System for sealingly holding cables which extend through an opening

Abstract

The invention relates to a system for sealingly holding cables through an opening. The system comprises a holder substantially in the form of a plate having a central portion with a first thickness between a first side and a second side of the plate and a peripheral portion with a second thickness which is smaller than the first thickness, the holder having in the central portion a plurality of conduits extending in the thickness direction of the plate, each conduit being suitable for having one or more cables extending there through, at least one multi-part sealing plug of an elastic material for sealing an annular space between an inner wall of one of the conduits and a cable extending there through and a gasket of an elastic material and of a shape for placement against the peripheral portion so as to provide a sealing in a circumferential direction of the plate. The plug has at least one circumferentially extending outer rib and at least one circumferentially extending inner rib. In an uninserted state, the following conditions apply: the outer rib has a sawtooth shape for easy insertion, the sawtooth is provided with an angled inward bend for facilitating flexing of the sawtooth in a transverse direction, the inner rib has a top surface extending in circumferential and longitudinal direction for facilitating sliding along the cable, and an imaginary straight line extending in a transverse direction coincides with a pivotal point of the angled bend and intersects the top surface.

Claims

1. System for sealingly holding one or more cables through an opening, the system comprising: a holder substantially in the form of a plate having a central portion with a first thickness between a first side and a second side of the plate and a peripheral portion with a second thickness which is smaller than the first thickness, the holder having in the central portion a plurality of conduits extending in the thickness direction of the plate, each of the plurality of conduits for having one or more cables extending there through; at least one multi-part sealing plug of an elastic material for sealing an annular space of the opening between an inner wall of one of the plurality of conduits and one or more cables extending there through, the plug having an axis running in a longitudinal direction; a gasket, of an elastic material and of a shape for placement against the peripheral portion so as to provide a seal; wherein the plug has at least one outer rib extending circumferentially around the axis and at least one inner rib extending circumferentially around the axis, wherein in an uninserted state; the outer rib has a sawtooth shape for easy insertion, the sawtooth is provided with an angled inward bend for facilitating flexing of the sawtooth in a transverse direction that is perpendicular to the longitudinal direction; and the inner rib has a top surface extending circumferentially around the axis and extending in the longitudinal direction for facilitating sliding along the one or more cables.

2. The system according to claim 1, wherein the gasket is of such a combination of hardness and design that in mounted and fixed condition, movement of the holder as a result of elastic deformation of the gasket can be accommodated for by the sealing plug without movement of a cable held by the plug relative to contact surfaces between the cable and the plug.

3. The system according to claim 1, wherein the peripheral portion is at least partly flush with the first or the second side.

4. The system according to claim 1, wherein each of the plurality of conduits has at one of the first and second sides an entrance-opening for sealingly inserting one of the sealing plugs and at the other one of the first and second sides a conduit-opening which is smaller than the entrance-opening.

5. The system according to claim 1, wherein the peripheral portion is provided with a plurality of through-holes for facilitating fixation of the holder against another holder or against a construction having the opening through which the one or more cables extend, and wherein the gasket has through-holes at positions which correspond to the positions of the through-holes in the peripheral portion of the plate.

6. The system according to claim 1, wherein the second thickness is more than 25% of the first thickness, preferably more than 30% of the first thickness.

7. The system according to claim 1, wherein each peripheral portion has a width which is in a range of about 3-10% of a total length of the plate.

8. The system according to claim 1, wherein the peripheral portion has a uniform width.

9. The system according to claim 1, wherein a distance between two conduits is 5 mm or less, preferably 3 mm or less.

10. The system according to claim 1, wherein the gasket has a maximum thickness of 6 mm, preferably a maximum thickness of 3 mm.

11. The system according to claim 1, wherein the gasket has areas of minimum thickness and areas of maximum thickness, wherein the areas of maximum thickness surround the areas of minimum thickness.

12. The system according to claim 11, wherein a transition between the areas of minimum thickness and the areas of maximum thickness is stepwise.

13. The system according to claim 1, wherein the holder is of a hard engineering plastic material, such as HMPE.

14. The system according to claim 1, wherein the axis is a central axis.

15. The system according to claim 1, wherein the outer rib extends circumferentially about the axis, the inner rib extends circumferentially about the axis and the top surface extends circumferentially about the axis.

16. The system according to claim 1, wherein a pivotal point of the angled inward bend is aligned with the top surface of the inner rib in the transverse direction.

Description

(1) The invention and further embodiments thereof are further explained with the aid of a drawing in which:

(2) FIG. 1 shows in cross-sectional view a part of an embodiment of a system according to the invention;

(3) FIG. 2 shows schematically in cross-sectional view a part of the embodiment as shown in FIG. 1, now inserted in a conduit;

(4) FIG. 3 shows in cross-sectional view a holder with conduits having sealing plugs inserted as a part of an embodiment of a system according to the invention;

(5) FIG. 4 shows a top view of the holder shown in FIG. 3.

(6) FIG. 5(a)-(c) show in perspective an embodiment of a system according to the invention in three different stages of its use;

(7) FIG. 6(a) shows a top view of a part of an embodiment of the system according to the invention;

(8) FIG. 6(b) shows in cross-sectional view the part indicated by the arrows CS shown in FIG. 6(a);

(9) FIG. 7(a) shows in cross section parts of an embodiment of a system according to the invention, in use;

(10) FIG. 7(b) shows a top view of a part of an embodiment of a system according to the invention;

(11) FIG. 8(a) shows in cross section parts of an embodiment of the system according to the invention, in use;

(12) FIG. 8(b) shows one part of an embodiment of the system according to the invention;

(13) FIG. 9(a) shows in cross section parts of an embodiment of a system according to the invention, in use;

(14) FIG. 9(b) shows a top view of a part of an embodiment of a system according to the invention;

(15) FIG. 10(a) shows in cross section parts of an embodiment of a system according to the invention, in use;

(16) FIG. 10(b) shows a top view of a part of an embodiment of a system according to the invention;

(17) FIG. 11(a) shows in cross section parts of an embodiment of a system according to the invention, in use;

(18) FIG. 11(b) shows a top view of a part of an embodiment of a system according to the invention,

(19) FIG. 12(a) shows in cross section parts of a system of an embodiment of a system according to the invention, in use;

(20) FIG. 12(b) shows a top view of a part of an embodiment of a system according to the invention;

(21) FIG. 13(a) shows a top view of a part of an embodiment of a system according to the invention; and

(22) FIG. 13(b) shows in cross section the part of which the top view is shown in FIG. 13(a).

(23) In the drawing, like features are referred to by like references.

(24) FIG. 1 shows in cross-sectional view a part of a first embodiment of a system for sealingly holding cables through an opening.

(25) The system comprises at least one multi-part sealing plug, in this example comprising two segmental parts 1 for forming the sealing plug in an annular space formed between an inner wall of a conduit and a cable. Each segmental part 1 is provided with a small-diameter-end 2 for facilitating insertion of the plug in the annular space. Later on in this description, it will be explained how the small-diameter-end 2 may differ from other parts of the segmental part 1.

(26) Each segmental part 1 is preferably provided with a large-diameter-end 3 for positioning at the end of the tubular opening from which the segmental parts 1 are inserted into the annular space. Each segmental part 1 has at least one but preferably a number of outer ribs 4 spaced apart in a longitudinal direction L. These outer ribs 4 are for realizing, in use outer contact surfaces 5 which extend in a circumferential direction between the sealing plug and the inner wall of the opening (see FIG. 2). Each segmental part 1 is further provided with one or a number of inner ribs 6, also spaced apart in the longitudinal direction L. These inner ribs are for realizing, in use, inner contact surfaces 7 which extend in a circumferential direction between the sealing plug and the tube, cable or duct. At least one of the outer ribs 4 and one of the inner ribs 6 meet in uninserted state of the plug the following geometric condition: the outer rib 4 has in cross-section the shape of a sawtooth for easy insertion. In this example, the sawtooth has a rising surface 8 rising radially outwardly toward the large-diameter-end 3 of the plug. The sawtooth further has an angled inward bend 10 for facilitating flexing of the sawtooth in a transverse direction. (In this example, the sawtooth has the angled inward bend 10 a falling surface 9 for relative movement of parts 11, 12 of the falling surface 9 on opposite sides of a pivotal point 13 of the angled bend 10); the inner rib 6 has a top surface 14 extending in circumferential direction and a longitudinal direction L for facilitating sliding along the cable. (In this example, the top surface 14 forms one of the inner contact surfaces 7); and an imaginary straight line (dashed line 15) extending in a transverse direction T both coincides with a pivotal point 13 of the angle bend 10 and intersects the top surface 14.

(27) Preferably, a lower part 16 of the falling surface 9 between the pivotal point 13 and an imaginary central axis A of the plug includes an angle α in a range of 30-60° with the longitudinal direction. Preferably, α is in the range of 40-50°. In a most suitable embodiment, α is 45°. An upper part 17 of the falling surface 9 between the pivotal point 13 and an apex 18 of the sawtooth, includes an angle of δ in the range of 90-70° with the longitudinal direction L. Preferably, lower part 16 of the falling surface 9 has a length which is about 70 percent of the length of the top surface 14 of an inner rib G. As shown in the embodiment of FIG. 1, an imaginary straight line 15 extending in a transverse direction T both coincides with an apex 18 of the sawtooth and intersects the top surface 14. As also shown in the embodiment of FIG. 1, preferably an imaginary straight line 15 extending in a transverse direction T both coincides with an upper part 17 of the falling surface 9 and intersects the top surface 14. As shown, it is possible that the rising surface 8 includes along its entire surface a constant angle in longitudinal direction L.

(28) However, in an alternative embodiment (not shown in the present drawing), a first part of the rising surface 8 adjoining the apex 18 of the sawtooth is provided with a leveling with respect to a second part of the rising surface 8 located further away from the apex 18. The leveling includes an angle γ with the longitudinal direction L that is equal to or greater than 0° and less than an angle θ of the second part 20 with longitudinal direction L. WO 2004/111513 A1 shows in, for instance, FIGS. 1, 5, 6a and 6b, such a leveling, there referred to by reference sign 15. These Figures are as example of this alternative embodiment explicitly incorporated by reference.

(29) In embodiments where such a leveling is applied, a meeting of the leveling and the segment part of the rising surface 8 located further away from the apex 18 forms an angled outward bend 21 located in the rising surface 8. The angled outward bend 21 in the rising surface 8 is located further away from an imaginary central axis A of the plug than the pivotal point 13 of the angled inward bend located in the falling surface 9.

(30) In any embodiment it is preferable that the inner rib 6 is on either side of the top surface 14 further provided with a sloped surface 22 which extends away from the top surface 14. The slope of each sloped surface 22 encloses an angle Φ in a transverse direction T of the segmental part 1 such that bending of the inner rib 6 is substantially inhibited when the segmental part 1 is inserted into the annular space.

(31) As shown, the inner ribs 6 are preferably in the longitudinal direction L positioned at a distance from each other. However, as shown in WO 2007/028443 A1, it is also possible to have the inner ribs adjacent each other.

(32) As shown in FIGS. 1, 2 and 3, the large-diameter-end 3 is suitable for positioning in the end of the tubular opening. In this embodiment, the diameter of the outer ribs 4 is slightly larger than the diameter of the large-diameter-end 3. The diameter of the large-diameter-end 3 may correspond to the diameter of the inner wall of the tubular opening. For such an embodiment, the flange contributes to the stability of the plug in the opening.

(33) As shown, four of the outer ribs 4 and four of the inner ribs 6 meet in uninserted state of the plug the geometric condition specified above. Although the effect can already be achieved by application of the condition for one outer rib 4 and one inner rib 6, the overall sealing can be improved if this effect can be achieved at various positions along the longitudinal direction of the plug.

(34) As also shown, particularly in FIGS. 1, 2 and 3, the first outer rib 24 at the small-diameter-end 2 has a smaller diameter than the other outer ribs 4. This diameter of the first outer rib 24 may deliberately be made only a tiny bit larger than the diameter of the inner wall of the tubular opening. This facilitates an initial stage of insertion of the segmental part 1 as part of the plug. The first outer rib 24 can then easily be inserted and still contribute a little to the stability of the plug after insertion. Once the first outer rib 24 has been inserted, the remaining part of the plug can more easily be inserted when relatively large forces are applied in the longitudinal direction onto the large-diameter-end 3

(35) Segmental parts can be manufactured by molding a vulcanizable polymer material under such conditions so that vulcanization takes place. Ideally, the materials and the processing thereof is such that a rubber having a Shore A hardness of 70-74° is produced in the form of the segmental part. These processes can easily be controlled by those skilled in the art.

(36) As shown in FIGS. 2 and 3, the segmental parts 1 can upon insertion in the tubular opening be placed against a shoulder 25 positioned in the tubular opening. The shoulder not only prevents the plug from being pressed out at the end of the opening opposite the end at which insertion took place, it also allows for a dynamic response of the plug in a situation where high pressure is applied against the large-diameter-end 3 of the plug. This dynamic effect is further described in WO 2008/023058 A1 as well as in WO 2007/107342.

(37) It has turned out that the plugs as shown in the drawing operate very well for building a water-tight transit of electric cables. The plugs are easily inserted in the tubular openings as for instance shown in FIGS. 2, 3 and 4. The tightness of both the plug and the electric cables improves within the first 24 hours after forming the sealing system in the tubular opening around the electric cable. The sealing system can very easily be applied. Only the frame needs to be fixed, possibly by screws.

(38) Having now described multi-part sealing plugs as part of a system according to the invention, attention is now drawn to FIGS. 5(a)-(c) for describing in more detail other parts of an embodiment according to the invention and for explaining how installation of such an embodiment works.

(39) FIG. 5(a) shows as part of a system for sealing the holding cables through an opening 40, a holder 41 substantially in the form of a plate. The plate has a central portion 31 with a first thickness between a first side 42 and a second side 43 of the plate. The plate further has a peripheral portion 30 with a second thickness which is smaller than the first thickness. The holder 41 has in the central portion 44 a plurality of conduits 27 which extend in the thickness direction of the plate. Each conduit 27 is suitable for having one or more cables 45 extending therethrough.

(40) A further part of a system according to the invention comprises a gasket, of an elastic material and of a shape for placement against the peripheral portion 30 so as to provide a sealing in a circumferential direction of the plate.

(41) FIG. 6(a) shows in more detail a top view of an embodiment of such a gasket 46. FIG. 6(b) shows a cross section of gasket 46 taken along the arrows CS shown in FIG. 6(a).

(42) Before describing in more detail the gasket 46, the description will now focus in more detail on an embodiment of holder 41. As indicated, the holder comprises a plurality of conduits 27. As is clear from FIG. 5(b), each of these conduits 27 is suitable for receiving cables, pipes or ducts. Although the drawing show each time that only one cable, pipe or duct is received by one conduit 27, it is of course also possible that two cables, pipes or ducts are received in one conduit 27. A multi-part sealing plug adapted for filling in the remaining space in the conduit 27 is known in the art, and can be presented in FIG. 12 of WO 2007/107342. Each of the conduits 27 is thus also suitable for receiving such an elastically deformable plug for sealingly filling space that is surrounded by the inner circumferential wall of the conduit and that is not occupied by a cable, pipe or duct, or a plurality thereof.

(43) As shown in the figures of the drawing which show the holder, the peripheral portion 30 is preferably flush with the first side 42. It is also possible that the peripheral portion is flush with the second side 43 of the holder 41. Each of the conduits 27 has at first side 42 an entrance opening 47 for sealingly inserting one of the sealing plugs 1. The conduits 2 have at the second side 43 a conduit opening 48 which is smaller than the entrance opening 47. Of course, this can also be the other way around, namely, that the smaller entrance opening 47 is at the second side 43 and the larger conduit opening 48 is at the first side 42. Clearly, towards one side of the holder 41, the conduits 27 are narrower than at the other side of the holder 41. A decrease of diameter in each conduit 27 results, effectively, in a blocking element, shoulder 28, which hinders in each conduit movement of one end of a sealing plug 1 inserted in that conduit 27. The blocking element is essentially a ring-shaped element. It is an integral part of the holder 41.

(44) The peripheral portion 30 could also be referred to as a flange. The peripheral portion 30 is provided with a plurality of through-holes 29 for facilitating fixation of the holder 41 against another holder 4 against the construction having the opening 40 through which the cables 45 extend. The gasket 46 has through-holes 49 at positions which correspond to positions of the through-holes 49 in the peripheral portion 30 of the holder 41. The holder is preferably made of a hard engineering plastic such as polyetherimide (PEI) or polyethersulfonamide (PES) or High Modulus Polyethylene (HMPE).

(45) The gasket 46 is normally also made of an elastic material and is preferably of such a combination of hardness and design that in mounted and fixed condition, movement of the holder 41 as the result of the elastic deformation of the gasket 46 can be accommodated for by the sealing plug 1 without movement of a cable 45 held by the plug 1 relative to contact surfaces between the cable 45 and that plug 1. The gasket 46 preferably has a maximum thickness of 6 mm, even more preferably a maximum thickness of 3 mm. The gasket 46 has areas of minimum thickness 50 and areas of maximum thickness 51. The areas of maximum thickness 51 surround the areas of minimum thickness 50, so that in use when the gasket is sandwiched between a partition surrounding the opening 40 and the peripheral portion 30 of the holder 41, air pockets are formed on both sides of the gasket. Such air pockets can resist over-tightening of the nuts when bolting the gasket 46, and the holder 41, against the partition surrounding the opening 40. The transition between the areas of minimum thickness 50 and the areas of maximum thickness 51 is preferably stepwise.

(46) FIG. 5(a) shows the first step of the installation of an embodiment of a system according to the invention. The gasket 46 is placed around the opening 40 by sliding the through-holes 49 in axial direction of the bolts 53 toward the partition surrounding the opening 40. Similarly, the holder 41 is positioned such that the peripheral portion 30 is placed against the gasket 46 and the bolts also extend through the through-holes 29 of the holder 41. As shown in FIG. 5(b), by means of nuts 54, the holder 41 can then tightly be positioned against the partition surrounding opening 40, therewith sandwiching gasket 46 which forms a sealing between the partition and the holder 41. Cables 45 can then be pulled through each of the conduits 27. Multi-part sealing plugs 1 can then be inserted in the space remaining in conduit 27 for sealingly holding cable 45 in the respective conduit 27. FIG. 5(c) shows the end result both in perspective and in cross-section.

(47) FIG. 7(a)-FIG. 12(a) show in cross-section various embodiments of a system according to the invention (without showing the gasket). FIG. 7(b)-FIG. 12(b) show the respective top views of the holders. The dimensions provided in these figures are examples. In general though, the thickness of the peripheral portion 32, i.e. the second thickness, is preferably more than 25% of the thickness of the central portion, i.e. the first thickness. Even more preferable is that the second thickness is more than 30% of the first thickness. The peripheral portions 32 have ideally a width which is in a range of about 3-10% of a total length of the plate-shaped holder 41. Preferably, all peripheral portions of a holder have a similar width. Most strikingly, a distance between two conduits 27 is preferably 5 mm or less. In certain embodiments it is even possible that this distance is 3 mm or less.

(48) As shown in the various figures, the arrangement of the conduits relative to each other can be in the form of a “column and row” pattern or in a more “densely packed” pattern, wherein the conduits 27 of a row are in row position between the conduits 27 of the previous row. To keep the number of uniform parts to a minimum, and thus the production costs relatively low, it is preferable to have the holders 41 such that the peripheral portions 32 of these holders 41 are identical. In those circumstances, it is possible to have only one type of gasket suitable for each of these holders 41. These holders can have their conduits 27 differently distributed over the central portion of the holder and, although not shown, can also have different sizes of conduits within one central portion of a holder 41.

(49) In principle though, it is possible to have much larger holders 41, such as for instance shown in FIGS. 14(a) and (b) to accommodate for sealingly holding a large number of cables extending through an opening.

(50) The invention is not limited to the examples shown above. Although each of the holders shown is rectangular, holders may also have differently shaped plate-like dimensions. Consequently, also the gaskets may have differently shaped dimensions, corresponding to the peripheral portions of the respective holders. Although the length of each conduit is preferably suitable for receiving a single plug 1 in its entirety, it is also possible that the length is suitable for receiving two plugs, neighbouring each other in axial direction. It is further possible that each conduit is provided with a blocking element positioned such that on either side of the blocking element the conduit has a length which is suitable for receiving a plug in its entirety. The holders are preferably machined out of a single block of material, however, also molding techniques are not excluded. As already mentioned, sealing plugs allowing for a plurality of cables extending through a single conduit may also be employed. It should further be borne in mind that the system may also be provided with at least one blind plug for sealingly filling a conduit sleeve which is at least temporarily free from having cables, pipes or ducts extending therethrough. Such a blind plug is presented in FIG. 13 of WO 2007/107342.

(51) Further, the plate-shaped holder may also have a varying thickness over the central portion of the plate. The conduits do not necessarily all have the same diameter, or all the same length. The plate-shaped holder may also be part of a transit system or of a cover.

(52) These embodiments are each understood to fall within the framework of the invention.