MULTIPLE LEAD-THROUGH FLANGE FOR CABLES

Abstract: The invention relates to a multiple lead-through flange for cable lead-through, comprising an inner part (13) made of an elastomeric material and provided with holes (1, 2), and a peripheral part (16) made of an elastomeric material and comprising fastening means (6, 7), the fastening means (6, 7) comprising a sealing lip (6) and an abutment means (7). To provide the multiple lead-through flange with a simple structure which is easy to manufacture the inner part (13) and the peripheral part are formed into an integrated plate-like unit with a diameter of 40 to 150 mm, whereby the through holes (1, 2) comprise openable locking blanks (3b) and the tightness of the multiple lead-through flange is based on a free edge (12) of the sealing lip (6), and the thicker the wall to be set between the sealing lip and the abutment means is, the more the sealing lip is arranged to yield and bend.

Description: MULTIPLE LEAD-THROUGH FLANGE FOR CABLES BACKGROUND OF THE INVENTION [0001] The invention relates to a multiple lead-through flange for cable lead-through and to be mounted at an opening in a wall, particularly a wall of an electrical and electronics enclosure, the multiple lead-through flange comprising an inner part made of an elastomeric material and provided with several resilient through holes for sealably surrounding the circumference of a cable, and a peripheral part made of an elastomeric material, surrounding the inner part and comprising fastening means for fastening the multiple lead- through flange to the opening in the wall, the fastening means comprising a resilient continuous sealing lip to be set against a first surface of the wall, and an abutment means to be set against a second surface of the wall, which is opposite to the first surface. [0002] In this context, the term "cable" refers basically to any con- ductor and typically to such a conductor that is surrounded by a sheath and typically contains multiple conductors. [0003] Multiple lead-through flanges of the above mentioned type are known to be used when several cables have to be passed sealably through an enclosure wall. Compared with several separate seals which are separately fixed to a wall, a substantial advantage of a multiple lead-through flange is that the wall surface area required by the through-holes is small. The contact areas between the cables and the seals which are at the through-hole, as well as between the multiple lead-through flange and the wall have to be tight so that no moisture enters the enclosure. [0004] The problem with known multiple lead-through flanges is that it is laborious to mount them in a wall. In addition, the flanges are often difficult to manufacture. The flange is conventionally fastened either with screws or with snap joints, whereby the multiple lead-through flange is sealed against the wall by means of a seal which is in the same plane as the enclosure wall and is set between the wall surface and the surface of the multiple lead- through flange. The seal is either embedded in the enclosure wall or it is on the circumference of the flange. Passing cables through the through holes of the known multiple lead-through flanges often requires that tools need to be used. [0005] European Patent 0580130 A1 discloses a lead-wire grommet of the above mentioned type for passing several wires through an opening in a wall. This known grommet comprises a separate inner member having an equal number of lead wires and insertion holes. The inner member is sup- ported by the surrounding outer member which is radially pressed against the inner edge of the opening in the wall. For said purpose, the opening comprises a cylindrical portion. A drawback of this known grommet is that due to its structure, it is not suitable for being mounted in large-diameter openings, because the grommet made of a resilient material would bend and twist if it was subjected to peripheral radial inwardly directed forces. Consequently, one application of the grommet, which is mentioned, is the fixing of electric wires in cars. Fitting such a grommet into an opening with a larger diameter requires in practice that the grommet is a multipart grommet comprising multiple parts to simultaneously provide for the required stiffness and tightness. Another draw- back of the grommet is that it must be dimensioned according to the thickness of the wall or cylindrical portion of the wall in which it is mounted. Thus, different kinds of grommets have to be manufactured. Also depending on the number of wires, the inner member of the grommet must also be different. BRIEF DESCRIPTION OF THE INVENTION [0006] It is an object of the present invention to provide a new multiple lead-through flange which does not have the drawbacks mentioned above. To achieve this, the multiple lead-through flange is characterized in that [0007] the inner part and the peripheral part are formed into an in- tegrated plate-like unit with a diameter of 40 to 150 mm, whereby the through holes of the inner part are covered by openable locking blanks defined by material reductions, and that [0008] the tightness of the multiple lead-through flange in the edge region of the opening in the wall is based on a free edge of the sealing lip, said lip extending continuously along the entire circumference of the peripheral part, and the thicker the wall to be set between the sealing lip and the abutment means is, the more the sealing lip is arranged to yield and bend. [0009] As the free edge of the sealing lip extends continuously along the entire circumference of the body and is capable of bending, it seals the opening in the wall even though the thickness of the wall would change. There is no need to have a seal on both sides of the wall. [0010] The abutment means preferably comprises a planar continuous abutment surface extending along the entire circumference of the body. Such an abutment surface and the continuous sealing lip provide a double sealing, which is tight even if one of the sealings would break. [0011] The abutment means preferably forms a locking shoulder, which is defined by a tapering section comprising an end with a large diameter and an end with a small diameter, whereby the large-diameter end is closer to the locking shoulder than the small-diameter end. Due to the tapering section, it is very easy to push the multiple lead-through flange to its place into the opening in the wall. [0012] The sealing lip and the locking shoulder are preferably cylindrical, because it is particularly easy to make a cylindrical opening into a wall. In addition, a cylindrical multiple lead-through flange can immediately be pushed into a cylindrical opening without having to have "a right angle of mounting" when initiating the mounting. In addition, when there is a 4 to 10 mm wide cylindrical surface between the sealing lip and the locking shoulder, and the free end of the sealing lip points to and extends towards the locking shoulder such that a 0.5 to 1 mm wide gap X remains between the free end and the locking shoulder, the same multiple lead-through flange can be mounted in all walls having the thickness of 1 to about 9 mm. [0013] Preferred embodiments of the multiple lead-through flange of the invention are disclosed in the attached claims 2 to 11. [0014] The major advantages of the multiple lead-through flange of the invention are that it is very easy to mount it sealably without tools in an entirely planar wall surface, whereby no separate resilient seal has to be used. The flange is also easy to manufacture. The fastening means serve not only as fastening means but also as primary sealing means. The same multiple lead-through flange can be used for walls with varying thicknesses, and since the resilient through holes are provided with locking blanks, the same multiple lead-through flange can be used for different numbers of lead cables. BRIEF DESCRIPTION OF THE DRAWINGS [0015] In the following the invention will be described in greater detail by means of a preferred embodiment and with reference to the attached drawing, in which [0016] Figure 1 shows an enclosure for electrical installations, and a multiple lead-through flange of the invention mounted at an end of the enclosure, [0017] Figure 2 is a side view partially in section of the multiple lead-through flange taken along arrow A of Figure 1 , [0018] Figure 3 shows the multiple lead-through flange of Figure 2 with a mounted cable, [0019] Figures 4 to 6 show the multiple lead-through flange, viewed from the side and from both ends, and [0020] Figures 7 and 8 illustrate the structure of the multiple lead- through flange, viewed from the opposite directions. DETAILED DESCRIPTION OF THE INVENTION [0021] Figure 1 shows a typical application of a multiple lead- through flange of the invention, the flange being mounted in a wall 5 of an electrical enclosure. The cylindrical multiple lead-through flange comprises a plate-like member 17 comprising a peripheral part 16 and an inner part 13, which are cast from an elastomeric material into one integrated entity. The peripheral part 16 of the member 17 is provided with several resilient seals 1 , 2, which can serve as through holes for cables. The size of the seal 2 at the cen- tre is bigger than that of the circumferentially arranged seals 1. The multiple lead-through flange allows eight cables to be mounted, provided that annular material reductions 3 of the seals, inside of which there are detachable locking parts or blanks 3b, are first broken in order to form an opening for a cable, cf. Figure 2 which shows the multiple lead-through flange from the side. The ma- terial reductions 3 can be broken with a relatively small force, for example by means of a screwdriver, a sharp edge or by pushing with a cable. [0022] In Figure 3 there is a cable 4 which is pushed through the seal 1 and the enclosure wall 5. The figure shows that the multiple lead- through flange is a plate-like member 17 comprising a sealing lip 6 set against an outer surface of the wall 5, and a locking shoulder 7 set against an inner surface of the wall. The free edge 12 of the sealing lip 6 provides a sealing against the surface of the wall 5. The locking shoulder 7 forms a planar continuous abutment surface extending sealably along the circumference of the body. Thus, in the structure of Figure 3 the multiple lead-through flange seals the wall 5 from both sides so that the entire opening in the wall is sealed from both sides; the wall 5 remains pressed between the sealing lip 6 and the locking shoulder 7. The flange 17 does not press against the inner edge of the opening in the wall; if it would, the plate-like flange 17 could yield and bend if the structure were not strengthened in some way. As it appears from Figure 2, the resilient sealing lip 6 and the locking shoulder 7 serve as means for fastening the multiple lead-through flange to the wall 5. No separate fastening means are required. [0023] Between the sealing lip 6 and the locking shoulder 7 there is a cylindrical part 8, whose width, or length in the axial direction of the multiple lead-through flange, is 5 mm. In a strainless state, the distance X between the free end 12 of the sealing lip 6 and the locking shoulder 7 is, at its minimum, 0.8 mm, preferably from 0.5 to 0.8 mm, cf. Figure 4. When the cylindrical part 8 and the distance X have these values, the same multiple lead-through flange can be used for walls having a thickness of 1 to 5 mm. The thicker the enclo- sure wall 5 is, the more the sealing lip 6 yields by bending outwards, so that the diameter of the circumference defined by the free edge 12 of the sealing lip becomes greater and the distance X between the free edge 12 and the surface on the side of the shoulder 7 of the plate increases. It is possible that the sealing lip is made to yield almost solely to the direction perpendicular to the plane of the plate-like member 17; thus, yield in the radial direction is not an absolute necessity, yet a preferable property. The length of the cylindrical part 20 is preferably selected to vary from 4 to 10 mm; the maximum point of this range allows the multiple lead-through flange to be mounted to walls even as thick as about 10 mm. The minimum wall thickness suitable for the multiple lead-through flange is determined by the distance X. When the distance X is from 0.5 to about 1 mm, the multiple lead-through flange can be mounted to most of the walls. [0024] The diameter of the multiple lead-through flange is about 60 mm; when a diameter of 40 to 100 mm is selected, a size suitable for most applications is achieved. In some applications, the diameter may even be about 150 mm. [0025] Due to a tapering section 9, it is easy to fix the multiple lead- through flange to the wall 5. The tapering section 9 comprises a narrow end 10 and a wide end 11 which is defined by the locking shoulder 7. [0026] Figures 4 to 6 show the multiple lead-through flange as a separate, and therefore strainless piece (i.e. the flange is not mounted), viewed from the side and from both ends. In Figure 4, the distance X between the free end 12 of the sealing lip 6 and the locking shoulder 7 is at its shortest or at its minimum. [0027] Figures 7 and 8 show that the multiple lead-through flange consists of two components: an elastomeric member 17 and a plastic body 14 supporting it. The seals 1 , 2, the sealing lip 6 and the locking shoulder 7 are defined by the elastomeric member 17, whereas the plastic body provides the multiple lead-through flange with a required stiffness. If the diameter of the multiple lead-through flange is large (about 100 mm or more), the plastic body 14 is a stiffening member comprising cylindrical support parts 15 surrounding the seals 1 , 2. PA (polyamide), for instance, is a suitable material for the plastic body 14, but a body made of a material other than plastic, such as aluminium, can also be used. It is, however, advantageous to use plastic as a material for the body, because the multiple lead-through flange can then be manu- factured in one single mould (not shown) by 2-component injection moulding. First, the plastic body 14 is manufactured in the mould, whereafter an elastomer is supplied to the mould in order to form the elastomeric member 17. Thus, a multiple lead-through flange is obtained, where the elastomeric member 17 is firmly fastened and supported to the plastic body 14. [0028] In the above, the invention is described by means of only one example and therefore it is to be noted that in its details, the invention can be implemented in a variety of ways within the scope of the attached claims. Consequently, for example, the multiple lead-through flange need not have a cylindrical shape, but it may be rectangular or elliptical. The cylindrical shape is, however, very advantageous when the mounting and the opening to be made into the wall are considered. Compared with the rectangular shape, for instance, the cylindrical shape is easy to accomplish even after the enclosure (or the wall in which the multiple lead-through flange is mounted) has already been mounted to the object in connection of which it is used. Instead of a locking shoulder, locking lugs or ears or locking bulges can serve as an abutment means. When compared with the last mentioned means, however, the advantage of the locking shoulder is that it provides a sealing and fastens the multiple lead-through flange very firmly to a wall. The number and location of through holes, i.e. seals 1 , 2, may vary: preferably there are at least four through holes, because otherwise it is typically more advantageous to provide separate lead-throughs without encompassing them in a multiple lead-through flange.

Claims: CLAIMS 1. A multiple lead-through flange for cable lead-through and to be mounted at an opening in a wall, particularly a wall of an electrical and electronics enclosure, the multiple lead-through flange comprising an inner part (13) made of an elastomeric material and provided with several resilient through holes (1 , 2) for sealably surrounding the circumference of a cable, and a peripheral part (16) made of an elastomeric material, surrounding the inner part and comprising fastening means (6, 7) for fastening the multiple lead- through flange to the opening in the wall, the fastening means (6, 7) compris- ing a resilient continuous sealing lip (6) to be set against a first surface of the wall, and an abutment means (7) to be set against a second surface of the wall, which is opposite to the first surface, c h a r a c t e r i z e d in that the inner part (13) and the peripheral part are formed into an integrated plate-like unit (17) with a diameter of 40 to 150 mm, whereby the through holes (1 , 2) of the inner part are covered by openable locking blanks (3b) defined by material reductions (3), and that the tightness of the multiple lead-through flange in the edge region of the opening in the wall is based on a free edge (12) of the sealing lip (6), said lip extending continuously along the entire circumference of the peripheral part (16), and the thicker the wall to be set between the sealing lip and the abutment means is, the more the sealing lip is arranged to yield and bend. 2. A multiple lead-through flange as claimed in claim ^ c h a r a c t e r i z e d in that the abutment means comprises a locking shoulder (7). 3. A multiple lead-through flange as claimed in claim 2, c h a r a c - t e r i z e d in that the locking shoulder (7) comprises a continuous planar abutment surface extending along the entire circumference of the body. 4. A multiple lead-through flange as claimed in claim 2, c h a r a c - t e r i z e d in that the locking shoulder (7) is defined by a tapering section (9) comprising an end (11 ) with a large diameter and an end (10) with a small di- ameter, whereby the large-diameter end is closer to the locking shoulder than the small-diameter end. 5. A multiple lead-through flange as claimed in claim 3, c h a r a c t e r i z e d in that the sealing lip (6) and the locking shoulder (7) form one single resilient piece. 6. A multiple lead-through flange as claimed in claim 3, c h a r a c - terized in that the sealing lip (6) and the locking shoulder (7) have a cylindrical shape. 7. A multiple lead-through flange as claimed in claim 6, c h a r a c - terized in that there is a 4 to 10 mm wide cylindrical surface (8) between the sealing lip (6) and the locking shoulder (7), and that the free end of the sealing lip points to and extends towards the locking shoulder such that only a 0.5 to 1 mm wide gap X remains between the free end and the locking shoulder. 8. A multiple lead-through flange as claimed in claim ^characterized in that the plate-like unit comprises a body (14) which makes the plate-like unit stiffer. 9. A multiple lead-through flange as claimed in claim 8, character i z e d in that the stiffening body (14) comprises cylindrical support parts (15) which are arranged to surround each through hole (1,2). 10. A multiple lead-through flange as claimed in claim 9, characterized in that the multiple lead-through flange is a product manufactured by 2-component injection moulding, whereby the body is a plastic body (14) which is firmly fastened to a plate-like unit (13) made of an elastomeric material. 11. A multiple lead-through flange as claimed in claim 1, characterized in that there are at least four through holes (1 , 2).

Inventors: KORHONEN OLLI, KORHONEN, OLLI
Applicants: FIBOX OY AB, KORHONEN OLLI, KORHONEN, OLLI
Application year: 2001
Main classification: H02G3
IPC codes: H02G15