Image heating apparatus having a pressure removal mechanism including a camshaft and a regulating portion that regulates flexure of the camshaft

An image heating apparatus comprising:

• (A) a first rotatable member;
• (B) a second rotatable member that cooperates with said first rotatable member to form a nip configured to heat a toner image on a recording material;
• (C) a pressing mechanism including a pressing spring configured to press said first rotatable member toward said second rotatable member at opposite longitudinal ends of said first rotatable member;
• and
• (D) a pressure removal mechanism including:
• (a) a camshaft;
• (b) a first cam portion provided at one longitudinal end of said camshaft;
• (c) a second cam portion provided at another longitudinal end of said camshaft, wherein said first cam portion and said second cam portion are capable of placing said pressing mechanism at a first position, in which said first rotatable member and said second rotatable member form the nip, and a second position, in which said pressing mechanism is moved against an urging force provided by said pressing spring at the first position and in which said first rotatable member and said second rotatable member are spaced from each other, and wherein said cam shaft rotates said first cam portion and said second cam portion;
• (d) a first bearing portion;
• (e) a second bearing portion, said first bearing portion and said second bearing portion being provided between said first cam portion and said second cam portion with respect to the longitudinal direction of said camshaft and configured to support said camshaft;
• (f) a first supporting portion supporting said first bearing portion;
• (g) a second supporting portion supporting said second bearing portion, wherein said first supporting portion and said second supporting portion rotatably support said camshaft;
• (h) a driving mechanism configured to rotate said camshaft;
• and
• (i) a regulating portion configured to regulate flexure of said camshaft by contacting said camshaft at a position between said first bearing portion and said second bearing portion with respect to the longitudinal direction of said camshaft, when said pressing mechanism is in the second position.

An image heating apparatus comprising:

• (A) a first rotatable member;
• (B) a second rotatable member that cooperates with said first rotatable member to form a nip configured to heat a toner image on a recording material;
• (C) a pressing mechanism including a pressing spring configured to press said first rotatable member toward said second rotatable member at opposite longitudinal ends of said first rotatable member;
• and
• (D) a pressure removal mechanism including:
• (a) a camshaft that has a cross section, taken across a longitudinal direction of said camshaft, having a corner portion;
• (b) a first cam portion provided at one longitudinal end of said camshaft;
• (c) a second cam portion provided at another longitudinal end of said camshaft, wherein said first cam portion and said second cam portion are capable of placing said pressing mechanism at a first position, in which said first rotatable member and said second rotatable member form the nip, and a second position, in which said pressing mechanism is moved against an urging force provided by said pressing spring at the first position and in which a force applied between said first rotatable member and said second rotatable member by said pressing mechanism is less than a force applied between said first rotatable member and said second rotatable member by said pressing mechanism when said pressing mechanism is in the first position, and wherein said camshaft is configured to rotate said first cam portion and said second cam portion;
• (d) a first bearing portion;
• (e) a second bearing portion, said first bearing portion and said second bearing portion being provided between said first cam portion and said second cam portion with respect to the longitudinal direction of said camshaft, and configured to support said camshaft;
• (f) a first supporting portion supporting said first bearing portion;
• (g) a second supporting portion supporting said second bearing portion, wherein said first supporting portion and said second supporting portion rotatably support said camshaft;
• (h) a driving mechanism configured to rotate said camshaft;
• (i) a first regulating member configured to regulate flexure of said camshaft at a position between said first bearing portion and said second bearing portion with respect to the longitudinal direction of said camshaft;
• and
• (j) a second regulating member provided on said camshaft at a position between said first bearing portion and said second bearing portion with respect to the longitudinal direction of said camshaft, said second regulating member regulating the flexure of said camshaft by approaching said first regulating portion when said pressing mechanism is in the second position.

An image heating apparatus comprising:

• (A) a first rotatable member;
• (B) a second rotatable member that cooperates with said first rotatable member to form a nip configured to heat a toner image on a recording material;
• (C) a pressing mechanism including a pressing spring configured to press said first rotatable member toward said second rotatable member at opposite longitudinal ends of said first rotatable member;
• and
• (D) a pressure removal mechanism including:
• (a) a camshaft having a cross section, taken across a longitudinal direction of said camshaft, that has a corner portion;
• (b) a first cam portion provided at one longitudinal end of said camshaft;
• (c) a second cam portion provided at another longitudinal end portion of said camshaft, wherein said first cam portion and said second cam portion are capable of placing said pressing mechanism at a first position, in which said first rotatable member and said second rotatable member form the nip, and a second position, in which said pressing mechanism is moved against an urging force provided by said pressing spring at the first position and in which said first rotatable member and said second rotatable member are spaced from each other, and wherein said cam shaft rotates said first cam portion and said second cam portion;
• (d) a first bearing portion;
• (e) a second bearing portion, said first bearing portion and said second bearing portion being provided between said first cam portion and said second cam portion with respect to the longitudinal direction of said camshaft, and configured to support said cam shaft;
• (f) a first supporting portion supporting said first bearing portion;
• (g) a second supporting portion supporting said second bearing portion, wherein said first supporting portion and said second supporting portion rotatably support said camshaft;
• (h) a driving mechanism configured to rotate said camshaft;
• (i) a first regulating member configured to regulate flexure of said camshaft at a position between said first bearing portion and said second bearing portion with respect to the longitudinal direction of said camshaft;
• and
• (j) a second regulating member provided on said cam shaft at a position between said first bearing portion and said second bearing portion with respect to the longitudinal direction of said camshaft, said second regulating member regulating the flexure of said camshaft by approaching said first regulating portion when said pressing mechanism is in the second position.