Resources Contact Us Home
Butterfly valve

Image Number 4 for United States Patent #3991974.

A butterfly valve comprising a body having an internal cylindrical bore with two radial co-axial passages diametrically opposed with respect to the bore and a butterfly including a spherical cap section and two co-axially projecting shafts rotatably mounted in the passages to provide pivotal movement of the butterfly in the body. An annular elastomeric seat member of U-shaped section covers the bore and the outer side faces of the body and the seat receives the shafts of the butterfly and includes at each of the passages a portion of spherical shape substantially complementary to that of the cap section of the butterfly. The seat has a cuff portion surrounding the associated shaft and a support which is independent of the seat bears against the base thereof. The support is constituted of an elastic material housed in an annular groove provided in the body and the support has cuffed portions surrounding the shafts and permanently compressing the spherical portions of the seat against the respective cap portions of the butterfly to assure sealing towards the exterior of the passages for the shafts and, in closed position of the butterfly, the continuity of the sealing upstream and downstream of the butterfly on the seat.

  Recently Added Patents
Detachably integrated battery charger for mobile cell phones and like devices
Modulation of HSP47 expression
Polarized film apparatus with bands of alternating orientation
High-accuracy centered fractional fourier transform matrix for optical imaging and other applications
Portable gaming device and gaming system combining both physical and virtual play elements
Philanthropy management apparatus, system, and methods of use and doing business
Color stable manganese-doped phosphors
  Randomly Featured Patents
Digital output temperature sensor and method of temperature sensing
Two wheel steering bicycle with each wheel having its own steering control operated by rider's left and right hand respectively and rider positioned facing the direction of motion
Spectrum communication method and apparatus for delaying read sequence series
Compensating stacker for magazines
Pressure detector and method of diagnosing blockage of impulse lines
Method and apparatus for controlling the sheet supply in a sheet-processing printing machine
Packaging apparatus
Horizontal solids recycler
Adaptive range snoop filtering methods and apparatuses
Heat curable silicone elastomer compositions