Structure and method for mounting a metal collar

A subassembly of a metal collar and a composite steel plate including a core material and steel plates on both sides of the core material;

• the metal collar defining an axis and having a flange, a sleeve which extends in the axial direction from the flange, a middle portion which is contiguous to the sleeve and which extends in the axial direction, a locking portion which is contiguous to the middle portion and which extends in the axial direction, and a through hole which passes through from the flange through the locking portion in the axial direction, the subassembly assembled by a method comprising:
• enlarging the diameter of the locking portion to form a first enlarged diameter portion;
• enlarging the diameter of the middle portion and the sleeve to form a second enlarged diameter portion;
• such that
• one steel plate of the composite steel plate is clamped between the first enlarged diameter portion and the second enlarged diameter portion;
• and
• the other steel plate of the composite steel plate is clamped between the second enlarged diameter portion and the flange.

A method of mounting a metal collar into a mounting hole of a composite steel plate including a core material and steel plates on both sides of the core material, wherein the metal collar defines an axis and includes a flange, a sleeve which extends in the axial direction from the flange, a locking portion which is contiguous with the sleeve, which extends in the axial direction and which is thinner than the sleeve, and a mounting hole which passes through in the axial direction from the flange through the locking portion;

• comprising:
• (a) inserting the sleeve and the locking portion of the metal collar from below into the mounting hole of the composite steel plate;
• (b) supporting the flange from below;
• (c) pushing downwards on the locking portion to enlarge the diameter of the locking portion to form a first enlarged diameter portion;
• (d) pushing downwards on the first enlarged diameter portion to enlarge the diameter of the sleeve to form a second enlarged diameter portion;
• such that
• (e) one steel plate of the composite steel plate is clamped between the first enlarged diameter portion and the second enlarged diameter portion;
• and
• (f) the other steel plate of the composite steel plate is clamped between the second enlarged diameter portion and the flange;
• whereby
• (g) the metal collar is mounted to the composite steel plate.

A method of mounting a metal collar into a mounting hole of a composite steel plate including a core material and steel plates on both surfaces of the core material, wherein the metal collar defines an axis and includes a flange, a sleeve which extends in the axial direction from the flange, a middle portion which is contiguous with the sleeve, which extends in the axial direction and which is thinner than the sleeve, a locking portion which is contiguous with the middle portion, which extends in the axial direction and which is thinner than the middle portion, and a mounting hole which passes through in the axial direction from the flange through the locking portion, comprising:

• (a) inserting the sleeve and the middle portion and the locking portion of the metal collar from below into the mounting hole of the composite steel plate;
• (b) supporting the flange from below,
• (c) pushing downwards on the locking portion to enlarge the diameter of the locking portion to form a first enlarged diameter portion;
• (d) pushing downwards on the first enlarged diameter portion to enlarge the diameter of the middle portion and the sleeve to form a second enlarged diameter portion;
• such that
• (e) one steel plate of the composite steel plate is clamped between the first enlarged diameter portion and the second enlarged diameter portion;
• and
• (f) the other steel plate of the composite steel plate is clamped between the second enlarged diameter portion and the flange;
• whereby
• (g) the metal collar is mounted to the composite steel plate.