Belt tensioner for motor vehicle

A belt tensioner for tensioning a drive belt or timing belt comprising:

• an eccentric adjusting member constructed and arranged to be mounted on a mounting surface for an engine frame;
• a pivoted structure mounted on said adjusting member for pivoted movement between a first position and a second position, said pivoted structure having first and second stop surfaces;
• a belt tensioning pulley mounted for rotational movement on said pivoted structure;
• a coil torsion spring constructed and arranged to resiliently bias said pivoted structure in a belt tightening direction away from said first position and toward said second position;
• said eccentric adjusting member being adjustable during installation of said belt tensioner to move said pivoted structure against the bias of said coil torsion spring into a position wherein said belt tensioning pulley is disposed in predetermined static tensioning relation with said belt, said pivoted structure having an indicator being movable into a position indicating that the pulley is in said predetermined static tensioning engagement with said belt during said installation;
• a base plate providing first and second stop surfaces, said base plate being temporarily attached to said pivoted structure for movement therewith during said installation such that said first stop surface of said pivoted structure is disposed a fixed predetermined distance from said first stop surface of said base plate and said second stop surface of said pivoted structure is disposed a fixed predetermined distance from said second stop surface of said base plate during concurrent rotation of said pivoted structure and said base plate during said installation of said tensioner;
• said eccentric adjusting member and said base plate being constructed and arranged to be manually fixed from further movement after said belt tensioning pulley is moved into said predetermined static tensioning relation with said belt, and wherein said tensioner is rendered operative after said base plate is fixed from further movement by unattaching said pivoted structure from said base plate to enable pivotal movement of said pivoted structure with respect to said eccentric adjusting member.

A belt tensioner for tensioning a drive belt or timing belt, comprising:

• a base plate constructed and arranged to mount said belt tensioner on an engine frame:
• an adjusting member mounted on said base plate;
• a pivoted structure mounted for pivoted movement with respect to said adjusting member between a first position and a second position, said pivoted structure having first and second stop surfaces providing limits to said movement thereof;
• said base plate constructed and arranged to engage said first and second stop surfaces to thereby limit movement of said pivoted structure between said first and second positions thereof during operation of said tensioner;
• a belt tensioning pulley mounted for rotational movement on said pivoted structure;
• and
• a coil torsion spring having one end thereof operatively connected with said pivoted structure and being constructed and arranged to resiliently bias said pivoted structure during operation of said belt tensioner in a belt tightening direction away from said first position and toward said second position, said torsion spring having a radially outwardly extending second end bearing against a spring engagement portion of an engine frame on which said belt tensioner is mounted;
• said adjusting member being adjustable during an installation procedure to move said pivoted structure against the bias of said coil torsion spring, so that said belt tensioning pulley is moved into an installation position at which point said adjusting member is to be fixed;
• wherein adjustment of said adjusting member during said installation procedure causes said second end of said torsion spring to be disposed in sliding contact relation to the spring engagement portion of the engine frame on which the belt tensioner is mounted.

A belt tensioner for tensioning a drive belt or timing belt comprising:

• an eccentric adjusting member constructed and arranged to be mounted on a mounting surface for an engine frame;
• a pivoted structure mounted for pivoted movement with respect to said adjusting member between a first position and a second position, said pivoted structure having first and second stop surfaces providing limits to said movement thereof;
• a belt tensioning pulley mounted for rotational movement on said pivoted structure;
• and
• a coil torsion spring having one end portion thereof operatively connected with said pivoted structure and being constructed and arranged to resiliently bias said pivoted structure during operation of said belt tensioner in a belt tightening direction away from said first position and toward said second position, said torsion spring having a radially outwardly extending second end portion including an area thereof bearing against said engine frame mounting surface so as to be fixed from rotation;
• said eccentric adjusting member being adjustable during an installation procedure to move said pivoted structure against the bias of said coil torsion spring into a predetermined installation position, at which point said eccentric adjusting member is to be fixed;
• wherein during operation of said tensioner, movement of said pivoted structure in a direction toward said first position is terminated at said first position by engagement of said first stop surface with said radially outwardly extending second end portion of said coil torsion spring, and wherein movement of said pivoted structure in a direction toward said second position is terminated at said second position by engagement of said second stop surface with said radially outwardly extending second end portion of said coil torsion spring.