Tube couplings

Abstract

The disclosure relates to a tube coupling comprising a coupling body having a throughway open at one end of the body to receive a tube. A collet is located in the throughway having an annular element and at least one radially resilient finger extending axially from the element toward said open end of the throughway. The coupling body has a stop face directed along the throughway axis away from said open end and the distal end of the finger has on its inner side a projection to engage a feature on the tube and on its outer side a first, axially facing abutment directed towards the open end of the throughway to engage with the stop face and a further, radially facing abutment engageable with the coupling body when the axially facing abutment engages the stop face to constrain the distal end of the finger against radial outward movement and thereby to prevent release of the projection on the finger from the feature on the tube and release of the tube from the coupling body.

1. A tube coupling comprising a coupling body having a throughway open at one end of the body to receive a tube, a collet located in the throughway having an annular sleeve and at least one radially resilient finger extending axially from the sleeve toward said open end of the throughway, the coupling body having a stop face directed along the throughway axis away from said open end, the distal end of the finger having on its inner side a projection to engage a feature on the tube and on its outer side a first axially facing abutment directed towards the open end of the throughway to engage with the stop face and a further, radially facing abutment engageable with the coupling body when the first axially facing abutment engages the stop face to constrain the distal end of the finger against radial outward movement and thereby prevent release of the projection on the finger from the feature on the tube and prevent release of the tube from the coupling body wherein said resilient finger has a first portion extending radially outward of said sleeve, a second portion extending axially from a radially outer end of said first portion and a radial element disposed at a distal end of said second portion, said projection and said first axially facing abutment disposed on said radial element. 
     
     
       2. A tube coupling as claimed in  claim 1 , wherein the first and further abutments on the distal end of the finger are formed adjacent each other to engage the stop face and an adjacent face of the throughway in the coupling body respectively. 
     
     
       3. A tube coupling as claimed in  claim 1 , wherein the projection on the distal end of the finger has an inwardly projecting tooth formation to engage the feature on the tube to be retained in the coupling body. 
     
     
       4. A tube coupling as claimed in  claim 1 , wherein the coupling body adjacent said open end of the throughway is of cylindrical form having a rectangular aperture in its wall for said resilient finger on the collet, the side of the aperture adjacent to and facing away from the open end of the coupling body providing said stop face. 
     
     
       5. A tube coupling as claimed in  claim 4 , wherein a plurality of resilient fingers are formed on the collet and a corresponding plurality of rectangular apertures are formed in the cylindrical portion of the collet wall. 
     
     
       6. A tube coupling as claimed in  claim 5 , wherein the collet has four resilient fingers. 
     
     
       7. A tube coupling as claimed in  claim 1 , wherein the coupling body adjacent said open end is formed with a channel section recess encircling the throughway, the side of which adjacent the open end of the coupling body faces away from the open end to provide said stop face. 
     
     
       8. A tube coupling as claimed in  claim 1 , wherein means are provided for displacing the collet in a direction away from said open end of the throughway to respectively disengage the first and further abutments on the collet finger from the stop face and coupling body to allow the finger to be displaced radially outwardly for axial movement of the tube within the throughway in the coupling body. 
     
     
       9. A tube coupling as claimed in  claim 8 , wherein the means to displace the collet comprise a cover slidably mounted on the coupling body for movement parallel to the throughway axis, the cover having an end wall extending over the end of the coupling body with an inner sleeve projecting into the throughway in the coupling body to engage the distal end of the collet finger to displace the collet inwardly of the open end of the coupling body, a tube being inserted into the coupling body through the inner sleeve in the cover. 
     
     
       10. A tube coupling as claimed in  claim 8 , wherein the collet sleeve has an aperture in which a resilient collet finger is disposed. 
     
     
       11. A tube coupling as claimed in  claim 8 , wherein said means comprise an extension on the collet, said collet extension projecting through the open end of the coupling body and formed with an annular head overlying the end of the coupling body around the open end of the throughway which can be depressed towards the end of the coupling body to release the first abutment of the collet finger from the stop face on the coupling body. 
     
     
       12. A tube coupling as claimed in  claim 11 , wherein a cover is slidably mounted on the coupling body to extend over the end of the coupling body and said head of the collet so that sliding movement of the cover over the coupling body in one direction displaces the collet head towards the end of the coupling body and thereby disengages the first abutment of the finger from the stop face on the coupling body, the cover having an aperture through which a tube is inserted into the coupling body. 
     
     
       13. A tube coupling as claimed in  claim 11 , wherein a fixed cover is mounted on the coupling body to extend over the open end of the throughway into the coupling body and having at least one resiliently displaceable cam element for engaging the outer side of the head of the collet to displace the collet head toward the end of the coupling body and thereby release the first abutment of the resilient finger of the collet from the stop face on the coupling body. 
     
     
       14. A tube coupling as claimed in  claim 1 , wherein a further collet is provided in the throughway, said further collet engaged with said collet, said further collet having a further resilient finger projecting axially along the throughway away from the open end thereof and a tapered cam surface is provided in the throughway reducing towards the open end of the throughway with which the further finger of the further collet is engageable to be compressed thereby and to grip the tube in the throughway. 
     
     
       15. A The tube coupling of  claim 1  further comprising:
 a coupling body having a throughway open at one end of the body to receive a tube;  
 a collet located in the throughway having an annular element and at least one radially resilient finger extending axially from the element toward said open end of the throughway, the coupling body having a stop face directed along the throughway axis away from said open end, the distal end of the finger having on its inner side a projection to engage a feature on the tube and on its outer side a first axially facing abutment directed towards the open end of the throughway to engage with the stop face and a further, radially facing abutment engageable with the coupling body when the first axially facing abutment engages the stop face to constrain the distal end of the finger against radial outward movement and thereby prevent release of the projection on the finger from the feature on the tube and prevent release of the tube from the coupling body; and  
 alignment means disposed between the collet and the coupling body for aligning the collet finger with the stop face while allowing the collet to axially slide relative to the coupling body, the alignment means disposed at an axial position whereby the stop face is axially located between the alignment means and the open end.  
 
     
     
       16. A tube coupling as claimed in  claim 15 , wherein the collet includes has plurality of fingers and the coupling body has a corresponding number of apertures, each of the apertures having a side surface facing away from the open end of the coupling body and defining the stop face for one of the fingers, and the alignment means is disposed between two of the apertures. 
     
     
       17. A tube coupling as claimed in  claim 15 , wherein the first and further abutments on the distal end of the finger are formed adjacent each other to engage the stop face and the adjacent face of the throughway in the coupling body respectively. 
     
     
       18. A tube coupling as claimed in  claim 15 , wherein the alignment means comprises at least one spline disposed on the collet engageable with an axially extending slot disposed in the throughway on the coupling body. 
     
     
       19. A tube coupling as claimed in  claim 15 , wherein the collet has an extension projecting through the open end of the coupling body and the alignment means comprises at least one spline disposed on the extension, the spline engaging an axially extending slot disposed in the throughway on the coupling body. 
     
     
       20. A tube coupling as claimed in  claim 19 , wherein said collet has a plurality of fingers and said coupling body has a corresponding number of apertures, each of the apertures having a side surface facing away from the open end of the coupling body and defining the stop face for one of the fingers, and the slot is disposed between two of the apertures. 
     
     
       21. The tube coupling of  claim 1  further characterized in that the collet has an extension projecting through the open end of the coupling body and formed with an annular head overlying the end of the coupling body around the open end of the throughway which can be depressed towards the end of the coupling body to release the first abutment of the resilient finger of the collet from the stop face on the coupling body. 
     
     
       22. The tube coupling of  claim 1  further characterized in that a cover is mounted on the coupling body and has one or more integral radial projections extending through an aperture or apertures in the coupling body to engage and act on the collet to displace the collet inwardly of the coupling body and thereby release said first abutment of the resilient finger of the collet from the stop face on the coupling body. 
     
     
       23. The tube coupling of  claim 1  wherein said collet further includes an extension projecting through said open end of said coupling body, said extension formed with an annular head overlying the end of the coupling body around the open end of the throughway, and
 a cover mounted on the coupling body to extend over the open end of the throughway into the coupling body and having at least one resiliently displaceable cam element for engaging the outer side of the head of the collet to displace the head toward the end of the coupling body and thereby release the first abutment of the resilient finger on the collet from the stop face on the coupling body.