Pivotal knife mounting arrangement

A disc for a rotary mower of a basic material thickness with a top surface and a bottom surface, including a mounting area comprising;

• a knife adapter for attaching a knife to bottom of said disc comprising:
• (a) a cylindrical aperture;
• and
• (b) a projection extending above said top surface.

A method of changing knives in a device for mowing including a disc mounted to a rotating driver, the disc providing a mount for at least one knife having a circular aperture therein, defining a first opening having a mounting axis when a pivot pin is retained to said disc, such that the knife can rotate about said pivot pin between a first extended position and any retracted position, the disc constructed of a basic material thickness and comprising a mounting surface the disc also having a second opening therein;

• a knife adapter comprising a cylindrical aperture and a projection;
• said pivot pin comprising a first cylindrical section of a first diameter to fit into said cylindrical aperture in knife adapter, and a second cylindrical section, of a second diameter, with a groove defined by a groove width and a pin section thickness at the groove of a dimension less than said second diameter;
• a retainer constructed of a material thickness equal to or less than said basic material thickness of said disc, with a first key-hole shaped aperture defined by a first circular section adjacent a first end thereof with a first inside diameter larger than said second diameter of said pin and a slot shaped section with a width that is greater than said pin section thickness but less than said second diameter of said pivot pin adjacent a second end thereof;
• wherein said slot-shaped section of the retainer engages said groove of said pivot pin to retain said pivot pin while said projection of said knife adapter engages said retainer, said method comprising:
• (a) moving the knife adapter from below the disc so that the projection thereof is disposed into the second opening in the disc;
• (b) moving the pin so that it extends through the aperture in the knife and through said cylindrical aperture in the knife adapter and through the first opening in the disc;
• (c) moving the retainer so that the first circular section of the key-hole shaped aperture extends around the pin;
• and
• (d) moving the retainer toward projection of the knife adapter until the first circular section of the key-hole shaped aperture of the retainer moves over the projection of the knife adapter and wherein the retainer engages the groove of the pin thereby securely holding the knife pivotally attached to the disc.

A method for pivotally mounting a cutting knife with an aperture therein to a disc, which disc is disposed for rotation about a first axis, an opening is disposed in the disc and a pin is disposed about a second axis, one end of the pin being configured so that it will not pass through the aperture and opening and the other end of the pin having a recess therein, said method comprising:

• extending the pin through the aperture in the knife and the opening in the disc;
• moving a retainer over the other end of the pin to a first position thereof;
• and
• moving the retainer in a direction transverse to the axis of the pin to a second position of the retainer so that a part of the retainer engages the recess in the pin and whereby another part of the retainer engages something other than the pin to hold the retainer from moving from the recess in the pin.

A method of locking a pin to a disc comprising:

• configuring a disc, that defines a cutting plane;
• mounting a pivot pin to the disc perpendicular to the cutting plane, the pivot pin comprising a first locking feature;
• and
• installing a retainer by moving it along a plane parallel to the cutting plane wherein a first movement results in engagement with the first locking feature on the pivot pin such that the pin is retained along a direction perpendicular to the cutting plane and a second movement results in engagement with a second locking feature such that the retainer is retained along a direction parallel to the cutting plane.

A method of locking a pin to a disc comprising;

• configuring a disc, that defines a cutting plane, comprising a second locking feature;
• mounting a pivot pin to the disc perpendicular to the cutting plane, the pivot pin comprising a first locking feature;
• and
• installing a retainer by moving it along a plane parallel to the cutting plane wherein a first movement results in engagement with the first locking feature on the pivot pin such that the pin is retained along a direction perpendicular to the cutting plane and a second movement results in engagement with the locking feature of the disc such that the retainer is retained along a direction parallel the cutting plane.

A method for pivotally mounting a cutting knife with an aperture therein to a disc, which disc is disposed for rotation about a first axis, an opening is disposed in the disc, a knife adapter disposed in said opening, said knife adapter having an aperture therein, a pin is disposed about a second axis, one end of the pin being operatively configured so that it will not pass through the aperture in the knife and the other end of the pin having a recess therein, said method comprising:

• extending the pin through the aperture in the knife and the aperture in the knife adapter;
• moving a retainer over the other end of the pin to a first position thereof;
• and
• moving the retainer in a direction transverse to the axis of the pin to a second position of the retainer so that a first part of the retainer engages the recess in the pin and whereby a second part of the retainer engages something other than the pin to hold the retainer from moving from the recess in the pin.

Apparatus comprising:

• a cutting knife with an aperture therein;
• a disc, the disc being disposed for rotation about a first axis, an opening is disposed in the disc;
• a knife adapter disposed in said opening, said knife adapter having an aperture therein;
• a pin disposed about a second axis, one end of the pin being operatively configured so that it will not pass through the aperture in the knife and the other end of the pin having a recess therein;
• said pin extending through the aperture in the knife and the aperture in the knife adapter, said retainer also being disposed over the other end of the pin to a first position thereof;
• and
• when the retainer is moved in a direction transverse to the axis of the pin to a second position of the retainer a first part of the retainer engages the recess in the pin and a second part of the retainer engages something other than the pin to hold the retainer from moving from the recess in the pin.