife roll  20 ( b ) when rotation of yoke  10  results in the positioning of knife roll  20 ( b ) proximal anvil roll  50 . Web  100  may or may not be in contact with knife roll  20  to effectuate a cut, with all that is required to effectuate a cut is contact between cutting element  88  of blade  80  and web  100 . 
     Further with reference to  FIGS.  2 ,  3   ( a ), and  3 ( b ), an embodiment of the present invention of orbital knife  1  further comprises one or more planet gears  40 , each of which is rigidly or fixedly attached to one of the one or more knife rolls  20 . Further, each planet gear  40  mates [i.e., in mesh contact] with a sun gear  30  whereby rotation of sun gear  30  effectuates rotation of planet gear  40 ; that is, sun gear  30  and planet gear  40  comprise a gear train whereby sun gear  30  is the driving gear and planet gear  40  is the driven gear. In embodiments of orbital knife  1  comprising a plurality of knife rolls  20 ( a ) and  20 ( b ), a first planet gear  40 ( a ) is rigidly or fixedly attached to first knife roll  20 ( a ) and mates with a first sun gear  30 ( a ), and a second planet gear  40 ( b ) is rigidly or fixedly attached to second knife roll  20 ( b ) and mates with a second sun gear  30 ( b ). 
     Each planet gear  40  has (a) an axis of rotation concentric with the axis of rotation  26  of the respective knife roll  20  (i.e., the knife roll  20  to which each planet gear  40  is attached; as shown in  FIG.  2   , knife roll  20 ( a ) has axis of rotation  26 ( a ) and knife roll  20 ( b ) has axis of rotation  26 ( b )) and (b) a pitch radius substantially tangential to the pitch radius of the sun gear  30  with which the planet gear  40  mates so that rotation of yoke  10  about its axis of rotation  16  while a sun gear  30  is held stationary with respect to the support structure  5  will effectuate a rotation of the associated planet gear  40  and its respective knife roll  20  about its axis of rotation  26  [in  FIG.  3   , axes of rotation  26 ( a ) and  26 ( b ) for knife rolls  20 ( a ) and  20 ( b ), respectively]. Moreover, the ratio of the sun gear  30  pitch radii to the planet gear  40  pitch radii is established using any means known in the art such that operation of orbital knife  1  produces a precise repeating pattern of the positioning of the cutting element  88  associated with each knife roll  20  with respect to the support structure  5 , which obviates cutting element  88  of blade  80  attached to knife roll  20  impinging or contacting anvil roll  50  during yoke  10  rotation. 
     In select embodiments of the present invention, yoke  10  may be directly connected to a drive motor  15  ( FIGS.  2 ,  3   ( a ), and  3 ( b )) to effectuate rotation of yoke  10  about its rotational axis  16 . Alternatively, rotation of yoke  10  about its rotational axis  16  may be effectuated by any suitable means known in the art causing rotation of yoke  10 . Moreover, in select embodiments of the present invention, anvil roll  50  may be connected to a drive motor  55  (see  FIGS.  2 ,  3   ( a ), and  3 ( b )) to effectuate rotation of anvil roll  50  about its rotational axis  56 . Alternatively, rotation of anvil roll  50  may be effectuated by any suitable means known in the art causing controlled rotation of anvil roll  50 . 
     Further, orbital knife  1  has, for a particular cut setting, a key operational parameter called the cut radius CR [depicted as CR(a) in  FIG.  4 ( a )  and CR(b) in  FIG.  4 ( b ) ] which is defined as the straight-line distance from the center of rotation of yoke  10  to cutting element  88  at the point in yoke rotation where the yoke center, the cutting element, and the anvil center lie in a common plane. The orientation of sun gear  30 -planet gear  40 , wherein sun gear  30  drives planet gear  40 , allows for modification of the cut radius CR during operations of orbital knife  1 . Further, each knife roll  20  of the orbital knife  1  according to the present invention having associated therewith a sun gear  30  that is not associated with any other knife roll  20  allows for independent adjustment of each knife roll  20 &#39;s cut radius CR. 
     The force required to effectuate the rotation of sun gear  30  can be achieved using any means known in the art. In preferred embodiments, orbital knife  1  comprises one or more phasing actuators  90  [depicted in  FIG.  2    as a plurality of phasing actuators  90 ( a ) and  90 ( b )] with an upper section and a lower section wherein the lower section is attached to support structure  5  of orbital knife  1  and a phasing link  92  is disposed at the upper section of actuator  90 . Each phasing actuator  90  produce a linear motion which is converted to a rotational motion by its respective phasing link  92 . 
     In preferred embodiments, orbital knife  1  further comprises a phasing arm  32  attached to each of the one or more sun gears  30 , each phasing arm  32  having a first end and a second end, wherein (a) the first end of phasing arm  32  is rotatably attached to phasing link  92  and the second end of phasing arm  32  is rigidly attached to sun gear  30 , and (b) rotation of phasing arm  32  effectuates rotation of sun gear  30  about its axis of rotation thereby controlling another key operational parameter called the phase angle PA [see  FIGS.  4 ( a ) and  4 ( b ) ] which is a measure of the amount of rotation of sun gear  30  relative to a fixed reference and wherein phase angle PA for the instant invention is defined as the angle from the upper lateral plane of support structure  5  to the lateral plane occupied by phasing arm  32  extending through the center of sun gear  30 . 
     In preferred embodiments of the present invention of orbital knife  1  comprising a plurality of sun gears  30 ( a ) and  30 ( b ), rigidly attached to sun gear  30 ( a ) is phasing arm  32 ( a ) and rigidly attached to sun gear  30 ( b ) is phasing arm  32 ( b ). Force is provided by one or more actuator motors  95  connected to one or more actuators  90 , with each motor  95  connected to one actuator  90 . In alternative preferred embodiments as shown in  FIG.  2   , orbital knife  1  comprises a plurality of actuators  90 ( a ) and  90 ( b ) wherein each such actuator  90  is connected to a plurality of actuator motors  95 ( a ) and  95 ( b ). 
     The rotation of the one or more sun gears  30  allows for operational control of phase angle PA of each of the sun gears  30 , with in-operation (on the fly) rotation of the one or more sun gears  30  (that is, rotation of the one or more sun gears  30  during active (ongoing) web  100  cutting operations, with such rotation driving planet gear  40 , allowing for a change of the cut radius CR of each of the one or more blades  80  resulting in a modification of deflection of cutting element  88  associated with each of the one or more blades  80  attached to each of the one or more knife rolls  20  associated with each such rotating sun gear  30 , thus obviating use of an adjustable anvil  53  in prior art cutting apparatus P and adjustment of such anvil  53  to effectuate a change in blade deflection and resulting in an apparatus (i.e., orbital knife  1 ) that has less parts and is less expensive to acquire and maintain than prior art cutting apparatuses P. In other words, the rotation of sun gear  30  according to the present invention allows a user of orbital knife  1  to change the cut radius CR, and hence blade deflection and the cutting force with which cutting element  88  on blade  80  contacts anvil roll  50 , of each of the one or more blades  80  on the fly during operations to allow for a continuous cutting operation during which the optimal blade  80  deflection is maintained without the need for multiple batch (run) operations (i.e., operation of prior art cutting apparatus P with a first cut radius CR, stoppage of operation [defining a first batch {run} operation], modification of prior art cutting apparatus P by adjusting the position of cutting element  88  of blade  80  relative to the center of rotation of the knife roll  20  to effectuate a change of cut radius CR and hence effectuating a change in the blade  80  deflection during the cutting operation or, alternatively, changing the deflection of the blade  80  of cutting apparatus P by changing the position of the anvil  53  relative to the center of rotation of the anvil roll  50  to effectuate a change in the deflection of blade  80  with cutting element  88 , with any of the foregoing requiring the aforementioned stoppage of operations of cutting apparatus P to change cutting element  88  deflection and thereafter recommencing operations of cutting apparatus P [defining a second batch {run} operation]). The on-the-fly CR adjustability provided by orbital knife  1  according to the present invention allows for optimal blade interference to make web  100  cutting operations more efficient. 
     In a cutting operation, cut radius CR is at a maximum when yoke radius YR, which is defined as the straight-line distance from the yoke axis of rotation  16  to the knife roll axis of rotation  26 , and the knife radius KR, another key operational parameter defined as the straight-line distance from the knife roll axis of rotation  26  to cutting element  88  of blade  80  of knife roll  20 , lie in a common plane as illustrated in  FIG.  4 ( a ) . Moving the knife roll axis of rotation  26  out of the common plane will cause a reduction of cut radius CR as illustrated in  FIG.  4 ( b )  and is effectuated by rotation of sun gear  30 . In practice, the optimal cut radius CR for any given circumstance is something less than the maximum cut radius CR. Further, the optimal blade  80  deflection with related cut radius CR may change over time depending on operating conditions. In the present invention, maintenance of an optimal blade deflection and associated cut radius CR can be achieved since cut radius CR of each of the one or more blades  80  of orbital knife  1  can be varied during web cutting operation without stopping orbital knife  1  operations as is required of a prior art cutting apparatus P. 
     During operation of orbital knife  1  with one or more knife rolls  20  on which is attached a blade  80  with cutting element  88 , yoke  10  rotates about its axis of rotation  16 , and anvil roll  50  rotates about its axis of rotation  56 . In preferred embodiments comprising an actuator  90 -phasing link  92 -phasing arm  32  arrangement as described herein, rotation of one or more sun gears  30  results from the displacement of a phasing link  92  associated with each sun gear  30 , with such displacement of phasing link  92  in preferred embodiments effectuated by actuator  90 . Phasing link  92  displacement effectuates displacement of phasing arm  32 , which in turn effectuates rotation of the associated sun gear  30 . Rotation of the sun gear  30  results in the rotation of the planet gear  40  with which the sun gear  30  is in mesh contact forming a gear train. Sun gear  30  rotation effectuates a rotation of the associated knife roll  20  about such knife roll  20 &#39;s axis of rotation  26 , thereby changing the relationship between the yoke radius YR and the knife radius KR with a corresponding change in the cut radius CR and therefore changing blade  80  deflection. 
     Web  100  passes through orbital knife  1  on the conveyor comprising two segments, being fed to orbital knife  1  by being disposed on infeed conveyor  104  which is spaced apart from discharge conveyor  105 , resulting in a gap between conveyor segments  104  and  105 . In the gap, web  100  is disposed on anvil roll  50  positioned below web  100 . Rotation of yoke  10  about its axis of rotation  16  results in the positioning of knife roll  20  proximal anvil roll  50  and cutting element  88  of blade  80  attached to knife roll  20  being positioned above web  100  in this gap, with cutting element  88  positioned above and in contact with web  100  which in turn is positioned above and in contact with anvil roll  50 . A load (force) is imposed on anvil roll  50  by the blade  80  of knife roll  20  which compresses web  100  in this gap, with web  100  cut into individual cut web pieces  101  by blade  80  of knife roll  20  when rotation of yoke  10  results in the positioning of knife roll  20  proximal anvil roll  50 . 
     In alternative embodiments of the present invention depicted in  FIGS.  5 ( a ) / 5 ( b ) and  6 ( a ), orbital knife  1  comprises (a) a support structure  5 , and (b) a yoke  10  rotatably attached to the support structure  5  with a yoke axis of rotation  16  and having a yoke hub  11  substantially concentric with yoke axis of rotation  16  and a plurality of yoke arms  12  [in the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ):  12 ( al ) and  12 ( a   2 );  12 ( b   1 ) and  12 ( b   2 );  12 ( cl ) and  12 ( c   2 );  12 ( d   1 ) and  12 ( d   2 ); in  FIGS.  6 ( a ) :  12 ( a   1 ) and  12 ( a   2 ); and  12 ( b   1 ) and  12 ( b   2 )] positioned laterally with respect to and attached to the yoke hub  11 . 
     Orbital knife  1  further comprises a plurality of knife rolls  20  [in the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ):  20 ( a ),  20 ( b ),  20 ( c ), and  20 ( d ); in the embodiment depicted in  FIGS.  6 ( a ) :  20 ( a ) and  20 ( b )]. Each of the plurality of knife rolls  20  is supported by an associated pair of yoke arms  12 . For example, with reference to  FIGS.  5 ( a ) and  5 ( b ) , knife roll  20 ( c ) is rotatably attached to and supported by yoke arms  12 ( cl ) and  12 ( c   2 ). Each of the remaining knife rolls  20  of the plurality of knife rolls  20  [ 20 ( a ),  20 ( b ), and  20 ( d )] is similarly rotatably attached to and supported by its associated pair of yoke arms  12  [ 12 ( a   1 ) and  12 ( a   2 ),  12 ( b   1 ) and  12 ( b   2 ), and  12 ( d   1 ) and  12 ( d   2 )]. And, for example, with reference to  FIGS.  6 ( a ) , knife roll  20 ( a ) is rotatably attached to and supported by yoke arms  12 ( a   1 ) and  12 ( a   2 ) and knife roll  20 ( b ) is rotatably attached to and supported by yoke arms  12 ( b   1 ) and  12 ( b   2 ). Yoke arms  12  are positioned so that the knife roll axis of rotation  26  is parallel to the yoke axis of rotation  16 . 
     Moreover, each of the plurality of knife rolls  20  has its own associated planet gear  40  and associated sun gear  30 . For example, with respect to the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ), knife roll  20 ( a ) has rigidly attached to it planet gear  40 ( a ) in mated contact with sun gear  30 ( a ), knife roll  20 ( b ) has rigidly attached to it planet gear  40 ( b ) in mated contact with sun gear  30 ( b ), knife roll  20 ( c ) has rigidly attached to it planet gear  40 ( c ) in mated contact with sun gear  30 ( c ), and knife roll  20 ( d ) has rigidly attached to it planet gear  40 ( d ) in mated contact with sun gear  30 ( d ). For example, with respect to the embodiment depicted in  FIGS.  6 ( a ) , knife roll  20 ( a ) has rigidly attached to it planet gear  40 ( a ) in mated contact with sun gear  30 ( a ), and knife roll  20 ( b ) has rigidly attached to it planet gear  40 ( b ) in mated contact with sun gear  30 ( b ). 
     Each of the one or more sun gears  30  is rotatably attached to support structure  5  and has an axis of rotation concentric with yoke rotational axis  16  and a pitch radius such that sun gear  30  pitch diameter is concentric with rotational axis  16  of yoke  10 . Each of the one or more planet gears  40  is rigidly or fixedly attached to each of the one or more knife rolls  20 , with each of the one or more planet gears  40  ( i ) in mated contact with one of the one or more sun gears  30  whereby rotation of sun gear  30  effectuates rotation of planet gear  40 , (ii) having an axis of rotation concentric with the axis of rotation  26  of the respective knife roll  20  to which such planet gear  40  is attached, and (iii) having a pitch radius substantially tangential to the pitch radius of the sun gear  30  with which the planet gear  40  mates so that rotation of yoke  10  about its axis of rotation  16  while sun gear  30  is held stationary with respect to the support structure  5  which will effectuate a rotation of the associated planet gear  40  and its respective knife roll  20  about its axis of rotation  26 . 
     Further, in such embodiment of the present invention of orbital knife  1  and with reference to  FIGS.  5 ( a ) and  5 ( b ) , each knife roll  20  has separably attached thereto a blade  80  [ FIGS.  5 ( a ) / 5 ( b )] or blade  85  [ FIG.  6 ( a ) ] comprising a cutting element  88  positioned parallel to the knife roll  20  to which the blade  80  or  85  is separably attached [in the embodiment shown in  FIGS.  5 ( a ) and  5 ( b ) , blade  80 ( a ) comprising cutting element  88 ( a ) is attached to knife roll  20 ( a ), blade  80 ( b ) comprising cutting element  88 ( b ) is attached to knife roll  20 ( b ), blade  80 ( c ) comprising cutting element  88 ( c ) is attached to knife roll  20 ( c ), and blade  80 ( d ) comprising cutting element  88 ( d ) is attached to knife roll  20 ( d ); in the embodiment shown in  FIGS.  6 ( a ) , blade  85 ( a ) comprising cutting element  88 ( a ) is attached to knife roll  20 ( a ), and blade  85 ( b ) comprising cutting element  88 ( b ) is attached to knife roll  20 ( b )]. By having a plurality of knife rolls  20 , each cut radius CR associated with each of the plurality of cutting elements  88  can be independently controlled or set, which is not possible with prior art cutting apparatuses, with each of the plurality of knife rolls  20  capable of having a cut radius CR distinct from any other one or more knife rolls  20  with cut radius or radii CR, as the case may be. Accordingly, the cut radius CR associated with each of the plurality of separate cutting elements  88  may be altered independently from any other cutting element  88 . The orientation of sun gear  30 -planet gear  40 , wherein sun gear  30  drives planet gear  40 , allows for modification of the cut radius CR during operations of orbital knife  1 . Further, with each knife roll  20  of the orbital knife  1  according to the present invention having associated therewith a sun gear  30  that is not associated with any other knife roll  20  allows for independent adjustment of each knife roll  20 &#39;s cut radius CR. 
     Such embodiment of the present invention of orbital knife  1  further comprises an anvil roll  50  rotatably connected to support structure  5 , wherein anvil roll  50  has an axis of rotation  56  parallel to rotational axis  16  of yoke  10 . In such embodiment of the present invention of orbital knife  1 , web  100  is compressed between anvil roll  50 , with which it is in contact in the gap separating conveyor segments  104  and  105 , and alternatively between knife rolls  20  [embodiment in  FIGS.  5 ( a ) / 5 ( b ):  20 ( a ),  20 ( b ),  20 ( c ), and  20 ( d ); embodiment in  FIGS.  6 ( a ) :  20 ( a ) and  20 ( b )] depending on the rotational position of yoke  10  and anvil roll  50 , with web  100  cut into individual cut web pieces  101  alternatively by the blades  80  depicted in  FIGS.  5 ( a ) / 5 ( b ) or blades  85  depicted in  FIGS.  6 ( a ) /(b) on the different knife rolls  20 . By way of example and with reference to the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ), web  100  is cut when (i) blade  80 ( a ) attached to knife roll  20 ( a ) when rotation of yoke  10  results in the positioning of knife roll  20 ( a ) proximal anvil roll  50 , (ii) blade  80 ( b ) attached to knife roll  20 ( b ) when rotation of yoke  10  results in the positioning of knife roll  20 ( b ) proximal anvil roll  50 , (iii) blade  80 ( c ) attached to knife roll  20 ( c ) when rotation of yoke  10  results in the positioning of knife roll  20 ( c ) proximal anvil roll  50 , and (iv) blade  80 ( d ) attached to knife roll  20 ( d ) when rotation of yoke  10  results in the positioning of knife roll  20 ( d ) proximal anvil roll  50 . Web  100  may or may not be in contact with knife roll  20  to effectuate a cut, with all that is required to effectuate a cut is contact between cutting element  88  of blade  80  and web  100 . 
     Further, in such embodiment of the present invention of orbital knife  1 , the ratio of sun gear  30  pitch radii to the planet gear  40  pitch radii (e.g., ratio of sun gear  30 ( a ) pitch radius to planet gear  40 ( a ) pitch radius, ratio of sun gear  30 ( b ) pitch radius to planet gear  40 ( b ) pitch radius [the foregoing for embodiments depicted in  FIGS.  5 ( a ) / 5 ( b ) and  6 ( a )], and, additionally for the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ), ratio of sun gear  30 ( c ) pitch radius to planet gear  40 ( c ) gear radius, and ratio of sun gear  30 ( d ) pitch radius to planet gear  40 ( d ) gear radius) for the plurality of sun gears  30  and planet gears  40  is established such that operation of orbital knife  1  produces a precise repeating pattern of the positioning of the cutting elements  88  [embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ): cutting elements  88 ( a ),  88 ( b ),  88 ( c ), and  88 ( d ) of blades  80 ( a ),  80 ( b ),  80 ( c ), and  80 ( d ) attached to knife rolls  20 ( a ),  20 ( b ),  20 ( c ), and  20 ( d ), respectively; embodiment depicted in  FIG.  6 ( a ) : cutting elements  88 ( a ) and  88 ( b ) of blades  85 ( a ) and  85 ( b ) attached to knife rolls  20 ( a ) and  20 ( b ), respectively] with respect to anvil roll  50  which obviates cutting element  88  contact with anvil roll  50  during yoke  10  rotation. 
     The force for rotation of yoke  10  and anvil roll  50  of this embodiment of the present invention of orbital knife  1  may be provided by any one of many known methods in the art. In preferred embodiments, orbital knife  1  further comprises a plurality of actuators  90  [actuators  90 ( a ),  90 ( b ),  90 ( c ), and  90 ( d ) in embodiment depicted in  FIGS.  5 ( a ) and  5 ( b )  and actuators  90 ( a ) and  90 ( b ) in the embodiment depicted in  FIGS.  6 ( a ) ], each such actuator  90  with an upper section and a lower section, wherein the lower section is attached to support structure  5  and a phasing link  92  [phasing links  92 ( a ),  92 ( b ),  92 ( c ), and  92 ( d ) in the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ); phasing links  92 ( a ) and  92 ( b ) in the embodiment depicted in  FIG.  6 ( a ) ] disposed at the upper section of actuators  90 . Each phasing actuator  90  produces a linear motion which is converted to a rotational motion by its respective phasing link  92 . 
     Orbital knife  1  according to such embodiment further comprises a plurality of phasing arms  32 , each phasing arm  32  attached to one of the plurality of sun gears  30  [phasing arms  32 ( a ),  32 ( b ),  32 ( c ), and  32 ( d ) attached to sun gears  30 ( a ),  30 ( b ),  30 ( c ), and  30 ( d ), respectively, in the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ); phasing arms  32 ( a ) and  32 ( b ) attached to sun gears  30 ( a ) and  30 ( b ), respectively, in the embodiment depicted in  FIG.  6 ( a ) ]. Each such phasing arm  32  has a first end and a second end, wherein the first end is rotatably attached to phasing link  92  and the second end is rigidly attached to sun gear  30 . Rotation of a phasing arm  32  effectuates rotation of the associated sun gear  30  about such sun gear  30 &#39;s axis of rotation thereby controlling the phase angle PA of each such sun gear  30 . 
     Further, in preferred select embodiments of orbital knife  1  according to this embodiment of the present invention where force for rotation of sun gears  30  is provided through actuator  90 , orbital knife  1  further comprises a plurality of actuator motors  95  [actuator motors  95 ( a ),  95 ( b ),  95 ( c ), and  95 ( d ) in the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ) and  95 ( a ) and  95 ( b ) in the embodiment depicted in  FIG.  6 ( a ) ] wherein each actuator motor  95  is attached to one of the plurality of actuators  90  [actuators  90 ( a ),  90 ( b ),  90 ( c ), and  90 ( d ) in the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b );  90 ( a ) and  90 ( b ) in the embodiment depicted in  FIG.  6 ( a ) ]. 
     The rotation of plurality of sun gears  30  in the embodiments of orbital knife  1  depicted in  FIGS.  5 ( a ) / 5 ( b ) [ 30 ( a ),  30 ( b ),  30 ( c ), and  30 ( d )] and  6 ( a ) [ 30 ( a ) and  30 ( b )] allows for operational control of the rotational position (i.e., the phase angle PA) of each of the sun gears  30 , with in-operation (on the fly) rotation of the plurality of sun gears  30  (that is, rotation of the plurality of sun gears  30  during active (ongoing) web  100  cutting operations driving the plurality of planet gears  40  [in the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ):  40 ( a ),  40 ( b ),  40 ( c ), and  40 ( d ); in the embodiment depicted  FIGS.  6 ( a ) :  40 ( a ) and  40 ( b )]), allowing for a change of the cut radius CR of each of the blades  80  [ FIGS.  5 ( a ) / 5 ( b )] and  85  [ FIG.  6 ( a ) ] attached to the plurality of knife rolls  20  [in the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ):  80 ( a ),  80 ( b ),  80 ( c ), and  80 ( d ) attached to knife rolls  20 ( a ),  20 ( b ),  20 ( c ), and  20 ( d ), respectively; in the embodiment depicted in  FIGS.  6 ( a ) : blades  85 ( a ) and  85 ( b ) attached to knife rolls  20 ( a ) and  20 ( b ), respectively] resulting in a modification of deflection of cutting elements  88  of blades  80  attached to knife rolls  20  associated with the sun gears  30  [in the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ): cutting element  88 ( a ) of blade  80 ( a ) attached to knife roll  20 ( a ) associated with sun gear  30 ( a ); cutting element  88 ( b ) of blade  80 ( b ) attached to knife roll  20 ( b ) associated with sun gear  30 ( b ); cutting element  88 ( c ) of blade  80 ( c ) attached to knife roll  20 ( c ) associated with sun gear  30 ( c ); and cutting element  88 ( d ) of blade  80 ( d ) attached to knife roll  20 ( d ) associated with sun gear  30 ( d ); in the embodiment depicted in  FIGS.  6 ( a ) : cutting element  88 ( a ) of blade  85 ( a ) attached to knife roll  20 ( a ) associated with sun gear  30 ( a ); cutting element  88 ( b ) of blade  85 ( b ) attached to knife roll  20 ( b ) associated with sun gear  30 ( b )], thus obviating use of an adjustable anvil  53  in prior art cutting apparatus P and adjustment of such anvil  53  to effectuate a change in blade deflection and resulting in an apparatus (i.e., orbital knife  1  according to the present invention) that has less parts and is less expensive to acquire and maintain than prior art cutting apparatuses P. In other words, the rotation of sun gears  30  according to the present invention allows a user of orbital knife  1  to change the cut radius CR, and hence blade defection and the cutting force with which cutting elements  88  on blades  80  and  85  contact anvil roll  50 , of each of the blades  80  and  85  on the fly during operations to allow for a continuous cutting operation during which the optimal blade  80  deflection is maintained without the need for multiple batch (run) operations and without having to effectuate the manual adjustments required of prior art cutting apparatus P to effectuate a change in blade deflection. In other words, the rotation of the plurality of sun gears  30  [ 30 ( a ) through  30 ( d ) { FIGS.  5 ( a ) / 5 ( b )} or  30 ( a ) and  30 ( b ) { FIGS.  6 ( a ) }] according to the present invention allows a user of orbital knife  1  to change the cut radius CR, and hence blade deflection, of blades  80  and  85  on the fly during operations to allow for a continuous cutting operation during which the optimal blade  80  and  85  deflection is maintained without the need for multiple batch (run) operations (i.e., operation of prior art cutting apparatus P with a first cut radius CR, stoppage of operation [defining a first batch {run} operation], modification of prior art cutting apparatus P by adjusting the position of cutting elements  88  of blades  80  relative to the center of rotation of the knife rolls  20  to effectuate a change of cut radius CR and hence effectuating a change in the blade  80  deflection during the cutting operation or, alternatively, changing the deflection of the blade  80  of cutting apparatus P by changing the position of the anvil  53  relative to the center of rotation of the anvil roll  50  to effectuate a change in the deflection of blade  80  with cutting element  88 , with any of the foregoing requiring the aforementioned stoppage of operations of cutting apparatus P to change cutting element  88  deflection and thereafter recommencing operations of cutting apparatus P [defining a second batch {run} operation]). The on-the-fly CR adjustability provided by orbital knife  1  according to the present invention allows for optimal blade interference to make web  100  cutting operations more efficient. 
     In a cutting operation with the present invention, cut radius CR is at a maximum when yoke radius YR, which is defined as the straight-line distance from the yoke axis of rotation  16  to the knife roll axis of rotation  26 , and the knife radius KR, another key operational parameter defined as the straight-line distance from the knife roll axis of rotation  26  to each of the cutting elements  88  of blades  80  of knife rolls  20  lie in a common plane. Moving the knife roll axis of rotation  26  out of the common plane will cause a reduction of cut radius CR and is effectuated by rotation of sun gear  30 . In practice, the optimal cut radius CR for any given circumstance is something less than the maximum cut radius CR. Further, the optimal blade  80  deflection with related cut radius CR may change over time depending on operating conditions. In the present invention, maintenance of an optimal blade deflection and associated optimal cut radius CR can be achieved since cut radius CR of each of the one or more blades  80  of orbital knife  1  can be varied during web cutting operation without stopping orbital knife  1  operations as is required of a prior art cutting apparatus P. The orientation of sun gear  30 -planet gear  40 , wherein sun gear  30  drives planet gear  40 , allows for modification of the cut radius CR during operations of orbital knife  1 . Further, with each knife roll  20  of the orbital knife  1  according to the present invention having associated therewith a sun gear  30  that is not associated with any other knife roll  20  allows for independent adjustment of each knife roll  20 &#39;s cut radius CR. 
     During operation of orbital knife  1  with knife rolls  20 ( a ),  20 ( b ),  20 ( c ), and  20 ( d ) on which is attached blades  80 ( a ),  80 ( b ),  80 ( c ), and  80 ( d ) with cutting element  88 ( a ),  88 ( b ),  88 ( c ), and  88 ( d ), respectively, yoke  10  rotates about its axis of rotation  16 , and anvil roll  50  rotates about its axis of rotation  56 . In preferred embodiments comprising an actuator  90 -phasing link  92 -phasing arm  32  arrangement as described herein, rotation of sun gears  30  [in the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ):  30 ( a ),  30 ( b ),  30 ( c ), and  30 ( d ); in the embodiment depicted in  FIGS.  6 ( a ) :  30 ( a ) and  30 ( b )] results from the displacement of phasing links  92  associated with sun gears  30  [phasing links  92 ( a ),  92 ( b ),  92 ( c ), and  92 ( d ) in the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ); phasing links  92 ( a ) and  92 ( b ) in the embodiment depicted in  FIG.  6 ( a ) ], with displacement of phasing links  92  effectuated by actuators  90  [actuators  90 ( a ),  90 ( b ),  90 ( c ), and  90 ( d ) in the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b );  90 ( a ) and  90 ( b ) in the embodiment depicted in  FIG.  6 ( a ) ]. Phasing link displacement effectuates displacement of phasing arms  32  [phasing arms  32 ( a ),  32 ( b ),  32 ( c ), and  32 ( d ) in the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ); phasing arms  32 ( a ) and  32 ( b ) in the embodiment depicted in  FIG.  6 ( a ) ], which in turn effectuates rotation of associated sun gears  30 . Sun gear rotation results in rotation of planet gears  40  [in the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ): planet gears  40 ( a ),  40 ( b ),  40 ( c ), and  40 ( d ); in the embodiment depicted in  FIG.  6 ( a ) : planet gears  40 ( a ) and  40 ( b )] which are in mesh contact with sun gears  30 , forming a plurality of gear trains. Rotation of sun gears  30  effectuates rotation of the associated knife rolls  20  about each such knife roll&#39;s axis of rotation  26  [in the embodiment depicted in  FIGS.  5 ( a ) / 5 ( b ): knife rolls  20 ( a ),  20 ( b ),  20 ( c ), and  20 ( d ) about axes of rotation  26 ( a ),  26 ( b ),  26 ( c ), and  26 ( d ), respectively; in the embodiment depicted in  FIG.  6 ( a ) : knife rolls  20 ( a ),  20 ( b ) about axes of rotation  26 ( a ) and  26 ( b ), respectively]. 
     Web  100  passes through orbital knife  1  on the conveyor comprising two segments, being fed to orbital knife  1  by being disposed on infeed conveyor  104  which is spaced apart from discharge conveyor  105 , resulting in a gap between conveyor segments  104  and  105 . In the gap, web  100  is disposed on anvil roll  50  positioned below web  100 . The aforementioned rotation of knife rolls  20  about axes of rotation  26  results in the alternatively positioning of each of the plurality of knife rolls  20  proximal anvil roll  50  and each of cutting element  88  of blades  80  or  85  attached to knife rolls  20  being alternatively positioned above and in contact with web  100  in this gap, with web  100  in turn positioned above and in contact with anvil roll  50 . A load (force) is imposed on anvil roll  50  alternatively by each of the plurality of blades  80  attached to each of the plurality of knife rolls  20  compresses web  100  in this gap, with web  100  cut into individual cut web pieces  101  alternatively by each of the plurality of blades  80  of each of the plurality of knife roll  20  when rotation of yoke  10  results in the alternative positioning of each of the plurality of knife rolls  20  proximal anvil roll  50 . 
     The embodiment of the present invention depicted in  FIG.  6 ( b )  is similar to that depicted in  FIGS.  5   a   (a)/ 5 ( b ) and  FIG.  6 ( a ) , with the distinct aspect of blade  85  attached to one or more of the plurality of knife rolls  20  comprises a rigid structure with an upper (secured) end proximal and attached to knife roll  20  and a lower (distal) end comprising cutting element  88 , wherein blade  85  is separably attached to each of the one or more knife rolls  20  of orbital knife  1  so that blade  85  is displaceable with respect to its respective knife roll axis of rotation  26 , with the result that the cut radius CR of blade  85  can be varied, with the result that the force with which the cutting element  88  disposed on blade  85  presses against the surface of the anvil roll  50  against which the web  100  is compressed can be varied. 
     Furthermore, in alternative embodiments of the foregoing embodiment of the present invention (see  FIG.  6 ( b ) ), a compressible member  86  is positioned between the upper (secured) end of blade  85  and the portion of knife roll  20  to which blade  85  is separably attached. Use of such a compressible member  86  allows for cutting element  88  to extend radially toward and proximal the center of knife roll  20 . Blade  85  effectuates a cut of web  100  distinctly from blade  80  of other embodiments described herein in that the cutting force is generated by the entire blade  85  moving and compressing an elastic support member  86  instead of the blade  80  itself flexing and behaving like a stiff spring. 
     An alternative embodiment of the present invention comprising an orbital knife  1  is depicted in  FIGS.  7 ,  8     a , and  8 ( b ). With respect to such embodiment, orbital knife  1  comprises (a) a support structure  5  and (b) a yoke  10  rotatably attached to the support structure  5  with a yoke axis of rotation  16  and having a yoke hub  11  substantially concentric with yoke axis of rotation  16  and one or more yoke arms  12  positioned laterally with respect to and attached to the yoke hub  11 . In the embodiment of orbital knife  1  shown in  FIG.  7   , the one or more yoke arms  12  comprise (i) plurality of yoke arms  12 ( a   1 ) and  12 ( a   2 ) with yoke arm  12 ( a   2 ) spaced apart from yoke arm  12 ( a   1 ) and (ii) plurality of yoke arms  12 ( b   1 ) and  12 ( b   2 ) with yoke arm  12 ( b   2 ) spaced apart from yoke arm  12 ( b   1 ). 
     In preferred embodiments of this alternative embodiment of orbital knife  1 , yoke  10  is connected to drive motor  15  which provides the rotational force to rotate yoke  10  about yoke rotational axis  16 . In yet other preferred embodiments of this alternative embodiment of orbital knife  1 , rotation of yoke  10  about yoke rotational axis  16  may be effectuated by any suitable means known in the art to rotate yoke  10 . 
     Orbital knife  1  further comprises one or more knife rolls  20  radially displaced from and parallel to yoke hub  11 , each of the one or more knife rolls  20  having its own axis of rotation  26 . In certain embodiments of this alternative embodiment, orbital knife  1  comprises a plurality of knife rolls  20 ( a ) and  20 ( b ), with knife roll  20 ( a ) having axis of rotation  26 ( a ) and positioned parallel to yoke hub  11  and knife roll  20 ( b ) having axis of rotation  26 ( b ) and positioned parallel to yoke hub  11 . Each of the one or more knife rolls  20  is securely connected to one or more yoke arms  12  of yoke  10  using means known in the art. 
     Yoke arms  12  are positioned so that the knife roll axis of rotation  26  is parallel to the yoke axis of rotation  16 . In preferred embodiments of this alternative embodiment of orbital knife  1  wherein orbital knife  1  comprises a plurality of knife rolls  20 ( a ) and  20 ( b ) such as that shown in  FIG.  7   , (a) first knife roll  20 ( a ) is securely connected to yoke  10  via first knife roll first yoke arm  12 ( a   1 ) and first knife roll second yoke arm  12 ( a   2 ) spaced apart from first knife roll first yoke arm  12 ( a   1 ) and (b) second knife roll  20 ( b ) is securely connected to yoke  10  via second knife roll first yoke arm  12 ( b   1 ) and second knife roll second yoke arm  12 ( b   2 ) spaced apart from second knife roll first yoke arm  12 ( b   1 ). First knife roll first yoke arm  12 ( a   1 ) can be attached to, integral with, or separate from yoke hub  11  and first knife roll second yoke arm  12 ( a   2 ) can be attached to, integral with, or separate from yoke hub  11 . Yoke arms  12  are positioned so that the knife roll axis of rotation  26  for the knife roll  20  secured by such yoke arms  12  is parallel to yoke axis of rotation  16 . 
     Further, separably attached to each knife roll  20  of orbital knife  1  according to this embodiment of orbital knife  1  is blade  80  comprising a cutting element  88  positioned parallel to the knife roll  20  to which blade  80  is separably attached. 
     This alternative embodiment of orbital knife  1  further comprises an anvil roll  50  rotatably attached to support structure  5 , such anvil roll  50  having anvil roll axis of rotation  56  parallel to the yoke axis of rotation  26 . In preferred embodiments of this alternative embodiment of orbital knife  1 , anvil roll  50  is connected to drive motor  55  which provides the rotational force to rotate anvil roll  50  about anvil roll rotational axis  56 . In yet other preferred embodiments of this alternative embodiment of orbital knife  1 , rotation of anvil roll  50  may be effectuated by any suitable means known in the art to rotate anvil roll  50 . 
     Web  100  is compressed between one of the one or more knife rolls  20  and anvil roll  50 , with web  100  cut into individual cut web pieces  101  alternatively by the blade  80  attached to the knife roll  20  of such one or more knife rolls  20  when rotation of yoke  10  results in the positioning of such knife roll  20  proximal anvil roll  50 . Web  100  may or may not be in contact with knife roll  20  to effectuate a cut, with all that is required to effectuate a cut is contact between cutting element  88  of blade  80  and web  100 . 
     For orbital knife  1  of this embodiment, rotation of the one or more knife rolls  20  is effectuated by a belt and pulley system. Such system comprises one or more sun pulleys  35  wherein each of the one or more sun pulleys  35  is connected to one of the one or more planet pulleys  45  connected to one or more knife rolls  20  wherein each of the one or more sun pulleys  35  has an axis of rotation concentric with the yoke rotational axis  16  of the yoke  10 . The one or more sun pulleys  35  may be held stationary relative to support structure  5  such that its pitch diameter is concentric with the rotational axis of the yoke  10  or, alternatively, rotated about the axis of rotation of such sun pulley  35 , with rotation of sun pulley  35  effectuated by using any one of many means known in the art. 
     Further, in such alternative embodiments of orbital knife  1 , attached to each knife roll  20  is a planet pulley  45  ( i ) having an axis of rotation concentric with the axis of rotation of the respective knife roll  20  and (ii) joined via a drive belt  46  with sun pulley  35  wherein drive belt  46  loops around both pulleys  35  and  45  such that rotation of sun pulley  35  causes rotation of planet pulley  45  effectuated by the force imparted by the displaceable drive belt  46  [see  FIGS.  7 ,  8   ( a ),  8 ( b )]. Such drive belt  46  is held in appropriate contact with pulleys  35  and  45  by tensioning member  47  attached to one of the yoke arms  12 . A separate drive belt  46  is associated with each pair of sun pulley  35  and planet pulley  45  such that each of a plurality of knife rolls  20  is driven independently from any other knife roll  20 , each knife roll  20  having its own pair of sun pulley  35  and planet pulley  45 . In preferred embodiments of this alternative embodiment of orbital knife  1 , (a) a first knife roll  20 ( a ) has rigidly attached thereto a first planet pulley  45 ( a ) joined via a first drive belt  46 ( a ) with a first sun pulley  35 ( a ) wherein first drive belt  46 ( a ) is held in appropriate contact with first pulleys  35 ( a ) and  45 ( a ) by first tensioning member  47 ( a ), and ( b ) a second knife roll  20 ( b ) has rigidly attached thereto a second planet pulley  45 ( b ) joined via a second drive belt  46 ( b ) with a second sun pulley  35 ( b ) wherein second drive belt  46 ( b ) is held in appropriate contact with second pulleys  35 ( b ) and  45 ( b ) by second tensioning member  47 ( b ). 
     In such embodiment of the orbital knife  1 , rotation of the yoke  10  about its axis of rotation  16  while a sun pulley  35  is held stationary with respect to the support structure  5  will effectuate a rotation of the respective planet pulley  45  and rotation of its respective knife roll  20  about its axis of rotation  26 . Further, the ratio of the sun pulleys  35  pitch radii and planet pulleys  45  pitch radii is established using any means known in the art such that operation of orbital knife  1  produces a precisely repeating pattern of locations of the cutting element  88  associated with each knife roll  20  with respect to anvil roll  50 , which obviates cutting element  88  of blade  80  attached to knife roll  20  impinging or contacting anvil roll  50  during yoke  10  rotation. Further, orbital knife  1  has, for a particular cut setting, a key operational parameter called the cut radius CR [ FIGS.  8 ( a ) and  8 ( b ) ] which is defined as the straight-line distance from the center of rotation of yoke  10  to cutting element  88 . 
     The force required to effectuate the rotation of sun pulley  35  can be achieved using any means known in the art. In preferred embodiments, orbital knife  1  comprises one or more phasing actuators  90  [depicted in  FIG.  7    as a plurality of phasing actuators  90 ( a ) and  90 ( b )], with an upper section and a lower section wherein the lower section is attached to support structure  5  of orbital knife  1  and a phasing link  92  is disposed at the upper section of actuator  90 . 
     With reference to  FIGS.  8 ( a ) and  8 ( b ) , rotation of the one or more sun pulleys  35  with respect to the support structure  5  causes rotation of the respective [mated] planet pulley  45 , thereby modifying the cut radius CR of knife roll  20  associated with the rotating sun pulley  35 /planet pulley  45 . That is, the orientation of sun pulley  35 -planet pulley  45 , wherein the rotating of sun pulley  35  effectuates the rotation of planet pulley  45  allows for modification of the cut radius CR during operations of orbital knife  1 . Further, with each knife roll  20  of the orbital knife  1  according to the present invention having associated therewith a sun pulley  35  that is not associated with any other knife roll  20  allows for independent adjustment of each knife roll  20 &#39;s cut radius CR. 
     In preferred embodiments of the invention wherein force for rotation of the one or more sun pulleys  35  is provided by one or more actuators  90 , orbital knife  1  further comprises a phasing arm  32  attached to each of the one or more sun pulleys  35 , each phasing arm  32  having a first end and a second end, wherein (a) the first end of phasing arm  32  is rotatably attached to phasing link  92  and the second end of phasing arm  32  is rigidly attached to sun pulley  35 , and (b) rotation of phasing arm  32  effectuates rotation of sun pulley  35  about its axis of rotation thereby controlling the rotational position of the sun pulley  35  relative to the stationary support structure  5  and thus another key operational parameter called the phase angle PA [see  FIGS.  8 ( a ) and  8 ( b ) ] which is a measure of the amount of rotation of sun pulley  35  relative to a fixed reference and wherein phase angle PA for the instant invention is defined as angle from the upper lateral plane of support structure  5  to the lateral plane occupied by phasing arm  32  extending through the center of sun pulley  35 . In embodiments of orbital knife  1  comprising a plurality of sun pulleys  35 ( a ) and  35 ( b ), rigidly attached to sun pulley  35 ( a ) is phasing arm  32 ( a ) and rigidly attached to sun pulley  35 ( b ) is phasing arm  32 ( b ) [see  FIG.  7   ]. 
     The force required to effectuate the rotation of phasing arm  32  can be achieved using any means known in the art. In preferred embodiments, force is provided by one or more actuator motors  95  connected to one or more actuators  90 , with each motor  95  connected to one actuator  90 . In alternative preferred embodiments as shown in  FIG.  7   , orbital knife  1  comprises a plurality of actuators  90 ( a ) and  90 ( b ) wherein each such actuator  90  is connected to a plurality of actuator motors  95 ( a ) and  95 ( b ). 
     The rotation of the one or more sun pulleys  35  allows for operational control of phase angle PA (i.e., a measure of the rotational position of each of the sun pulleys  35  with respect to the stationary support structure  5 ), with in-operation (on the fly) rotation of the one or more sun pulleys  35  (that is, rotation of the one or more sun pulleys  35  during active (ongoing) web  100  cutting operations driving the one or more planet pulleys  45 ), allowing for a change of the cut radius CR of each of the one or more blades  80  of orbital knife  1  resulting in a modification of deflection of cutting element  88  associated with each of the one or more blades  80  attached to each of the one or more knife rolls  20  associated with each such rotation sun pulley  35 , thus obviating use of an adjustable anvil  53  in prior art cutting apparatus P and adjustment of such anvil  53  to effectuate a change in blade deflection and resulting in an apparatus (i.e., orbital knife  1  according to the present invention) that has less parts and is less expensive to acquire and maintain than prior art prior cutting apparatuses P. In other words, the rotation of sun pulley  35  of orbital knife  1  according to the present invention allows a user of orbital knife  1  to change the cut radius CR, and hence blade deflection and the cutting force with which cutting element  88  on blade  80  contact anvil roll  50 , of each of the one or more blades  80  on the fly during operations to allow for a continuous cutting operation during which the optimal blade  80  deflection is maintained without the need for multiple batch (run) operations (i.e., operation of prior art cutting apparatus P with a first cut radius CR, stoppage of operation [defining a first batch {run} operation], modification of prior art cutting apparatus P by adjusting the position of cutting element  88  of blade  80  relative to the center of rotation a of the knife roll  20  to effectuate a change of cut radius CR and hence effectuating a change in the blade  80  deflection during the cutting operation or, alternatively, changing the deflection of the blade  80  of cutting apparatus P by changing the position of the anvil  53  relative to the center of rotation of the anvil roll  50  to effectuate a change in the deflection of blade  80  with cutting element  88 , with any of the foregoing requiring the aforementioned stoppage of operations of cutting apparatus P to change cutting element  88  deflection and thereafter recommencing operations of cutting apparatus P [defining a second batch {run} operation]). The on-the-fly CR adjustability provided by orbital knife  1  according to the present invention allows for continuous maintenance of optimal blade interference to make web  100  cutting operations more efficient. 
     In a cutting operation, cut radius CR is at a maximum when yoke radius YR, which is defined as the straight-line distance from the yoke axis of rotation  16  to the knife roll axis of rotation  26 , and the knife radius KR, another key operational parameter defined as the straight-line distance from the knife roll axis of rotation  26  to cutting element  88  of blade  80  of knife roll  20 , lie in a common plane as illustrated in  FIG.  8 ( a ) . Moving the knife roll axis of rotation  26  out of the common plane will cause a reduction of cut radius CR as illustrated in  FIG.  8 ( b )  and is effectuated by rotation of sun pulley  35 . In practice, the optimal cut radius CR for any given circumstance is something less than the maximum cut radius CR. Further, the optimal blade  80  deflection with related cut radius CR may change over time depending on operating conditions. In the present invention, maintenance of an optimal blade deflection and associated cut radius CR can be achieved since cut radius CR of each of the one or more blades  80  of orbital knife  1  can be varied during web cutting operation without stopping orbital knife  1  operations as is required of a prior art cutting apparatus P. 
     During operation of orbital knife  1  with one or more knife rolls  20  on which is attached a blade  80  with cutting element  88 , yoke  10  rotates about its axis of rotation  16 , and anvil roll  50  rotates about its axis of rotation  56 . In preferred embodiments comprising an actuator  90 -phasing link  92 -phasing arm  32  arrangement as described herein, rotation of one or more sun pulleys  35  resulting from the displacement of a phasing link  92  associated with each sun pulley  35 , with such displacement of phasing link  92  in preferred embodiments effectuated by actuator  90 . Phasing link  92  displacement effectuates displacement of phasing arm  32 , which in turn effectuates rotation of the associated sun pulley  35 . Rotation of the sun pulley  35  results in the rotation of the planet pulley  45  with which the sun pulley  35  is in contact via drive belt  46  forming a belt and pulley system. Sun pulley  35  rotation effectuates a rotation of the associated knife roll  20  about such knife roll  20 &#39;s axis of rotation  26 , thereby changing the relationship between the yoke radius YR and the knife radius KR with a corresponding change in the cut radius CR and therefore changing blade  80  deflection. 
     Web  100  passes through orbital knife  1  on the conveyor comprising two segments, being fed to orbital knife  1  by being disposed on infeed conveyor  104  which is spaced apart from discharge conveyor  105 , resulting in a gap between conveyor segments  104  and  105 . In the gap, web  100  is disposed on anvil roll  50  positioned below web  100 . Rotation of yoke  10  about its axis of rotation  16  results in the positioning of knife roll  20  proximal anvil roll  50  and cutting element  88  of blade  80  attached to knife roll  20  being positioned above web  100  in this gap, with cutting element  88  positioned above and in contact with web  100  which in turn is positioned above and in contact with anvil roll  50 . A load (force) is imposed on anvil roll  50  by the blade  80  of knife roll  20  which compresses web  100  in this gap, with web  100  cut into individual cut web pieces  101  by blade  80  of knife roll  20  when rotation of yoke  10  results in the positioning of knife roll  20  proximal anvil roll  50 . 
     Yet another preferred embodiment of the alternative embodiment entails orbital knife  1  comprising a blade  85  ( FIG.  8 ( c ) ) comprising a rigid structure with an upper secured end proximal and attached to knife roll  20  and a lower (distal) end comprising cutting element  88 , wherein a blade  85  is separably attached to each of the one or more knife rolls  20  of orbital knife  1  (i.e., each knife roll  20  having at least one blade  85  that is not attached to any other knife roll  20 ) so that blade  85  is displaceable with respect to its respective knife roll axis of rotation  26  (with the result that the force of contact between the leading end of blade  85  comprising cutting element  88  and the surface of the anvil roll  50  against which the web  100  is compressed can be varied). Furthermore, in alternative embodiments of the foregoing embodiment of the present invention (see  FIG.  8 ( c ) ), a compressible member  86  is positioned between the upper (secured) end of blade  85  and the portion of knife roll  20  to which blade  85  is separably attached. Use of such a compressible member  86  allows for cutting element  88  to extend radially toward and proximal the center of knife roll  20 . Blade  85  effectuates a cut of web  100  distinctly from blade  80  of other embodiments described herein in that the cutting force is generated by the entire blade  85  moving and compressing an elastic support member  86  instead of the blade  80  itself flexing and behaving like a stiff spring. 
     An alternative embodiment of the present invention comprising an orbital knife  1  is depicted in  FIG.  9   . With respect to such embodiment, orbital knife  1  comprises (a) support structure  5  and (b) yoke  10  rotatably attached to the support structure  5  with a yoke axis of rotation  16  and having a yoke hub  11  substantially concentric with yoke axis of rotation  16  and one or more yoke arms  12  positioned laterally with respect to and attached to the yoke hub  11 . In the embodiment shown in  FIG.  9   , the one or more yoke arms  12  comprise (i) plurality of yoke arms  12 ( a   1 ) and  12 ( a   2 ) spaced apart from yoke arm  12 ( a   1 ) and (ii) plurality of yoke arms  12 ( b   1 ) and  12 ( b   2 ) spaced apart from yoke arm  12 ( b   1 ). Yoke arms  12  are positioned so that the knife roll axis of rotation  26  is parallel to the yoke axis of rotation  16 . 
     Further with reference to  FIG.  9   , radially displaced from yoke hub  11  is one or more knife rolls  20 , each knife roll  20  having its own axis of rotation  26  and positioned parallel to the yoke hub  11 . In certain embodiments of this alternative embodiment, orbital knife  1  comprises a plurality of knife rolls  20 ( a ) and  20 ( b ), with knife roll  20 ( a ) having axis of rotation  26 ( a ) and positioned parallel to yoke hub  11  and knife roll  20 ( b ) having axis of rotation  26 ( b ) and positioned parallel to yoke hub  11 . 
     Further with reference to  FIG.  9   , an embodiment of the present invention of orbital knife  1  further comprises one or more blades  80  attached to each of the one or more knife rolls  20 , wherein each blade  80  comprises an upper end proximal the knife roll  20  and a lower end comprising a cutting element  88  positioned parallel to the knife roll  20  to which the blade  80  is attached. An embodiment of the present invention of orbital knife  1  further comprises an anvil roll  50  rotatably connected to support structure  5 , wherein anvil roll  50  has an axis of rotation  56  parallel to rotational axis  16  of yoke  10 . 
     In preferred embodiments of orbital knife  1  comprising a plurality of knife rolls  20 ( a ) and  20 ( b ), first knife roll  20 ( a ) has separably attached thereto first blade  80 ( a ) comprising first blade cutting element  88 ( a ) and second knife roll  20 ( b ) has separably attached thereto second blade  80 ( b ) comprising second blade cutting element  88 ( b ). In preferred embodiments of orbital knife  1  comprising a plurality of knife rolls  20 ( a ) and  20 ( b ) and a rotating yoke  10 , web  100  is compressed alternatively between blade  80 ( a ) and blade  80 ( b ) with disposed cutting elements  88 ( a ) and  88 ( b ) separably attached to knife rolls  20 ( a ) and  20 ( b ) depending on the rotational position of yoke  10 , and anvil roll  50 , with web  100  cut into individual cut web pieces  101  alternatively by blade  80 ( a ) attached to knife roll  20 ( a ) when rotation of yoke  10  results in the positioning of knife roll  20 ( a ) proximal anvil roll  50  and blade  80 ( b ) attached to knife roll  20 ( b ) when rotation of yoke  10  results in the positioning of knife roll  20 ( b ) proximal anvil roll  50 . Web  100  may or may not be in contact with knife roll  20  to effectuate a cut, with all that is required to effectuate a cut is contact between cutting element  88  of blade  80  and web  100 . 
     This embodiment of orbital knife  1  differs from the embodiment described above and depicted in  FIGS.  2 ,  5   ( a )/ 5 ( b ), and  6 ( a ) in that rotation of the one or more knife rolls  20  is effectuated by a gear train comprising a driving gear, driven gear, and idler gear placed between the driving and driven gears rather than a gear train with simply driving and driven gears or a belt and pulley system. Specifically, and with reference to  FIG.  9   , orbital knife  1  according to this embodiment further comprises one or more a sun gears  30  attached to support structure  5 , one or more planet gears  40  with each of the planet gears  40  attached to a knife roll  20 , and one or more idler gears  43  wherein each idler gear  43  is inserted between and in simultaneous mated [mesh] contact with at least one sun gear  30  and at least one planet gear  40 . 
     Each of the one or more planet gears  40  has an axis of rotation concentric with the axis of rotation of the respective knife roll  20  and having a specified pitch radius so that rotation of the yoke  10  about its axis of rotation while the sun gears  30  are held stationary with respect to the support structure  5  will effectuate a rotation of idler gear  43  which in turn causes a rotation of the respective planet gear  40  and in turn the associated knife roll  20 . 
     In preferred embodiments and with reference to  FIG.  9   , orbital knife  1  comprises (a) a first sun gear  30 ( a ) and a second sun gear  30 ( b ), ( b ) a first planet gear  40 ( a ) and a second planet gear  40 ( b ), and ( c ) a first idler gear  43 ( a ) inserted between and in simultaneous mated contact with first sun gear  30 ( a ) and first planet gear  40 ( a ) and a second idler gear  43 ( b ) inserted between and in simultaneous mated contact with second sun gear  30 ( b ) and second planet gear  40 ( b ). Each sun gear  30  has an axis of rotation concentric with the yoke rotational axis  16  and has a pitch radius such that the sun gear  30  pitch diameter is concentric with yoke rotational axis  16 . 
     Further, the ratio of the sun gear  30  pitch radii and planet gear  40  pitch radii is established such that operation of orbital knife  1  produces a precisely repeating pattern of locations of the positioning of the cutting element  88  associated with each knife roll  20  with respect to support structure  5 , which obviates cutting element  88  of blade  80  attached to knife roll  20  impinging or contacting anvil roll  50  during yoke  10  operation. Further, orbital knife  1  has, for a particular cut setting, a key operational parameter called the cut radius CR which is defined as the straight-line distance from the center of rotation of yoke  10  to cutting element  88 . 
     The force required to effectuate the rotation of sun gear  30  can be achieved using any means known in the art. In preferred embodiments, orbital knife  1  further comprises one or more phasing actuators  90  [depicted in  FIG.  9    as a plurality of phasing actuators  90 ( a ) and  90 ( b )] with an upper section and a lower section wherein the lower section is attached to support structure  5  of orbital knife  1  and a phasing link  92  is disposed at the upper section of actuator  90 . The orientation of sun gear  30 -idler gear  43 -planet gear  40  allows for modification of the cut radius CR during operations of orbital knife  1 . Further, with each knife roll  20  of the orbital knife  1  according to the present invention having associated therewith a sun gear  30  that is not associated with any other knife roll  20  allows for independent adjustment of each knife roll  20 &#39;s cut radius CR. 
     In embodiments wherein force for rotation of the sun gear  30  is provided by one or more actuators  90 , orbital knife  1  further comprises a phasing arm  32  attached to each of the one or more sun gears  30 , each phasing arm  32  having a first end and a second end, wherein (a) the first end of phasing arm  32  is rotatably attached to phasing link  92  and the second end of phasing arm  32  is rigidly attached to sun gear  30 , and (b) rotation of phasing arm  32  effectuates rotation of sun gear  30  about its axis of rotation thereby controlling the rotational position of sun gear  30  relative to support structure  5  which is measured by the key operational parameter called the phase angle PA which is a measure of the amount of rotation of sun gear  30  relative to a fixed reference and wherein phase angle PA for the instant invention is defined as the angle from the upper lateral plane of support structure  5  to the lateral plane occupied by phasing arm  32  extending through the center of sun gear  30 . In embodiments of orbital knife  1  comprising a plurality of sun gears  30 ( a ) and  30 ( b ), rigidly attached to sun gear  30 ( a ) is phasing arm  32 ( a ) and rigidly attached to sun gear  30 ( b ) is phasing arm  32 ( b ) [see  FIG.  9   ]. 
     Further, in preferred embodiments wherein the force for rotation of sun gears  30  is provided through one or more actuators  90 , force is provided by one or more actuator motors  95  connected to one or more actuators  90 , with each motor  95  connected to one actuator  90 . In alternative preferred embodiments as shown in  FIG.  9   , orbital knife  1  comprises a plurality of actuators  90 ( a ) and  90 ( b ) wherein each such actuator  90  is connected to a plurality of actuator motors  95 ( a ) and  95 ( b ). 
     The rotation of the one or more sun gears  30  allows for operational control of phase angle PA of each of the sun gears  30  (i.e., the rotational position of each of the sun gears  30  with respect to the stationary support  5 ), with in-operation (on the fly) rotation of the one or more sun gears  30  (that is, rotation of the one or more sun gears  30  during active (ongoing) web  100  cutting operations, with such rotation driving planet gear  40  via idler gear  43 ), thus allowing for a change of the cut radius CR of each of the one or more blades  80  resulting in a modification of deflection of cutting element  88  associated with each of the one or more blades  80  attached to each of the one or more knife rolls  20  associated with each such rotating sun gear  30 , thus obviating use of an adjustable anvil  53  in prior art cutting apparatus P and adjustment of such anvil  53  to effectuate a change in blade deflection and resulting in an apparatus (i.e., orbital knife  1 ) that has less parts and is less expensive to acquire and maintain than prior art cutting apparatuses P. In other words, the rotation of sun gear  30  according to the present invention allows a user of orbital knife  1  to change the cut radius CR, and hence blade deflection and the cutting force with which cutting element  88  on blade  80  contact anvil roll  50 , of each of the one or more blades  80  on the fly during operations to allow for a continuous cutting operation during which the optimal blade  80  deflection is maintained without the need for multiple batch (run) operations (i.e., operation of prior art cutting apparatus P with a first cut radius CR, stoppage of operation [defining a first batch {run} operation], modification of prior art cutting apparatus P by adjusting the position of cutting element  88  of blade  80  relative to the center of rotation of the knife roll  20  to effectuate a change of cut radius CR and hence effectuating a change in the blade  80  deflection during the cutting operation or, alternatively, changing the deflection of the blade  80  of cutting apparatus P by changing the position of the anvil  53  relative to the center of rotation of the anvil roll  50  to effectuate a change in the deflection of blade  80  with cutting element  88 , with any of the foregoing requiring the aforementioned stoppage of operations of cutting apparatus P to change cutting element  88  deflection and thereafter recommencing operations of cutting apparatus P [defining a second batch {run} operation]). The on-the-fly CR adjustability provided by orbital knife  1  according to the present invention allows for continual maintenance of optimal blade interference to make web  100  cutting operations more efficient. 
     In a cutting operation, cut radius CR is at a maximum when yoke radius YR, which is defined as the straight-line distance from the yoke axis of rotation  16  to the knife roll axis of rotation  26 , and the knife radius KR, another key operational parameter defined as the straight-line distance from the knife roll axis of rotation  26  to cutting element  88  of blade  80  of knife roll  20 , lie in a common plane. Moving the knife roll axis of rotation  26  out of the common plane will cause a reduction of cut radius CR and is effectuated by rotation of sun gear  30 . In practice, the optimal cut radius CR for any given circumstance is something less than the maximum cut radius CR. Further, the optimal blade  80  deflection with related cut radius CR may change over time depending on operating conditions. In the present invention, maintenance of an optimal blade deflection and associated cut radius CR can be achieved since cut radius CR of each of the one or more blades  80  of orbital knife  1  can be varied during web cutting operation without stopping orbital knife  1  operations as is required of a prior art cutting apparatus P. 
     During operation of orbital knife  1  with one or more knife rolls  20  on which is attached a blade  80  with cutting element  88 , yoke  10  rotates about its axis of rotation  16 , and anvil roll  50  rotates about its axis of rotation  56 . In preferred embodiments comprising an actuator  90 -phasing link  92 -phasing arm  32  arrangement as described herein, rotation of one or more sun gears  30  resulting from the displacement of a phasing link  92  associated with each sun gear  30 , with such displacement of phasing link  92  in preferred embodiments effectuated by actuator  90 . Phasing link  92  displacement effectuates displacement of phasing arm  32 , which in turn effectuates rotation of the associated sun gear  30 . Rotation of the sun gear  30  results in the rotation of the planet gear  40  via the idler gear  43  with which the sun gear  30  forms a gear train. Sun gear  30  rotation effectuates a rotation of the associated knife roll  20  about such knife roll  20 &#39;s axis of rotation  26 , thereby changing the relationship between the yoke radius YR and the knife radius KR with a corresponding change in the cut radius CR and therefore changing blade  80  deflection. 
     Web  100  passes through orbital knife  1  on the conveyor comprising two segments, being fed to orbital knife  1  by being disposed on infeed conveyor  104  which is spaced apart from discharge conveyor  105 , resulting in a gap between conveyor segments  104  and  105 . In the gap, web  100  is disposed on anvil roll  50  positioned below web  100 . Rotation of yoke  10  about its axis of rotation  16  results in the positioning of knife roll  20  proximal anvil roll  50  and cutting element  88  of blade  80  attached to knife roll  20  being positioned above web  100  in this gap, with cutting element  88  positioned above and in contact with web  100  which in turn is positioned above and in contact with anvil roll  50 . A load (force) is imposed on anvil roll  50  by the blade  80  of knife roll  20  which compresses web  100  in this gap, with web  100  cut into individual cut web pieces  101  by blade  80  of knife roll  20  when rotation of yoke  10  results in the positioning of knife roll  20  proximal anvil roll  50 . 
     While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the sprit and scope of the invention.