Abstract A braking and locking structure for frictionally supporting a shaft, such as a valve stem, for axial and rotational movement in a housing comprising a cylindrical surface on the periphery of the shaft, a friction sleeve in frictional engagement with the cylindrical surface and axially located between abutment washers in the housing. The friction sleeve is plastically deformed in a radially outward direction for engagement with the cylindrical surface with a frictional force independent of the actual amount of radial deformation from its original nominal size and, additionally, the sleeve is provided with an axially extending lip plastically deformed to allow the sleeve to assume a length equal to the spacing between the abutment washers determined by the dimensions of the various components to eliminate axial lost motion of the friction sleeve.
A frictional braking and locking structure for a valve having a housing and a valve stem shaft supportedly guided in said housing for helical movement therein, comprising a smooth cylindrical portion of said shaft, a friction sleeve in said housing carried on said smooth portion and in frictional engagement therewith, friction abutment means axially fixed with respect to said housing at each axial end of said sleeve including radially extending abutment surfaces each facing the other and separated by a predetermined spacing, said friction sleeve having a first portion of generally tubular cylindrical shape defining the major part of the axial length of the friction sleeve, said first portion having a first surface of a diameter equal to the diameter of said smooth cylindrical portion and a second outer surface of a second diameter, said friction sleeve having at one end of said first portion a face extending radially from said inner surface to said outer surface and in abutting engagement with one of said abutment surfaces, said friction sleeve having adjacent its other end an end face extending radially outward from said inner surface to an inner side of a lip portion of the friction sleeve, said lip portion extending axially and radially outward from said end face and having a cross-sectional area and therefore a compressive strength less than the first portion, said lip portion being plastically deformed in an axial direction by the other of said abutment surfaces and being in tight abutting engagement with such other abutting surface, the plastic deformation of the lip portion resulting in a sleeve length equal to the predetermined axial spacing between said abutment surfaces and thereby preventing movement of said sleeve in said housing due to axial reciprocation of said shaft.
Claim 2
Dependent Claim
49 words
A frictional braking and locking structure as set forth in claim 2 wherein said sleeve is circumferentially continuous and plastically deformed beyond its elastic limit to provide a frictional gripping between said sleeve and said smooth cylindrical portion substantially independent of the amount of plastic deformation of said sleeve.
Claim 3
Dependent Claim
30 words
A frictional braking and locking structure as set forth in claim 2 wherein said friction sleeve is a longitudinally split ring elastically gripping said smooth portion of said valve stem.