GB2036906A

GB2036906A - Snap-joints for Coupling Pipes

Info

Publication number: GB2036906A
Application number: GB7932404A
Authority: GB
Original assignee: CICCOLALLO G
Current assignee: CICCOLALLO G
Priority date: 1978-10-04
Filing date: 1979-09-19
Publication date: 1980-07-02
Also published as: IT1103793B; ES245684U; DE2939218C2; FR2438226A1; IT7812817A0; FR2438226B1; ES245684Y; DE2939218A1; GB2036906B

Abstract

A snap-action joint for coupling pipe ends is provided in which a male section 17 is snapped into an outer female section 1 and in this action two sliding plate wedges 9 are displaced outwardly and then spring back to engage contact surfaces of the male section. The surfaces of the male section and wedges 9 which engage to lock the male section to the female section 1 are arcuately curved so as to lie with the centre of curvature on the joint axis and so as to subtend a substantial angle, e.g. of the order of 90 DEG for each wedge. The joint is released by means of an outer sleeve 2 which is displaced axially of the joint, and which displaces a first ring 12 so as by a wedging action to retract the locking wedges 9, and also by wedging action, to displace a second ring 14 axially of the joint, in turn compressing a spring 20 which urges the locking wedges 9 in locking engagement with the inner section on release of the sleeve 2. <IMAGE>

Description

SPECIFICATION Snap-Joints for Coupling Pipes This invention relates to snap-joints for coupling pipes.

Various kinds of snap-joints are already known for coupling of two pipes. These joints mainly consist of two sections or components one of which is fitted on a pipe end to be coupled to the other section mounted on the other pipe and movable balls are used as the means to connect the two parts. These balls are located on the outside of the joint and their movement is controlled by a sleeve which engages in a groove or spline or is blocked against a projection inside the joint to retain it in a fixed position. These joints require handling of the sleeve and of the balls both for coupling and uncoupling of the two joint sections.

Snap joints or couplings are also known which allow for automatic coupling without need to manoeuvre the sleeve. Instead of balls, these have round pins for snap coupling of the two joint sections while uncoupling can only be achieved by moving the sleeve to draw the pins back.

This joint has however the drawback that the blocking action of the joint is limited to two opposite pins which extend only over a small stretch of a projection located inside and therefore the joint will be subject to high local wear which can lead quickly to the undesired uncoupling of the components even under the slightest traction force on the connected pipes.

The two pins of this known joint slide in oblique slots and are kept in place by two flat rings which are axially movable to cause an obliged shifting of the pins. Automatic coupling of the joint is achieved simply by pushing the internal part of the joint into the external component which displaces the pins, while the pins block its removal. The two above mentioned rings are movable axially by a sleeve to retract the pins, against the action of a spring which returns the pins to the blocking position.

The invention provides an automatic snap coupling based upon the operating principle of the latter example but it eliminates the above mentioned drawback since the pins are replaced by wedge plates or blocks each of which substands a substantial angle, (of the order of 900) of the outer surface of the inner coupling section, thus ensuring firm interlocking of the two joint components. Since each wedge plate or block has a contact arc of approximately 900 it is clear that the two wedge blocks or plates extending over a total of approximately 1 800 arc, ensure a great stability with minimum local wear between the various fixed and mobile contact components.

To achieve the required movement of the two wedge blocks or plates in the slanting slots, rings having a peculiar configuration may be utilized. As in the described, known joint, these rings are movable by a sleeve against the action of a spring.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 shows a side view of the outer joint section; Figure 2 shows a side view of the section illustrated in Figure 1 looking in the direction of the arrow in Figure 1; Figure 3 shows a diametrical cross section of the section illustrated in Figure 1; Figure 4 shows a horizontal section of the joint section of Figure 1, the section being taken on line X-X in Figure 3; Figure 5 is a side view, partly in section, of the control sleeve of the joint; Figure 6 shows a top view of the sleeve illustrated in Figure 5; Figure 7 shows a side view of one locking wedge plate or block of the joint; Figure 8 is an end view of the wedge plate or block illustrated in Figure 7;; Figure 9 shows a central, sectional end view of the wedge block or plate illustrated in Figure 7; Figure 10 shows a side view of the wedge plate or block illustrated in Figure 7 the view being from the opposite side from that shown in Figure 7; Figure 11 is an underneath plan of the wedge plate or block illustrated in Figure 7; Figure 12 is a plan of the wedge plate or block illustrated in Figure 7; Figure 13 shows a side view, partly in section, of the upper wedge ring; Figure 14 shows a side view, partly in section, of the lower wedge ring; Figure 15 shows a side view, partly in section of the inner coupling section; Figure 16 shows the assembly of the outer coupling section with the wedge plates or blocks in retracted, i.e. uncoupling position; and Figure 17 shows a side view, partly in section of the joint assembly when the two wedge plates or blocks lock the joint sections together.

The external coupling section consists of a circular sectioned body 1 having the inner boring illustrated in Figure 3. This body is surrounded by the sleeve 2 illustrated in the Figures 5 and 6. The sleeve 2 has an internal circular projection 3 fitted with a small upper tooth 4 which penetrates in the circular recess 5 of the body 1 when the sleeve is mounted on the body. Vertical semicylindrical swellings or projections 6 are located on the circular projection 3. These "swellings" are symmetrical and penetrate in the recesses 7 of the body 1 when the joint is assembled. The sleeve can thus move axially on the body 1, guided in this movement by the projections 6 engaging in the recesses 7, this movement being limited in height by the tooth 4 located in the recess 5.The body 1 of the external coupling component has through slots 8, which in the illustrated example have been limited to two opposite slots, slanting upwards as shown. Each of these through slots 8 is for housing a sliding plate wedge 9 (Figures 7 to 12) for fastening and unfastening of the two coupling sections. Each of the slots 8 has four flat walls the upper and lower (as shown in Figure 3) of which are parallel and one upwardly inclined, whereas the side walls are slightly slanting so as to converge in an upwards direction.

The sliding wedge plate 9 illustrated in Figures 7 to 12 has two flat, lateral or edge surfaces which converge towards the face which is viewed in Figure 7. In the face A which is viewed in Figure 7, there is formed a curved said tooth 10 of such curvature that the centre of curvature will lie on the joint axis when the joint is assembled. The upper (in the assembled joint) surface 11 of this tooth 10 engages to the upper ring 12 (Figure 13) whereas a curved end surface 13 of the plate 9 engages the lower ring 14 (Figure 14) in the assembled joint. The wedge plate 9 also has in the face B shown in Figure 10 a recess 15 which is curved so as in the assembled joint, to lie with its centre of curvature on the joint axis and to rest on the projection 16 of the inner section 17 (Figure 1 5) of the joint to block removal of the inner section 17 after it is snapped into the outer section.Furthermore, the end plate 9 adjacent the recess 15 has also a curved surface 21 which is engaged by the projection 16 during automatic snap fastening of the two coupling sections.

The upper ring 12, (which is toroidal), has a conical lower edge portion 18 as shown, which as shown in Figures 16 and 17 slants down and inwards whereas the lower ring 14, which is also toroidal, has an upper conical edge portion 19 slanting down and inwards (in the assembled joint) so that the two portions 18 and 19 lie in the joint with their surfaces parallel to each other and transverse to the top and bottom surfaces of the through slot 8. The inclination of the portions 1 8 and 19 should be preferably 450 in one direction whilst that of the upper and lower surfaces of the slot 8 should be preferably 450 in the other direction. The complete coupled joint is illustrated in Figure 17 and will be seen to include the spring 20 which urges the lower ring 14 upwards. The ring transmits this upwards thrust to the wedge plates 9 by means of the slanting portion 19 and the surface 13.As a result of this thrust, the wedge plates will be held inwards against the internal coupling section 17. Upon any inward sliding movement the wedge plates 9 the upper surfaces 1 1 thereof will by engagement with and sliding relative to the slanting portion 1 8 of the upper ring 12, the said ring 12 will move upwards also lifting the sleeve 2 until its projection 4 engages the upper edge of the recess 5 in the body 1.

In these conditions, the two coupling sections are connected in a stable way, since any attempt at separation of same would cause the projection 1 6 to press against the recess 1 5 of the wedge plates 9, which prevent such operation.

To disconnect the sections, i.e. to remove the inner section from the outer section it is necessary to displace the sleeve 2 downwards which In turn will lower the upper ring 12. The engagement and relative sliding between the plates 9 and the ring 12 will cause the plates 9 to move outwards with a pressure action upon the lower ring 14 and compression of the spring 20.

Figure 16 shows the outer coupling component with the wedge plates 9 in joint disconnected position.

When the sleeve is released, the spring 20 brings the wedge plates automatically back to their locking position. For coupling of the two joint components there is no need to move the sleeve, but it will be sufficient to press the internal section 17 into the external section by which action the projection 1 6 presses against the surface 21 of the wedge plates to displace same outwards. After the projection 16 has passed the wedge plate surfaces 21 wedge plates return automatically to the locking positions as illustrated in Figure 17.

The Figures 16 and 17 also illustrate, for examplification purposes, a check valve 22 which closes automatically when the joint is coupled.

The invention provides an automatic snap joint designed for a long and satisfactory operation because of its long fixed surfaces (between wedge plates and projection of the inner section) and of its sliding contact surfaces (such as between the projection 16 and the wedge plates or between the wedge plates and the rings 12 and 14.

Another advantage of the invention lies in the fact that the joint can be manufactured completely in plastic material, including its rights and wedges because of its large sliding contact surfaces. This is impossible for the already mentioned solutions, because the pins and the rings in the known arrangements have to be fabricated in metal.

Obviously, the embodiment herein described by a general but not limiting outline, may be subject to changes and adjustments based upon a vast application range, including substitution of some parts by others that are similar and having the same scope, provide they remain within the following:

Claims

1. Automatic snap joint coupling comprising an internal section and an external section, the internal section having a projection, whereas the external component has at least two throughholes; the coupling and uncoupling devices being housed in these through-holes and actuatable by an upper ring and a lower ring, an external sleeve and a spring means characterised in that the coupling and uncoupling devices of the two joint sections are wedge plates or blocks with large upper and lower curved surfaces respectively engageable with the upper and lower rings and with the projection so as to allow for automatic coupling of the two joint sections pushing the sections together, thus ensuring a stable connection and long life of the joint because of the large size of the fixed and sliding contact surfaces.

2. A joint according to Claim 1, characterised in that the through holes are slots which are inclined relative to the joint axis, each slot having four flat walls, two of which are parallel to each other and to the direction of slanting, whereas the other two converge slightly towards each other.

3. A joint according to Claim 1, characterised in that each coupling and uncoupling device is a wedge plate, one face of which has a curved tooth whose axis of curvature lies on the joint axis a curved surface of this tooth being in sliding contact with the upper ring, while a curved surface of an edge of the plate makes sliding contact with the lower ring.

4. A joint according to Claim 3, characterised in that each wedge plate has in its other face a recess which engages the projection of the internal joint section when the joint is assembled, and there is a curved surface at an adjacent edge of the plate to be engaged by the said projection when the sections are snap coupled together.

5. A joint according to Claim 3 or 4, characterised in that each wedge plate has a pair of opposite slightly converging flat edge walls.

6. A joint according to any preceding claim, characterised in that the upper ring is toroidal, and has a conical edge portion which engages with the wedge plates or blocks.

7. A joint according to any claim, characterised in that the lower ring is toroidal, and has a conical edge portion which engages with the wedge plates or blocks.

8. A joint according to Claim 1, characterised in that the contact surfaces between each wedge plate or block and the projection substand an arc of approximately 900 relative to the joint axis.

9. A joint according to any preceding claim, characterised in that the two wedge plates or blocks are diametrically opposite.

10. A joint substantially as described hereinbefore and illustrated in the accompanying drawings.

11. A snap-joint for coupling pipe ends comprising an inner section and an outer section into which the inner section is snapped to establish the joint, said outer section having slots receiving locking plates or blocks which lie in the path of movement of the inner section as it is pushed into the outer section but are displaceable outwardly thereby against spring means by the inwards movement of the inner section until they can spring back so as to engage via curved contact surfaces of the plates or blocks with curved surfaces or a curved surface of the inner section thereby to lock the inner section to the outer section, the joint further comprising an outer sleeve which can be displaced axially if the joint to displace said wedge plates or blocks outwardly against said spring means, to enable the joint section to be uncoupled, the joint being characterised in that the said curvature curved contact surfaces of the plates or blocks and the said curved surfaces or curved surface of the inner section are around the axis of the joint.