Wayne D Calder
Engineers in Simpsonville, SC
License number
Utah 190498-2202
Issued Date
Oct 13, 1992
Expiration Date
Dec 31, 2000
Category
Engineer/Land Surveyor
Type
Professional Engineer
Address
Address
Simpsonville, SC
Professional information
Adjustable Screed System
US Patent:
6890125, May 10, 2005
Filed:
Jan 30, 2003
Appl. No.:
10/355129
Inventors:
Wayne D. Calder - Simpsonville SC, US
David M. Calder - Taylors SC, US
David M. Calder - Taylors SC, US
Assignee:
Calder Brothers Corporation - Greenville SC
International Classification:
E01C019/22
US Classification:
404104, 404118
Abstract:
A mechanical linkage having a geometry designed to substantially hold the plane of a main screed and the plane of an extension screed at a generally constant relative angle with respect to one another through a predetermined range of screed depth adjustments. The linkage is configured to allow the extension screed to be raised and lowered by an amount sufficient to compensate for angle of attack and elevation changes in the main screed. In particular, the linkage compensates for the effect of the radial distance differences from the axis of rotation of tow bars of the main screed and extension screed as the main screed pivots with respect to the tow point of the tow bars for different asphalt mat depths. An alternate embodiment includes actuators, together with sensors, for sensing the position of the extension screed with respect to the main screed and automatically compensating for changes in main screed position to properly orient the extension screed with respect to the main screed.