SE541192C2

SE541192C2 - Service pit and method for assembling and installing the service pit

Info

Publication number: SE541192C2
Application number: SE1650128A
Authority: SE
Inventors: Jan Elgemark; Kennet Andersson; Lars Rosenquist
Original assignee: Bill Andersson Fordonslyftar Ab
Priority date: 2016-02-03
Filing date: 2016-02-03
Publication date: 2019-04-30
Also published as: DK3411544T3; EP3411544B1; WO2017135863A1; EP3411544A1; PL3411544T3; EP3411544A4; SE1650128A1

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 ASSEMBLING AND INSTALLING THE SERVICE PIT TECHNICAL FIELD The present invention relates to a service pit to be installed on a foundation and comprising a module, which have a metal support frame, e.g. steel, and have at least two longitudinal side walls and a bottom, where at least the side walls exhibiting an inner wall and an outer wall arranged at a distance from each other, said side walls, bottom and foundation bounding a hollow space. The invention also relates to a method for assembling 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 and DE4345415, and are used in e.g. workshops for installation or maintenance of motor vehicles, 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 between the bottom and the foundation is normally filled with a settable material, such as concrete and/or an isolating foam. In order to have the necessary strength to resist the pressure stresses to which the pit is subjected to, the known pits are made of relatively thick steel plates and having a relatively large distance of about 200 mm between their side walls. Thus, the known pits suffer from the disadvantage that a large amount of steel and also fill material have to be used to obtain the required strength.

Further, according to known prior art normally the outer wall of the pit extends all the way down to the foundation. Accordingly, the fill material will be filled into the hollow space bounded by the outer side walls, the inner side walls, the bottom and the foundation, implying difficulties in detecting desired filling in all parts of the hollow space, especially if the filling is performed in one step via an upper gap between said side walls, as described in the above cited prior art. Hence, there is a risk of air being trapped in the hollow space, especially in the bottom region, thus resulting in a weakened 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 INVENTION It is an object of the present invention to solve, or at least to minimise the above mentioned 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 being characterized as defined in claim 1, e.g. in that it comprises a number of ribs being arranged in the hollow space and securely attached to at least the inner and outer walls. Hereby is achieved that at least the inner and outer walls may be made with a smaller thickness, hence reducing the amount of steel used. This is due to the ribs make the service pit structure more rigid and thus stronger. In addition, the thus reinforced service pit may be manufactured with less 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 steel plate. The rib plates extend essentially perpendicular to the plane of the side walls and may be formed as smaller plate sections that are evenly distributed in the hollow space. It is, however, preferred that the rib plates extend over the whole hollow space and have the 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 ribs are preferably provided with engagement means for cooperation with corresponding means provided in the inner walls. In a preferred embodiment said engagement means on the ribs comprise protruding fitting members adapted to exactly fit in to corresponding recesses in the inner walls. In order to obtain high accuracy and precision the 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 provided at a wide angle relative to vertical, preferably about 45°. Further, the service pit may be provided with a horizontal longitudinal beam arrangement in the hollow space of the lower 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 is preferred that the inner walls are attached to the ribs by bringing engagement means on the ribs in engagement with corresponding means provided in the inner walls. In a preferred 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 is provided, and that the space above the fill wall is kept 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 of the service pit in relation to the foundation, but instead use a separate fill wall that is easily accessible and handled. It also provides the advantages of enabling good control that the first filling step is performed in a desired and predetermined manner, by means of visibly checking that the level is optimal, i.e. when fill material everywhere reaches the upper edge of the fill wall. 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 FIGURES Fig. 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 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 separate substantially 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 DESCRIPTION The invention will hereinafter be described in more detail with reference to the appended drawings. The following description should be considered as preferred form 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 of the 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 a longitudinal length M of about 1800 - 3200 mm, more preferred 2400 mm. The reason why it is preferred to use modular lengths as mentioned above, is that it is preferred to use modules that are multiples of the basic building module measurement 600 mm and that it from the perspective of other aspects with this kind of construction project is an advantage to use four times the basic modularity due to the fact that it will fit well into most existing production lines for producing the metal plates forming 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 outer wall 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 a number of ribs 11 (see Fig 3) being arranged transversally in the space 10 and securely attached to at least the inner and outer walls 8, 9. In the shown preferred embodiment the ribs 11 are made of the same kind of metal plate as the inner walls 8, preferably 2-6 mm steel plate (most preferred 2-4 mm) and extend perpendicular to the plane of the side 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 applied amount 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 of about 3 mm thickness. In addition, the thus reinforced service pit may be manufactured with less distance, preferably about 80 - 120 mm, between the inner 8 and the outer wall 9 of the side walls 5, 6 thereby reducing the required amount of fill material to be used. To provide for extra material for secure attachment of the outer rib 11a, to abut the vertical edges of the walls 8,9, the outer rib 11a is somewhat larger than the other, intermediate ribs 11.

At the top of the pit 1 there are arranged two parallel U-beams 51, which preferably span 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 of the ribs 11 are provided at a first wide angle a relative to vertical, preferably about 110-135°, thus making the construction stronger. The upper edge of the ribs 11 are also provided at a wide angle ? relative to vertical, which is less wide than the first angle a, to have the floor plates 70 inclined at an angle ? relative to vertical, preferably about 95-105°, to allow liquid to collect in a preformed channel 74 in the floor plate 70, i.e. in the middle of the pit. The shown service pit 1 is also provided with a horizontal longitudinal beam arrangement 19 in the lower comer region 18, which further contributes to a strong construction and enables a reduced width PW inside of the bottom part. It enables arranging a path way for lifting devices of reduced span width in the 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 invention. As schematically indicated in this Fig. 3 each rib half 11 is provided with protruding fitting members 13, preferably at least two fitting members 13 along the inner edge. These fitting members preferably protrude about the same distance as the thickness of the wall 8 to be fitted there. Further, the ribs 11 are provided with holes 14, so that the amount of steel is reduced without appreciably compromising the strength of the construction. To facilitate the manufacturing of the U-shaped ribs 11, these are preferably made of two identical rib halves, which are welded together, thus making the ribs 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 its height H. The portion of the rib half 11 spanning the major portion of the space between the walls 8, 9, which also is the most thin part of the rib half 11, has a transversal width T that is about 80 -120 mm.

Further Fig. 3 indicates that at the outer periphery of the rib 11 there is arranged a flange, preferably by bending the edge of the plate, which flange 60 (e.g. 20-30 mm wide) is used for attachment of the outer plates 9 to the ribs 11. Preferably this is achieved by using screws, more preferably self-threading kind, e.g. having premade holes in the flange 60 of about 5-6 mm and appropriate corresponding screws adapted to that hole size. Thanks to the use of screws an efficient manufacturing is achieved that also eliminates possible difficulties related to welding, e.g. facilitates the use of less corrosive metal plates (e.g. galvanized) that are more difficult to weld. In the preferred embodiment the inner plates 8 are made of conventional (black) steel plates that are relatively 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 16 adapted to exactly accommodate the protruding fitting members 13 on the ribs 11. In order to obtain high accuracy and precision the fitting members 13 and recesses 16 are preferably produced by the use of laser cutting. The ribs 11 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 area 18 of the service pit 1. The beam 19 preferably has a length 1 that is larger than the modular 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 5-10 m.

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

In the following some preferred production steps will be presented regarding the production of the pre- fabricated pit structure according to the invention. Firstly the upper U-shaped supporting beams 51 will be positioned on to the floor and are accurately positioned in relation to each other by means of transversal support and distance members 50 (see Fig. 1). Some of the distance elements 52 are specifically designed to be used for lifting and moving of the pit 1.

Thereafter a jig (not shown) is positioned on to the support beams 51. In the next step the inner walls 8 will be correctly positioned by means of the jig (n.b., the pit 1 will be upside down during the prefabrication thereof). Now the beam arrangement 19 is welded on to the inner plates 8 and thereafter also the floor plates 70. In the next step the ribs 11 will be attached to the pit 1, by means of lifting each rib half 11 in to position by the use of the inter fit between the fitting member 13 and recesses 16. Now the rib halves 11 are welded, preferably by means of intermittent welding, into connection with the inner walls 9, the floor plate 70 and also to each other at the joining centrally 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, e.g. by means of screws.

Fig. 8 shows an adjustable foot 20 for adjusting the position of the service pit 1 during installation. The shown adjustable foot 20 comprises a bottom plate 21 with holes 22 for securing the foot 20 to a foundation 40, a substantially vertical threaded rod 23 bearing a movable supporting element 24, comprising holes 25 for attachment to the outer wall 9. 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 attachment member 30 for attachment of a wheel track 32, not shown in this figure. The wheel track attachment 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 mounting member 34 for attachment thereof to the attachment member 30. On the other side there is an anchoring member 35 for anchoring of the wheel track in the floor of the service place. 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. 1 provided with a wheel track 32, and Fig. 11 and 12 show in more detail the attachment of 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 1 situated a predetermined distance above the foundation 40.

A separate substantially vertical fill wall 41 is, as shown in Fig. 13, attached to the foundation 40 adjacent the extension of both the outer walls 9. This fill wall 41 has a limited height, about 300-500 mm. Sufficiently high to reach above the level of the floor 70, but not higher than needed to fill the bottom region and the comer area 18 of the pit 1. Then soil is refilled into the cavity outside of the fill wall 41 and up to its upper edge.

Thereafter, as shown in Fig. 14, fill material 42, such as concrete, is supplied to the lower region 43 up to the upper edge 44 of the fill walls 41. This will provide the possibility for inspecting that filled material 42 has actually been supplied to all desired parts of the bottom region of the pit, since it will be easily detected visually that the fill material reaches the upper edge, at least adjacent the upper edge of the fill wall 41.

In Fig. 15 the final filling step is shown, where fill material 42 is supplied in to the hollow space 10 between the inner and outer walls 8, 9 to the top. This step will be performed 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 the bottom region, and secondly it keeps the space above the fill wall 41 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 14 of the pit in regard to the base plate 60, but instead use a separate fill wall 100 that is easily accessible and handled. It also provides the advantages of enabling good control that the first fill stage is performed in a desired and predetermined manner, by means of visibly checking that the level is optimal, i.e. when fill material everywhere reaches the upper edge of the fill wall 41. 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 person skilled in the art. Further it is evident that the advantages of using a separate fill wall , as defined in claim 15, 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

1. A service pit (1) to be installed on a foundation (40) and comprising a plurality of modules (3), which have a metal support frame, e.g. steel, 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 space (10), comprising a plurality of rib plates (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 rib plates (11), wherein the rib plates (11) extend essentially perpendicular to the plane of the side walls (5, 6), characterized in that the rib plates (11) extend substantially over the whole hollow space (10) and have the form of an U and wherein upper edges of the rib plates (11) are provided at a wide angle (?) relative to vertical, to have floor plates (70) inclined at said angle (?) relative to vertical.

2. A service pit (1) according to claim 1, characterized in that centrally in between said wide angled upper edges of the rib plates (11) is a channel portion arranged to house a preformed liquid channel (74) of the floor plate (70) of said bottom (7), to allow liquid to collect in said preformed liquid channel (74).

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

4. A service pit (1) according to claim 3, characterized in that the width of a rib plate (11) in a longitudinal direction of the pit (1) substantially equals to the material thickness of a rib plate (11).

5. A service pit (1) according to claim 1, characterized in that the rib plates (11) are provided with 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 rib plates (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 outer edge of said rib plates (11) are arranged with an attachment flange (60), preferably a bent portion of the rib plates (11).

9. A service pit (1) according to claim 1, characterized in that lower outer comers (18) between the side walls (5, 6) and lower edges of the rib plates are provided at a wide angle (a) relative to vertical, preferably about 110-135°.

10. A service pit (1) according to claim 9, characterized in that the service pit is provided with a horizontal longitudinal beam arrangement (19) in each inner lower comer region (18), and which preferably interconnects floor plates (70) with the inner walls (8), more preferred wherein said beam arrangement (19) delimits a pathway (PW) for lifting equipment in the pit (1), less than 1500 mm.

11. 1 1. A method for assembling the service pit (1) as claimed in any of the previous claims 1-10 comprising the steps of, a) arranging two base frame members (51) in parallel a predetermined distance apart, b) attaching inner walls (8) on each side to said frame members (51) c) attaching longitudinal beams (19) and a floor plate (70) to form a U with the inner walls (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-shaped rib plates (11) spaced equidistantly, extending substantially over the whole hollow space (10) and wherein the upper edges of the rib plates (11) are provided at a wide angle (?) relative to vertical, and e) attaching outer walls (9) to the rib plates (11).

12. A method according to claim 11, characterized in that the rib plates (11) are attached to inner walls (8) by introducing protruding fitting members (13) on the rib plates (11) into corresponding recesses (16) in the inner walls (8).

13. A method according to claim 11 or 12, characterized in that the assembly is modularized by means of having at least most plates of the inner (8) and outer (9) walls forming a module of a predetermined length (M) and using a plurality of interconnected modules to form said service pit (1), wherein preferably at least one of said longitudinal beams (19) and/or base frame member (51) have a length that is substantially larger than the length (M) of a module.

14. A method for installing the service pit (1) as claimed in any of the previous claims 1-10 comprising the steps of, a) providing a cavity in the ground where the service pit (1) is going to be positioned, b) providing a foundation (40) for the service pit (1) to safely and rigidly stand on, c) arranging the service pit (1) on the foundation (40), d) adjusting the position of the service pit (1) to its intended position by means of adjustable means, such as adjustable feet (20), where outer walls (9) are situated at a predetermined distance above the foundation (40), e) attaching a separate substantially vertical fill wall (41) to the foundation (40) in the extension of both the outer walls (9), where said fill wall (41) has a height sufficient to reach above level of a bottom plate (70), but not higher than needed to fill a lower region (43) and the comer area of the service pit (1), f) supplying fill material (42) to the lower region (43) up to an upper edge (44) of the fill walls (41), g) arranging attachments, such as supply channels for ventilation, compressed air, electricity, etc., h) supplying fill material (42) in the hollow space (10) between inner walls (8) and the outer walls (9) to the top.

15. A method according to claim 14, wherein soil is filled into the cavity outside of the fill wall (41) after step e) and that step h) is not proceeded with before it has been visually confirmed that said lower region (43) is fully supplied.