GB2143607A

GB2143607A - A hose coupling

Info

Publication number: GB2143607A
Application number: GB08418539A
Authority: GB
Inventors: Takeshi Miyazaki; Kenji Sugiyama
Original assignee: Toyoda Gosei Co Ltd
Current assignee: Toyoda Gosei Co Ltd
Priority date: 1983-07-21
Filing date: 1984-07-20
Publication date: 1985-02-13
Also published as: JPS6026876A; DE3426838A1; JPS6245011B2; GB8418539D0; GB2143607B; DE3426838C2

Abstract

This invention relates to a hose coupling made from metal and suitable for connecting a brake hose or the like. In more detail the hose coupling of the invention comprises a collar 1, a hose connecting portion 3 including a nipple 2 and an internally threaded connecting portion 5 with the portions extending coaxially and in opposite directions from the collar, the base of the threaded connection terminating in an annular seat. The seat has two faces 6, 11 which converge towards each other. <IMAGE>

Description

SPECIFICATION A hose coupling This invention relates to a hose coupling made of metal to be connected to the end portion of a brake hose or the like.

A hose coupling of this kind is exemplified, in Figure 1, and includes a hose connecting portion 3 having a nipple 2, and a threaded connecting portion 5 having an internally threaded portion 4. The portions 3 and 5 project coaxially, from each side of a hexagonal, square or rounded collar I, (hereinafter referred to as the collar) positioned centrally of the hose coupling. Formed at the bottom of the threaded connecting portion 5, is a tapered mating seal seat 6 (hereinafter referred to as "seal seat".

This seal seat 6 provides a metal to metal seal in the seal seat 6, which mates with an inverted tapered surface formed at the front end of an externally threaded connecting member.

This hose coupling is manufactured in such a manner that each piece or blank is of a predetermined length and cut from a metal bar, such as a steel bar or the like, the collar portion I, and a hole wherein the internal thread 4, is to be formed, are preformed by cold forging and there-after, the nipple 2, the seal seat 6, the internally threaded portion 4, are formed by cutting. However, a number of cutting operations are involved. Especially, upon the formation of the seal seat for which a complicated cutting tool is required, and abrasion of the seal seat is necessary.

Consequently, a considerable amount of time is required to manufacture the hose coupling . Alternatively, the seal seat 6, may be formed by means of cold forging. However, upon the formation of the seal seat 6, shown in Figure 1, by forging, a seal seat annular projection 9, formed at the front end of a punch 8, may easily be damaged due to loading from the inner periphery as shown by arrows and therefore, such measure is not practical.

According to the present invention, there is provided a hose coupling made of metal wherein a hose connecting section including a nipple, and a thread connecting portion having an internally threaded portion projecting coaxially from each side of a collar respectively, and a tapered mating seal seat formed at the bottom of the said thread connecting portion, an inverted tapered inclined surface forms a continuous sequence of an inner peripheral wall, at the bottom of the said thread connecting portion, said inverted tapered inclined surface being in confrontation with said seal seat.

The invention also includes a hose coupling comprising a collar, a hose connecting portion including a nipple and an internally threaded connecting portion with the portions extending coaxially and in opposite directions from the collar, the threaded connection terminating inwardly in a annular seating with the confronting faces of the annulus converging towards each other to form two annular seating surfaces.

Formation of the seal seat, by cold forging, eliminates or at least considerably reduces damage to the seal seat forming projection, formed at the front end of a punch, since loading from the inside is counteracted by that from the outside. Accordingly, as the seal seat may be formed by means of cold forging instead of cutting, abrasion of the seal seat is usually unnecessary and manufacturing time may greatly be reduced. Furthermore, greater accuracy is achieved due to the fitting of the metal moulds, thereby improving the coincidence of the axes of the internal thread and the seal seat.

This invention will now be described by way of example with reference to the accompanying drawings.

Figure 1 is a vertical section showing one embodiment of the prior art hose coupling; Figure 2 is a vertical section showing one embodiment of a hose coupling according to this invention; Figure 3 is a vertical section showing a modified bottom configuration of a thread connecting section in the hose coupling of Figure 2; Figure 4 is a vertical section of a preformed article at the stage before a seal seat in the hose coupling of Figure 2 is to be formed; and Figure 5 is a vertical section of the preformed article at the stage in which the seal seat in the hose coupling of Figure 2 is in the course of formation.

One embodiment of the hose coupling of the present invention, is shown in Figure 2, and is similar in certain respects to the hose coupling of Figure 1. The hose coupling is made from metal and comprises a collar I, a hose connecting portion 3, having a nipple 2, and a thread connecting portion 5, having an internally thread 4. In addition, a tapered seal seat 6, is formed at the bottom of the thread connecting portion 5. The difference between the couplings of Figure I and Figure 2 is such that an inverted, tapered inclined surface 11, is successively formed with an inner peripheral wall 5a, at the bottom of the thread connecting portion 5, and confronts the seal seat 6.The angle a of the inclined surface 11, is in the range of 30 to 45 , and the length of the inclined surface 11, is one half to one quarter of that of the seal seat 6. it is not necessary that, as shown in Figure 2, the inclined surface 11, is successively formed with the seal seat 6 and, as shown in Figure 3, a horizontal or slightly inclined portion 12, may be formed therebetween.

The hose coupling in the above embodiment is manufactured substantially in the same manner as in the prior art with the exception of the seal seat.

In forming the seal seat 6, as shown in Figure 4, a hole 16, wherein the internal thread is to be formed, is formed by means of cold forging and then, the seal seat 6, is formed by means of the cold forging by the use of a punch 18, shown in Figure 5. At this time, loading from the inside is applied to a seal seat forming a projection 19, formed at the front end of the punch 18, via a surface 19a, wherein the seal seat 6, is to be formed.

However, another loading from the outside counteracts thereagainst, so that damage of the seal seat 6, forming a projection 19, may be prevented.

Escaping hole 20, is for allowing lubricating agent to pass out. Surface roughness of the seal seat 6, formed by means of the cold forging, is normally less than 10S and therefore, further-abrasion is unnecessary. Surface roughness formed by means of cutting is normally 185. The unit "S" representing the surface roughness is defined in Japanese Industrial Standard, (JIS) B 601-55.

Claims

1. A hose coupling made of metal wherein a hose connecting section including a nipple, and a thread connecting portion having an internally threaded portion projecting coaxially from each side of a collar respectively, and a tapered mating seal seat formed at the bottom of the said thread connecting portion, an inverted tapered inclined surface forms a continuous sequence of an inner peripheral wall, at the bottom of the said thread connecting section, said inverted tapered inclined surface being in confrontation with said seal seat.

2. A hose coupling according to claim I, wherein said inverted tapered inclined surface is in a directly serial relation to said tapered mating seal seat.

3. A hose coupling according to claim 2, wherein the angle of inclination of said inverted tapered inclined surface is somewhere in the region of 30 to 450 and the length thereof is one half to one quater of that of the seal seat.

4. A hose coupling according to claim I, wherein said tapered mating seal seat is in a serial relation to said inverted tapered inclined surface via a horizontal portion or slightly inclined surface portion.

5. A hose coupling according to claim 4, wherein the angle of inclination of said inverted tapered inclined surface is somewhere in the region of 30 to 450 and length thereof is one half to one fourth of that of said seal seat.

6. A hose coupling comprising a collar, a hose connecting portion including a nipple and an internally threaded connecting portion with the portions extending coaxially and in opposite directions from the collar, the threaded connection terminating in an annular seating with the confronting faces of the annulus converging towards each other to form two annular seating surfaces.

7. A hose coupling according to claim 6, wherein the two annular seating surfaces are inclined at different angles to the coaxial axis of the said portions.

8. A hose coupling according to claim 6 or claim 7, wherein the inclined dimension of each of the two annular seating surfaces are different.

9. A hose coupling according to claim 8, wherein the radically inner annular seating surface is of greater inclined length than the inclined length of the radically outer seating surface.

10. A hose coupling according to claim 9, wherein the angle of inclination of the radically outer sealing surface is within the range 30 to 45 .

11. A hose coupling according to any of claims 1 to 5 or any one of claims 6 to 10, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.