FR2472953A1 - CUTTING ELEMENT FOR SOLID RESIDUE FRACTIONING MACHINE - Google Patents

Abstract

CUTTING ELEMENT INCLUDING A DISCOID BODY 12 INTENDED TO RECEIVE A MACHINE SHAFT ALONG AN AXIS OF CENTRAL ROTATION SYMMETRY. THE ELEMENT INCLUDES SEVERAL TEETH 18A-18C PROJECTING RADIALLY ON ITS BODY 12. EACH TEETH INCLUDES A PART FORMING A SHRINKAGE 20 WHICH JOINS THE BODY AND DELIMITS AN OUTER CUTTING EDGE 28, 30. THE CUTTING EDGES OF THE TEETH DELIMINE A CUTTING TRAJECTORY 32 WHICH IS COAXIAL WITH THE CENTRAL SYMMETRY AXIS 16 AND EACH OF THE TOOTH PARTS FORMING A SHRINKAGE ALSO INCLUDES A CONCAVE SURFACE 24, 26 MARKING AN ANGLE WITH THE CUTTING TRAJECTORY 32 SO AS TO REFOULER THE MATERIAL. GENERAL APPLICATION TO WASTE FRACTIONATION MACHINES.

Description

The invention relates generally to fractionating machines

  of solid detritus and more particularly to an improved cutting element for

to such a machine.

  There are various known machines for breaking up solid detritus into very small particles. U.S. Patent No. 4,046,324, incorporated herein by reference, discloses such a fractionating machine. The machine described by this patent comprises a fractionation chamber inside which there are two stacks of shredding elements. Each of these stacks comprises a shaft supporting a plurality of cutting blades which are spaced apart from each other in the direction of the axis by a plurality of spacer blades. Stacks of shredding elements are disposed within the splitting chamber so that the cutting blades of the first stack are in the spaces between the cutting blades of the second stack.

to perform the splitting.

  The cutting elements of the machine described above

  above have the general shape of a disc on which several teeth are projecting radially. Each tooth comprises two concave surfaces located along an axis substantially

  parallel to the central axis of symmetry of the cutting element.

  Although these cutting elements can fractionate solids that may or may not be entrained in a liquid, experience has shown that in the absence of liquid, the particles produced by the fractionation of a solid dry matter are frequently trapped by the concave surfaces of the teeth of the cutting elements. This pile of material dulls the cutting surfaces of the corresponding elements and may break the teeth of the element thereby reducing

  the efficiency and performance of the machine.

  Another known cutting element for a fractionating machine is described in U.S. Patent No. 3,664,592. The cutting element described in this patent includes a single tooth having a narrowing or chamfer and whose cutting edge is located in a plane perpendicular to the axis of the cutting element so that it shears the material introduced into the machine. However, the tooth is not self-cleaning and thus the cutting element must also include a rear tooth which occupies the free space between adjacent cutting elements to help remove the granular material from these elements. Moreover, a cutting element of this type is only able to operate in one direction of rotation and therefore it can not be turned over to allow

to extend the useful life.

  The cutting element according to the invention eliminates the

  mentioned drawbacks and includes teeth with

  cleaning which are capable of splitting dry solids and which also allow the splitting machine to operate with great efficiency. The cutting element according to the invention comprises a body of general discord and which is intended to house the shaft of a fractionating machine. A plurality of protruding teeth on the body each comprise opposite-facing lateral cutting edges and a narrowing portion including concave surfaces which connect the cutting edges to the body. The lateral cutting edges determine a cutting path that is coaxial with the body and the concave surfaces are inclined to the cutting path. The lateral cutting edges and the curvature of the concave surfaces cooperate to cut or score the material introduced into the machine so as to produce particles having relatively uniform dimensions and having the general shape of loops closely

  tight or balls. The concave surfaces inclined

  The particles thus produced on the side of the cutting element are prevented thereby preventing the particles from accumulating or piling up in the narrowing portions. The cutting edges are inclined at the same angle on the cutting path, these two inclinations having the effect of improving the efficiency of the fractionation of the solids and thereby increase by about 70% the efficiency of the machine

splitting.

  The invention therefore relates to an improved cutting element for a fractionating machine, which is practically self-cleaning and whose efficiency is increased. The invention will be described in more detail with reference to the accompanying drawing as a non-limiting example.

and on which;

  - Figure 1 is a plan view of a cutting element according to the invention; and - Figure 2 is an elevation along the line

2-2 of Figure 1.

  The drawing shows a cutting element 10 comprising a substantially discoidal body 12. A hexagonal opening 14 which the body 12 comprises in the center is intended to receive a shaft of a fractionating machine, for example the shaft of the stack of shredding elements described in the preamble. The hexagonal opening 14 is coaxial with

  the central axis of symmetry 16 of the body 12.

  Several teeth 18 protrude from the body 12. Although the cutting element 10 of Figures 1 and 2 comprises three teeth 18a to 18c, it is understood that the number of teeth 18 may vary, but it is preferable that the element includes at least two. It is also quite obvious that the number of teeth is determined by several factors among which the material to be introduced into the machine, the fineness of the particles produced as well as the power and the multiplication of

  the transmission gear of which the machine is equipped.

  Each of the teeth 18a-18c comprises a portion 20 forming a narrowing and starting from the body 12 to end

  circumferential surface 22. The circumferential surface

  22 of each tooth 18 defines on its side a cylindrical surface element which is coaxial with the axis of symmetry

central 16 of the body 12.

  The part 20 of the tooth that forms a narrowing

  Furthermore, it comprises two concave surfaces 24 and 26 which connect to the outer surface of the body 12 and which intersect the circumferential surface 22 so as to

  forming the cutting edges 28 and 30.

  The cutting edges 28 and 30 are sensitively

  along a circular-base helical element which is coaxial with the axis 16 and whose inclination angle is preferably approximately 30. The concave surfaces 24 and 26 are substantially parallel to the cutting edges 28 and 30. Although the aforementioned helical arrangement gives an exact definition of the element shown in FIGS.

  and 2, it should be noted that this particular provision

  is not of major importance in the context of the

  vention. The cutting edges 28 and 30 may be considered more generally as elements delimiting a cutting path bearing the reference 32 in FIGS. 1 and 2. The cutting path 32 is coaxial with the axis 16 and the concave surfaces 24 and 26 as well

  that the cutting edges 28 and 30 are inclined approximately

  300 in a plane transverse to the trajectory and parallel to the axis 16. This angle of 30 is only indicated by way of example and different angles may be provided depending on the advantages to be conferred by the element. of

section according to the invention.

  It is also quite obvious that the thickness of the cutting element 10 as well as the number of teeth 18 can vary with consequent variation in the size of the particles produced. Thus, the thickness of the cutting element 10 can be increased or decreased with a corresponding decrease or increase in the dimension.

particles produced.

  Several cutting elements 10 may be installed for example in the fractionating machine described in the aforementioned U.S. Patent No. 4,046,324 and may rotate about the central axis of symmetry 16. Where the cutting element 10 rotates dextrorsum in the representation of Figure 1, the cutting edge 30 of each tooth 18 cut or notch particles in the form of loops or balls closely wound on themselves in the material introduced into the machine, and these particles are in turn removed or removed from the cutting element by the concave surface 26 of each tooth 18 to be

  sent in the area between the cutting elements

  neighbors 10 and determined by the bracing blades described above. When the cutting edge 30 of each tooth 18 has been blunted or has become inoperative in another way, it is possible to return the cutting element 10 so that the cutting edge 28 and the concave surface 24

  cooperate exactly as described.

  It goes without saying that the invention has only been described by way of example and that various modifications can

  to be brought without leaving his domain.

Claims (8)

  1. Cutting element intended for a fractionating machine and comprising a body (12) intended to receive a shaft of the machine along its central axis of symmetry, element characterized in that it comprises several teeth (18a-18c) each of which comprises a narrowing portion (20) which connects to said body (12) and which delimits an outer cutting edge (28, 30), the cutting edges of said teeth delimiting a cutting path (32) which is coaxial central axis of symmetry and the portion of each narrowing tooth (20) further comprising a concave surface (24, 26) which is inclined on said cutting path so as to   the material of the tooth portion forming a narrowing ment.   Cutting element according to Claim 1, characterized in that the cutting edges (28, 30) are   inclined on said cutting path.   3. Cutting element according to claim 2, characterized in that the angle between said concave surface (24, 26) and said cutting path (32) and the angle between said cutting edge (28, 30). ) and   said cutting path (32) is substantially equal.   4. A cutting element according to claim 3, characterized in that said angle is approximately   300 with a plane transverse to said cutting path.   5. A cutting element for a fractionating machine and comprising a body (12) for receiving a shaft of said machine along a central axis of symmetry (16), characterized in that it comprises a plurality of teeth (18a). -18c) each of which comprises a narrowing portion (20) which connects to said body (12) and defines an outer cutting edge (28, 30), said cutting edges of said teeth defining a cutting path (32). which is coaxial with said central axis of symmetry (16), the narrowing portion (20) of each tooth further comprising * a concave surface (24, 26) and said cutting edge (28, 30) and said surface 24-72953   concave (24, 26) inscribing an angle with respect to said cutting path (32).   6. Cutting element according to claim 5, characterized in that said cutting edge (28, 30) and said concave surface (24, 26) inscribe an angle of about 300 relative to a plane transverse to said path of movement. cutting (32).   7. Cutting element according to claim 5,   characterized in that it comprises at least two teeth (18- 18c).   Cutting element according to Claim 5, characterized in that each of said teeth (18a-18c) comprises two cutting edges (28, 30) situated on the opposite sides of the tooth, as well as two concave surfaces (24, 26). ) located on the opposite sides of the tooth, so as to enable cutting in both directions of rotation   of the cutting element about said central axis of symmetry.