Patent ID: 6478173
Filing Date: 2002-11-12
Classification: B61G

Abstract:
A friction/elastomeric draft gear comprising:hollow housing open at a first end and closed toward a second end, said housing defining a major axis and having a series of extended tapered inner surfaces opening toward and longitudinally extending from a front portion arranged adjacent the first end of said housing, a series of friction members equally and annularly spaced about said major axis, each friction member including a first end portion with a first angled surface, a second end portion, and an outer surface between said first and second end portions, with said outer surface being configured to complement one of said extended tapered inner surfaces provided on said housing and such that a first sliding surface is cooperatively defined between the outer surface of each friction member and one of said extended tapered inner surfaces on said housing, with said first sliding surface between the outer surface of each friction member and the extended tapered inner surface on said housing defining an angle of about 2.25 degrees, plus or minus about 0.25 degrees, relative to the major axis of said housing, a wedge arranged for axial movement relative the open end of said housing and against which an external force can be applied, said wedge defining a series of outer tapered surfaces configured to complement the first angled surface at the first end portion of each friction member and such that a second sliding surface is cooperatively defined between the outer tapered portions on said wedge and the first angled surface of each friction member, and with the second sliding surface defined between the outer tapered portions on said wedge and the first angled surface of each friction member defining an angle of about 35 degrees, plus or minus 3 degrees, relative to the major axis of said housing; a spring seat arranged within and at a generally normal disposition relative to the major axis of said housing, said spring seat defining on one side thereof a face configured to complement and engage a second surface arranged adjacent the second end portion of each friction member, and such that a third surface is defined at the conjuncture of the face on said spring seat and the second surface on each friction member, with said third surface being disposed as to define an angle of about 90 degrees, plus or minus 4 degrees, relative to the major axis of said housing; an elastomeric spring disposed within said hollow housing between the closed end of said housing and a side of said spring seat opposed to said one side for storing energy generated during compression of said draft gear; and wherein said elastomeric spring in combination with the configuration of said housing, said wedge, said friction shoes and said spring seat along with the angularity of said first sliding surface, said second sliding surface and said third surface relative to the major axis of said housing permit said draft gear to resist impact forces applied thereto while cushioning said impact forces over an extended range of operation exceeding 3.5 inches in either axial direction.