Pellet mill

A pellet mill for forming pellets from a material comprising:

• supply means for said material;
• forming means including perforated die means having substantially cylindrical inner and outer surfaces;
• at least a first press roller rotatable about an axis for rotation over a cylindrical surface of said die means;
• drive means for imparting relative rotational movement between said die means and said press roller;
• overload determining means for determining an overload condition on said forming means in which the load on said forming means exceeds a predetermined first nominal value, and for stopping the operation of at least said supply means, when an overload condition occurs, said overload determining means including program operated means;
• bearing means for said press roller, said bearing means being displaceable for moving said press roller toward to and away from said cylindrical surface;
• and
• displacing means for said bearing means, comprising:
• displacement drive means connected to said bearing means;
• and
• control means for said displacement drive means, said control means being connected to said program operated means;
• said program operated means causing said displacement drive means through said control means in a first step to displace said press roller away from said cylindrical surface, when an overload condition occurs, and then to redisplace in a second step said press roller toward said cylindrical surface until the press roller engages said second cylindrical surface, said redisplacement movement being interrupted, when an overload condition occurs in which the load exceeds a predetermined second nominal value, said second step being reinitiated when the load has fallen below said predetermined second nominal value.

A pellet mill for forming pellets from a material, comprising:

• perforated die means having substantially cylindrical inner and outer surfaces;
• at least a first press roller having a circumferential surface and being rotatable about an axis for rotation over a cylindrical surface of said die means;
• drive means for imparting relative rotational movement between said die means and said press roller, the movement resulting in a certain wear of the surfaces of said die means and said press roller, said wear being a function of the operating time of said pellet mill;
• bearing means for said press roller, said bearing means being displaceable for moving said press roller towards and away from said cylindrical surface;
• and
• displacing means for said bearing means, comprising:
• displacement drive means connected to said bearing means;
• control means for said displacement drive means and including memory means having an input for inputting the wear operation time, and having an output to deliver an output signal;
• timer means for determining the operation time, said timer means providing a clock pulse signal;
• and
• a position correcting circuit for correcting the position of said press roller, said circuit being connected to said memory means and said timer means to receive said clock signal and for controlling the displacement drive means as a function of the operation time and the wear inputted in said memory means.