Flexible coupling sleeve and a flexible shaft coupling

Abstract

A flexible shaft coupling device including a coupling sleeve comprising a sleeve shaped body having a central annular portion and a coupling receiving portion at each of two opposing sleeve ends, and at least one end piece coupled to such sleeve. The sleeve's coupling receiving portions include axially extending teeth on their inner surfaces. The flexible shaft coupling sleeve is formed of a polyurethane elastomer composition.

1 . A coupling device comprising a coupling sleeve for use in a sleeve-type flexible shaft coupling device, the coupling sleeve comprising a generally annular body portion having an inner periphery and an outer periphery; and two opposing sleeve end portions defining respective coupling receiving portions; said coupling receiving portions each comprising a plurality of circumferentially spaced axially extending teeth arranged along at least a portion of said inner periphery; at least one end piece coupled to said sleeve at said coupling receiving portion; and characterized in that at least one of said annular body portion and said coupling receiving portions comprises a polyurethane elastomer composition.  
     
     
         2 . The coupling device of  claim 1  wherein said end piece comprises a series of axially extending grooves which are complementary forms of said teeth of said coupling receiving portions for engagement of the end pieces with the coupling receiving portions in driving relationship.  
     
     
         3 . A coupled assembly comprising a driving shaft, a driven shaft, and the coupling device of  claim 1  operatively connecting the shafts generally along the axes thereof and in driving relation so as to transmit power therebetween.  
     
     
         4 . The coupling device of  claim 1  further characterized by the absence of a metallic reinforcing shell positioned about said coupling sleeve.  
     
     
         5 . The coupling device of  claim 1  further comprising at least one textile reinforcement selected from a tensile cord disposed within said sleeve-shaped body, a fabric jacket, and fiber loading of said composition with from about 1 to about 30 phr of fibers.  
     
     
         6 . The coupling device of  claim 1 , wherein said teeth are in alternating arrangement with a plurality of grooves, each of said grooves having a width spanning a portion of the circumference of the sleeve-shaped body inner periphery, and wherein the ratio of the sum of said groove widths to the sum of said tooth widths is less than 0.65:1.  
     
     
         7 . The coupling device of  claim 1  wherein said polyurethane elastomer composition provides at least a substantial amount of said coupling sleeve's resistance to radial stress or to circumferential shear stress in operation of said device; and has M100, tensile stress at 100% elongation according to ASTM D412, of at least about 800 psi.  
     
     
         8 . The coupling device of  claim 7  having a coupling sleeve constructed in the absence of at least one of a tensile cord, a fabric jacket and a fiber loading of said composition.  
     
     
         9 . The coupling device of  claim 8  constructed in the absence of both a tensile cord and a fabric jacket, and in the absence of a metallic reinforcing shell positioned about said coupling sleeve.  
     
     
         10 . The coupling device of  claim 1  wherein said polyurethane elastomer composition comprises the reaction product of, 
 (a) a polyisocyanate prepolymer composition being prepared by reacting, 
 (i) a diisocyanate selected from the group consisting of; 
 (A) aromatic diisocyanates with compact and symmetric structure, and  
 (B) aliphatic diisocyanates with trans or trans, trans geometric structure,  
 with;  
 
 (ii) a polyol selected from; 
 (A) polycarbonate polyols,  
 (B) polyester polyols, and  
 (C) a mixture of any two or more of said polycarbonate polyols and said polyester polyols,  
 
 and;  
   (b) a chain extender selected from; 
 (i) symmetric primary diamine chain extenders,  
 (ii) a mixture of any one or more said symmetric primary diamine chain extenders and a secondary diamine chain extender, and,  
 (iii) a mixture of any one or more said symmetric primary diamine chain extenders and any one or more said polyols.