High-pressure integral tube coupling arrangements

Abstract

Metal tubes, such as the small diameter metal tubes ( 50 ) used in hydraulic braking systems, are connected to hoses ( 23 ) also used in such systems by fittings ( 52 ) which are configured to receive radially projecting beads ( 62 ) on the metal tubes ( 50 ). Each of the fittings includes a body portion ( 51 ) with a bore therethrough and a crimping collar ( 53 ) which is unitary with the body portion ( 51 ). The body portion ( 51 ) receives an insertion end of the tube ( 50 ) therethrough, which insertion portion projects into the unitary crimping collar ( 53 ). A radially extending bead ( 62 ) on the tube is received in a recess adjacent the bore through the body portion ( 51 ). In one embodiment, the tube ( 50 ) is held in place by another bead ( 58 ) which is seated in another recess at the opposite end of the bore.

What is claimed is:  
     
         1 . A coupling for connecting a tube to a hose comprising: 
 a tube having a main portion and an insertion portion;    at least one outwardly extending radial projection on the tube, with the insertion portion of the tube extending beyond the radial projection;    a fitting having a body portion with a bore for receiving the tube therethrough and a hollow portion extending from the first portion for receiving the hose therein;    an inside radial surface on the body portion facing toward the hollow portion; and    the tube being disposed in the bore of the body portion with the outwardly extending radial projection abutting the inside radial surface on the body portion and the insertion portion extending into the hollow portion of the fitting for receipt in the hose.    
     
     
         2 . The coupling of  claim 1 , wherein the body portion of the fitting includes an abutment surface thereon facing away from the hollow portion and engaging a portion of the tube.  
     
     
         3 . The coupling of  claim 2 , wherein the portion of the tube engaged by the abutment surface is on said one outwardly extending radial projection.  
     
     
         4 . The coupling of  claim 3 , wherein the abutment surface is on a portion of the fitting which is radially and axially deformed into abutment with said one outwardly extending radial fitting.  
     
     
         5 . The coupling of  claim 2 , wherein there is a second outwardly extending radial projection on the tube, spaced axially from said one outwardly extending radial projection, and wherein the abutment surface on the fitting engages the second outwardly extending radial projection on the tube.  
     
     
         6 . The coupling of  claim 5 , wherein the second axially extending abutment is at a radially extending end of the fitting.  
     
     
         7 . The coupling of  claim 6 , wherein the insertion portion has a diameter less than that of the main portion of the tube.  
     
     
         8 . The coupling of  claim 7 , wherein the hollow portion of the fitting is a crimping collar for radially engaging the hose with the insertion portion of the tube within the hose.  
     
     
         9 . The coupling of  claim 1 , wherein the inside radial surface facing the hollow portion is a flat surface engaged by the radial projection and wherein there is an outside radial surface facing away from the hollow portion and defining another flat surface which is engaged by another radial projection on the tube.  
     
     
         10 . A coupling for connecting a tube to a hose comprising: 
 a metal tube having a main portion and an insertion portion, the insertion portion having an outer diameter corresponding to the inner diameter of the hose for insertion therein and a controlled inner diameter;    a radial projection on the metal tube adjacent the insertion portion, the radial projection having oppositely facing surfaces;    a layer of plastic material covering the main portion of the tube and terminating at the radial projection, the radial projection being free of plastic material;    a fitting having a bore therein slidably receiving the main portion of the metal tube, the fitting including an abutment surface extending radially of the bore and including an annular recess in which the radial projection on the tube seats, the abutment surface being within a crimping collar that is unitary with the fitting; and    an annular deformed portion adjacent the annular recess, which annular deformed portion is deformed into abutment with the radial projection to form a metal-to-metal fluid tight seal which also fixes the metal tube to the fitting.    
     
     
         11 . The coupling of  claim 10 , wherein the metal tube has an outer diameter which is larger than the outer diameter of the insertion portion.  
     
     
         12 . The coupling of  claim 11 , wherein the fitting has a unitary hollow portion which extends beyond the abutment surface and surrounds the insertion portion of the metal tube wherein the hollow portion receives the hose.  
     
     
         13 . The coupling of  claim 11 , wherein the unitary hollow portion receives the hose therein and wherein the hollow portion is crimped against the hose with the insertion portion of the tube received within the hose.  
     
     
         14 . The coupling arrangement of  claim 13 , wherein the hollow portion is coaxial with both the main portion and insertion portion of the metal tube.  
     
     
         15 . The coupling of  claim 13 , wherein the tube, hose and fitting are components of a hydraulic or other automotive fluids as required and are adapted to be filled with hydraulic fluid.  
     
     
         16 . The coupling of  claim 10 , wherein the layer of plastic material is in a sealing relationship with the bore of the fitting.  
     
     
         17 . The coupling arrangement of  claim 16 , wherein the layer of plastic material is selected from the group consisting of polyamide, polyvinylfluoride and polypropylene.  
     
     
         18 . The coupling arrangement of  claim 12 , wherein the metal tube has a tapered section joining the insertion portion to the main portion and wherein the bore has a corresponding tapered portion against which the tapered portion of the metal tube seats.  
     
     
         19 . The coupling arrangement of  claim 18 , wherein the abutment surface of the fitting is disposed adjacent the metal tube within the fitting when the annular deformed portion is deformed against the radial projection and the main portion of the tube extends away from the fitting and wherein the tapered portion of the fitting is positioned adjacent a crimping collar that is unitary with the fitting so that the insertion portion of the metal tube extends within the crimping collar for receiving and clamping the hose therein with the insertion portion in the hose.