String and string trimmer operation
US5996233A · kind A · utility
Inventors
Key dates
| Filing date | Jan 22, 1998 |
| Grant date | Dec 7, 1999 |
| Priority date | — |
| Expiry date | Jan 22, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2978
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An elongated flexible cutting string, or substantially self-supporting strut cutting element, is connectable to a rotating device for use in a method of cutting vegetation. The cutting string has numerous advantages over conventional cutting strings, having a drag coefficient which is at least about 5% (e.g. 10-300%) less than the drag coefficient of a string having a substantially round and smooth cross-section. The drag coefficient of aerodynamic line 10 is 1.0 or less, e.g. about 0.35 or less. The cross-sectional configuration preferably simulates a tear drop (with or without an extension nose), and can have a textured (e.g. with golf ball simulating dimples, saw toothed or a wavy configuration) exterior surface. The pitch of the line is positively maintained while it is rotated in a cutting plane, e.g. controlled with an eyelet and/or a compound taper. Other cross-sectional configurations are an ellipse of at least 1.25:1 ratio, those that simulate a spearhead, keyways of different sorts, a diamond with rounded apices, or an ice cream cone. When a single string having a dimension perpendicular to the direction of movement of about 0.08 inches is rotated it uses less than the th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.