GB801044A - Improvements in or relating to hose couplings - Google Patents

Abstract

801,044. Hose end fittings. PARKER APPLIANCE CO. Sept. 28, 1956 [Oct. 4, 1955], No. 29736/56. Class 99(1). A hose 3 is frictionally gripped between a socket 7 and a nipple 1, the socket 7 having relatively blunt and sharp internal ribs 11 and 12 respectively, the latter cutting a continuous thread in the outer surface of the hose and the minor diameter of the ribs 11 being at least as great as that of the ribs 12. The socket 7 has a threaded bore 8 into which the nipple 1 screws so that a tapered end 4 extends through the socket, adjacent to the bore 8 there being an annular recess 9 in which the hose end is compressed and held against withdrawal by an abutment shoulder 10. The remaining length of socket 7 is internally threaded to provide the ribs 11, 12, the truncations of ribs 11 being relatively wide compared with the truncations of ribs 12 and the ribs having equal major, minor and pitch diameters and equal pitches. Preferably the width of ribs 11, 12 at their major diameter is less than one-half of the width of the grooves between them and the depth of the ribs is the same as the thickness of the outer layer of hose 3. Between the sharp rib 12 and blunt ribs 11 there is an intervening rib 13 which has a progressively widening minor diameter truncation. The major diameter of ribs 11, 12 is the same as the outside diameter of the hose 3 and the outer end of socket 7 is counter-sunk to facilitate the hose entry. In assembling, the hose 3 is threaded into socket 7 so that the sharp rib 12 embeds in the hose outer layer 16 and cuts through it, the rib 13 progressively spreading apart the helical cut made for positioning the blunt threads 11 to directly engage the reinforcing layer 15 of the hose, the engagement being continued until the hose end abuts the end of the recess 9. The hand of the ribs 11, 12 is opposite to that of the thread 8 so that when finally the nipple 1 and socket 7 are screwed together the hose is securely tightened and the tapered end 4 of the nipple jams the hose into the grooves between the ribs 11, 12 and compresses the hose end into the recess 9. There are provided three gripping zones ; (a) between the recess 9 and largest diameter of nipple 1 in which the hose abuts the shoulder 10, (b) between the blunt ribs 11 and large portion of nipple 1 wherein the minor diameter of the ribs exerts a high pressure clamping action directly on the braided reinforcing layer and (c) between the remainder of the ribs and tapered portion 4 of the nipple where the pressure is gradually lessened so as to avoid a high pressure concentration plane at the junction of the socket end and hose 3. The threads 8 and ribs 11, 12 may be lubricated on assembly and the fitting may be reused since the blunt ribs 11 are not deformed by contact with the wire braid 15 and the sharp ribs 12 are not damaged by contact with the braid 15. The sharp ribs need not have knife edges but may be truncated to approximately 0À01 inch and the included angle may be 30 degrees less for saw-tooth form or 60 degrees or less for V-form.