EP0393094B1

EP0393094B1 - Telescopic well or column pipe

Info

Publication number: EP0393094B1
Application number: EP88910170A
Authority: EP
Inventors: Tage Skönvall
Original assignee: Uponor AB
Current assignee: Uponor AB
Priority date: 1987-11-19
Filing date: 1988-11-18
Publication date: 1991-08-07
Anticipated expiration: 2008-11-18
Also published as: DK122790A; NO902201L; SE459592B; DK167542B1; SE8704544L; FI86569B; WO1989004895A1; NO165884C; FI902460A0; NO902201D0; SE8704544D0; DK122790D0; DE3864146D1; NO165884B; EP0393094A1; ATE66034T1; FI86569C; AU2729188A

Abstract

Telescopic well or column pipe comprising an outer tube and an insert tube (B) axially displaceable therein, and a covering which receives in a socket (12) thereof the upper end of the insert tube. Between the socket and the insert tube there is provided as an axially locking rotary mounting an extruded rib (18) having round cross section and smooth surface and consisting of a plastic material having good bearing properties, said rib being received in an annular groove (15, 16) which is located partly in the curved surface of the socket and partly in the curved surface of the insert tube, said groove being available for the insertion of the rib through a passage (17) joining the annular groove substantially tangentially and opening at the outside or the inside of the socket of the insert tube. The insert tube engages at the upper end surface (14) thereof an annular shoulder surface (13) on the covering.

Description

The invention relates to a telescopic well or column pipe comprising an outer tube and an insert tube axially displaceable in said outer tube, and a cap which receives in a socket the upper end of the insert tube and is rotatably connected therewith.
A telescopic well of this type is disclosed in SE-B-398,904.
In common embodiments of such telescopic wells or telescopic column pipes the two tubes are made of plastic while the cap is made of cast iron or nodular iron. It is necessary that the cap can be rotated either for adjusting the position thereof in relation to a curb in case of a rectangular cap, or for adjusting the cap to different levels in case of a cap which is provided with a helical flange embedded in surrounding packing material and providing axial displacement of the cap when rotated.
The purpose of the invention is to provide a rotary connection between the insert tube and the cap, which provides easy movement between plastic and iron and allows simple interconnection of said two elements and will be affected neither by existing load when the cap is run on, nor by the surrounding ground, said rotary connection being in working order also after having been used for a long time.
For said purpose the telescopic well or telescopic column pipe according to the invention has obtained the characteristics appearing from the claim.
Connections between tubular elements, comprising a key received in an annular groove which is located partly in one and the other of the elements, are known per se as shown in US-A-3,606,402 and SE-A-8505685.
In order to explain the invention in more detail reference is made to the accompanying drawing in which

FIG 1 is a vertical cross-sectional view of a telescopic well of the invention,
FIG 2 is an enlarged view, partly an elevational view and partly a vertical cross-sectional view, of the cap and the insert tube as well as the rotary mounting arranged therebetween.
FIG 3 is a fragmentary vertical cross-sectional view of the cap and the insert tube before they are put together to be interconnected, and
FIG 4 is a fragmentary horizontal cross-sectional view of the socket of the cap and the insert tube.

FIG 1 discloses a telescopic well having an outer tube A and an insert tube B, both made of plastic, and a well cap C. As will be seen in FIG 2 the cap comprises a cap frame 10 and a cap lid 11 which can both be made of cast iron or nodular iron, the cap lid being received in a recess in the cap frame. The cap frame forms a cylindrical socket 12 on the lower side thereof, and an inside shoulder 13 is provided therein.
The insert tube B which should be made of plastic material, is inserted at one end thereof into the socket 12 to engage the shoulder 13 at the end surface 14 of the tube. In the inner surface of the socket 12 an annular groove 15 is provided having semi-circular cross section, and a corresponding semi-circular annular groove 16 of the same dimension as the grove 15 is provided in the outer surface of the insert tube B, the two grooves being located so that they are in register when the insert tube is inserted into the socket, to form together an annular groove having circular cross section. A through passage 17 is provided in the socket 12, which has the same dimension and shape as the annular groove formed by the grooves 15 and 16, said passage joining tangentially said annular groove as will be seen from FIG 4.
For interconnecting the cap and the insert tube an extruded elastically flexible key of a suitable plastic material having good bearing properties is driven into the groove 15, 16. The key has a smooth outside surface and the same cross-sectional form as the groove 15, 16 and should be dimensioned so that it fills completely said groove. The length thereof should be substantially equal to the circumference of the groove 15, 16.
When the key 18 is located in the groove 15, 16 the cap frame 10 and the insert tube B are effectively locked together axially by said key. The key allows the cap frame to be easily rotated in relation to the insert tube, which is an advantage when it is desired to adjust the position of the cap frame because in that case such adjustment can be easily done without the necessity of rotating the insert tube as a whole. Such rotation can be impaired by the surrounding packing material pressing against the insert tube.
When the cap is run on, the key 18 will not be loaded because the load will be taken up by the engagement of the shoulder 13 with the annular end surface 14 of the insert tube. Thus, it is necessary for the key 18 to take up such forces only to which it may be exposed when the insert tube is lifted at the cap frame for adjustment of the level of the cap frame. Such load is not particularly great.
Between the shoulder 13 and the annular end surface 14 of the insert tube, engaging said shoulder, a gasket or a sealing compound can be provided as may be necessary in case of an access well for a remote heating system.
The groove 16 can be provided by turning or form milling but it can also be provided by embossing, the insert pipe forming at the inside surface thereof a corresponding annular bead.
The invention is not limited to an embodiment wherein the groove 15, 16 and the key 18 have circular cross-sectional shape. The groove can have another round cross-sectional shape and can be arranged to a major part in the socket 12 and to a minor part in the insert tube B, or vice versa. The key should of course have a cross-sectional shape which is adapted to the shape of the groove.

Claims

1. Telescopic well or column pipe comprising an outer tube (A) and an insert tube (B) axially displaceable therein, and a cap (C) which receives in a socket (12) thereof the upper end of the insert tube and is rotatably connected therewith, characterized in that there is provided as an axially locking rotary mounting between the socket (12) and the insert tube (B) an extruded key (18) having round cross section and smooth surface and consisting of a plastic material having good bearing properties, said key being received in an annular groove (15, 16) which is located partly in the curved surface of the socket and partly in the curved surface of the insert tube, said groove being available for the insertion of the key through a passage (17) joining the annular groove substantially tangentially and opening at the outside or inside surface of the socket or the insert tube, and that the insert tube engages at the upper end surface (14) thereof an annular shoulder surface (13) on the cap.