GB2104607A

GB2104607A - Hose couplings

Info

Publication number: GB2104607A
Application number: GB08213462A
Authority: GB
Inventors: John Walter Petschel
Original assignee: Wilkinson Sword Ltd
Current assignee: Wilkinson Sword Ltd
Priority date: 1981-08-21
Filing date: 1982-05-10
Publication date: 1983-03-09

Abstract

A hose coupling of the snap-in type comprises a female main body portion 10 and a male fitting portion 40. The main body portion has cams 24 attached to a support ring 51 which snap over and engage behind a shoulder 46 on the fitting portion when the fitting portion is inserted into the main body portion, thus making the coupling. A sleeve 30 on the main body portion holds the cams in this engaged position when the sleeve is in a neutral position. Axial displacement of the sleeve relative to the main body portion allows the fitting portion to be withdrawn. The support ring is located externally of the main body portion and includes resilient projections 65 which extend from the support ring and bias the sleeve into the neutral position. <IMAGE>

Description

SPECIFICATION Hose couplings This invention relates to a hose coupling and in particular, to a snap-in type of hose coupling.

According to a first aspect of the invention, there is provided a snap-in coupling comprising a female coupling member surrounded by a support ring formed integrally with cam members which are urged into the interior of the female coupling member via apertures in said member, a sleeve surrounding the female member and the support ring and, in a neutral position of the sleeve, preventing radially outward movement of the cams so that a male coupling member, on insertion into the female coupling member, engages the cam with a snap action to prevent withdrawal of the male member to make the coupling, the sleeve being movable from said neutral position to a position in which radially outward movement of the cams is permitted, to allow withdrawal of the male coupling member.

According to a second aspect of the invention, there is provided a snap-in coupling comprising a female coupling member surrounded by a support ring formed integrally with resilient projections which engage a sleeve surrounding the female coupling member and the support ring to bias the sleeve to a neutral position, there being provided cam members urged into the interior of the female coupling member and being prevented from radially outward movement by the sleeve, when in the neutral position, so that a male coupling member, on insertion into the female coupling member, engages the cam members with a snap action to prevent withdrawal of the male coupling member and to make the coupling, the sleeve being movable from said neutral position, against the biassing force, to a position in which radially outward movement of the cams is permitted, to allow withdrawal of the male coupling member.

According to a third aspect of the invention, there is provided a cam and spring assembly for the coupling of either the first or the second aspects of the invention, and comprising a support ring, a plurality of pairs of arms extending from the support ring in an axial direction, the pairs of arms being equi-angularly spaced around the support ring, each pair of arms carrying a cam at the end thereof remote from the support ring, and the assembly being of a plastics material.

The following is a more detailed description of two embodiments of the invention given by way of example only, with reference to the accompanying drawings in which:~ Fig. 1 is an exploded perspective of a hose coupling attached to the end of a length of hose, Fig. 2 is a cross-sectional view of the coupling of Fig. 1 in an unassembled state, Fig. 3 is a cross-sectionaí view of the coupling of Figs. 1 and 2, similar to Fig. 2 and showing the coupling on insertion of a fitting member, Fig. 4 is a cross-sectionaí view, similar to Figs.

2 and 3, but showing the coupling of Figs. 1 to 3 when coupled to a fitting member, Fig. 5 is a cross-sectional view, similar to Figs.

2 to 4, but showing the coupling of Figs. 1 to 4 in a release position, Fig. 6 is a cross-sectional view of an alternative form of a coupling in an uncoupled state, Figs. 7A and 78 are respectively side and perspective views of a first form of cam and spring assembly for the couplings of Figs. 1 to 6, Figs. 8A and 8B are respectively side and perspective views of a second form of cam and spring assembly for modified forms of the coupling of Figs. 1 to 6, Fig. 9 is a side-on sectional view of a main body portion of the hose coupling of Figs. 1 to 5, Fig. 10 is a sectional view taken along the lines C-C of Fig. 9, Fig. 11 is an end-on view of an outer sleeve of the hose coupling of Figs. 1 to 5,9 and 10.

Fig. 1 2 is a cross-sectional view taken along the line A-A of Fig. 10.

Referring first to Figs. 1 to 5 of the accompanying drawings, the hose coupling comprises a female main body portion 10, a sleeve 30 and a one piece cam and spring assembly 50. The coupling co-operates with a male fitting member 40.

The main body portion has an inlet end 11 and an outlet end 12, the inlet and outlet ends being connected by an axially extending throughway 13.

The inlet end 11 of the main body portion is provided with a wall 71 which carries a plurality of radially inwardly extending saw-tooth clamps 70.

The wall 71 has an external screw thread and leads to radially outwardly extending main shoulder 48. Following this, there is a second shoulder 73, which does not extend radially outwardly as far as the main shoulder 48. The body portion then includes a main cylindrical portion 19 having four cut-outs 21 equi-angularly spaced around the circumference of the portion 1 9. As best seen in Fig. 9, the cut-outs 21 have inclined axial wall portions 75.

Towards the outlet end, the cylindrical portion 1 9 is radially outwardly enlarged and terminates in an annular lip 26 formed at the outlet end 12.

Four equi-angularly spaced radially and axially extending ribs are provided around the outer surface of the portion 1 9 (see Figs. 3 to 5 and 10).

The sleeve 30 is generally cylindrical and at one end 31 is provided with a plurality of inwardly projecting fingers 32. In addition, as best seen in Figs. 11 and 12, adjacent the projections there is provided a step 81 leading to an annular end portion 83. A second step 82 is provided towards the other end of the sleeve 30. As best seen in Fig.

10, the sleeve is provided with four equi-angularly spaced axially extending grooves 78 along the inner surface thereof.

The one piece cam and spring assembly is shown in more detail in Figs. 7A and 78, in one embodiment. The assembly is injection moulded in plastics and comprises a support ring 51 with four equally spaced gaps 59 around its periphery. Each gap 59 is bridged by a pair of axially extending arms 53 which are mutually inclined and carry a cam 22 at their ends remote from the ring 51.

Thus, at a position axially spaced from the support ring, there are four equi-angularly spaced cams 22. Each cam comprises a cam head 24 and a cam body 55. In addition, each cam head 24 is provided with leading and trailing edges 56, 57 inclined at 450 to the axis of the assembly. The head 24 of each cam is connected to the remainder of the cam by a neck portion 85 (see Figs. 2, 3, 4 and 5). In addition, the radially outer end of each cam terminates in a tip 84.

The radially outer surface of the support ring 51 is provided with four outwardly extending resilient projections 65 in the form of arcuate strips which extend axially towards the cams 22. Each resilient projection 65 extends approximately half the axial length of the arms 53 and terminates in a bulbous end portion 67.

The fitting member 40 is provided with a chamfered lead-in 42 which merges into a recess 43 accommodating an O-ring seal. The recess 43 terminates in a shoulder 45 which in turn merges with a radially outwardly axially extending inclined step 46 which has a reverse slope leading to an annular recess.

The main body portion 10, the cam spring assembly 50 and the sleeve 30 are assembled as follows, to form a coupling. The support ring 51 of the cam and spring assembly 50 is forced over the cylindrical portion of the main body portion 10 until the support ring 51 abuts the shoulder 73 on the body portion. The gaps 59 around the support ring 51 allow the ring to distort to facilitate this movement. When the support ring 51 is in abutment with the shoulder 73, the arms 53 extend axially along and around the coupling with each pair of arms located between two ribs 76.

The heads 24 of the cams 22 are then located within a respective one of the cut-outs 21. The arms 53 provide a degree of resilience in a radially inward direction ensuring that the heads 24 remain within the cut-outs. The width of each cutout 21 is arranged so that the head of the associated cam is positively located in a circumferential sense within the cut-out. As seen in Figs. 2 and 3, the length of each cut-out 21 is greater than the length of the associated head 24 of the cam 22 to allow a certain degree of axial movement of the cams 22.

Next, the retaining sleeve is forced over the cylindrical portio with the fingers bending resiliently to ride over the annular lip 26 at the outlet 12 of the body portion 1 0. Once these fingers have passed the lip 26, they move radially inwardly to prevent the sleeve 30 being drawn off the body in the same direction.

When in a neutral position as seen in Fig. 2, the sleeve 30 is urged axially against the lip 26 by the spring action of the resilient projection 65 against the step 82 provided on the interior of the sleeve.

The resilience of the projection 65, however, allows axial movement of the sleeve 30 in a direction opposite to the spring force. However, the spring force will always return the sleeve 30 to this neutral position in the absence of any counterforces.

The extremities 77 of the ribs 76 on the main body portion 1 9 engage in the channels 78 provided in the sleeve 30. This prevents rotation of the sleeve 30 relative to the portion 1 9.

The coupling operates as follows.

An end 14 of a length of hose 1 5 is connected to the inlet end 11 of the main body portion 10 by pushing the hose 15 over the inlet end 11 and beneath the annular wall 71. A screw threaded nut 16 is engaged with the thread on the wall 71 and as the nut 1 6 is tightened, the clamps 70 are pressed into engagement with the hose 1 5. In this way the hose 1 5 is securely locked to the body portion 10.

The fitting member 40 is coupled to the end of a further length of hose, a sprinkler, a spray gun or any other suitable member.

The fitting member 40 is then inserted into the throughway 1 3 in the main body portion 10. The sleeve 30 is in the neutral position. Initially, the inclined surface 42 on the fitting member 40 engages the leading edge 56 of each cam head to cause each cam head to bend outwardly about the neck 85 to move into the associated cut-out 21 in the main body portion. The remainder of the cams 22 is prevented from movement by engagement with the sleeve 30. This movement, in turn, causes the arms 53 to deflect or bow outwardly.

Further inward movement of the fitting member, moves the shoulder 46 past the head 24 of the cam and the heads 24 of the cams to pivot radially inwardly and snap into the recess 47 behind the shoulder 46 on the fitting member. When the cam heads 24 snap into this engagement (as shown in Fig. 4), the coupling is complete and the engagement of the front faces 58 of the cams against the back slope of the recess 47 is such that any attempt to pull the fitting member out of the coupling is resisted.

Thus, it will be seen, that the fitting member 40 can be simply snapped into coupled engagement with the coupling without having to pull back the sleeve 30. The resilience of the cam spring assembly 50 ensures a positive snap in fit and also prevents the fitting member 40 from being simply pulled axially out of the coupling with displacement of the sleeve.

To release the coupling, the sleeve 30 is pulled back axially towards the hose, as shown in Fig. 5.

This axial movement is against the force provided by the resilient projection 65 of the cam and spring assembly 50 until the sleeve 30 abuts the shoulder 48 on the main body portion 10. In this position, the enlarged annular end 83 of the sleeve is positioned over the radially outward tips 84 of the cams 22. The fitting member is then pulled axially out of the main body portion and the shoulder 46 of the fitting member 30 engages the cam heads to move them radially outwardly into the end 83, to allow free passage of the fitting member.

After removal of the fitting member 30, the sleeve is released and the resilient projection 65 on the spring assembly urges the sleeve back into the neutral position and the stepped portion 81 of the sleeve 30 engages the outer tips 84 of the cams to force the cams back into the position shown in Fig. 2, that is ready to engage the fitting member on re-insertion.

The design and location of the combined cam and spring assembly 50 provide some important advantages in the manufacture and assembly of the hose coupling.

The fact that the four cams are integrally supported by the support ring via the pairs of arms enables the cam and spring assembly to be very simply located on the exterior of the main body portion. The gaps in the periphery of the support ring provide the necessary distortion of the support ring to fit onto the main body portion. In a known hose coupling that incorporates a cam to provide a snap-in coupling the inserts or cams have to be separately positioned within the cutouts and then a special jig is required to hold the inserts in position whilst the sleeve is assembled.

In the embodiment of the invention described above, with reference to the drawings, the arms 53 effectively hold the cams within the cut-outs and no special jig is required to ensure that the cams remain within the cut-outs.

Furthermore, the provision of the resilient fingers projecting axially from the support ring does away with the requirement of a coil spring to urge the sleeve into the neutral position. It has been found that the axially projecting fingers when trapped between a shoulder on the sleeve and a shoulder on the main body portion effectively provide enough axial resilience to urge and maintain the sleeve in the neutral position. The cam and spring assembly can be simply injection moulded in one piece and therefore the number of components that make up the snap-in coupling can be reduced by doing away with the metal coil spring that conventionally operates between the sleeve and the inner member.

A further advantage of the construction described above is that the size of the cam and spring assembly is such that there is no danger of the inserts and coil springs becoming entangled on assembly. There is also no need for complicated jigs on assembly and the only additional tool that is required is a press to stamp the fingers of the sleeve to extend radially inwardly to engage the lip on the outer end of the main body portion.

It is understood that within the scope of the present invention many variations and alterations are envisaged, such as the use of three cam assemblies instead of four. Such a three cam assembly is shown in Figs. 8A and 8B, with parts common to Figs. 7A and 7B and to Figs. 8A and 8B bearing the same reference numerals and not being described in detail. The cam and spring assembly of Figs. 8A and 8B has only three cams 22 equi-angularly spaced by 1200. The body portion 10 will thus have three equally spaced cutouts 21. This cam and spring assembly will operate in exactly the same way as the cam and spring assembly described above with reference to Figs. 7A and 7B.

The cams 22 need not be constructed exactly as shown in Figs. 7A, 78, 8A and 8B. For example, as shown in Figs. 2 and 6, each cam 22 may include a head 24 formed on a generally curved portion which leads to a tip 84. On insertion of the fitting member 40, the cams 22 flex, due to their curved shape, but do not move due to the engagement of the tips 84 with the sleeve 30.

When the sleeve 30 is drawn-back, movement of the cams 22 is permitted to allow withdrawal of the fitting member 40.

A stop valve may be incorporated within the interior of the main body portion. It is further understood that, as shown in Fig. 6, the main body portion 10 can be split into two components 90 and 91, one 90 which locates the stop valve 93 and the other 91 which is furnished with the cutouts 21 for location of the cams 22. It is further understood that the hose may be coupled to the inlet end of the main body portion in a number of ways such as the manner illustrated in Fig. 2 where the saw teeth on the inner surface of the inlet end of the main body portion are compressed into the outer surface of hose (not shown), the hose being located on a tapered spigot and the compressive force being provided by an internally threaded coupling 16 that fits over the hose. In another alternative (Fig. 6), the saw teeth on the inner surface of the inner member may be removed and the hose can be simply secured on the tapered spigot by use of a screw threaded coupling that screws onto an externally threaded portion of the main body portion. In Fig. 8 an alternative construction is also illustrated where the sleeve 30 axially slides within an annular cutout 94 provided in a portion of the two-part main body portion.

Claims

1. A snap-in coupling comprising a female coupling member surrounded by a support ring formed integrally with cam members which are urged into the interior of the female coupling member via apertures in said member, a sleeve surrounding the female member and the support ring and, in a neutral position of the sleeve, preventing radially outward movement of the cams so that a male coupling member, on insertion into the female coupling member, engages the cam with a snap action to prevent withdrawal of the male member to make the coupling, the sleeve being movable from said neutral position to a position in which radially outward movement of the cams is permitted, to allow withdrawal of the male coupling member.

2. A coupling according to claim 1 wherein there are provided axially extending arms connecting the cams to the support ring and urging said cams into the interior of the female coupling member.

3. A coupling according to claim 2 wherein each cam is carried at the ends of a pair of axially extending arms and wherein the cams are equiangularly spaced around the support ring.

4. A coupling according to any one of claims 1 to 3, wherein each cam includes a portion which engages the sleeve when the sleeve is in the neutral position to prevent radially outward movement of the cam and wherein each cam also includes a male-member-engaging head which extends into the passage and which is radially resilient to allow the head to move as the male coupling member snaps past the head.

5. A coupling according to claim 4 wherein the head of each cam is connected to the remainder of the cam by a neck which allows the head to move resiliently radially outwardly as the male member snaps past the head.

6. A coupling according to claim 4 wherein the head of each cam is formed on a curved cam portion which deforms to allow the head to move resiliently outwardly as the male member snaps past the head.

7. A coupling according to any one of claims 1 to 6 wherein a support ring is formed integrally with resilient projections which engage the sleeve to bias the sleeve to the neutral position.

8. A snap-in coupling comprising a female coupling member surrounded by a support ring formed integrally with resilient projections which engage a sleeve surrounding the female coupling member and the support ring to bias the sleeve to a neutral position, there being provided cam members urged into the interior of the female coupling member and being prevented from radially outward movement by the sleeve, when in the neutral position, so that a male coupling member, on insertion into the female coupling member, engages the cam members with a snap action to prevent withdrawal of the male coupling member and to make the coupling, the sleeve being movable from said neutral position, against the biassing force, to a position in which radially outward movement of the cams is permitted, to allow withdrawal of the male coupling member.

9. A coupling according to claim 8 wherein the sleeve is moveable from the neutral position in an axial direction relative to the female coupling member, and wherein the resilient projections extend axially along and radially around the female coupling member and engage an annular step around the interior of the sleeve.

10. A coupling according to any one of claims 1 to 9 wherein the support ring and the parts formed integrally therewith are of a plastics material.

11. A cam and spring assembly for a snap-in coupling according to claim 1 or claim 8 and comprising a support ring, a plurality of pairs of arms extending from the support ring in an axial direction, the pairs of arms being equi-angularly spaced around the support ring, each pair of arms carrying a cam at the ends thereof remote from the support ring, and the assembly being of a plastics material.

12. A snap-in coupling substantially as hereinbefore described with reference to Figs. 1 to 5, 7A and 7B, 10, 11 and 12 or to Figs. 1 to 5, 10, 11 and 12 as modified by Fig. 6 and/or Figs. 8A and 8B and/or Fig. 9 of the accompanying drawings.

13. A cam and spring assembly for a snap-in coupling substantially as hereinbefore described with reference to Figs. 7A and 7B or Figs. 8A and 8B of the accompanying drawings.