EP0859088A1

EP0859088A1 - Well ring arrangement for a well cover of the like

Info

Publication number: EP0859088A1
Application number: EP98850016A
Authority: EP
Inventors: Olav Röd
Original assignee: Gustavsberg Rorsystem AB
Current assignee: Gustavsberg Rorsystem AB
Priority date: 1997-02-18
Filing date: 1998-02-05
Publication date: 1998-08-19
Also published as: NO980661D0; NO980661L; SE508618C2; SE9700564L; SE9700564D0

Abstract

The invention relates to arrangements for fixing a pipe element (12) to a well ring (10), having a shank portion (18) with cavities (24) in which lock elements (26) are mounted in such a manner that they can be forced in against the cavities (24) by the pipe (12) so that the lock elements (26) permit insertion or pushing on of the end portion of the pipe past the lock elements but prevents removal of the pipe element. The shank portion and the cavities can be made for external pushing on of the pipe or internal insertion of the same.

Description

The present invention relates to a well ring arrangement for a well cover or the like, for fixing a pipe element insertable in the well ring, said well ring having a shank portion, with an inner circumferential wall, defining an opening to receive an end portion of the pipe element.

In an previously known arrangement for fixing a pipe element in a well ring, the end of the pipe element is made with special cavities or holes cooperating with corresponding fixed projections on the inside or the outside of the shank portion of the well ring. The projections snap into the cavities or holes as the pipe element is pushed onto or into the well ring.

In a another known well ring arrangement, the end of the pipe element has a annular groove which is to fit a complementary annular formation on the well ring shank. A well lock wire element can be inserted into the annular groove formed between the shank and the pipe element to form an annular lock element holding the well ring and the pipe element together. These previously known pipe lock designs thus require factory made pipe ends and are complicated to manufacture.

Another known manner of fixing a pipe end to a well ring is to heat the pipe end and allow it to contract on to the well ring shank as it cools. Such work is very difficult to preform at the work site, and therefore it must be done at the factory. This makes the transport of the finished well units more difficult.

The present invention intends to remove the disadvantages of the known arrangements and suggests an arrangement which makes possible simple fixing of ordinary smooth-wall pipe elements in a well ring so that any require shortening of the pipe element can be done on site and the pipe then be simply fixed to the well ring.

This is achieved in an arrangement of the type described by the way of introduction by virtue of the fact that at least one lock element is mounted in the cavity in the shank portion in such a manner that the lock element is movable from a first position, in which a grip edge portion, directed obliquely inwards in the insertion direction of the pipe element, of the lock element extends radially into the path of insertion of the pipe element to be fixed in the well ring, to a second position, in which the lock element, against the effect of a force, is held pressed against the cavity by the pipe element so that the lock element permits insertion of the end portion of the pipe element past the lock element, but prevents extraction of the pipe element from the well ring counter to said insertion direction, by pivoting the grip edge portion of the lock element to engagement with the outside of the pipe element when a separating force is applied between the well ring and the pipe element.

The present invention can be applied in an equivalent manner to a well ring to fix a pipe element pushed onto it, where the well ring has a shank portion with an outer circumferential wall over which an end portion of the pipe element is to be pushed. The locking element is in this case mounted in a cavity in the shank portion in such a manner that the lock element can be moved from a first position, in which a grip edge portion of the lock element extending obliquely outwardly in the push-on direction of the pipe element extends radially outwards into the push-on path of the pipe element to be fixed to the well ring, to a second position in which the lock element is held, against the effect of a force, pressed in by the pipe element against the cavity, so that the lock element permits pushing on of the end portion of the pipe element past the lock element but prevents removal of the pipe element from the well ring counter to said push-on direction, by the grip edge portion of the lock element pivoting out into engagement with the inside of the pipe element when a separating force is applied between the well ring and the pipe element.

Each cavity has suitable opposite abutment surfaces to limit the pivotal movement of the grip edge portion of the lock element in the removal direction of the pipe element.

Furthermore the lock element is perferably biased to this first position with the aid of an elastic means, for example a compression spring, a rubber elastic element or the like, which acts directly on the lock element to facilitate engagement of its grip edge portion in the pipe wall, when a separating force is applied between the well ring and the pipe element.

In order to make possible strong and symmetrical fixing of a pipe element in the well ring, at least two, but preferably three or more, lock elements are evenly spaced around the circumference of the well ring shank.

The invention will be described in more detail below with reference to the enclosed drawings, in which:

Fig. 1 is a sectioned side view of a pipe lock according to the invention;

Fig. 2a-c are enlarged views in section which show the positions of the pipelock before, during, and after insertion of a pipe element into the well ring;

Fig. 3 is a sectioned plan view of a well ring having four pipe locks according to the invention, seen essentially along the section III in Fig 1; and

Fig. 4 shows the alternative placement of the pipelock according to the invention.

In Fig. 1, a well ring is generally designated 10, and is to be placed at ground level to support a well cover and a well pipe 12. The ring 10 has an annular flange portion 14, the top 16 of which is to be at ground level, and a downwardly directed cylindrical shank portion 18. An annular flange 20 extends from the inside of the shank portion 18, the top 21 thereof forming a seat for a well cover (not shown). Furthermore, the underside 22 of the annular flange 20 forms an abutment for the pipe element 12, which is to be inserted and fixed in the well ring 10. The well ring 10 is preferably made of metal, for example cast iron, while the pipe element 12 preferably consists of a lighter and softer material, such as plastic, for example polyethylene.

In order to make possible simple and rapid mounting on site of a common, not specially made pipe, which can be cut to a suitable length on site, according to the invention there is suggested a pipelock which can automatically lock securely and strongly such a pipe to the well ring. For this purpose, there are around the interior circumference of the annular shank portion 18 one, or preferably more, evenly spaced cavities 24 for locking elements 26. In a prefered embodiment of the invention four such locking elements 26 and cavities 24 are symmetricaly arranged circumferentially, as shown in Fig. 3.

The cavity 24 has an inclined lower seat surface 28 on which the lock element 26 can rest in a passive state, as shown in Fig. 2a. A resilient means 30, for example in the form of a rubber elastic body, is disposed to bias lock element 26 to the position shown in Fig. 2a. The lock element 26 has a pointed grip edge portion 32 obliquely inwardly projecting into the path of insertion for the pipe element 22, and a rear edge 34, around which the lock element 26 can pivot at an interior corner 36 of the cavity 24, when the lock element 26 is acted on and by the end portion of the pipe element 12.

The pipe lock according the invention functions in the following manner:

When the pipe element 12 is inserted into the central opening in the well ring 10, the end of the pipe 12 strikes the bevelled surface 38 of the grip edge portion 32 (Fig. 2a), and the lock elements 26 are pressed into the cavities 24 pivoting about the rear edge 34 in the corner 36 against the force of the resilient element 30 to the position shown in Fig. 2b so that the pipe 12 can be inserted to the abutment surface 22 (Fig. 1) in the well ring 10. By virtue of the fact that the grip edge portions 32 of the lock elements 26 are directed obliquely into the pipe 12 in its insertion direction and are in contact with the outer wall of the pipe 12, the edges of the lock elements 26 will immediately penetrate and "bite into" the softer pipe wall when a force is applied to the pipe in a direction to counter the insertion direction. This force is normally the weight of the pipe element 12. A lock position shown in Fig. 1 arises automatically after insertion of the pipe element 12, thereby effectively preventing removal of the pipe 12.

Tests have shown that a pipe lock according to Figs. 1 and 3 can resist forces on the order of 2.5 tons for a normally dimensioned well pipe with a diameter of 400 mm.

In order to limit the movement of the grip edge portion 32 in the removal direction of the pipe element 12 should a very large force be applied to the pipe in the removal direction, the cavity 24 has an abutment surface 40 against which the rear portion of the lock element 26 can abut as shown in Fig. 2c.

Within the scope of the present invention, it is of course possible to apply the suggested pipe lock to a well ring 10', where the pipe element 12' is pushed on over the outside of the shank portion 18' of the well ring 10', as shown in Fig. 4. The cavities 24' are in this case disposed on the outside of the shank portion 18' and the grip edge portions of the lock elements 26 are directed obliquely outwards in the direction which the pipe element 12' is pushed on to achieve a lock engagement with the inside of the pipe element 12'. The function of this embodiment is identical to that describe in connection with Figs. 1-3.

Even if the cavities 24, 24' in the embodiment shown are made as separate pockets for each lock element 26, it is also conceivable to make the cavities as a common circumferential groove in the shank portion of the well ring.

Claims

Well ring arrangement for a well cover or the like, for fixing a pipe element (12) insertable in the well ring, said well ring (10) having a shank portion (18), with an inner circumferential wall, defining an opening to receive an end portion of the pipe element (12), characterized in that at least one lock element (26) is mounted in a cavity (24) in the shank portion in such a manner that the lock element (26) is movable from a first position, in which a grip edge portion (32), directed obliquely inwards in the insertion direction of the pipe element (12), of the lock element (26) extends radially into the path of insertion of the pipe element to be fixed in the well ring, to a second position, in which the lock element (26), against the effect of a force, is held pressed against the cavity (24) by the pipe element (12) so that the lock element (26) permits insertion of the end portion of the pipe element past the lock element, but prevents extraction of the pipe element from the well ring counter to said insertion direction, by pivoting the grip edge portion (32) of the lock element (26) to engagement with the outside of the pipe element (12) when a separating force is applied between the well ring and the pipe element.
Well ring arrangement (10') for a well cover or the like, for fixing a pipe element (12') which can be pushed onto the well ring, said well ring (10') having a shank portion (18') with an outer circumferential wall made for an end portion of the pipe element (12') to be pushed thereon, characterized in that at least one lock element (26) is mounted in a cavity (24') in the shank portion in such a manner that the lock element (26) can be moved from a first position, in which a grip edge portion (32) of the lock element (26) extending obliquely in the push-on direction of the pipe element extends radially outwards into the push-on path of the pipe element to be fixed to the well ring, to a second position in which the lock element (26) is held, against the effect of a force, pressed in by the pipe element against the cavity (24'), so that the lock element (26) permits pushing on of the end portion of the pipe element past the lock element but prevents removal of the pipe element from the well ring counter to said push-on direction, by the grip edge portion (32) of the lock element (26) pivoting out into engagement with the inside of the pipe element (12') when a separating force is applied between the well ring and the pipe element.
Arrangement according to Claim 1 eller 2, characterized in that the cavity (24, 24') has opposing abutment surfaces (28, 40) for limiting the movement of the grip edge portion (32) of the lock element (26) in the removal direction of the pipe element (12, 12').
Arrangement according to any one of Claims 1-3, characterized in that an elastic means (30) is arranged to bias the lock element (26) to the said first position.
Arrangement according to Claim 4, characeterized in that the elastic means (30) consists of a compression spring element acting on the lock element (26).
Arrangement according to Claim 5, characterized in that the compression spring element has the form of a rubber elastic body (30).
Arrangement according to any one of Claims 1-6, characterized in that two or more spring-biased lock elements (26) are spaced symmetrically around the circumference of the shank portion (18) of the well ring.