Coupling

Abstract

A coupling is provided preferably for a vortex valve for use on an outlet pipe in a sewerage system. The coupling comprises an outer component for insertion into a bore of a pipe ( 62 ), and an inner component ( 26 ) which is inserted into the outer component, ramp means being provided between the two components, whereby the outer component is expanded to seal against the bore when the inner component ( 26 ) is inserted into the outer component so as to engage the second ramp portion. The ramp means comprise first and second portions ( 28, 30 ) of different inclinations. The vortex valve has a circumferential inlet ( 11 ) which is adjustable.

1 . A coupling for engagement with a bore, the coupling comprising an outer component having an expandable ring, and an inner component which is longitudinally displaceable within the ring, ramp means being provided between the inner component and the ring whereby longitudinal displacement of the inner component within the ring causes radial expansion of the ring to engage the bore, the ramp means comprising a ramp surface on one of the components and a circumferential projection on the other component, the ramp surface having first and second portions of differing inclination to the is direction of longitudinal displacement, whereby the circumferential projection engages the ramp surface portions successively as the inner component is displaced longitudinally relative in the ring.  
   
   
       2 . A coupling as claimed in  claim 1 , wherein the first portion of the ramp means is inclined by a smaller angle than the second portion to the direction of longitudinal displacement, and is situated ahead of the second portion with respect to the direction of longitudinal displacement of the inner component corresponding to expansion of the ring.  
   
   
       3 . A coupling as claimed in claim z, wherein the ramp surface is provided on the inner component, and the circumferential projection is provided on the outer component for engagement with the ramp surface.  
   
   
       4 . A coupling as claimed in any one of the preceding claims, wherein the first portion of the ramp surface is inclined to the longitudinal direction by an angle of 2° to 10°.  
   
   
       5 . A coupling as claimed in any one of the preceding claims, wherein the first portion of the ramp surface is inclined to the longitudinal direction by an angle of 5°.  
   
   
       6 . A coupling as claimed in any one of the preceding claims, wherein the second portion of the ramp surface is inclined to the longitudinal direction by an angle of 30° to 50°.  
   
   
       7 . A coupling as claimed in any one of the preceding claims wherein the second portion of the ramp surface is inclined to the longitudinal direction by an angle of 40°.  
   
   
       8 . A coupling as claimed in any one of the preceding claims, wherein the ring is provided with at least one longitudinal slot to provide for the radial expansion of the ring.  
   
   
       9 . A coupling as claimed in  claim 8 , wherein a plurality of the longitudinal slots are provided in the ring, which divide the ring circumferentially into a plurality of resilient fingers.  
   
   
       10 . A coupling as claimed in  claim 9 , wherein the circumferential projection comprises a plurality of segments at the free ends of the fingers.  
   
   
       11 . A coupling as claimed in any one of the preceding claims, further comprising rotational ramp means wherein rotation of the inner component relatively to the outer component longitudinally displaces the two components in relation to each other.  
   
   
       12 . A coupling as claimed in  claim 11  when appendant to  claim 3 , wherein the rotational ramp means is engaged when the circumferential projection contacts the second portion of the ramp surface.  
   
   
       13 . A coupling as claimed in  claim 11  or  12 , wherein the rotational ramp means further comprises at least one peg provided on one of the components which engages a helical groove on the other component.  
   
   
       14 . A coupling as claimed in any one of the preceding claims, wherein a seal is provided on the outer surface of the ring.  
   
   
       15 . A vortex valve having a coupling as claimed in any one of the preceding claims.  
   
   
       16 . A vortex valve as claimed in  claim 15 , wherein the inner component is releasably mounted on an end wall of the vortex valve.  
   
   
       17 . A vortex valve as claimed in  claim 15  or  16 , wherein the inner component comprises a spigot projecting axially from the vortex valve.  
   
   
       18 . A method of installing a vortex valve in accordance with any one of  claims 15  to  17  on a pipe, the method comprising the steps of: 
 fitting the ring of the outer component within the bore of the pipe,    longitudinally displacing the inner component into the ring, such that the first portion of the ramp surface provides a first expansion of the ring and subsequently the second portion of the ramp surface provides a second expansion of the ring into sealing engagement with the bore.    
   
   
       19 . A method as claimed in  claim 18 , the vortex valve having a coupling in accordance with any one of  claims 11  to  14 , in which method the inner component is displaced longitudinally into the outer component to engage the rotational ramp means, and subsequently rotation of the vortex valve causes operation of the rotational ramp means to displace the inner component longitudinally to cause the second expansion of the ring.  
   
   
       20 . A vortex valve comprising a vortex chamber having a circular cylindrical outer wall and a tangential inlet passage, the inlet passage opening into the vortex chamber at a circumferential aperture which is adjustable by means of arcuate sliding plate which is displaceable over the external surface of the outer wall.  
   
   
       21 . A vortex valve as claimed in  claim 20 , wherein retaining means is provided to retain the sliding plate in an adjusted position.  
   
   
       22 . A vortex valve as claimed in  claim 20  or  21 , wherein the inlet passage of the vortex valve is defined by a tangential extension of the cylindrical outer wall of the vortex valve and by extensions of the axial end walls of the vortex valve whereby the inlet passage is of rectangular form.