Valve actuator

#This application is entitled to the benefit of and incorporates by reference essential subject matter disclosed in International Patent Application No. PCT/DK2005/000692 filed on Oct. 27, 2005 and Danish Patent Application No. PA 2004 01664 filed Oct. 28, 2004.

#The present invention relates to a valve actuator having a rotatable positioning element. In particular, the present invention relates to a valve actuator having a near circular positioning element arranged in an associated sliding bearing in a support member.

#A majority of known valve actuators, especially for larger valves, suffer from significant wear of the mechanical part. For example, significant wear often occurs between a rotatable and user operable positioning element and a support member.

#The present invention will now be explained in further details with reference to the accompanying figures, wherein

#FIG. 1 shows a cross-sectional view of a first embodiment of the present invention,

#FIG. 2 shows a detailed cross-sectional view of a second embodiment of the present invention, and

#While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

#FIG. 1a shows a cross-sectional view of a valve comprising a valve actuator according to a first embodiment of the present invention. The cross-sectional view shown in FIG. 1a is taken along line AA in FIG. 1b.

#According to FIG. 1a the valve has a housing 1 of aluminium or stainless steel and a cover part 2 of a synthetic material, such as plastic. However, other materials may also be applicable. The valve actuator itself comprises a positioning element 3, a track 4 arranged in an asymmetric manner relative to the positioning element 3, a hand grip 5, a support member 6 having a bearing for holding the positioning element 3, a track follower having a set of ball bearings 7, and the guiding slit 8 adapted to guide the track follower. The track follower is biased against the track 4 by a helical spring 9 which is encapsulated in a bellow 10 of stainless steel. A valve rod (not shown) connects the track follower and a closing element 11 of the valve. The closing element 11 rests on the valve seating 12 when the valve is closed. In order to ensure a hermetic sealing between the inlet 13 and outlet 14 an o-ring may be positioned in the closing element 11. Alternatively, the o-ring or a similar sealing element may be positioned in the valve seating 12.