Patent ID: 6394405
Filing Date: 2002-05-28
Classification: E04G,E21D,Y10T

Abstract:
An continuously adjustable strut comprising:an outer housing with first and second ends having a cylindrical bore therein, a cylindrical extensible member with first and second ends, a first end of said cylindrical extensible member received in said cylindrical bore through a first end of said outer housing, a helical groove formed in cylindrical surface of at least a portion of said cylindrical extensible member adjacent said second end, a collar secured to said first end of said outer housing portion, said collar comprising, an outer cylindrical sleeve, an inner cylindrical sleeve, said inner cylindrical sleeve secured to said outer cylindrical sleeve and being provided with a series of holes arranged in a helical pattern, an intermediate cylindrical sleeve, said intermediate cylindrical sleeve being provided with an internal helical groove, said internal helical groove having a curved is base and sides which are asymmetrical with respect to a radius of said intermediate cylindrical sleeve which passes through the center of said curved base, a plurality of ball bearings, said ball bearings being retained between said inner cylindrical sleeve and said intermediate cylindrical sleeve in said Internal helical groove and said series of holes, a spring for applying a force between said outer sleeve and said intermediate sleeve to hold said outer sleeve and said intermediate sleeve in a first position with respect to each other, in said first position, said ball bearings are engaged in said groove in said cylindrical extensible member, such that rotation of said outer sleeve with respect to said cylindrical extensible member will result in adjustment of the position said outer housing with respect to said cylindrical extensible member, in said first position, said outer housing portion and said cylindrical extensible member resisting a compressive force applied between the second end of the outer housing and the second end of the cylindrical extensible member, and when a force is applied between said outer cylindrical sleeve and said intermediate cylindrical sleeve, to overcome the force of said spring, said outer cylindrical sleeve and said intermediate cylindrical sleeve are moved to a second position in which said ball bearings are disengaged from said groove in said cylindrical extensible member and said outer housing and said cylindrical extensible member may be reciprocated with respect to each other.