Band mill strain mechanism

A bandmill having:

• a column;
• a first wheel mounted for rotation on a first arbor;
• a second wheel mounted for rotation on a second arbor, the wheels being spaced and coplanar and adapted to mount and to drive an endless saw;
• means to strain the saw supported by the column so that the first arbor can be moved relative to the second arbor, a first portion of the means to strain the saw including:
• a. a first wheel support carrying the first arbor, the support being adapted to move relative to the column to strain the saw,
• b. a plunger having inner and outer ends, the outer end cooperating with the first wheel support, the plunger being supported in the column and being adapted to move axially relative to the column so as to strain the saw,
• c. a knife edge seat assembly including a first knife cooperating with the first wheel support, a second knife cooperating with the plunger, and a seat portion cooperating with the first and second knives,
• d. a torque arm coupled to the seat portion, the arm having an inner end mounted for rotation relative to the plunger,
• e. an extensible and retractible air spring cooperating with the plunger and the torque arm, the air spring having a pressurized gas containing chamber defined in part by a flexible membrane, the chamber having an inlet port,
• f. means for maintaining the pressurized gas contained in said chamber essentially constant comprising a reservoir to contain pressurized gas and a conduit to connect the reservoir to the inlet port of the air spring so that the air spring contains the pressurized gas and force from the air spring is applied to the first wheel support to provide a resilient mounting for the first wheel.