Patent Publication Number: US-3874602-A

Title: Chipper apparatus for articles such as tree limbs and the like

Description:
Apr. 1, 1975 United States Patent [191 Ciriegio [57] ABSTRACT A compact portable chipper incorporates a housing CHIPPER APPARATUS FOR ARTICLES SUCH AS TREE LIMBS AND THE LIKE Inventor: Joseph J- C g q OhiO which encloses a hammermill rotor effective to shred 73 A I E ,l articles into small pieces. The articles are positively sslgnee ngmeermg nc lqua l0 fed into engagement with the rotor by a generally hor- Sept. 10, 1973 [22] Filed:  
 izontal guide chute and a feed roll positioned above the chute. The feed roll has outwardly projecting longitudinal ribs and is supported by a set of arms pivot- [21] App]. No.: 395,723  
 ally supported by the rotor shaft, and one of the two arms carries a chain drive reducer for connecting the feed roll to the driven member of a centrifugal clutch mounted on one end of the rotor shaft. The opposite end of the rotor shaft is connected by a belt drive to the shaft of a gasoline engine positioned under the 1% A l 6 0 00 mm m 40 4 22 2 0 B 6 8 l l 4 2 [52] US. [51] Int. [58] Field of Search. 241/92, 101.7, 101 M, 186 R,  
 [56] References Cited UNITED STATES PATENTS guide chute. When the speed of the rotor and engine reduces as a result of an increase in the load on the 3.724767 4/1973 Scarbrough................. 241/1017 x TOW, the Centrifugal Clutch automatically reduces or stops the rotation of the feed roll until the rotor speed has returned to a predetermined normal operating Primary E.ruminerRoy Lake Assistant Examiner-E. F. Desmond F. A110; m Agent, 01 um Jacox &amp; Meckstroth 13 Clalms 4 Drawmg Flgures CHIPPER APPARATUS FOR ARTICLES SUCH AS TREE LIMBS AND THE LIKE BACKGROUND OF THE INVENTION In the art of hammermill-type&#39;shredder-grinders or chippers, for example. as disclosed in US. Pat. No. 3,724,767 which issued to the assignee of the present invention, the hammermill rotor is supported by a housing which defines an inlet and an outlet located generally on opposite sides of the rotor. A generally horizontal support surface or guide chute extends outwardly from the inlet for directing articles such as tree limbs, shrubs, small trees, etc., into radial engagement with the hammers of the rotor. Preferably, a feed roll is supported above the chute by a pair of pivotal arms, and the feed roll is commonly driven by the same en gine which drives the rotor. The drive for the feed roll may also incorporate an endless belt which may be disengaged by manually actuating a belt tightener, for ex ample, as shown in US. Pat. No. 3,510,075.  
  It has been found that the use of a hammermill-type rotor within a wood chipper is effective to minimize the power required to drive the rotor and to obtain complete shredding of the limbs, brush, etc. That is, a limb chipper which employs a rotor having fixed knives projecting outwardly from a rotating drum, requires substantially more power to drive the rotor than the power required to drive a hammermill rotor such as shown in above US. Pat. No. 3,724,767. In the construction of a small compact portable limb chipper, it is even more important to obtain optimum use of the engine which drives the rotor so that a relatively light-weight, low horsepower and low cost engine may be used and still obtain effective chipping of hardwood limbs up to several inches in diameter.  
 SUMMARY OF THE INVENTION The present invention is directed to a shreddergrinder or chipper which incorporates an improved system for positively feeding articles into engagement with the chipping rotor in a manner which is effective to obtain maximum operating efficiency of the drive engine, prevent stalling of the rotor, and assure that each article is reduced to small pieces of generally uniform size. The feeding system of the invention is ideally suited for incorporation in a relatively small, compact portable chipper which is adapted for use by nurserymen, farmers and homeowners. since a relatively low horsepower engine may be used to drive the chipping rotor and feed roll.  
  In accordance with the illustrated embodiment of the invention, the above features are provided in a chipper which incorporates a wheel supported frame or housing for enclosing a hammermill rotor and for defining a downwardly directing outlet and a horizontal directed inlet. A pivotal guide chute extends outwardly from the inlet over a gasoline engine which is mounted on the frame and is connected to drive the rotor. A feed roll is supported adjacent the inlet by a set of arms which are free to pivot on the axis of the rotor shaft. One of the arms supports a dual chain reducing drive which connects a large diameter sprocket mounted on one end of the feed roll to a substantially smaller sprocket of a centrifugalclutch mounted on the corresponding end of the rotor shaft. The centrifugal clutch is effective to control the peripheral speed of the feed roll in response to the speed of the rotor so that stalling of the hammermill rotor is prevented and each article is progressively reduced into small chips.  
  Other features and advantages of the invention will be apparent from the following description, the accompanying drawing and the appended claims.  
 BRIEF DESCRIPTION OF THE DRAWING FIG. I is a perspective view of a small compact portable chipper constructed in accordance with the invention and as viewed from one side;  
  FIG. 2 is another perspective view of the chipper, as viewed from the opposite side;  
  FIG. 3 is a perspective view of the hammermill rotor and feed roll used in the chipper shown in FIGS. I and 2 and showing the drive system for the feed roll: and  
  FIG. 4 is a fragmentary plan view of the drive system for the feed roll and shown in FIGS. 1 and 3.  
 DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and 2 show a small compact limb chipper which includes a fabricated sheet steel frame 10 supported by a pair of rearwardly located wheels 12 and a single forward support leg (not shown). The frame I0 includes a horizontal base portion 14 which supports a pair of vertical side walls or plates 16 rigidly connected by a cross member or vertical plate 17, a partcylindrical bottom wall plate 18 (FIG. 4) and a flat generally horizontal bottom wall plate 19. The bottom wall plates I8 and I9 cooperate to form the lower portion of a housing.  
  A generally cylindrical hammermill rotor 25 is positioned concentrically with the bottom wall plate 18 and includes a rotor shaft 26 which is rotatably supported by a set of flange-type bearings 27 secured to the outer surfaces of the side walls 16. The rotor 25 is preferably constructed as disclosed in above-mentioned US. Pat. No. 3,724,767 and includes a plurality of axially spaced circular plates 28 secured to the shaft 26. Each of the plates 28 includes diametrically opposed offset portions which support a set of axially extending rods 3 l each supporting a set of block-like steel hammer members 32.  
  A V-belt drive pulley 36 (FIG. 2) is mounted on one end of the rotor shaft 26 and is connected by one or more endless V-belts 37 to a pulley 38 mounted on the shaft of a gasoline driven engine 40 mounted on the forward part of the base portion 14 of the frame I0. An inverted generally U-shaped tubular handle member 42 includes lower end portions 43 which are secured to the base portion 14 of the frame 10. and slopes upwardly in front of the engine 40 to provide for conveniently moving and positioning the chipper.  
  A set of rigid arms 46 and 48 are supported by corresponding bearing 49 (FIG. 4) rotatably mounted on the rotor shaft 26. Another set of bearings 51 are mounted on the forward end portions of the arms 46 and 48 and rotatably support a shaft 52 forming part of a feed roll 55. The shaft 52 extends laterally through arcuate slots 56 (FIG. 2) within the side walls 16 of the frame 10 and supports a set of longitudinally extending and outwardly projecting ribs 58 directly above the plate 19 of the frame 10. In one chipper constructed as shown in the drawing and which performed very satisfactorily. the rotor 25 had an overall diameter of 8-Ainches including the outwardly projecting hammer members 32,  
 and the feed roll had an overall diameter of &#39;lfitinches including the outwardly projecting ribs 58.  
  A centrifugal clutch 60 includes a hub portion 62 which is rigidly secured to the outer end portion of the rotor shaft 26 outboard of the feed roll support arm 48. The hub 62 supports a set of peripherally spaced friction shoes (not shown) which are spring biased inwardly and move outwardly by centrifugal force into engagement with the inner cylindrical surface of a surrounding cup-shapcd drum member 64. A small diameter sprocket 66 is rigidly secured to the drum member 64 for rotation therewith. The sprocket 66 drives an endless chain 68 which extends around a larger sprocket 69 rotatably supported by a bearing 71 rigidly secured to the rearward end portion of the feed roll support arm 48 by a bolt 72 and a nut 74. An adjustment screw 76 is secured to the nut 74 and extends through a hole within the rearward end portion of the arm 48 for receiving a nut 77. Adjustment of the nut 77 controls the tension within the endless chain 68.  
  Another sprocket 79 is rigidly secured to the sprocket 69 for rotation therewith and is connected by an endless chain 81 to a substantially larger diameter sprocket 82. The sprocket 82 is secured by a hub 83 to the corresponding end portion of the feed roll shaft 52 outboard of the support arm 48. The entire chain drive assembly including the centrifugal clutch 60, is covered by a protective housing (not shown) which is secured to the adjacent side wall 16 of the frame 10. A similar protective housing covers the drive belt 37 and the pulleys 36 and 38.  
  A formed sheet steel cover member 90 has an inverted generally U-shaped configuration and is secured to the side plates 16 of the frame to form the upper portion of the housing which encloses the hammermill rotor and the feed roll 55. The forward end of the cover member 90 cooperates with the bottom wall plate 19 to define a generally rectangular inlet which extends between the side plates 16. The inlet is adapted to receive articles to be shredded or chipped. such as tree limbs, shrubs, etc. which are directed into the inlet by a channel-like guide chute 95 pivotally connected to theside walls 16 by a set of screws 96.  
  When the chipper is being used, the guide chute 95 extends substantially horizontally (FIGS. 1 and 2) over the engine 40 where the guide chute is retained by a set of pivotal strap-like brackets 98. The forward end of each bracket 98 is pivotally secured to the corresponding side of the cover housing 90 by a bolt 99. and a longitudinal slot 101 is formed within each bracket 98 for slidably receiving a screw which is secured to the sides ofthe guide chute 95 by a lever-type nut 103. When the nuts 103 are released, the guide chute 95 may be pivoted to an upwardly projecting position (not shown) to provide convenient access to the handle member 42 and the gasoline engine 40.  
  The opposite end of the cover housing 90 cooperates with the forward edge of the bottom plate 18 to define an outlet which receives a part-cylindrical steel sizing screen 108 positioned substantially concentric with the hammermill rotor 25. The screen 108 includes a set of laterally extending sizing slots 109 (FIG. 3). The discharge outlet and screen 108 are covered by a downwardly curved deflector hood 115 which is secured to the cover member 90 and directs the pieces or chips discharged through the slots 109 downwardly to a suitable receptacle or container (not shown) such as a baskct positioned under the deflector hood 115 or a plastics bag attached to the hood 115.  
  The chipper shown in FlGS. 1-4 operates in the following manner. The hammermill rotor 25 is normally driven at a speed of approximately 3,600 rpm which is substantially the same as the speed of the shaft of the engine 40. At this rotor speed. the centrifugal clutch 60 is engaged. and the feed roll 55 is driven at a substantially lower speed of approximately l5()20() rpm as a result of the reduction provided by the chain drive which includes the cndlessehains 68 and 81 and the sprockets 66, 69, 79., and 83.  
  An article such as a tree limb is fed into the chipper along the guide chute and is engaged by the feed roll 55 which is free to move upwardly but is urged downwardly against the article as a result ofthc weight of the feed roll sub-assembly including the support arms 46 and 48, the feed roll 55 and the sprocket 82. In the event that the article or limb is difficult to shred by the hammermill rotor 25. and the speed of the rotor decreases as a result of an increased load, the centrifugal clutch 60 automatically senses the decrease in speed of the rotor 25 and permits slipping of the drum member 64 of the clutch relative to the hub member 62 so that the feed roll 55 rotates at a slower speed and the article is fed into the rotor 25 at a slower rate. If the speed of the rotor 25 continues to decrease, the clutch 60 complctely disengages, and the feed roll 55 stops until the speed of the rotor 25 returns to its higher normal operating speed. At this point, the centrifugal clutch 60 reengages and continues to drive the feed roll 55 at a predetermined correlated specd so that the article continues to be positively fed by the feed roll 55 into engagement with the hammer members 32 of the rotor 25.  
  From the drawing and the above description, it is apparent that a shredder-grinder apparatus or chipper constructed in accordance with the present invention, provides desirable features and advantages. For example, the centrifugally actuated clutch 60 is effective to control automatically the speed of the feed roll 55 so that the engine 40 transmits substantially constant power to the rotor 25. and the article being fed by the feed roll 55 is reduced into substantially uniform pieces or chips. The more constant power demand from the engine 40 provides for more efficient operation of the engine and enables the rotor 25 to be driven with an engine of relatively low horsepower. For example, it has been found that an engine having a rating of about eight horsepower is sufficient to drive the motor 25 and the feed roll 55 is a manner which is effective to reduce hardwood limbs up to two and three inches in diameter. into small pieces or chips of substantially uniform size.  
  The support ofthe chain drive system for connecting the centrifugal clutch 60 to the shaft 52 of the feed roll 55., also provides an important feature ofthe invention. That is, the arrangement of the endless chains 68 and 81 and the sprockets 66, 69, 79 and 82 on the arm 48, provides for substantially reducing the speed of the feed roll 55 relative to the speed of the rotor 25 while also permitting the feed roll 55 to move generally vertically relative to the bottom plate 19 for accommodating articles of various sizes. In addition, the arrangement of the engine 40 under the inlet guide chute 95, provides for an overall compact unit which can be easily transported and maneuvered, and the discharge deflector hood provides for conveniently collecting the discharge pieces or chips in a suitable container.  
  While the form of chipper apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope and spirit of the invention as defined in the appended claims.  
  The invention having thus been described, the following is claimed:  
  I. In chipper apparatus for cutting articles such as tree limbs and the like, and including a rotor having means for cutting each article into small pieces, means for supporting said rotor for rotation and for defining an inlet and an outlet, a rotary feed member for positively feeding each article into said inlet for engagement with said cutting means on said rotor, and power operated means for driving said rotor and said fecd member, the improvement wherein said means for driving said feed member comprise a clutch having means for sensing the speed of rotation of said rotor, and means responsive to said sensing means for automatically controlling the speed of rotation of said feed member.  
  2. Chipper apparatus as defined in claim 1 wherein said clutch comprises at least one centrifugally actuated drive member connected to rotate with said rotor, and a driven member connected to drive said feed member and engagable by said drive member when said rotor attains a predetermined speed.  
  3. Chipper apparatus as defined in claim 1 wherein said feed member comprises a feed roll having means for engaging each article, means supporting said feed roll for movement relative to said guide surface for aceommodating articles ofvarious sizes, and speed reducing means connecting said clutch to said feed roll and movable with said means supporting said feed roll.  
  4. Chipper apparatus as defined in claim 1 wherein said rotor includes a shaft, said&#39;clutch includes at least one centrifugally actuated clutch member mounted on said shaft for rotation therewith, a second clutch member adapted to be engaged by said one clutch member, and endless drive means connecting said second clutch member to said feed member.  
  5. Chipper apparatus as defined in claim I wherein said means for supporting said rotor include a frame having a base portion, said means for driving said rotor include an internal combustion engine mounted on said base portion of said frame, and a guide chute mounted on said frame and extending outwardly over said engine to provide an over-all compact assembly.  
  6. Chipper apparatus as defined in claim 5 including means supporting said guide chute for pivotal movement in a generally vertical direction above said engine.  
  7. Chipper apparatus for efficiently cutting articles such as tree limbs and the like, comprising a rotor including a rotor shaft and means for cutting each article into small pieces, means for supporting said rotor for rotation and for defining an inlet and an outlet, means forming a guide surface extending to said inlet for directing each article into engagement with said cutting means on said rotor, a feed roll positioned above said guide surface, a set ofpivotal arms supporting said feed roll for movement relative to said guide surface for accommodating articles of various sizes, a drive engine connected to rotate said rotor shaft, a speed responsive clutch including at least one centrifugally actuated drive member connected to rotate with said rotor shaft, and said clutch further including a driven member connected to drive said feed roll and engagable by said drive member when said rotor attains a predetermined speed.  
  8. Chipper apparatus as defined in claim 7 wherein said arms are mounted for rotation on said rotor shaft, and speed reducing means supported by one of said arms for movement therewith and connecting said driven member of said clutch to said feed roll.  
  9. Chipper apparatus as defined in claim 8 wherein said speed reducing means comprise a set of sprockets supported for rotation by said one arm, and a corresponding set of endless drive chains extending around said sprockets.  
  l0. Chipper apparatus as defined in claim 7 wherein said drive engine is connected to one end of said rotor shaft for driving said rotor, and said drive member of said clutch is mounted on the opposite end of said rotor shaft.  
  ll. Chipper apparatus for efficiently cutting articles such as tree limbs and the like, comprising a wheel supported frame including a base portion, a rotor including a rotor shaft and means for cutting each article into small pieces, said frame including housing means supporting said rotor shaft and defining an inlet and an outlet, means forming a guide surface extending to said inlet for directing each article into engagement with said cutting means on said rotor and including a generally horizontal guide chute, an engine mounted on said base portion of said frame under said guide chute and connected to drive one end of said rotor shaft, a feed roll supported above said guide surface for generally vertical movement, and drive means including a clutch for connecting the opposite end of said rotor shaft to said feed roll.  
  l2. Chipper apparatus as defined in claim 11 wherein said clutch automatically controls the speed of said feed roll in response to the rotational speed of said rotor shaft.  
  l3. Chipper apparatus as defined in claim 1 I wherein said guide chute is disposed on one end of said frame, and including a hood member covering said outlet and effective to deflect the discharged cut pieces downwardly adjacent the opposite end of said frame.