Abstract:
A cutter for cutting elongate material into sections, the cutter including a motor coupled to a blade shaft, wherein said motor selectively rotates said blade shaft, a blade mounted on said blade shaft and rotatable therewith, and an actuator adapted to drive said blade along a drive axis toward the material.

Description:
TECHNICAL FIELD 
   In general, the present invention relates to a cutter used to section elongate materials. More particularly, the present invention relates to a cutter having a rotating blade. 
   BACKGROUND OF THE INVENTION 
   The present invention generally relates to a cutter used to cut elongate products into sections. For example, the cutter may be used to cut extruded profiles with or without reinforcement. These materials have proven difficult to cut with existing cutters. 
   One existing cutter uses a curved blade that cuts through the material in a scythe like manner. This type of blade may be used to cut material as it comes off an extruder in a continuous manner. Unfortunately, the curved blade cutter often distorts the material as it cuts making it difficult to maintain dimensional accuracy. This distortion also may result in a defective cut surface that is scalloped or otherwise irregular. These problems are pronounced when cutting softer materials. 
   Another existing cutter operates in a lathe-like manner with the material being mounted inside a rotating mandrel. Since the mandrel has a finite length, extruded material must be pre-cut and mounted before additional cuts are made. Consequently, such cutters are not suitable for continuous operation. 
   SUMMARY OF THE INVENTION 
   The present invention generally provides a cutter for cutting elongate material into sections, the cutter including a blade motor having a blade shaft, a blade mounted on the blade shaft, and an actuator adapted to move the blade along a drive axis into contact with the material to cut the material. 
   The present invention further provides a cutter for cutting elongate material into sections, the cutter including a motor coupled to a shaft, wherein the motor selectively rotates the shaft, a blade mounted on the shaft and rotatable therewith, a guard enclosing the blade, the guard defining an opening for receiving the material, a guard shutter mounted adjacent the opening and moveable to selectively cover the opening, and an actuator attached to the guard shutter and adapted to move the guard shutter between an open position and a closed position. 
   The present invention further provides a cutter for sectioning elongated material, the cutter including a shaft rotatably supported by bearings and coupled to a motor, wherein the motor rotates the shaft, an arm supported on the shaft and extending radially outward relative to the shaft, the arm being rotatably fixed to the shaft and rotatable therewith, a blade mounted on the arm and rotatable independently of the arm, and a blade motor coupled to the blade and adapted to rotate the blade. 
   The present invention further provides a cutter for cutting elongate material into sections, the cutter including a blade motor having a blade shaft; a blade mounted on the blade shaft, wherein the blade motor is adapted to selectively rotate the blade at a selected speed to cut the material; wherein the blade is supported by an actuator adapted to move the blade into contact with the material to cut the material; and a winding assembly including a spool located downstream of the blade, the spool being adapted to gather the material, and a controller adapted to activate the actuator as the spool becomes full, driving the blade to cut the material. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a partially sectioned side elevational view of a cutter according to the concepts of the present invention; 
       FIG. 2  is a top plan view of the cutter of  FIG. 1  depicted with the guard shutter in an open position; 
       FIG. 2A  is a top plan view of a cutter similar to the cutter shown in  FIG. 2  with the guard shutter depicted in a closed position; 
       FIG. 3  is a front elevational view of a turret winding assembly having a cutter similar to the one depicted in  FIG. 1 ; 
       FIG. 4  is a top plan view of a first alternative cutter according to the concepts of the present invention; 
       FIG. 5  is a front plan view of the cutter shown in  FIG. 4 ; 
       FIG. 6  is side elevational view of a second alternative cutter according to the concepts of the present invention shown in a non-cutting position; 
       FIG. 7  is a side elevational view, similar to  FIG. 6 , with the cutter depicted in a cutting position; and 
       FIG. 8  is a top plan view of the cutter depicted in  FIG. 6 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The cutter according to the present invention generally includes a blade that is rotated on its axis by a motor. The blade speed may be controlled according to the type of material that is being cut. As shown, the blade may be circular and is constructed of a suitable material, such as, a metal or ceramic material. Other materials may be used depending on the particular application. In one example, a surgical steel blade was found suitable for cutting through both soft materials and harder materials, including those containing Kevlar™ fibers. Optionally, a lubricant, such as water, soap, or air, may be applied to the blade to facilitate cutting. 
   A guard may be provided to reduce the likelihood of injury. The guard may include a slotted opening exposing a portion of the blade. The opening may include walls that guide the material into contact with the blade. A guard shutter may be used to limit exposure to the blade by selectively closing the opening when the blade is not cutting material providing further protection against inadvertent cutting. The shutter may be any member that is moveable to block or otherwise limit access to the opening. The shutter&#39;s movement may be controlled manually by a switch or trigger, or controlled automatically by a system controller depending upon the application. 
   In the example shown in  FIG. 1 , a cutter according to the concepts of the present invention is generally indicated by the numeral  10 . Cutter  10  includes a motor  20 , which may be an electric motor, as shown, or any other conventional motor that causes the blade  30  to rotate. 
   Motor  20  has a drive shaft  21 , which may be housed within a sleeve  22 . The drive shaft  21  may connect to a gear box  25 . In the example shown in  FIG. 1 , a collar  23  extends from the gear box  25  and receives the shaft  21 . Drive shaft  21  may be slideably mounted within sleeve  22  and collar  23  to allow the cutter  10  to travel along the drive shaft axis D. It will be understood that gear box  25  is optional. The gear ratio created by gear box  25  may be used to improve motor torque. For example, a 2:1 reduction occurs in the depicted example. This particular gear ratio is not considered limiting, and it will be appreciated that other gear ratios may be used depending on the cutting application. 
   As shown in  FIG. 1 , the gear box  25  may be used to allow the blade  30  to rotate on a different axis than the axis of the motor&#39;s drive shaft. This axis may be parallel to the drive shaft  21  or at angle as shown. In the depicted embodiment, the gear box  25  creates a 90° angle between the drive shaft axis D and the blade axis B. This particular angle, however, is not considered limiting, and the relative angle between blade axis B and drive axis D may vary depending on the location of the cutter  10  relative to other components and the material M to be cut. 
   Blade  30  attaches to a blade shaft  27  that extends outward from gear box  25  along the blade&#39;s axis B. The blade  30  may be attached to blade shaft  27  in any known manner. In the example shown, the blade  30  includes key  31  that fits within a keyway  29  formed on blade shaft  27 . 
   The blade  30 , so connected, is rotated by the motor  20  at a selected speed based on the type of material M that is being cut. In the example shown, the blade  30  is circular having generally circular cutting edge  33  at its radial outward extremity. Other blade shapes suitable for rotary cutting may be used. 
   As discussed more completely below, the cutter  10  may carry a sensor in monitoring its operation. For example, a sensor  35  may be mounted is sensing relation to the blade  30  to monitor its operation. As will be appreciated, the sensor  35  may be used to generate various information including blade speed, number of revolutions, or simply to determine whether the blade  30  is rotating. In the depicted example, sensor  35  is used to visually check for a broken blade. A second sensor may be used in conjunction with sensor  35  to reduce the likelihood that a broken blade  30  would go undetected. To that end, the second sensor may be circumferentially spaced from sensor  35 . In  FIGS. 2 and 2A , openings  34  are provided in guard  40  to mount the sensors  35  and provide a line of sight to the blade  30 . 
   As best shown in  FIG. 1 , guard  40  may include a plate  43 , which may be attached to gear box  25 , as by bolts. Plate  43  lies parallel to blade  30  on an inner side of blade  30 . Guard  40  may further include a sidewall  44  that extends axially outward relative to plate  43  to cover the edge  33  of blade  30 . To completely enclose blade  30 , guard  40  may include a cover  45  opposite plate  43  on the outer side of blade  30 . As shown, cover  45  may be removably attached against the guard  40  to cover the outer-side of blade  30  yet allow access to the blade  30  for repair and inspection purposes. As shown, the cover  45  may be made of a transparent or semi-transparent material, such as Lexan™ to allow visual inspection of blade  30 . 
   An opening, generally indicated by the numeral  46 , is formed in the guard  40  to expose a portion of the blade  30 . While only the edge  33  of blade  30  may be exposed as by an opening in sidewall  44 , opening  46  may extend radially inward to allow inward movement of material M relative to blade  30 , as shown in  FIG. 2 . To that end, a slotted opening  46  may include slots  48  formed in plate  43  and cover  45  that extend radially inward from the radial outer extremity of a plate  43  and cover  45 . The slotted opening  46  may be configured for a particular application. For example, the walls of slots  48  may have a profile that generally conforms to the profile of the material M being cut. As shown, a rounded slot surface may be useful when receiving material having a circular cross-section. To that end, opening  46  may generally conform to the material M being cut to serve as a guide and hold the material while it is being cut. 
   For improved safety, a guard shutter  50  may be provided to selectively close the opening  46 . In the example shown, guard shutter  50  is rotatably mounted on guard  40  and may be rotated from a closed position ( FIG. 2A ), where the guard shutter  50  covers the opening  46  to an open position ( FIG. 2 ) away from the opening  46 . As shown, guard shutter  50  may have a somewhat C-shaped cross section ( FIG. 1 ) including a guard plate  53  located within guard  40  on the inner side of blade  30 , a guard sidewall  54  extending axially outward from guard plate  53  beyond the edge  33  of blade  30 , and a lip  55  extending radially inward from guard sidewall  54  outside of blade  30 . As shown, lip  55  may extend radially inward on the slot side to cover slots  48  formed in guard  40  to completely enclose edge  33  of blade  30 . To prevent lip  55  from interfering with sensors  35 , lip  55  may extend radially inward to a lesser extent to prevent the lip  55  from extending into the line of sight of sensor  35 . This would prevent the sensor  35  from falsely reporting that the blade  30  was intact due to the lip  55  extending into its line of sight. As an alternative to shortening the extension of lip  55 , openings may be provided in the lip  55  to ensure that it does not extend into the sensor&#39;s line of sight. 
   To accommodate sensors  35  that protrude inwardly from guard  40 , guard shutter  50  may define a slot  51  that extends circumferentially a distance suitable for providing the necessary range of motion for the guard shutter  50  to rotate between the open position ( FIG. 2 ) and the closed position ( FIG. 2A ). Also, the shutter  50  may define an opening  52  that corresponds to opening  46 , so that opening  46  opens when the opening  52  in the guard shutter  50  is aligned with opening  46 . Movement of the shutter  50  may be controlled by any known actuator or motor, which for simplicity will be generally referred to as an actuator and indicated by the numeral  60 . In the example shown, actuator  60  includes a pair of pneumatic cylinders  61 ,  62  that attach to guard shutter  50  on opposite sides of guard shutter  50 . The cylinders  61 ,  62  respectively push and pull shutter  50  to cause it to rotate in an alternating fashion to open and close the shutter  50 . Two cylinders  61 ,  62  may be used to provide a measure of safety because guard shutter  50  will not open unless both cylinders  61 ,  62  are in operation. 
   In accordance with the concepts of the present invention, cutter  10  may be used in connection with a winding assembly, generally indicated by the number  75  in  FIG. 3 . Winding assembly generally includes a spool  77  that gathers material M in a continuous fashion until the spool  77  is full. At that point, cutter  10  may be driven toward a cutting position by an actuator  79 , such as a pneumatic or hydraulic cylinder, to make a cut. To make the cut, the blade  30  is rotated and advanced to contact the material M at a selected angle. The rotating blade  30  may be driven through the material M by actuator  79 . When using a guard  40 , the opening  46  of guard  40  is aligned with material M, so that the material M is received within opening  46  while making the cut. To further improve the safety of the winding and cutting system, a shutter  50  may be used to selectively expose the blade  30  within opening  46 . In this example, shutter  50  is opened as actuator  79  advances blade  30  toward material M allowing the material M to enter the opening  46  and be held by the walls of the slotted opening  48  as the blade  30  cuts through the material M. In the example shown, advancement of blade  30  is controlled by an air cylinder that drives gear box  25  and blade  30  along the drive shaft axis D. This actuator  79  also retracts blade  30  after the cut has been made allowing the material M to begin winding on a second spool. To facilitating cutting, a gripper  83  may be used to hold the material M as it is cut. Similarly, a traverse guide, generally indicated by the number  85 , may orient the material M relative to the spool  77  to provide successive coils and align the material M with the gripper  83  in preparation for a cut. 
   It will be appreciated that the cut of material M gathered on spool  77  may be timed or a controller C in communication with spool  77  and actuator  79  may be used to detect a selected amount of material on the spool  77  and activate actuator  79  to make a cut. It will be appreciated that the selected amount of material M on spool  77  might not always coincide with the capacity of the spool  77 . For sake of simplicity, however, this condition will generally be referred to as the spool being “full.” 
   In the example shown, two spools  77  are mounted on a turret. In this way, once the first spool  77  is full it is rotated by the turret counterclockwise away from the cutter  10  to a cut/unload position  77 A. At the same time, an empty spool rotated to a load position  77 B adjacent to the cutter  10 . In this position, the material M spans both spools  77  and the traverse guide  85  positions the material M in the path of the open gripper  83 B on the empty spool. Then, in preparation for the cut, gripper  83 B on empty spool grips material M just to the right of the cutter  10 . At the time of the cut, the spool  77 A stops winding and the gripper  83 A on the full spool closes. To make the cut, as actuator  79  drives blade  30  toward material M, the motor brings the blade  30  up to speed and the guard shutter is opened so that the material M is received within the slot formed in the guard as the blade  30  cuts through material M. Once the cut is made, actuator  79  retracts the blade  30  and the guard shutter is closed. Controller C monitors the cutter to ensure that it is in a fully cleared position before spool rotation begins. 
   Meanwhile, after the cut, the operator may open the gripper  83 A on the full spool  77  and removes full spool  77 A from the turret. Then, an empty spool is placed on the spindle at the cut/unload position  77 A. The process of turreting the spools  77  from the unload position  77 A to the load position  77 B continues making for a fully automatic winding and cutting system. 
   An alternate cutter according to the concepts of the present invention is shown in  FIGS. 4 and 5 , and generally indicated by the numeral  110 . Cutter  110 , like cutter  10 , includes a rotating blade  130 , but differs in the method of bringing blade  130  into contact with material M. In this embodiment, blade  130  is mounted on a rotating arm  111 . Rotating arm  111  rotates in a plane that intersects the material M ( FIG. 4 ) and is used to periodically bring blade into contact with material M and make a cut. For cutting purposes, blade  130  may be caused to rotate independently of the arm  111 . In the example shown, arm  111  is mounted on a shaft  112 . The shaft  112  is rotatable and may be coupled to a motor  113 . A floating gear  114  is also mounted on shaft  112  and supported by dual bearings  118  such that it is freely rotatable on the shaft  112 . The floating gear  114  may be sized to accommodate two belts respectively connected to the blade  130  and motor  120 . As depicted in  FIG. 4 , a belt  115  extends from the gear  114  to a gear  116  coupled to blade  130 . A second belt  117  extends from the floating gear  114  to a blade motor  120  to drive the blade  130  independently of shaft  112 . Notably, both the motor  113  and the blade motor  120  can be mounted to a stationary support  133 , and the floating gear  114  and the belts  115 ,  117  permit the driving of blade  130  independently of shaft  112 . 
   As shown, the blade pulley  116  and blade  130  may be mounted on opposite sides of the arm  111  with a shaft  119  connecting the blade  130  to the pulley  115 . Blade shaft  119  may be supported in suitable bearings, as shown. 
   The blade  130  may be attached to blade shaft  119  in any known manner including the clamp assembly, generally indicated by the numeral  136  as shown. Clamp assembly  136  is keyed to blade shaft  119  such that it rotates therewith, and includes a chuck  136 A on which the blade  130  is mounted. A portion of the chuck  136 A extends through blade  130  and has a threaded end onto which a cap assembly  136 B is attached to clamp the blade  130  in place. So clamped, blade motor  120  via the belts and pulleys causes the blade  130  to rotate independently of the arm  111 . 
   As best shown in  FIG. 5 , an arm motor  113  rotates the arm  111  to bring the rotating blade  130  into contact with the material M. The speed of the arm  111  may be varied depending on the type of material M to ensure an accurate cut. To improve efficiency, arm speed is generally the fastest speed that still produces an accurate cut. To increase the maximum arm speed, lubricants including but not limited to water, soapy water, alcohol, and cold air may be used. 
   The speed of arm  111  may also be varied along its rotational path. For example the speed after a cut is made may be increased to bring the blade  130  to the cutting position in a shorter period of time and then slowed to the cut speed at the time of making the cut. In this way, more cuts may be made than when operating the arm  111  at a constant rotational speed. Also, an increase or decrease in the non-cut speed can be used to compensate for the change in speed caused by blade  130  cutting through material M, referred to as “cut dwell.” The speeds and cut dwell may be measured in milliseconds (ms). For example, as schematically shown in  FIG. 4 , as the blade  130  approaches a cutting position, the arm  111  may be slowed to the speed needed to cut the material M. Moving the arm  111  too fast could cause an inaccurate cut, mar the cut surface, or damage blade  130 . After the material M has been cut, for example when the blade  130  reaches a cleared position, the rotational speed of arm  111  may be increased to return the blade  130  to the cutting position. This phase of the arm&#39;s rotation is referred to as the “fast swing” in  FIG. 5 . To maintain proper cuts, a controller C accounts for the changes in the arm&#39;s speed going from the non-cut phase to the cutting phase, referred to as the “cut swing” of the arm&#39;s cycle in  FIG. 5 . The fast swing and cut swing phases may be defined by angular positions. In the example shown, the cut swing occupies an 80° segment located 140° from a home position located 180° opposite the center of the material M. After traveling through the cut swing, the arm rotated through the fast swing phase of approximately 280°. It will be appreciated that the cut swing and accordingly the fast swing will vary depending on the size of material M being cut. Therefore the angles shown for the cut swing and fast swing are not limiting. Also, any change in speed caused by blade  130  passing through material M may be accounted for by the controller C. With this information and the feed rate of the material M into cutter  110 , the controller C rotates the arm  111  to cut the material into desired lengths. 
   One example cut cycle is described in  FIG. 5 . The example described is purely for illustration purposes and does not limit the invention. In this example, with the arm rotating at 200 rpm, one revolution equals 300 ms and the cut dwell is equivalent to 0.22 revolutions or 67 ms. The example follows with an explanation of the time and milliseconds for a given cut length, for example, 0.125 inches at a given cuts per minute speed. This speed is used to determine the feed rate and feet per minute. 
   The example further provides one cut cycle using the given example and discusses the coordination of the cutter  110  and the feeder (not shown). As described in the example, the part is selectively clamped and released as it is cut and then pulled away from the cutter  110  after the cut has been made. To that end, a guiding system may be provided for the exact placement of material. One guiding system includes a pair of arbors  148  split at the point of circular blade travel to support the product during the cutting process. The feeder may move material M at a speed and distance that is timed to provide the required cut length. As described, controller C may use a run/stop motion of the feeder and/or the arm  111  to achieve the desired cut length. As mentioned, the swing arm  111  can have varying speeds that may be independent of the cut window area. In this way, the cutter  110  can provide best cut quality at fast cut per minute rates for short parts, or for a long part, the arm  111  can be stopped until the required length is reached. 
   A counter weight CW may be attached to the arm  111  on the opposite side of blade  130 . The amount of weight and radial position may be adjusted to counterbalance the blade  130 . 
   The cutter  110  may be housed within a shroud to help protect the user and prevent foreign objects from interfering with the cutter&#39;s operation. 
   In another embodiment of the present invention, the cutter is incorporated in a hand-held device. For example, as shown in  FIGS. 6-8 , the cutter  210  may include a rotating blade  230  driven by a motor  220  as described in the previous embodiments. As will be appreciated motor  220  may be any type of motor including, for example, an air motor, as shown. In this embodiment, the motor  220  is incorporated as the handle  275  for the device. In the example shown, an air motor is used and a nozzle  277  is provided on the end of the handle  275  to connect the motor  220  to an air supply (not shown). 
   The cutter  210  may be provided with a guard  240  that generally surrounds the blade except for an opening  246  exposing a portion of the blade  230 . As in the previous embodiment, guard  240  may include a cover  245  attached on one side of the guard  240 . The cover may have walls  246   a ,  246   b  that define an elongated slot-like opening  246  for receiving material M. In the example shown, the opening  246  is formed opposite the handle  275 . 
   As in the previous embodiment, guard shutter  250  may be provided to further protect the user from blade  230  and also to guide the material M into contact with blade  230 . In the example shown in  FIGS. 6-8 , guard  240  defines a central recess  270  for receipt of a guard shutter  250  that defines a central slot  255 . Central slot  255  may be oriented generally perpendicular to the centerline of handle  275 . To prevent the user from contacting the blade  230 , shutter  250  may be actuated by an actuator  260  that can be activated to draw guard shutter  250  inward causing the material M located within the shutter&#39;s slot  255  to contact the blade  230 . As the first embodiment, actuator  260  may include a pair of air cylinders  261 ,  262  to draw the material M toward a cutting position. In this position, the outer leg  256  of guard shutter  250  generally closes opening  246  formed by guard  240 . The inner leg  257  of guard shutter  250  also generally closes the opening  246  when guard shutter  250  is in an outwardly extended position ( FIG. 6 ) reducing the likelihood of the user accidentally touching blade  230  at any time. Operation of guard shutter  250  and blade motor  220  may be controlled by a trigger  280  mounted on handle  275 . For example, to cut material M, the user would locate the material M within the shutter&#39;s slot  255  and then depress the trigger  280  to start the blade&#39;s rotation and activate actuator  260  to draw the material M within the shutter  250  inward into contact with the blade  230  ( FIG. 6 ). Release of the trigger  280  could cause the actuator  260  to drive the shutter  250  outward releasing the material M. Alternatively, the actuator  260  may pull the guard shutter  250  inward against the force of a spring (not shown) such that release of the trigger  280  would deactivate the actuator  260  allowing the spring to force the guard shutter  250  outward. 
   It will be appreciated that other guard shutters may be used including one similar to the shutter  50  described in the first embodiment in connection with cutter  210 . 
   As can be seen from the above description, a novel cutter system has been shown and described. In accordance with the patent statutes, at least one embodiment of the present invention has been described. The embodiments discussed are for example purposes and do not limit the scope of the invention. For an appreciation of the scope of this invention, reference should be made to the appended claims.