A METHOD AND ARRANGEMENT FOR INSTALLING TRUNKING SYSTEMS

Abstract: A method and arrangement for mounting on a wall or like support structure trunking comprising one or more elongated trunking sections (1) intended for accommodating electrical conductors and the like, such as telephone cables. At least two mounting brackets (6), intended to support a trunking section (1), are first fitted to the wall in the longitudinal direction of the trunking, whereafter a support or holding bracket (8) is fitted to each of the mounting brackets (6), these latter brackets being spaced at a mutual distance apart which is shorter than the length of the trunking section (1). Each support bracket (8) has a support section (9) which extends substantially horizontally and outwardly from respective mounting brackets (6) when the support bracket (8) is fitted to the mounting bracket (6). A trunking section (1) is supported on the support section (9) of respective support brackets (8) and is then secured to the mounting brackets (6), for example with the aid of one or more screws (22, 24) or like fasteners, whereafter the support brackets (8) can be removed. The trunking section (1) can be secured with the aid of self-drilling screws or with screws inserted into holes which are drilled while the trunking section (1) rests on the support section (9).

Description: A METHOD AND ARRANGEMENT FOR INSTALLING TRUNKING SYSTEMS TECHNICAL FIELD The present invention relates to a method for installing trunking intended for accommodating electrical cable and like electrical conductors, for example telephone cables, on a wall or like supporting structure. The invention also relates to an arrangement with which the method can be carried out. The trunking may comprise one or more elongated thin-walled trunking or ducting sections, pref¬ erably of rectangular cross-sectional configuration. BACKGROUND PRIOR ART Trunking which comprises elongated trunking sections of rectangular cross-sectional profile is described and illustrated in Swedish Patent Specification No. 394057. Each trunking section is provided along one side thereof with two slots or channels which co-act with two mounting brackets when mounting the trunking sections on to a wall. The brackets are U-shaped and, when mounted, present a web, which abuts the wall, and two legs, which extend outwardly from the wall, preferably horizontally, and which enter respective slots in the trunking sections, so as to hold said sections in position. Located on the opposite of respective trunking sections is an opening which is covered with a covering strip or panel, this strip being removed when placing the electric cables in the trunking. The cheapest method of manufacturing such trunking sections is to extrude the sections from alu¬ minium or a plastics material, owing to the relatively complicated configuration of the cross-sectional profile of said sections, and in particular the mounting slots provided therein. Plastic trunking sections cannot be used, however, in those cases where the electric cables or like conductors enclosed in the trunking are required to be particularly well protected against fire, and although trunking made of aluminium offers an alternative in this respect, such trunking is often too expensive to consider. Consequent¬ ly, there is a need for less expensive trunking which satisfies the aforesaid demands on fire precaution. It has been found that trunking made of thin steel sheet satisfactorily meets this desideratum. However, the known method of installing the trunking and the mounting arrangement or devices associated therewith cannot be readily used in connection with trunking made of steel sheet. One reason for this is because it is necessary to shape the steel sheet trunking sections in a roll bending machine, which limits the possibility of producing a complicated cross-sectional configuration. In this regard it has been found that the simplest method of mounting a sheet metal trunking section on a wall or like support structure is to use mounting brackets simil¬ ar to those mentioned above, and by first securing the brackets to the wall or like support structure and then nailing or screwing the trunking section to the support. It has been found that the installation of pre-drilled trunking sections which are intended to be screwed into position requires the employment of two persons, one for holding the sections in position against the mounting brackets and one for screwing the screws through the pre- drilled screw holes. This represents a disadvantage in relation to known trunking systems capable of being in¬ stalled by a single person. It has also been found nec¬ essary to provide rows of pre-drilled screw holes along the 'lengths of respective trunking sections, in order to afford flexibility in positioning the brackets on the wall. The provision of such pre-drilled holes renders the trunking more expensive, and it would be preferable to drill the screw holes on site, in conjunction with installing the trunking. SUMMARY OF THE INVENTION The object of the present invention is to provide a sim¬ ple and reliable method for fitting trunking comprising one or more elongated trunking sections to a wall or like support, each trunking section being supported by at least two mounting brackets fitted to the wall in the longitudinal direction of the trunking. A further ob¬ ject of the invention is to provide a simple arrangement of devices with which the method of installation accord- ing to the invention can be carried out and which as¬ sists in eliminating the aforementioned disadvantages. The arrangement is characterized by a support bracket which when installing a trunking section is temporarily fitted on a respective one of two mounting brackets which are spaced apart at a distance shorter than the length of said section, and in that each support bracket has a support section which extends substantially horiz¬ ontally and outwardly from respective trunking section mounting brackets when fitting said trunking section to its respective mounting brackets. The support section of respective supporting brackets has at least one spacing section through which the support bracket is connected with the mounting bracket and through which the support section is brought into the position desired relative to the mounting bracket when fitting the support bracket thereto. The support section of respective support brackets is preferably provided with a relatively long spacing section at one end thereof and a shorter spacing section at the other end thereof, these spacing sections extending in mutually opposite directions in relation to the support section of the sup¬ port bracket. The fact that the two spacing sections are of mutually different lengths enables respective trunking sections to be arranged at two different levels in rela¬ tion to the mounting brackets, or enables the centre lines of two trunking sections located at mutually diff¬ erent heights to be placed on one and the same level in relation to the mounting brackets. By progressively in¬ creasing the length of the spacing sections of respective support brackets, it is possible to provide brackets which are adapted to trunking sections for installation in series at progressively increasing heights. The method of installation according to the invention is characterized by placing a trunking section on the sup¬ port sections of repective support brackets, with the front opening of said trunking section facing outwardly away from the mounting brackets and with the rear defining wall of the opening abutting the legs of the mounting brackets, and by securing the rear defining wall directly to the mounting brackets with the aid of self-penetrating screws at locations marked on the rear defining wall, which wall extends along the length of the trunking sec¬ tion. The work of mounting the trunking sections is therewith effected through the front openings of respect¬ ive sections, which openings can then be closed-off with a removeable front panel, which enables the opening to be re-exposed. Because the trunking sections are preferably of rectang- ular cross-sectional configuration and are symmetrical about a plane extending along the length thereof at right angles to the aforesaid rear defining wall, by means of which the trunking section is secured to the mounting brackets, each section can be placed on any of the two sides surrounding the rear defining wall while supporting against the support section of respective support brackets with the centre line of the support bracket still located on one and the same level in relat- ion to the mounting brackets. This makes possible an alternative method of installation in accordance with the invention which, in addition to placing a support or holding bracket on each of the two mounting brackets and bringing respective trunking sections into supporting abutment with the support sections of respective support brackets with a front opening of respective ultimate front sides of the sections facing inwardly towards the respective mounting brackets, is also preferably charact¬ erized by drilling mounting holes in the rear wall of the trunking section at locations marked along the length of said section and at the positions of respective mounting brackets. The trunking section is then turned through 180 and screwed firmly to the mounting brackets with t aid of screws inserted through the drilled holes. Each free end of the spacing sections of respective sup¬ port brackets is provided with an attachment plate which extends substantially parallel with the plane passing through the support section, and is intended to be in¬ serted into a corresponding T-groove, preferably prov- ided on the underside of the lowermost leg of the mounting bracket in the wall fitted position of the bracket. Each attachment plate has a screw-threaded hole into which a locking screw is screwed. When the support bracket is fitted onto the mounting bracket, the locking screw is tightened in a manner such that the end of the screw penetrates the hole and exerts a locking force on the bottom of the T-groove. The legs of the mounting brack- ets have specially formed free end portions onto which the trunking section is screwed. The web of the mount¬ ing bracket carrying the two legs is provided with screw holes for screwing the bracket to the wall. The mounting brackets are mounted on the wall in a known man- ner, for example by measuring up the locations of the attachment points and making any necessary adjustments with the aid of a spirit level, sighting line or some like levelling device. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described in more de¬ tail with reference to an exemplifying embodiment thereof illustrated in the accompanying drawings. Figure 1 is a so-called exploded view of a trunking sec¬ tion intended to be mounted on a wall with the aid of two mounting brackets, the attachment of the trunking section to the mounting brackets being effected with the aid of two support or holding brackets which are intended to be fitted onto respective mounting brackets. Figure 2 is an enlarged view of a support bracket accord- ing to Figure 1. Figure 3 illustrates an end portion of the trunking sec¬ tion shown in Figure 1 placed on a support bracket, which in turn is fitted to a mounting bracket, the view being shown in the longitudinal direction of the trunking section. Figure 4 illustrates a trunking section as seen in the direction of its longitudinal axis, the trunking section being placed on a support bracket in readiness to be screwed to respective mounting brackets with the aid of self-drilling screws. Figure 5 illustrates an alternative trunking section, seen in the direction of its longitudinal axis, placed on a support bracket in a position in which the trunking section can be pre-drilled. Figure 6 illustrates mounting brackets which are fitted to a wall and the vertical height position of which can be adjusted with the aid of a levelling line. PREFERRED EMBODIMENT OF THE INVENTION The installation trunking according to Figure 1 comprises an elongated trunking section 1 of rectangular cross-sec¬ tional configuration and presenting a front side 2 having provided therein a front opening 3 which can be closed and re-exposed with the aid of a front panel 4 , which is shown removed from the trunking section, and further pre- sents a rear wall or side 5 which is exposed to the front opening 3. Located on the inner surface of the rear wall 5 are attachment means for securing cable shelves within the trunking. Two mounting brackets 6 are intended to be fitted to a vertical wall with the aid of screws 7 , the mutual spacing between the brackets being shorter than the length of the trunking section 1. The mounting brac¬ kets 6 are intended to co-act with support or holding brackets 8 , on which the trunking section 1 can be placed and supported while securing said section to the mounting brackets 6. The support brackets 8 are intended to be removed from the mounting brackets 6 once the trunking section is secure. As will be seen from Figure 2, each support bracket 8 has a support section 9, which is provided with a layer of rubber in order to prevent damage to the surface of the trunking section 1 when said section rests on the support section 9. Preferably, the support section 9 extends horizontally outwards from the mounting brackets 6 when the support brackets 8 are mounted thereon. The support section 9 is provided at one end with a relatively long spacing section 11 and at the other end with a shorter spacing section, the two spacing sections 10, 11 extend¬ ing in mutually opposite directions in relation to the support section 9. All sections 9, 10, 11 are made of flat steel bar bent at right angles at both ends so as to form the spacing sections 10, 11. Each spacing section 10, 11 is provided at its free end with a respective att¬ achment plate 12 and extends parallel with the plane passing through the support section 9 and is intended to be inserted into a corresponding T-groove 13 provided on a lower leg 14 of a respective mounting bracket 6. The attachment plate 12 is provided with a screw-threaded hole 15 the axis of which extends at right angles to the plane and in which a locking screw 16 is intended to be screwed. In this regard, each spacing section 10, 11 is provided along the length thereof with a central aperture in which the locking screw 16 is located when screwed into the hole 15 in the attachment plate 12. In the embodiment illustrated in Figures 1 and 3, the mounting bracket 6 has a web plate 31, from which the lower leg 14 projects at right angles to the plane pass¬ ing through the plate. An upper leg 17, parallel with the lower leg 14, projects outwardly to the same dist- ance from the base or web plate 31 as the lower leg 14. Both legs 14, 17 present an attachment groove or slot 18, best seen from Figures 4 and 5. The method of installation according to the invention is shown in Figure 4, which illustrates a trunking section 1 placed on the support section 9 of two support brackets 8, of which only one is shown in the Figure. In this ex¬ ample the front opening 3 of the trunking section faces outwardly away from the mounting brackets 6, with the rear wall 5 of the trunking abutting the legs 14, 17 of the mounting brackets. The rear wall 5 of the trunking section is provided with markings in the form of drill weakenings 19, each of which consists of a depression in the form of a groove extending in the longitudinal dir- ection of the trunking section 1 on the inner surface of the rear wall 5. Respective drill weakenings 19 are sym¬ metrically arranged around the longitudinal centre line of the rear wall 5 at a mutual spacing equal to the mut¬ ual spacing between the attachment grooves 18 on the legs 14, 17 of the mounting brackets 6. In this regard, the longer spacing section 10 on the support brackets 8 has a length adapted so that the support section 9 is located at the same distance from the attachment groove 18 in the lower leg 14 as the distance between the lower side 20 of the trunking section 1 and the nearest drill weakening 19. Since the upper side 21 of the trunking section 1 is located symmetrically in relation to the lower side 20, the trunking section 1 can be turned through 180 such that the lower side 20 and the upper side 21 exchange places. The trunking section 1 is firmly screwed with the two self-drilling screws 22, illustrated schematical¬ ly prior to being inserted into respective mounting brac¬ kets 6, whereafter the support or holding brackets 8 are removed, by backing-off the locking screws 16. Figure 5 illustrates an alternative method of installat¬ ion according to the invention, in which a trunking sect¬ ion 1 is placed on the support section 9 of a support bracket 8, with the rear wall 5 of the trunking section facing outwardly away from the mounting bracket 6. As with the aforedescribed method of installation, the rear wall of the trunking section is provided with drill weak¬ enings 19, although with the difference that in this case each drill weakening 19 comprises a groove formed by de¬ pressing the outer surface of the rear wall 5. In the method according to this embodiment two holes are drill¬ ed with the aid of a drill 23, illustrated schematically prior to attachment in the two intended positions at each mounting bracket 6. Subsequent to drilling the holes, the trunking section 1 is turned about its longitudinal axis through 180 and screwed firmly in the mounting brackets 6 with the aid of screws 24, which are shown screwed into respective legs 14, 17 on the mounting brackets 6 of Fig- ure 3. When practicing the aforedescribed two alternative methods of installation the mounting brackets 6 are fitted to the wall in a known manner in accordance with the Figure 6 illustration, which also shows an alternative embodiment of the mounting brackets 6. The location of the mounting brackets 6, e.g. the positional location of the upper edge of said brackets, is determined, for example, in rel¬ ation to a floor surface or some element located in a hor¬ izontal position, and is marked on the wall with a pen, as is also the position of the brackets along the longitudin¬ al axis of the installation trunking. Holes for the mounting bracket attachment screws 7 are drilled at a given distance beneath respective markings, wherewith the one mounting bracket 6 is accurately aligned with a corresponding marking, by displacing the bracket with the screw 7 running in an adjustment groove or slot 24 pro- vided on the web plate 31, whereafter the screw is tight¬ ened. The adjustment groove 24 has provided at its low¬ er end an opening 25 having a diameter which is larger than the head of the securing screw 7. In the Figure 6 embodiment this mounting bracket corresponds to the right-hand mounting bracket 6. The left-hand mounting bracket 6 is only fitted provisionally to the wall. A line 26 having a weight 27 attached at both ends thereof is hung over the two mounting brackets 6 and adjusted to a horizontal level by adjusting the vertical height of the left-hand mounting bracket 6 , which when the line is horizontal is screwed firmly to the supporting wall. The positions of the mounting brackets 6 are then secured, if considered necessary, with the aid of fixing screws 28 placed in downwardly directed grooves 29 on respective mounting brackets. The mounting brackets 6 can be re¬ moved, through the agency of the downwardly directed grooves 29, by slightly loosening the screws 7, 28 so that the mounting brackets 6 can be moved upwardly. The alternative embodiment of the mounting brackets 6 illustrated in Figure 6 has both the T-groove 13 on its lower leg 14 and the attachment groove 18 on the two legs 14, 17. The upper side of the upper leg 17 is also prov¬ ided with attachment means 30 for decoration strips, not shown. It will be understood that the support or holding bracket according to the invention is not limited to the afore¬ described embodiments and that modifications can be made within the scope of the concept of the invention. For ex¬ ample, the attachment plate 12 can be replaced by a later¬ ally open bifurcate device or stirrup-shaped device capable of being pushed onto the bracket leg 14 from one side and locked thereto with the aid of a stop groove. This elim¬ inates the need for a T-groove on the bracket leg.

Claims: CLAIMS 1. A method for mounting installation trunking comprising one or more elongated trunking sections (1) intended for accommodating electrical conductors and the like, such as telephone cables, on a wall or like support structure, in which at least two trunking section mounting brackets (6) are first fitted to the wall in the longitudinal direction of the trunking, characterized by placing a support or holding bracket (8) on each of the mounting brackets (6) , which are mutually spaced apart at a distance shorter than the length of the trunking sectiond), each support brack¬ et (8) having a support section (9) which extends substan¬ tially horizontally and outwardly from respective mounting brackets (6); and by supporting a trunking section (1) on the support sections (9) of respective support brackets (8) and securing the trunking section to the mounting brac¬ kets (6) , e.g. with the aid of one or more screws (22, 24) or like fasteners, whereafter the support brackets (8) are removed. 2. A method according to Claim 1 , characterized in that a trunking section (1) having a front opening (3) extending along said trunking section (1) is supported on the sup¬ port sections (9) of respective support brackets (8) with the front opening (3) facing outwardly from the mounting braclets (6) ; and in that the rear wall (5) of the trunk¬ ing section (1), said wall being opposite the front opening (3) , is screwed firmly to the mounting brackets (6) with the aid of self-drilling screws (22) at marked locations (19) which extend ' along the length of the trunking section (1) and in the location of respective mounting brackets (6) . 3. A method according to Claim 1, characterized in that a trunking section (1) of substantially rectangular cross- sectional configuration and presenting a front side (2) provided with a front opening (3) is supported on the sup¬ port sections (9) of respective support brackets (8) with the front opening (3) facing inwardly towards respective mounting brackets (6) ; in that mounting holes are drilled In a rear wall (5) on the trunking section (1), said rear wall being oposite the front opening (3) , at marking loca¬ tions (19) extending along the length of the trunking section (1) and being located at respective mounting brac¬ kets (6); and in that the trunking section (1) is turned around its longitudinal axis through 180° and screwed firmly to the mounting brackets (6) with the aid of screws (24) inserted through the mounting holes. 4. An arrangement for mounting on a wall or like support structure installation trunking comprising one or more elongated trunking sections (1) intended for accommodating electrical conductors and the like, such as telephone cables, at least two mounting brackets (6) intended for supporting a trunking section (1) being fitted to the wall in the longitudinal direction of the trunking, character¬ ized by a support or holding bracket (8) which when mount¬ ing the trunking is fitted temporarily to each of the two mounting brackets (6) spaced at a mutual distance apart at a distance shorter than the length of respective trunking sections (1); and in that respective support brackets (8) present a support section (9) which extends substantially horizontally and outwardly from respective mounting brac¬ kets (6) and on which respective trunking section (1) are placed while securing said sections to respective mount¬ ing brackets (6) . 5. An arrangement according to Claim 4, characterized in that the support section (9) of the mounting brackets (8) is provided with at least one spacing section (10, 11) through which the support bracket (8) connects with the mounting bracket (6) and through which the support section (9) is brought to a desired position in relation to the mounting bracket (6) when the support bracket (8) is fit¬ ted to the mounting bracket (6) . 6. An arrangement according to Claim 4, characterized in that the support section (9) of the support bracket (8) is provided with a relatively long spacing section (10) at its one end and a shorter spacing section (11) at its other end, the spacing sections (10, 11) being directed in mutually opposite directions in relation to the support section (9) . 7. An arrangement according to Claims 5 - 6, characterized in that respective spacing sections (10, 11) are each pro¬ vided at their free ends with a respective attachment plate (12) , said free ends extending substantially parallel with the plane passing through the support section (9) and being intended for insertion into a corresponding T-groove (13) arranged on a mounting bracket surface which faces down¬ wardly when the mounting bracket (6) is fitted to the wall. 8. An arrangement according to Claim 7 , characterized in that respective plates (12) are provided with a screw- threaded hole (15) into which a locking screw (16) is screwed, said screw, subsequent to fitting the support brackets (8) to the mounting bracket (6) , being capable of being tightened so that one end penetrates through the hole (15) and exerts a locking force on the bottom of the T- groove (13) .

Inventors: BECK KLAUS, LARSSON ULF, LOEFVING STIG-ARNE, BECK, KLAUS, LARSSON, ULF, LOEFVING, STIG-ARNE
Applicants: THORSMAN & CO AB
Application year: 1986
Main classification: H02G1
IPC codes: H02G1, H02G3