SE1650128A1 - Service pit and method for for assembling and installing theservice pit - Google Patents

Abstract

The following invention relates to service pit (1) to be installed on a foundation (40) and comprising a module (3), which consists of steel or the like and have at least two longitudinal side walls (5, 6) and a bottom (7), where at least the side walls (5, 6) exhibiting an inner wall (8) and an outer wall (9) arranged at a distance from each other, said side walls, bottom and foundation bounding a hollow space (10), where service pit (1) comprises a number of ribs (11) being arranged in the hollow space (10) and securely attached to at least the inner and outer walls (8, 9). Hereby is achieved that at least the inner and outer walls (8, 9) may be made with a smaller thickness, hence reducing the amount of steel used, and that the service pit may be manufactured with less distance between the inner and the outer wall (8, 9), thereby reducing the required amount of fill material to be used.

Description

SERVICE PIT AND METHOD FOR FOR ASSEMBLING AND INSTALLING THESERVICE PIT TECHNICAL FIELD The present invention relates to a service pit to be installed on a foundation andcomprising a module, which have a metal support frame, e.g. steel, and have at least twolongitudinal side walls and a bottom, where at least the side walls exhibiting an innerwall and an outer wall arranged at a distance from each other, said side walls, bottomand foundation bounding a ho llow space. The invention also relates to a method forassembling the service pit according to the invention, and further it relates to a method for installing the service pit on a foundation in a space in the ground.

BACKGROUND ART Service pits of the above mentioned kind are known from e. g. DE4324339 andDE43454l5, and are used in e.g. Workshops for installation or maintenance of motorvehicles, hence the staff in a comfortable upright position may work under the vehicle.During installation of such a pit the hollow space between the side walls and betweenthe bottom and the foundation is norrnally filled with a settable material, such asconcrete and/or an iso lating foam. In order to have the necessary strength to resist thepressure stresses to which the pit is subjected to, the known pits are made of relativelythick steel plates and having a relatively large distance of about 200 mm between theirside walls. Thus, the known pits suffer from the disadvantage that a large amount of steel and also f1ll material have to be used to obtain the required strength.

Further, according to known prior art norrnally the outer wall of the pit extends all theway down to the foundation. Accordingly, the fill material will be filled into the hollowspace bounded by the outer side walls, the inner side walls, the bottom and thefoundation, implying diff1culties in detecting desired f1lling in all parts of the hollowspace, especially if the filling is performed in one step via an upper gap between saidside walls, as described in the above cited prior art. Hence, there is a risk of air beingtrapped in the ho llow space, especially in the bottom region, thus resulting in aweakened construction. Moreover, according to prior art methods it may be complicated to install supply channels, etc. (e. g. for ventilation, compressed air, electricity).

DISCLOSURE OF THE INVENTIONIt is an object of the present invention to solve, or at least to minimise the abovementioned problems and to provide a service pit which exhibits the necessary strength while the amount of steel and/or fill material to be used is reduced.

This is achieved by a service pit of the kind mentioned in the introduction and beingcharacterized in that it comprises a number of ribs being arranged in the ho llow spaceand securely attached to at least the inner and outer walls. Hereby is achieved that atleast the inner and outer walls may be made with a smaller thickness, hence reducingthe amount of steel used. This is due to the ribs make the service pit structure more rigidand thus stronger. In addition, the thus reinforced service pit may be manufactured withless distance between the inner and the outer wall of the side walls, thereby reducing the required amount of fill material to be used.

In principle, the ribs may have any suitable form that strengthen the pit construction,such as bars or tubes. However, it is preferred that the ribs are made of plate material,preferably the same kind of metal plate as the inner and outer walls, e. g. 3 mm steelplate. The rib plates extend essentially perpendicular to the plane of the side walls andmay be formed as smaller plate sections that are evenly distributed in the ho llow space.It is, however, preferred that the rib plates extend over the whole hollow space and havethe form of an U like the ribs in a double-hulled vessel.

In order to ensure a good and precise attachment of the ribs to the inner walls, the ribsare preferably provided with engagement means for cooperation with correspondingmeans provided in the inner walls. In a preferred embodiment said engagement meanson the ribs comprise protruding fitting members adapted to exactly fit in tocorresponding recesses in the inner walls. In order to obtain high accuracy and precisionthe fitting members and recesses are preferably produced by the use of laser cutting, as well as the contours of the ribs.

To make the construction stronger the lower comers of the side walls may be providedat a wide angle relative to vertical, preferably about 45°. Further, the service pit may beprovided with a horizontal longitudinal beam arrangement in the hollow space of thelower comer region. This facilitates a strong construction and enables a reduced width inside of the bottom part, which enables arranging path way for lifting devices in the pit that is only 1300 mm. In many pits there is a need of using 1500 mm, Which requires more costly equipment.

According to another aspect of the invention the service pit is assembled by a method comprising the steps as defined in claim 12.

It is hereby obtained that the service pit structure is more rigid and thus stronger.

The inner Walls may be attached to the ribs in any suitable manner, hoWever it ispreferred that the inner Walls are attached to the ribs by bringing engagement means onthe ribs in engagement With corresponding means provided in the inner Walls. In apreferred embodiment protruding fitting members on the ribs are introduced into corresponding recesses in the inner Walls.

According to yet another aspect of the invention the service pit is installed by a method comprising the steps as defined in claim 15.

It is hereby obtained many advantages, e. g. that extra stability of the bottom region isprovided, and that the space above the fill Wall is kept freely available to enablearranging supply passages channels for ventilation etc. Further it is an advantage not tohave to make any adjustment to the outer Wall of the service pit in relation to thefoundation, but instead use a separate fill Wall that is easily accessible and handled. Italso provides the advantages of enabling good control that the first filling step isperformed in a desired and predeterrnined manner, by means of visibly checking that thelevel is optimal, i.e. When fill material everyWhere reaches the upper edge of the fillWall. Furthermore is facilitates the use of a specific kind of fill material in the bottom region, Which may be advantages in some applications.

The service pit according to the invention may be pre-produced or it may be assembled on site.

Further features and details of the service pit according to the invention Will be apparent from the detailed description.

BRIEF DESCRIPTION OF THE FIGURESFig. 1 is a perspective view of a service pit according to one embodiment of the invention, Fig. 2 is a cross section view of the service pit shown in Fig. 1, Fig. 3 is a view of a rib according to a preferred embodiment of the invention, Fig. 4 is a perspective view of an inner wall , Fig. 5 is a perspective view of a beam arrangement, Fig. 6 is a perspective view of a floor plate, Fig. 7 is a perspective view of an attachment member for attachment of a wheel track, Fig. 8 is a view of an adjustable foot for adjusting the position of the service pit during installation, Fig. 9 is a side view and a view from above of a wheel track, Fig. 10 is a perspective view of a portion of the service pit in Fig. 1 provided with a wheel track, Fig. 11 is a view of details for attachment of a wheel track to the service pit, Fig. 12 is a side view of the attachment of the wheel track in Fig. 9 to the service pit by means of the attachment member in Fig. 7, Fig. 13 is a view of an installation step of the service pit in Fig. 2, where a separatesubstantially vertical fill wall is attached to the foundation in the extension of both the outer walls, Fig. 14 is a view of an installation step of the service pit in Fig. 2, where fill material is supplied to the lower region up to an upper edge of the fill walls, and, Fig. 15 is a view of an installation step of the service pit in Fig. 2, where fill material is supplied in to the hollow space between the inner and outer walls to the top.

DETAILED DESCRIPTIONThe invention will hereinafter be described in more detail with reference to theappended drawings. The following description should be considered as preferred forrn only, and is not decisive in a limiting sense.

In Fig. 1 is shown a perspective view of a service pit 1 according to one embodiment ofthe invention. In the shown embodiment the service pit 1 comprises several modules 3,each having two longitudinal side walls 5, 6 and a bottom 7. Each module 3, has alongitudinal length M of about 1800 - 3200 mm, more preferred 2400 mm. The reasonwhy it is preferred to use modular lengths as mentioned above, is that it is preferred touse modules that are multiples of the basic building module measurement 600 mm andthat it from the perspective of other aspects with this kind of construction project is anadvantage to use four times the basic modularity due to the fact that it will fit well intomost existing production lines for producing the metal plates forrning the inner 9 and outer 8 walls of the pit 1.

In Fig. 2 it is shown that each side wall 5, 6 comprise of an inner wall 8 and an outerwall 9 arranged at a distance from each other, thus bounding a space 10 them between.Fig. 2, shows a cross section of the service pit shown in Fig. 1, further comprises anumber of ribs 11 (see Fig 3) being arranged transversally in the space 10 and securelyattached to at least the inner and outer walls 8, 9. In the shown preferred embodimentthe ribs 11 are made of the same kind of metal plate as the inner walls 8, preferably 2-6mm steel plate (most preferred 2-4 mm) and extend perpendicular to the plane of theside walls over the whole space 10, thus exhibiting the form of an U. Hereby the width(in the longitudinal direction of the service pit 1) of a rib plate 11 substantially equals to the material thickness of a rib plate 11.

As these ribs 11 make the service pit structure more rigid and thus stronger, the appliedamount of steel may be reduced, because the inner and the outer wall of the side walls 8,9 may be made with a smaller thickness than conventionally used, e. g. steel plate ofabout 3 mm thickness. In addition, the thus reinforced service pit may be manufacturedwith less distance, preferably about 80 - 120 mm, between the inner 8 and the outerwall 9 of the side walls 5, 6 thereby reducing the required amount of fill material to beused. To provide for extra material for secure attachment of the outer rib 1 la, to abut thevertical edges of the walls 8,9, the outer rib 1 la is somewhat larger than the other, interrnediate ribs 11.

At the top of the pit 1 there are arranged two parallel U-beams 51, which preferablyspan the Whole length of the pit 1. Supporting distance members 50 extend transversally between the two beams 51, as also lifting members 52.

As shown, the lower outer comers 18 between the side walls 5, 6 and the lower edge ofthe ribs 11 are provided at a first wide angle ot relative to vertical, preferably about 110-135°, thus making the construction stronger. The upper edge of the ribs 11 are alsoprovided at a wide angle ß relative to vertical, which is less wide than the first angle ot,to have the floor plates 70 inclined at an angle ß relative to vertical, preferably about 95-105°, to allow liquid to collect in a preforrned channel 74 in the floor plate 70, i.e. inthe middle of the pit. The shown service pit 1 is also provided with a horizontallongitudinal beam arrangement 19 in the lower comer region 18, which furthercontributes to a strong construction and enables a reduced width PW inside of thebottom part. It enables arranging a path way for lifting devices of reduced span width inthe pit, e.g. that is only 1300 mm. In many pits there is a need of using 1500 mm, which requires more costly equipment.

The service pit 1 is further shown to comprise a stairway 12, which is positioned at an end wall 15 of the service pit 1.

Fig. 3 shows one half of an U-shaped rib 11 according to the preferred embodiment ofthe invention. As schematically indicated in this Fig. 3 each rib half 11 is provided withprotruding f1tting members 13, preferably at least two f1tting members 13 along theinner edge. These fitting members preferably protrude about the same distance as thethickness of the wall 8 to be f1tted there. Further, the ribs 11 are provided with holes 14,so that the amount of steel is reduced without appreciably compromising the strength ofthe construction. To facilitate the manufacturing of the U-shaped ribs 11, these arepreferably made of two identical rib halves, which are welded together, thus making theribs symmetric, also facilitating use of the same plates for the walls 8, 9 at both sides 5,6 of the pit. Preferred measures of a rib half 11 is a height H of about 1700 - 2000 mm,a width W of about 800 - 900 mm, i.e. wherein the width W is about 40-60 % of itsheight H. The portion of the rib half 11 spanning the major portion of the space betweenthe walls 8, 9, which also is the most thin part of the rib half 11, has a transversal widthT that is about 80 - 120 mm.

Further Fig. 3 indicates that at the outer periphery of the rib ll there is arranged aflange, preferably by bending the edge of the plate, which flange 60 (e. g. 20-30 mmwide) is used for attachment of the outer plates 9 to the ribs ll. Preferably this isachieved by using screws, more preferably self-threading kind, e. g. having premadeholes in the flange 60 of about 5-6 mm and appropriate corresponding screws adapted tothat hole size. Thanks to the use of screws an efficient manufacturing is achieved thatalso eliminates possible difficulties related to welding, e.g. facilitates the use of lesscorrosive metal plates (e. g. galvanized) that are more difficult to weld. In the preferredembodiment the inner plates 8 are made of conventional (black) steel plates that arerelatively cheap and easy to weld, whereas on the outer walls 9 are mad from galvanized plates.

In Fig. 4 is shown is a perspective view of an preferred embodiment of the inner wall 8,which is provided with recesses l6 adapted to exactly accommodate the protrudingf1tting members 13 on the ribs ll. In order to obtain high accuracy and precision thefitting members 13 and recesses l6 are preferably produced by the use of laser cutting.

The ribs ll may similarly be attached to the outer walls 9.

In Fig. 5 there is shown one piece of the beam arrangement 19 used in the comer areal8 of the service pit l. The beam l9 preferably has a length l that is larger than themodular width M, i.e. a width that is larger than 2,4 m, preferably a width that can span at least two modules, e. g. between 5-l0 m.

In Fig. 6 there is shown a floor plate 70. The length of the floor plate is preferably thesame as the length M of a module, e. g. 2400 mm. As can be seen there is preferablyarranged an L-bend 72 adjacent the longitudinal outer sides of the floor plate 70, whichL-bends 72 are used to sealingly join the floor plate 70 with the lower edge of the innerside wall 8, preferably by the use of welding.

In the following some preferred production steps will be presented regarding theproduction of the pre- fabricated pit structure according to the invention. Firstly theupper U-shaped supporting beams 51 will be positioned on to the floor and areaccurately positioned in relation to each other by means of transversal support anddistance members 50 (see Fig. l). Some of the distance elements 52 are specifically designed to be used for lifting and moving of the pit l.

Thereafter a j ig (not shown) is positioned on to the support beams 51. In the next stepthe inner walls 8 will be correctly positioned by means of the jig (n.b., the pit 1 will beupside down during the prefabrication thereof). Now the beam arrangement 19 iswelded on to the inner plates 8 and thereafter also the floor plates 70. In the next stepthe ribs 11 will be attached to the pit 1, by means of lifting each rib half 11 in toposition by the use of the inter fit between the fitting member 13 and recesses 16. Nowthe rib halves 11 are welded, preferably by means of interrnittent welding, intoconnection with the inner walls 9, the floor plate 70 and also to each other at the j oiningcentrally positioned vertical edges. In the next step the outer plates 8 are fit on to the outer edges, i.e. the flange 60, of the ribs 11, eg. by means of screws.

Fig. 8 shows an adjustable foot 20 for adjusting the position of the service pit 1 duringinstallation. The shown adjustable foot 20 comprises a bottom plate 21 with holes 22 forsecuring the foot 20 to a foundation 40, a substantially vertical threaded rod 23 bearinga movable supporting element 24, comprising ho les 25 for attachment to the outer wall9. The supporting element 24 is vertically movable by means of a nut arrangement 26,interacting with the threaded rod 23 Fig. 7 shows a perspective view of a horizontally extending support and attachmentmember 30 for attachment of a wheel track 32, not shown in this figure. The wheel trackattachment member 30 is also shown in Fig. 2 and Figs. 10 to 12, and it comprises a number of screw holes 31. The wheel track 32 is an optional, auxiliary equipment.

In Fig. 9 is seen a side view and a top view of a wheel track 32 having a mountingmember 34 for attachment thereof to the attachment member 30. On the other side thereis an anchoring member 35 for anchoring of the wheel track in the floor of the serviceplace. The wheel track comprises a water tray 33 to collect waste water from the tires of a vehicle.

Fig. 10 shows a perspective view of a portion of the service pit 1 shown in Fig. 1provided with a wheel track 32, and Fig. 11 and 12 show in more detail the attachmentof a wheel track 32 to the support and attachment member 30, where screws, (not shown), may be used to attach the housing member 34 by means of in the holes 31, 39 In Figs. 13 to 15 are shown three consecutive steps of an installation of the service pit 1.Thus, first the service pit 1 has been positioned in a cavity in the ground, not shown, to stand on a foundation 40 and adjusted into its intended position by means of the adjustable feet 20. To have the pit l situated a predeterrnined distance above thefoundation 40.

A separate substantially vertical fill wall 41 is, as shown in Fig. 13, attached to thefoundation 40 adjacent the extension of both the outer walls 9. This fill wall 4l has alimited height, about 300-500 mm. Sufficiently high to reach above the level of thefloor 70, but not higher than needed to fill the bottom region and the corner area 18 ofthe pit l. Then soil is refilled into the cavity outside of the fill wall 4l and up to itsupper edge.

Thereafter, as shown in Fig. l4, fill material 42, such as concrete, is supplied to thelower region 43 up to the upper edge 44 of the fill walls 4l. This will provide thepossibility for inspecting that filled material 42 has actually been supplied to all desiredparts of the bottom region of the pit, since it will be easily detected visually that the fillmaterial reaches the upper edge, at least adjacent the upper edge of the fill wall 4l.

In Fig. 15 the final filling step is shown, where fill material 42 is supplied in to theho llow space 10 between the inner and outer walls 8, 9 to the top. This step will beperforrned after the fill material 42 in the lower region 43 has solidified, or at least to a certain extent.

There are several advantages thanks to this. Firstly it provides for extra stability of thebottom region, and secondly it keeps the space above the fill wall 4l freely available to enable arranging supply passages channels for ventilation etc.

Further it is an advantage not to have to make any adjustment to the outer wall l4 of thepit in regard to the base plate 60, but instead use a separate fill wall 100 that is easilyaccessible and handled. It also provides the advantages of enabling good control that thefirst fill stage is perforrned in a desired and predeterrnined manner, by means of visiblychecking that the level is optimal, i.e. when fill material everywhere reaches the upperedge of the fill wall 4l. Furthermore is facilitates the use of a specific kind of fill material in the bottom region, which may be advantages in some applications.

Many other variations are also possible, as will be readily understood by the personskilled in the art. Further it is evident that the advantages of using a separate fill wall , asdefined in claim l5, may also be used in connection with other pit designs, e. g. pit modules using a more traditional design including beams in place of ribs, and therefore it is foreseen that separate protection may be applied for regarding this aspect in a divisional application.

Claims (16)

1. A service pit (1) to be installed on a foundation (40) and comprising a plurality ofmodules (3), Which have a metal support frame, e.g. steel, and have at least twolongitudinal side Walls (5, 6) and a bottom (7), Where at least the side Walls (5, 6)exhibiting an inner Wall (8) and an outer Wall (9) arranged at a distance from each other,said side Walls, bottom and foundation bounding a space (10), characterized in that itcomprises a plurality of ribs (11) being arranged transversally in the space (10) to securely attach said inner and outer Walls (8, 9) and bottom (7) by means of said ribs (11).

2. A service pit (1) according to claim 1, characterized in that the ribs (11) are madeof metal plate material, preferably having a thickness of 2-6 mm, more preferred 4 mm or less.

3. A service pit (1) according to claim 1 or 2, characterized in that the rib plates (11)extend essentially perpendicular to the plane of the side Walls (5, 6), Wherein the Widthof a rib plate (11) in a longitudinal direction of the pit (1) preferably substantially equalsto the material thickness of a rib plate (11).

4. A service pit (1) according to claim 3, characterized in that the rib plates (11) extend substantially over the Whole holloW space (10) and have the form of an U.

5. A service pit (1) according to claim 1, characterized in the ribs (11) are providedWith engagement means (13) for cooperation With corresponding means (16) provided in the inner Walls (8).

6. A service pit (1) according to claim 5, characterized in that the engagement means(13) on the ribs (11) comprise protruding fitting members (13) adapted to exactly fit in to corresponding recesses (16) in the inner Walls (8).

7. A service pit (1) according to claim 6, characterized in that the fitting members (13) and/or recesses (16) are produced by the use of laser cutting.

8. A service pit (1) according to any preceding claim, characterized in that the outeredge of said ribs (11) are arranged With an attachment flange (60), preferably a bentportion of the rib (11). 12

9. A service pit (1) according to claim 1, characterized in that the lower edges of the ribs are provided at a Wide angle (ot) relative to vertical, preferably about 110-135°.

10. A service pit (1) according to claim 9, characterized in that the service pit isprovided With a horizontal longitudinal beam arrangement (19) in each inner lowercorner region (18), and Which preferably interconnects floor plates (70) With the innerWalls (8).

11. A service pit (1) according to claim 10, characterized in that said beamarrangement (19) delimits a pathWay (PW) for lifting equipment in the pit (1), Whereinsaid pathWay (PW) preferably is less than 1500 mm.

12. A method for assembling the service pit (1) as claimed in any of the previous claims1-10 comprising the steps of, a) arranging tWo base frame members (51) in parallel a predeterrnined distanceapart, b) attaching inner Wall plates (8) on each side to said frame members (51) c) attaching a longitudinal beams (19) and a floor plate to form a U With the innerWalls (8), d) attaching rib halves (11) outside of the inner Walls (9), longitudinal beams (19)and floor plate (70) and attach them to form a number of substantially U-shapedribs (11) spaced equidistantly, and e) attaching outer Walls (9) to the ribs (11).

13. A method according to claim 12, characterized in that the ribs (11) are attached toinner Walls (8) by introducing protruding f1tting members (13) on the ribs (11) in to corresponding recesses (16) in the inner Walls (8).

14. A method according to claim 11 or 12, characterized in that the assembly ismodularized by means of having at least most plates of the inner (8) and outer (9) Wallsforming a module of a predeterrnined length (M) and using a plurality of interconnectedmodules to form said service pit (1), Wherein preferably at least one of said longitudinalbeams (19) and/or base frame member (51) have a length that is substantially larger thanthe length (M) of a module.

15. A method for installing the service pit (1) as claimed in any of the previous claims 1-9 comprising the steps of, 13 a) providing a cavity in the ground Where the service pit (l) is going to bepositioned, b) providing a foundation (40) for the service pit (l) to safely and rigidly stand on, c) arranging the service pit (l) on the foundation (40), d) adjusting the position of the service pit (l) to its intended position by n1eans ofadjustable n1eans, such as adjustable feet (20), Where the outer Walls (9) issituated in a predeterrnined distance above the foundation (40), e) attaching a separate substantially vertical fill Wall (4l) to the foundation (40) inthe extension of both the outer Walls (9), Where said fill Wall (4l) has a heightsufficient to reach above level of the bottom plate (7), but not higher thanneeded to fill the botton1 region (43) and the corner area of the service pit (l), f) supplying fill n1aterial (42) to the lower region (43) up to an upper edge (44) ofthe fill Walls (4l), g) arranging attachments, such as supply channels for ventilation, con1pressed air,electricity, etc., h) supplying fill n1aterial (42) in the ho lloW space (l0) between the inner and outerWalls (8, 9) to the top.

16. l6. A n1ethod according to clain1 l5, Wherein soil is filled into the cavity outside of thefill Wall (l) after step e) and that step h) is not proceeded With before it has beenvisually confirrned that said