The present invention relates to a vehicle inspec¬ tion pit, that is, a pit which is constructed in the floor of a garage or other area and over which a motor or other vehicle may be positioned for inspection and maintenance of the underside of the vehicle by a person situated in the pit.

Vehicle inspection pits are conventionally con¬ structed in situ from bricks, blocks or concrete and are relatively costly to install. Hitherto, in the main, they have only been installed in commercial garages and service centres to which vehicles are taken by customers for serv¬ icing by professional mechanics, and the cost of installa¬ tion has prohibited their common use in domestic garages to facilitate home or "do it yourself" servicing and mainte¬ nance of motor vehicles.

It is an object of the present invention to provide an inexpensive vehicle inspection pit which may be more readily and cheaply installed than hitherto known inspec¬ tion pits, thus making it attractive for installation in domestic garages as well as commercial garages and servic¬ ing centres.

The present invention consists in a prefabricated liner for use in constructing a vehicle inspection pit, comprising a shell of generally rectangular shape in plan and having end, side and bottom walls, the shell being formed from synthetic resin material, preferably, glass fibre reinforced plastics material.

In order to construct the inspection pit, it is merely necessary to excavate a hole of suitably larger size than the prefabricated liner in the floor of a garage or other area in which the pit is to be installed, locate the liner in the hole with its top substantially level with the

floor and back fill the hole behind the liner with concrete mix or other suitable material. An anchoring system may also be required in order to retain the liner in place and prevent it from floating above floor level, even after the concrete has cured.

In addition to facilitating and reducing the costs of installing inspection pits, the invention effectively eliminates any problem of water ingress through the sides and bottom of the pit.

The present invention also consists in a vehicle inspection pit having the prefabricated liner of the inven¬ tion forming the end, side and bottom walls of the pit.

The invention further consists in a method of con¬ structing a vehicle inspection pit comprising the steps of pref bricating a liner for the pit comprising a shell of rectangular shape in plan and having end, side and bottom walls, the shell being formed from synthetic resin materi¬ al, excavating at the floor site for the pit a hole for receiving the liner and which is of larger size than the liner, installing anchoring members projecting from the ends and/or sides of the hole, installing projecting an¬ choring members on the outside of the liner, positioning the liner within the hole with the top of the liner sub¬ stantially level with the adjacent floor area, and back filling the space between the liner and the bottom and sides of the hole with concrete.

To improve stiffness and reinforce the liner, which is preferably formed from a moulded one-piece shell, gener¬ ally horizontal ledges may be formed along the insides of at least the side walls of the shell. At least one of the end walls of the shell may also be formed with two or more such horizontal ledges which may serve as steps to provide easy access to the bottom of the pit, when installed. The ledges also provide storage space for tools and other

servicing items, and may be formed along their inner edges with lips for retaining the items on the ledges. The lips may be formed at spaced intervals with drainage gaps.

Conveniently, the shell is formed with two verti¬ cally spaced horizontal ledges extending along the insides of each of its side walls which adjoin two such ledges on the inside of one of the end walls and serving as steps. The upper pair of opposite ledges on the side walls may serve as supporting runs for a sliding tray for tools, a waste oil container and other items required in servicing and maintenance, and the lower ledges can support a sliding seat. Recesses may be moulded on the inside of the shell at appropriate positions adjacent the top for the installa¬ tion of electrical sockets and switches, bulk head type light fittings and a fire extinguisher.

Conveniently, rebates are formed at least along the insides of the top edges of the side walls of the shell for receiving one or more covering sheets which may be wooden boards or sheets and which are fitted into the top of the liner and rest on the rebates to cover or close the inspection pit when not in use and prevent accidents.

The side and end walls of the shell preferably have a downwardly tapering configuration to permit stacking of the liners in nested relation one within another and facil¬ itate transport and storage of the liners. The bottom wall of the liner may be sloped towards a drainage sump disposed adjacent one end of the liner and facilitating collection and removal of water and other liquid spillages draining into the pit. The smooth inside surfaces of the liner allow for easy cleaning of the pit.

Reinforcing battens or boards may be bonded, lamin¬ ated or otherwise secured to the underneath of some or all of the ledges and the bottom wall of the shell to reinforce these parts of the liner. These battens or boards may be

oversized so as to project outwardly from the walls of the liner and serve as the anchoring members for the latter.

In order that the present invention may be more readily understood, reference will now be made to the accompanying drawings in which:

Figure 1 is a perspective view of a prefabricated liner according to the invention.

Figures 2 and 3 are respectively a longitudinal section and a cross section through a vehicle inspection pit embodying the liner of Figure 1, and

Figure 4 is a cross section illustrating a modified embodiment of the liner of Figure 1.

Referring to Figure 1 of the drawings, the prefab¬ ricated liner 1 comprises a one-piece shell 2 moulded from glass fibre reinforced plastics material. The shell is of generally rectangular shape in plan and comprises opposite side and end walls 3-6 and a bottom wall or floor 7. The side and end walls have a downwardly tapering configuration to permit stacking of a plurality of similar liners in nested relation to facilitate transport and storage of the liners. At two different vertically spaced levels, hori¬ zontal ledges 8,9 are moulded on the insides of the side and end walls to provide the shell with stiffness and reinforcement. Along the side walls 3,4, the ledges 8,9 are made of sufficient width to form shelves on which may be stored tools and other items required for servicing and maintenance. Along their inside edges, these ledges may be moulded with upwardly projecting lips 10 for retaining in place items placed on the ledges, and drainage gaps 11 may be formed at spaced intervals along the lips. The ledges in one end wall 6 may be formed of sufficient depth so as to serve as steps 12 providing access to the floor of the liner and these steps may be moulded or fitted with anti-slip surfaces 13. At the opposite end wall 5, the ledges 8,9 are of narrow width and merely serve a reinforc¬ ing and stiffening purpose.

In addition to providing storage space, the pair of opposite upper ledges 8 along the insides of the side walls 3,4 may be used to support a tool tray 14, whilst the lower ledges 9 may support a slidable seat 15. The depth of the linerand the lower ledges 9 is preferably such that, when installed as an inspection pit, a user may work on the underneath of a vehicle from the seated position. The seat and tray may be conveniently fabricated or moulded from plastics material and the tray may be formed with a top adapted to receive a waste oil container 16 and an underside having a paper roll holder 17 and guides for a pull-out container or drawer 17a. (see Figure 3).

An outwardly projecting flange is moulded around the top rim of the shell and an anti-slip surface 18 may be moulded in the top surface of the rim flange 8 at the step end 6 of the shell. A rebate 20 is moulded on the inside of the shell adjacent the rim flange 18 and along the side walls 3,4 and the end wall 5 to provide a supporting ledge for a covering system which may be fitted into the rebate when the liner is installed in an inspection pit in order to close the pit. The rim flange 18 and rebate 20 also serve to stiffen and reinforce the top edge of the pit. Recesses 21 are moulded on the inside of the shell extending downwardly from the rebate 20 for housing bulk head type light fittings 22, an electrical switch and plug 23 and a fire extinguisher 24 (see Figure 2). Services may be con¬ nected to the light and electrical fittings through the outside of the shell.

Reinforcing battens or boards 25,26, for example, wooden battens or boards, are bonded or laminated to the outside of the shell and underneath the ledges 8,9 and floor 7.

The bottom wall 7 of the shell slopes slightly downwardly towards the end 5, adjacent to which a sump 27 is formed for collecting and facilitating the removal of water and other liquid spillages (see Figures 2 and 3) .

Outwardly projecting anchor members 28,29 in the form of lengths of angle iron are bolted to the underneaths of the reinforcing battens 25 along the outsides of the top ledges 8 in the shell side walls 3,4 and to the underneath of the floor reinforcing board 26. Alternatively, instead of providing separate individual anchoring members, the battens 25 and the floor reinforcing board 26 may be made oversized to provide projecting portions 30 serving as the liner anchoring (see Figure 4) .

Referring more particularly to Figures 2 and 3, the method of installing the liner 1 to construct an inspection pit is as follows:-

After checking for possible cables and pipes under the floor area where the pit is to be installed, a rectangular area to receive the prefabricated liner 1 is marked out and the existing concrete floor 31 is cut, for example, using a concrete disc cutter. Having removed the broken concrete, a suitable oversized hole is excavated in the ground below the concrete floor, for example, with the use of a template or construction dimensions supplied with the liner. Spaces 32 are cleaned out under the edges of the concrete floor 31 to provide an additional anchoring effect and floor support and anchor stakes 33 for providing earth to concrete an¬ choring are driven into the sides 34 of the hole. Thereaf¬ ter, a suitable first wet concrete mix is prepared and poured to the excavated hole to form a base support 35 for the liner which base support may, for example, be approximately 10cms (4 inches) thick. Another template may be used to ensure the correct level for the concrete base support. The prefabricated liner 1 is then lowered into the hole and suspended by its corners, whereafter it may be pushed down with weights or one of the installers may climb into the liner to ensure that it is properly seated on the concrete base layer. The space between the liner 1 and the hole

sides 34 is then back filled with a wet concrete mix to the level A-3 sufficiently to cover the lower anchoring members 29 or 30. The concrete is tamped down with a suitable tamper and left to cure for a suitable period. After this curing period, there follows a series of backfilling stages in which alternate layers of a dryish mix concrete DM are deposited against the flat surface portions of the side walls to reduce pressure and wet runny mix concrete WM is deposited in the areas of the ledges 8,9 to ensure full support beneath the latter.

If the floor slab 31 has a polyurethane or similar damp proof membrane, a further drying period will be neces¬ sary at this time before the top of the back fill can be brushed with synthaproof or similar bitumen solution to seal the existing damp proof membrane to the liner. Alter¬ natively, if during breaking out, the existing membrane can be folded back and retained, it can be repositioned and, if punctured or damaged, be reinforced with another layer of polyurethane or similar material. The back fill is then completed to the underside of the liner rim flange 18 and the apron 36 between the rim flange and the floor levels finished with a cement mix using a trowel to provide an acceptable finish.

When the pit is not in use and in order to avoid the risk of accidents, it may be covered with one or more wooden boards fitted over the top of the liner and resting in the rebate 20.

Whilst particular embodiments have been described, it will be understood that modifications can be made with¬ out departing from the scope of the invention as defined by the appended claims. For example, the liner may be used to construct a pit which may alternatively, or in addition be utilised to store wine or other beverages in a cool under- floor area. When used for a wine cellar or the like, slidable wine racks may be mounted on the ledges 8,9.