Power-delivery belt-tensioning system

• US 4,781,665 A
• Filed: 08/31/1987
• Issued: 11/01/1988
• Est. Priority Date: 08/31/1987
• Status: Expired due to Term

• Current Assignee: Walker Manufacturing Co. (Apollo Global Management, Inc.)
• Original Assignee: Walker Manufacturing Co. (Apollo Global Management, Inc.)
• Inventors: Walker, Dean M.
• Primary Examiner(s): Bui, Thuy M.
• Application Number:
  US07/091,412
• Time in Patent Office: 428 Days
• Field of Search: 474/101, 474/109, 474/111, 474/113, 474/114, 474/115, 474/117, 474/133, 474/135, 56/16.6
• US Class Current: 474/133
• CPC Class Codes: F16H 2007/0808 Extension coil springs
• CPC Class Codes: F16H 2007/0893 Circular path
• CPC Class Codes: F16H 7/129 with means for impeding reverse motion

Abstract

A first pulley is coupled by a flexible belt to a second pulley for delivering power from a source to a driven device. An idler pulley is urged against the belt to create tension therein. A cam, coupled for swinging movement to the idler pulley, faces against a cam guide in a manner to vary the spacing between the guide and the idler pulley in correspondence with the amount of swinging movement. A spring secured to the cam nudges the latter in a direction to incrementally increase the spacing between the guide and the pulley in order to maintain a pre-selected degree of tension in the belt upon the occurrence of a surge in power delivered from the source to the driven device with consequent incremental permanent stretching of the belt.

Claims

1. A power-delivery belt-tensioning system comprising:

a source of rotary motive power;

a first pulley mounted for rotation about a predetermined axis;

means for coupling said power from said source to said pulley;

a second pulley mounted for rotation about a given axis spaced from and parallel to said predetermined axis;

a driven device responsive to rotary power;

means for coupling rotary power from said second pulley to said driven device;

a flexible endless belt seated on and circling around said first and second pulleys to deliver power from said first pulley to said second pulley;

an idler pulley mounted for rotation about another axis parallel to said given axis and displaceable to move said idler pulley toward and away from said belt with said idler pulley being aligned with said first and second pulleys to seat against a portion of said belt and, during operation, normally said belt in a preselected degree of tension;

means associated with said power delivery system for changing the level of power available to be delivered to said driven device;

means for resiliently urging said idler pulley against said belt to create tension in said belt;

and means responsive to a surge in power delivered from said source to said driven device, with consequent incremental increase of tension in said belt, for maintaining said preselected degree of tension in said belt upon cessation of said surge in power.

2. A power-delivery belt-tensioning system comprising:

a source of rotary motive power;

a first pulley mounted for rotation about a predetermined axis;

means for coupling said power from said source to said pulley;

a second pulley mounted for rotation about a given axis spaced from and parallel to said predetermined axis;

a driven device responsive to rotary power;

means for coupling rotary power from said second pulley to said driven device;

a flexible endless belt seated on and circling around said first and second pulleys to deliver power from said first pulley to said second pulley;

an idler pulley mounted for rotation about another axis parallel to said given axis and displaceable to move said idler pulley toward and away from said belt with said idler pulley being aligned with said first and second pulleys to seat against a portion of said belt which, during operation, is placed in tension;

means associated with said power delivery system for changing the level of power available to be delivered to said driven device;

means for resiliently urging said idler pulley against said belt to create tension in said belt;

means responsive to a surge in power delivered from said source to said driven device, with consequent incremental increase of tension in said belt, for maintaining a preselected degree of tension in said belt upon cessation of said surge in power;

a cam guide mounted in a location spaced from and facing said idler pulley;

a cam effectively pivotally coupled to said idler pulley for swinging movement about an axis and positioned to face against said cam guide with said cam having a shape which varies the spacing between said cam guide and said other axis in correspondence with the amount of said swinging movement;

and means effective upon the occurrence of said increase of tension in said belt for nudging said cam in a given direction which incrementally increases said spacing between said cam guide and said other axis to maintain said preselected degree of tension in said belt.

3. A belt-tensioning system as defined in claim 2 in which said nudging means includes a resilient element fixedly secured at one end and secured at its other end to said cam.

4. A belt-tensioning system as defined in claim 2 in which said cam is formed and disposed to offset its center of mass with respect to said cam guide and in which said nudging means includes the force of gravity acting upon said mass.

5. A belt-tensioning system as defined in claim 2 in which said other axis and said idler pulley are located inside the loop defined by said belt.

6. A power-delivery belt-tensioning system comprising:

a source of rotary motive power;

a first pulley mounted for rotation about a predetermined axis;

means for coupling said power from said source to said pulley;

a second pulley mounted for rotation about a given axis spaced from and parallel to said predetermined axis;

a driven device responsive to rotary power;

means for coupling rotary power from said second pulley to said driven device;

a flexible endless belt seated on and circling around said first and second pulleys to deliver power from said first pulley to said second pulley;

an idler pulley mounted for rotation about another axis parallel to said given axis and displaceable to move said idler pulley toward and away from said belt with said idler pulley being aligned with said first and second pulleys to seat against said belt during operation;

means associated with said power delivery system for changing the level of power available to be delivered to said delivery device;

means for resiliently urging said idler pulley against said belt to create tension in said belt;

a cam guide mounted in a location spaced from and facing said idler pulley;

a cam effectively pivotally coupled to said idler pulley for swinging movement about an axis and positioned to face against said cam guide with said cam having a shape which varies with spacing between said cam guide and said other axis in correspondence with the amount of said swinging movement;

and means responsive to a surge in power delivered from said source to said driven device, with consequent incremental increase of tension in said belt, for nudging said cam in a given direction which incrementally increases said spacing between said cam guide and said other axis to maintain a preselected degree of tension in said belt upon cessation of said surge in power.