Check valve with restricted backflow

Claim 2

A valve comprising a pair of separably connected housing parts providing a through flow passage and an intermediate chamber, a spider at one end of the chamber traversing the flow passage and having openings connecting the flow passage with one end of the chamber, a valve seat at the other end of the chamber, a ball valve in the chamber with a substantial clearance with the wall thereof to permit substantial flow of fluid through the clearance when the ball valve is not on said seat, said ball having a bore therethrough, a stem carried by the spider and having an end projecting into said bore, said spider being gripped between clamping shoulders formed on said parts, and said clamping shoulders being radially offset to permit slight deformation of the spider portion gripped thereby whereby the sealing shoulders may engage despite manufacturing inaccuracies in the dimensioning of the parts.

Claim 3

The valve of claim 1 in which said spider has a central hub from which the stem projects, and said ball is engageable with the hub to limit movement of the ball away from said seat.

Claim 4

The valve of claim 2 in which the outer diameter of the hub exceeds the diameter of the bore by an amount no less than the radial width of the clearance.

Claim 5

The valve of claim 2 in which the parts have engaged shoulders forming a seal therebetween.

Claim 6

The valve of claim 1 in which the radially outermost of said clamping shoulders is of narrower width than the radially inner clamping shoulder.

Claim 7

The valve of claim 1 wherein the grip spider portion is devoid of threads and is held in position solely by the gripping forces of said clamping shoulders.

Claim 8

The valve of claim 1 wherein said spider is constructed from deformable material.

Claim 9

The valve of claim 6 wherein said spider is constructed from deformable material.

Claim 10

The valve of claim 1 wherein said end is of a slightly less diameter than said bore to provide a slight clearance therebetween to permit restricted flow of fluid therethrough when the ball is on said seat.

Claim 11

The valve of claim 1 including means for limiting the clamping force exerted upon said grip spider portion by said clamping shoulders. 11 A valve comprisIng a pair of housing parts connected by thread means providing an inlet passage, an outlet passage, and a valve chamber therebetween, an annular valve seat defined by a first of said housing parts, said annular valve seat facing in a direction toward a second of said housing parts, a spider at an end of said chamber remote from said valve seat traversing the chamber and having openings connecting the chamber with the outlet passage, a ball valve in the chamber with a substantial clearance with the wall thereof to permit substantial flow of fluid through the clearance when the ball valve is not on said valve seat, said ball valve having a bore therethrough, a stem carried by said spider projecting toward said inlet passage and into said bore, said spider being gripped between clamping shoulders formed on said housing parts, and means radially exterior of and apart from said thread means for limiting the clamping force exerted upon said spider by said clamping shoulders.

Claim 12

The valve of claim 11 wherein said clamping force limiting means are exterior abutting surfaces of said housing parts.

Claim 13

The valve of claim 10 wherein said clamping force limiting means are exterior abutting surfaces of said housing parts.