GB2355028A

GB2355028A - Panel with a reinforced insert for engagement with a lifting tool

Info

Publication number: GB2355028A
Application number: GB0000763A
Authority: GB
Inventors: Martin Thompson
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-10-07
Filing date: 2000-01-13
Publication date: 2001-04-11
Also published as: GB0000763D0; GB9923704D0

Abstract

A panel (10, fig 1, not shown) that can be removed from an aperture defined by a surrounding floor or wall, where the exposed surface of the panel is flush with the surrounding surface. The panel (10) is provided with a reinforcing insert (18) that has an outer rim (20) which defines an opening and is flush with the surface of the panel (10). The insert receives a lifting tool (40b) to enable the panel (10) to be removed. The insert (18) can have an internal dimension of 8 - 10 mm and be in the form of a frustoconical sleeve (33) that can be open either at one or both ends. Engagement with the lifting tool (44b) can be by contact with an internal thread (32, fig 4, not shown) on the insert contacting an external thread on the lifting tool (44b). The lifting tool (44b) may have a pivot (50) close to the portion which engages the insert (18).

Description

2355028 Panels This invention relates to panels which rely on gravity to

hold them in position such as covers, paving slabs or stones, tiles, screens and such forth, and more particularly to panels which are 5 removable from a floor, wall or ground surface of which they form a part.

For some time the concept of using a removable cover which allows access to an area or void behind or underneath the cover has been used successfully in many situations and environments. A simple example is a so-called manhole cover, which can be removed to gain access to an area underground, be it a utility supply, a sewer, drain or such like.

The basic use of a removable cover is often applied to many other situations. For example, it is not uncommon to observe access panels in the floors and walls of ships, trains, buses, planes etc., particularly where key areas need to be accessed quickly and easily and where it is impractical or not possible to provide access from another location.

The same concept has made its way into our living and office environments. Greater demands are now placed on maximising the use of space to store safely utilities of various types whilst simultaneously providing access to same.

Offices, warehouses, factories and studios all have service ducts and inspection ducts for housing and carrying pipes, cables and other equipment. Such locations often have suspended floors with voids underneath to carry such items. To this is added a vast increase in data and telecommunication cabling. Air conditioning, heating, electrical and gas supplies have increased the volume of plant and utilities behind walls, under floors and in the ceilings of the places where we work, live and relax. Coupled with this is a desire to have aesthetically pleasing environments where such items are hidden from view.

With access panels, the main consideration is often given to how quickly and easily access to the void behind the panel can be achieved. In many cases, practicality may give way to aesthetic appeal.

2 For example, with respect to floor panels, these are often configured to be flush with the floor area surrounding the panel. Obviously the main reason for this is for safety, as to allow a portion of the panel to project above the surrounding floor area may result in someone tripping over the panel.

However, having a panel which is simply flush with the surrounding floor area can cause difficulties in the removal and replacement of the panel to gain access to the area underneath. Often the method employed in lifting the panel away from the floor is simply to insert a levering device into the gap between the panel and the surrounding floor area. Once a sufficient gap is wedged open the panel can be removed, this usually being achieved by inserting one's fingers into the gap and lifting the panel away from the floor. This may result in injury if one's fingers were caught between the panel and the edge of the surrounding floor area. An appropriate tool could be made available to wedge the panel away from the floor, but invariably what is used is what is at hand, such as a screwdriver, chisel or the like. Such methods can damage the panel and if the panel is frequently removed and replaced, the condition of the panel and particularly the edges of same can rapidly deteriorate. Such panels are typically large, i.e. around 600MM2 or 750MM2, with heavy weights of 11.65kg and 21.45kg respectively so that they are retained in position by gravity, and strong so as play their part in supporting whatever furniture or equipment is being supported on the floor.

The method mentioned above is far from ideal in emergencies such as fire or flooding where the panel or a plurality of panels may need to be accessed or replaced very quickly. Existing methods of achieving this may lead to injuries or the misplacement of the panel such that it jams in the surrounding aperture or even falls into the floor void leading to delay and possible damage to equipment. Indeed, Applicants were advised that in a real-life situation in a building involving a fire, maintenance staff attempted to use screw drivers to prise open access panels in the rush to find the seat of the fire. Some maintenance staff incurred injuries to their fingers including a broken finger in one instance and back strains. The result of all this is that the maintenance staff have now refused to remove the panels and rightly so because of the lack of compliance with the UK "Health & Safety at Work Etc Act 1974", "Management of Health and Safety at Work Regulations 1992" and "Manual Handling Operations Regulations 1992".

3 So-called manhole covers must be of extremely robust construction given the environment in which they are to be used and are heavy and unwieldy, thereby increasing the possibility of injury, even with current lifting implements, during removing and replacing the cover.

Similar problems can arise in the case of concrete paving slabs, which are also heavy and unwieldy and which have to be relaid from time to time because of unevenness, replaced because of breakage or removed to provide access to underground services.

The problems in removing and replacing an access panel in a floor have already been addressed by accommodating a movable lifting ring in a recess in the exposed surface of the panel. The ring can be lifted up out of the recess to allow one or more fingers to be inserted into the ring, thus the panel can be lifted away from the surrounding area. However, with the heavier and larger panels referred to above the effectiveness of such a lifting ring diminishes significantly. It is often not practical to provide larger ring sizes for larger panels, as to do so would require the provision of a larger recess in the exposed surface of the panel to store the lifting ring. This increases the risk of accidents should, for example, the heel of a shoe be caught within the recess or the ring as someone walks over the panel. This would especially be relevant if, over time or through damage, the lifting ring failed to remain flush with the exposed face of the panel and therefore projected from the recess to form a potential tripping hazard. What is more, such lifting rings are unsightly and may detract from the aesthetic appeal of the exposed surface of the panel.

In all the examples mentioned above, removal of the panel or paving slab away from the floor or ground area involves the physical act of lifting. It is very difficult for the person accessing the panel or paving slab to avoid lifting with the back bent and/or at an awkward angle and always avoid the panel or slab sticking or jamming in the aperture and not lifting away easily. So the risk of back strains or even spinal injuries is ever present with large heavy panels or slabs. Indeed the risk of injury in such circumstances would still be high even if the panel or slab were relatively light and/or relatively small.

The above situations and comments may also be applicable to wall panels which are held by gravity within a wall aperture.

4 The main object of the present invention is to provide removable panels and methods and kits of parts for, and for use in, providing or removing panels, covers, paving slabs or stones, tiles, screens and any other panel-like elements which rely on gravity to hold them in position which 5 overcome or at least substantially reduce the aforementioned disadvantages and problems. Hereinafter such a panel, cover, paving slab, paving stone, tile, screen or other panel-like element will be generically referred to, for convenience, as a "panel".

Accordingly in one aspect, the invention resides in a panel that is removable from a position in which it is held by gravity in an aperture defined by a surrounding floor, wall or ground surface where the exposed surface of the panel is flush with the surrounding surface, the said panel being provided with a reinforcing insert having an outer rim defining an opening, said reinforcing insert being held within the body of the said panel such that the said outer rim is flush with that surface of the said panel which is exposed in use, said reinforcing insert being adapted to receive through said opening, and be engaged by, a lifting implement whereby the said panel is removable from the said aperture.

The provision of a reinforcing insert within the body of the panel permits the positive engagement of a lifting implement within the body of the panel, thus allowing the safe and controlled removal of the panel from the aperture. This greatly reduces the chances of the panel being dropped and lost back into the aperture and even jamming same. Moreover in an emergency situation in which the panel covers an access aperture to services, the speed at which the panel can be removed from the aperture is increased. Also, the risks of injury caused by dropping or mishandling the panel can be reduced to the point of non-existence, thereby providing considerable health and safety advantages. Indeed, Applicants believe that their invention satisfies "The Provisions and Use of Work Equipment Regulations 1998".

By means of the reinforcing insert, the lifting implement can be engaged within the body of the panel and the panel removed from the aperture without the need for crude levering tools traditionally used for such a task, such as screwdrivers, chisels etc. Therefore, unnecessary damage to the edges of the panel and possibly the floor or wall surface defining the aperture can be avoided. This is of particular importance if the panel needs to be removed frequently from the aperture, as consistent and frequent damage to the edges of the panel could result in the panel or the surrounding floor, wall or ground surface having to be replaced much earlier than expected or planned, with consequential increased costs. Moreover, if there is any delay in making good the damage, this may present a health and safety hazard.

The invention makes for a versatility which has not hitherto been possible as the panels with their reinforcing inserts are not only applicable to service ducts but also can be used to form an entire floor area or large portions of same by supporting the panels from a variety of supporting means, for example, a number of adjustable props such as screw jacks, above a subfloor, which may be of concrete construction.

The reinforcing insert acts as an engagement interface between the body of the panel and the lifting implement and protects the panel from damage by frequent engagement with the lifting implement.

By virtue of the ease of operation, simplicity and low cost of manufacture, and health and safety characteristics, the invention is of considerable commercial significance.

The reinforcing insert may be located in any suitable position within the body of the panel, but in order to facilitate lifting of the panel from the aperture and to minimise any risk of back strain and injury, the reinforcing insert is preferably offset from the centre of the panel and advantageously adjacent an edge of the panel. A single reinforcing insert is usually all that is required but two or more reinforcing inserts may be provided if desired or necessary.

The reinforcing insert may be provided within the body of the panel during manufacture, for example when the panel is made of a mouldable material such as a suitable plastics material, for example a resin, or a cementitious material such as concrete. Alternatively, a hole is made within the body of the panel as by drilling for example, and the reinforcing insert is inserted into the hole so that its outer rim is flush with the surrounding floor, wall or ground surface.

The hole may be in the form of a "blind" hole or a through-hole and the reinforcing insert can be in the form of an open-ended sleeve or a sleeve that has one end which is the lowermost in use closed, like a thimble. The use of a blind hole or a reinforcing insert with a closed end is 6 preferred because it prevents, say in the case of a floor panel, draughts, flows of gas or the transmission of deleterious substances through the panel from a service duct, or in the case of a panel in the form of a paving slab, emissions from a broken sewer.

Ideally, the internal dimensions of the opening of the reinforcing insert should be such that the insert itself does not form a health and safety hazard, for example, to those walking over the panel if the reinforcing insert is provided within a ground or floor panel and additionally allows the overall aesthetic appeal of the panel to be maintained.

The reinforcing insert may be held within the body of the panel by a variety of holding means consistent with maintaining the reinforcing insert held within the panel despite repeated removal and replacement operations. This can be achieved by a suitable adhesive, an external thread, ribbing, ridging or rivets, a combination of any of these methods, or by any other suitable means.

Preferably the external thread is a coarse thread and/or a multi-start thread which bites into the wall of the hole by a sufficient amount to hold the reinforcing insert within the body of the panel whilst facilitating speed of insertion into the hole. Speed of insertion is further facilitated by the external wall of the reinforcing insert being of a frusto-conical shape.

To ensure more readily that the reinforcing insert is flush with the surrounding surface, the opening preferably has a countersunk mouth and the outer rim of the reinforcing insert is in the form of an outwardly projecting peripheral lip which fits within the countersunk mouth.

The means whereby the insert is engaged by the lifting implement can be of any suitable form consistent with obtaining a positive engagement and therefore optimal lifting purchase in a comparatively short time. For example, the reinforcing insert may be hollow with its internal wall being of cylindrical shape and internally threaded to be engageable by a complimentary external thread on the lifting implement.

7 Alternatively, the hollow reinforcing insert may provide a passage, for example in the form of a slot, the passage having a shoulder beneath which a projection on the lifting implement can be positively engaged by turning the lifting implement in relation to the reinforcing insert.

6 In another aspect the invention resides in a method of providing a panel that is removable from a position in which it is held by gravity in an aperture defined by a surrounding floor, wall or ground surface where the exposed surface of the panel is flush with the surrounding surface, said method including providing a panel with a reinforcing insert having an outer rim defining an opening, said insert being held within the body of the said panel such that the outer rim is flush with that surface of the panel which is exposed in use, said reinforcing insert being adapted to receive through said opening, and be engaged by, a lifting implement whereby the said panel is removable from the aperture.

From a further aspect the present invention resides in a kit of parts comprising a reinforcing insert having an outer rim defining an opening and being adapted to be held within the body of a panel that is removable from a position in which it is held by gravity in an aperture defined by a surrounding floor, wall or ground surface where the exposed surface of the panel is flush with the surrounding surface such that the outer rim is flush with that surface of the panel which is exposed in use, and a lifting implement which is engageable within the said reinforcing insert.

The kit of parts may also include a panel having any of the other features referred to hereinabove.

In yet another aspect the invention resides in a lifting implement for removing a panel from an aperture as aforesaid, the said lifting implement comprising a handle terminating in an engagement member, wherein the said engagement member is receivable through the opening of, and engageable within, the reinforcing insert of any of the panels defined hereinabove.

By means of the lifting implement, the panel may be easily and safely removed.

8 More particularly, the use of a lifting implement which positively engages within the body of the panel via the reinforcing insert allows the panel to be removed ftom the aperture without risk of injury. So, there is no need for a person to bend and strain their back and injure their hand or fingers by catching them between the edges of the panel and the aperture in the 5 surrounding surface.

The engagement member of the lifting implement can be of any suitable form consistent with obtaining a positive engagement with the reinforcing insert and therefore optimal liffing purchase in a comparatively short time. For example, the engagement member may be provided with an external screw thread which is complimentary to and engageable with the internal screw thread of the reinforcing insert.

Alternatively, the engagement member may be provided with an outwardly extending projection, the engagement member being insertable in a passage in the reinforcing insert which provides a shoulder beneath which the projection on the lifting implement can be positively engaged by turning the lifting implement in relation to the reinforcing insert.

In yet another alternative, the engagement member may be provided with at least one engagement element that is movable between a first position in which the said at least one engagement element permits entry of the engagement member through the opening of the reinforcing insert and into a passage defined by the reinforcing insert and a second position in which the said at least one engagement element is actuated to hold the engagement member within the reinforcing insert.

To move the said at least one engagement element between the first and second positions an actuating member may be provided which acts in use upon the said at least one engagement element when the engagement member reaches the bottom of the passage.

Preferably, the said at least one engagement element may take the form of a plurality of balls or movable gripping lugs which are supported by the engagement member and are inoperable in the said first position and which project from the engagement member into an annular recess in the wall of the passage in the said second position to hold the engagement member within 9 the reinforcing insert.

In order to prevent damage to the engagement member and the reinforcing insert by overengaging the lifting implement, and also to signal full engagement for optimum lifting as well as to provide for a more solid connection between the two, the lifting implement is advantageously provided with a surface which abuts against the exposed surface of the panel.

There may be situations where the panel may not be simply removed out of the aperture. For example, the weight or dimensions of the panel may be such that a pivot motion, perhaps using an edge of the aperture itself as a fulcrum, is needed to remove the panel from the aperture. In such instances, the liffing implement is advantageously connected to the engagement member by pivotable means which may be of any suitable form, such as a simple hinge for movement in one plane or a universal joint like a ball and socket joint.

When pivotable means are provided, the actuating member for the said at least one engagement element may be constituted by such pivotable means which is actuated when the pivotable means is operated.

To ensure that the panel is not subjected to sudden uncontrolled movements during lifting, it is preferable to provide restricting means which will allow the pivoting of the engagement member relative to the elongate element only when required. Such restricting means may conveniently take the form of an outer sleeve, biased, for example by a compression spring, to cover the pivotable means between the engagement member and the elongate element. VV%en pivoting of the lifting implement is required, the outer sleeve may be moved sufficiently against the bias to allow motion of the pivotable means.

By providing a lifting implement with pivotable means with or without the restricting means, the versatility and safety characteristics of the lifting implement are considerably improved.

The invention also comprehends a method of removing any of the panels defined hereinabove from a position in which the panel is held by gravity in an aperture defined by a surrounding floor, wall or ground surface where the exposed surface of the panel is flush with the surrounding surface and there being a reinforcing insert held in the body of the panel utilising any of the lifting implements defined hereinabove by engaging the lifting implement in the said reinforcing insert and operating the said lifting implement to remove the panel from the aperture.

In order that the invention may be more readily understood, reference will now be made, by way of example only, to the accompanying drawings in which:

Figure I is a plan view of a removable floor panel forming part of a floor which surrounds the panel and which is constructed in accordance with the invention; Figure 2 is a cross-section through the floor panel of Figure I to expose, in part sectional side elevation, a reinforcing insert forming part of the panel; Figure 2a is a part-sectional side elevation of an alternative construction which is a further cross-section of the floor panel of Figure 2 with its reinforcing insert; Figure 3 is a detail view of the floor panel and reinforcing insert of Figure 2 to an enlarged scale; Figure 4 is a part-sectional side elevation of the reinforcing insert of Figure 3; Figure 5 is side elevation of the reinforcing insert of Figure 4, laid on its side on a panel; Figure 6 is a side elevation of one embodiment of lifting implement which is adapted to engage within the reinforcing insert to lift the removable panel from the floor; Figure 7 is a side elevation of another embodiment of lifting implement; Figures 8 and 9 are a side elevation and a part-sectional side elevation respectively of a ftuther embodiment of lifting implement in one position; Figure 10 is a part-sectional side elevation showing the lifting implement of Figures 8 and 9 in another position; and Figures I I to 14 show a method of removing the floor panel of Figures I and 2 from the floor using the lifting implement of Figures 8 to 10.

Referring to Figures I and 2 of the drawings, there is shown a rectangular panel 10, in this case a floor tile, that is removable from a position in which it is held by gravity in an aperture 12 defined by a surrounding floor, wall or ground surface 14 where the exposed (outer) surface 16 of the panel 10 is flush with the surrounding surface 14. The panel 10 is provided with a hollow reinforcing insert 18 in the form of a stud having an outer rim 20 in the form of an outwardly projecting peripheral lip defining an opening 22. The stud insert 18 is held within the body 21 of the panel in a hole 19 such that the outer rim 20 is flush with the exposed surface 16 of the panel. A bevel 20a is provided on the undersurface of the rim 20. The stud insert 18 is adapted to be received through the opening 22, and be engaged by, a lifting implement, to be described, to remove the panel 10 from the aperture 12. To facilitate liffing, the reinforcing insert 18 is offset from the centre of the panel 10 at a location adjacent one edge 13 of the four edges of the panel 10.

As will be more readily appreciated from Figure 2, the panel 10 is an access panel for a service duct 24 housing service lines such as any of electricity, computer, telephone, fax and ISDN lines, central heating, gas and water supply conduits, which are collectively indicated by the reference 25, for the purpose of allowing easy, quick and hazard free access to the service duct for installation, maintenance and repair, in particular in the case of an emergency such as fire or flood. The panel 10 rests on supports 26 to close a service access opening 27 in the service duct 24.

Instead of covering a service duct 24, Figure 2a shows the panel 10 and its reinforcing insert 18 forming part of a suspended floor area above a subfloor 9 and which is supported by adjustable props in the form of screw jacks 8. This form of suspended floor construction allows any area of beneath a plurality of the said panels 10 to be accessed at a given moment and is particularly useful where frequent access to the subfloor area is required.

12 Referring now to Figure 2, the panel 10 is made of a solid core 10a of wood, or wood composite such as chipboard, with an external surrounding sheath l0b of steel which imparts the requisite strength. Practically, however, the panel 10 can be constructed of any other suitable natural or synthetic material such as plastics, metal, concrete, marble, slate or any combination of materials that gives the requisite strength and weight. The dimensions of the panel 10 and thus of the aperture 12 and service access opening 27 are sufficient to enable ease of access into the service duct 24 through the aperture 12 and service access opening 27.

Although, for clarity of illustration, gaps are shown between the panel 10 and the surrounding floor surface 12, in practice, these gaps will not be present. Typical sizes for the panel 10 are 600mm. by 600mm square with a weight of 11.65kg and 750mm by 750MM with a weight of 21.45kg. This enables the panel 10 to sit snugly and firmly within the aperture 12 to remain flush with the surrounding floor surface 14, with the panel strength enabling the panel to support the weight of whatever is carried by the panel and surrounding surface, for example, furniture and office equipment such as computers, photocopiers, etc. The exposed surface 16 of the panel 10 may be presented by whatever is the particular floor covering of the surrounding surface 14, for example by a floor tile such as a carpet tile, or a resin coating.

Clearly, the reinforcing stud insert 18, by definition, must be of a stronger and harder material than that of the core 10a to be able to fulfil its reinforcing function and to withstand repeated engagement and disengagement with the lifting implement. In this instance, the reinforcing stud insert 18 is made of steel.

Drilling is the method of choice for forming the hole 19 in the body 21 of the panel 10 without going all the way through so as to form a "blind" hole, either during manufacture of the panel 10 or in an existing panel 10 in situ. The drilling process involves forming the blind hole 19 with a countersunk mouth 23 having a bevel 23a and a closed end 28.

Figure 3 shows more fully how the stud insert 18 is inserted into the hole 19 and held within the body 21 of the panel 10. Referring to Figures 3 and 4, the stud insert 18 is in the form of an open-ended sleeve 29 having the entry opening 22 for the lifting implement at that end which is the uppermost in use and defining a cylindrical passage 30 extending between the rim 20 defining the entry opening 22 and the lowermost, in use, open end 3 1. The cylindrical internal wall of the passage 30 of the sleeve 29 has an internal multi-start coarse screw thread 32 which 13 is engageable by a complimentary external multi-start coarse screw thread on the lifting implement in a manner to be described. The sleeve 29 has an external frusto-conical surface 33 provided with a coarse external screw thread 34 which bites into the wall 35 of the hole 19 by a sufficient amount so that the stud insert 18 is held within the body of the panel 10 against 5 repeated engagement and lifting by the lifting implement.

Speed of insertion of the stud insert 18 into the hole 19 by means of a screwing action is facilitated by the coarse screw thread 34 and frustoconical external surface 33. As shown in Figure 5, this example of the invention has the screw thread 34 interrupted to provide two longitudinal channels 36 (only one visible) which permit ease of exit of panel material removed from the wall 35 of the hole 19 by the action of screwing the stud insert 18 into the hole 19. Although not normally strictly necessary, a suitable adhesive may be used to enhance the holding of the stud insert 18within the body of the panel 10 by applying it to the hole 19 prior to screwing in the stud insert 18. The bevel 23a of the countersunk mouth 23 receives the outer rim 20 which, by virtue of its bevel 20a being of complementary shape to the countersunk bevel 23 a, ensures that the outer rim 20 is flush with the exposed surface 16 of the panel 10.

The opening 22 of the stud insert 18 is of a size which, in addition to the bevels 23a and 20a providing for flush mounting of the stud insert with the panel surface 16, guards against or even prevents the stud insert forming a health and safety hazard, for example, to those walking over the panel 10. Moreover, the opening size and flush mounting allow the overall aesthetic appeal of the panel to be maintained. This will be more readily appreciated from Figure 1 which shows that the size of the opening 22 is very small in relation to the overall size of the panel and will be virtually unnoticed in a floor surface. Typical sizes for opening 22 are 8min to 1 Ornm diameter, depending upon where the panel is laid.

Referring to Figure 6, this shows a lifting implement 40 having a handle 41 terminating in a stud insert elongate engagement member 42 to which the handle 41 is rigidly connected via a shaft 43 and an enlargement 44 which is rigid with the shaft and has a panel abutment surface 45. The engagement member 42 has a coarse multi- start external screw thread 46 which is engageable with the internal screw thread 32 of the reinforcing insert 18 by presenting the free 14 end of the engagement member 42 to the opening 22. The lifting implement 40 is turned to interengage the respective screw threads 46 and 32 with each other and turning is continued until it is stopped by abutment of abutment surface 45 with the rim 20 and exposed surface 16 of the panel 10. So, the abutment surface 45 acts as a stop to prevent over-turning of the lifting implement 40 with consequential damage to the reinforcing insert 18 and also prevents bending of the threaded elongate engagement member 42. Thus, the combination of the multi start coarse threaded engagement member 42 and multi-start coarse threaded stud insert 18 with the abutment surface 45 not only prevents damage to the lifting implement 40 but ensures positive engagement and optimal lifting purchase in a very short time.

The lifting implement 40a shown in Figure 7 differs from that of Figure 6 in that a pivotable means constituted by a pivotal connection 50 in the form of a hinge is provided between the handle 41 and the engagement member 42 for enabling the handle 41 to move relative to the engagement member 42 during the removal of the panel 10 from the aperture 12. The pivotal connection 50 comprises a pivot recess 51 in the enlargement 44 into which a free end region 52 of the shaft 43 projects and a pivot pin 53 which is rigid with the shaft 43 projects radially outwards of the free end region 52 and into bearing holes 54 in the walls of the recess 5 1.

Whilst the embodiment of Figures 8 and 9 has a pivotal connection 50 between the handle 41 and the engagement member 42, the lifting implement 40b differs from that of Figure 7 by having a restricting means that is generally indicated by the reference 60 and which is moveable between a position in which movement of the pivotal connection 50 is prevented and permitted respectively. The restricting means comprises a tubular member 61 within which the shaft 43 of the handle 41 is telescopically mounted, a gripping member 62 like the handle 41 and a tubular sleeve 63 mounted on the enlargement 44 which are rigid respectively with the proximal end of the shaft 43 adjacent the handle 41 and with distal end of the shaft 43 adjacent the pivotal connection 50.

Biasing means in the form of a compression spring 64 encircles a normally exposed length 43a of the shaft 43 lying between the handle 41 and the gripping member 62. The spring 64 acts on the gripping member 62 and tubular member 61 to urge the tubular sleeve 63 into the position shown in Figure 9 in which the sleeve 63 normally covers the pivotal connection 50 to prevent movement of the handle 41 relative to the engagement member 42. In the normally covered position, the tubular sleeve 63 surrounds the enlargement 44 which acts as a guide with the free end 63a of the tubular sleeve 63 being urged into abuttment with a radial flange 44a acting as an end stop to delimit the amount "covering" movement of the tubular sleeve 63. To uncover the pivotal connection 50, with both hands holding the handle 41, the gripping member 62 is gripped by the fingers of both hands and moved towards the handle 41 against the bias of the spring 64 with the sleeve 63 being moved with the gripping member 62 via the tubular member 61 and with respect to the enlargement 44 until, at full or substantially full spring compression, as shown in Figure 10, the sleeve clears the enlargement 44 and uncovers the pivotal connection 50 to permit movement of the handle 41 relative to the engagement member 42.

In all the embodiments of Figures 6, 7 and 8 to 10, the engagement member 42 is turned and screwed into the stud insert 18 of the panel 10 until the abutment surface 45 of the enlargement 44 abuts against the outer rim 20 of the stud insert 18 and exposed surface 16 of panel 10 as shown in Figure 10, although in Figure 10 a normally non-existent gap is shown between the surface 16 and rim 20 and abutment surface 45 for clarity of illustration. It is then a simple matter for the maintenance worker to grasp the handle 41 with both hands, bend the knees and then, keeping the back straight, lift the panel 10 temporarily onto an edge 70 shown in dashed lines of the aperture 12, by straightening the knees, whereafter the panel 10 is immediately removed from the aperture 12.

In the case of Figure 6, the panel 10 has again to be to be lifted by raising the handle 41 of the lifting implement 40, as well as a dragging motion which is not easily accomplished and whilst a considerable improvement on existing techniques can, if not handled carefully, result in a maintenance worker incurring back strain. This potential problem is largely solved by the use of a pivotal connection 5 0 in the embodiment of Figure 7 because once the panel 10 has been lifted onto the edge 70 of the aperture 12, the handle 41 can be pivotally moved in relation to the engagement member 42 in the stud insert 18 to occupy a position in which the shaft 43 is at a suitable angle with respect to the engagement member 42 that facilitates removal because the lifting implement 40a is pulled with both hands through the handle 41 to remove the panel 10 from the aperture 12 with a sliding motion over the suffounding surface 14.

16 However, there is still a risk with the embodiment of Figure 7 that the movable pivotal connection 50 will permit sudden, unrestrained and uncontrollable movements of the panel 10 with respect to the handle 41 which could result in back strain or injury. Whilst such a risk would not occur with the embodiment of Figure 6 because the handle 41 is rigid with the engagement member 42, this embodiment has disadvantages which have already been mentioned.

The embodiment of Figures 8 to 10, has the advantages of both Figures 6 and 7 by immobilising the pivotal connection 50 so that the handle 41 is a rigid with the engagement member 42 when lifting the panel 10 but permits immediate freeing of the pivotal connection 50 by pulling the gripping member 62 towards the handle 41 into the position of Figure 10 when the panel 10 has been lifted onto the edge 70 of the aperture 12, as shown in Figures 12 and 13. Then, by gripping both the gripping member 62 and handle 41 against the biasing action of the spring 64, as shown in Figures 13 and 14, the panel 10 can be pulled from the aperture 12 and slid along the surrounding surface 14 by a maintenance worker 71 as will be apparent from Figure 14. A pulling motion with the maintenance worker's back 72 straight, as illustrated, maximises what strength the maintenance worker 71 has without putting the worker at risk from back strain and injury. The gripping member 62 can then be released from the 20 position shown in Figure 10 in which the restricting means 60 uncovers the pivotal connection 50 to occupy the position shown in Figure 11 in which the released spring 62 has moved the sleeve 63 back to where it covers the pivotal connection 50, the lifting implement can be turned to unscrew the threaded engagement member 42 from the stud insert 18 to be available for another lifting operation. It will be appreciated that the lifting implement 40b of Figures 8 25 to 10 and shown in action removing a panel 10 from the aperture 12 in Figures 12 to 14 has significant health and safety advantages. Whilst the invention has been described primarily with respect to the use of the panel 10 in relation to a floor surface, the panel 10 is also suitable for use in a wall and in an exterior 30 environment. For instance, the panel 10 may be a paving stab for use in a sidewalk, pavement, garden or park under which is laid, for example, a drain, pipe, telephone, television, and electric cables and gas lines. In this situation it may be undesirable to have the area underneath 17 the slab empty, in which case the slab may rest on sand or earth. The paving slab is removed in the same way as described and the exposed earth or sand underneath the paving slab is dug up to gain access to the drain, pipe, telephone, television and electric cables or gas lines.

18

Claims

1. A panel that is removable from a position in which it is held by gravity in an aperture defined by a surrounding floor, wall or ground surface where the exposed surface of the panel is flush with the surrounding surface, the said panel being provided with a reinforcing insert having an outer rim defining an opening, said reinforcing insert being held in the body of the said panel such that the said outer rim is flush with that surface of the said panel which is exposed in use, said reinforcing insert being adapted to receive through said opening, and be engaged by, a lifting implement whereby the said panel is removable from the said aperture.

2. A panel as claimed in claim 1, wherein the reinforcing insert is offset from the centre of the panel.

3. A panel as claimed in claim 2, wherein the reinforcing insert is adjacent an edge of the 15 panel.

4. A panel as claimed in any of claims I to 3, wherein the opening of the reinforcing insert has an internal dimension which is such as to guard against the reinforcing insert being a health and safety hazard.

5. A panel as claimed in any of claims I to 4, wherein the internal dimension of the opening of the reinforcing insert is between 8mm and 1 Omm.

6. A panel as claimed in any of claims I to 5, wherein the reinforcing insert is in the form of a 25 sleeve having said outer rim and said opening at one end and another opening at its other end.

7. A panel as claimed in any of claims 1 to 5, wherein the reinforcing insert is in the form of a sleeve having said outer rim and said opening at one end and its other end closed.

8. A panel as claimed in any of claims I to 7, wherein the reinforcing insert is provided with means for holding the reinforcing insert within the body of the panel.

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9. A panel as claimed in claim 8, wherein the holding means is an external thread.

10. A panel as claimed in claim 9, wherein the holding means is a coarse external screw thread.

11. A panel as claimed in any of claims 1 to 10, wherein the reinforcing insert is of frustoconical external shape.

12. A panel as claimed in any of claims I to 11, wherein the reinforcing insert is hollow and has an internal wall of cylindrical shape which is internally threaded to be engageable by a complimentary external thread on the lifting implement.

13. A panel as claimed in claim 12, wherein the internal thread of the reinforcing insert is a coarse screw thread.

14. A panel as claimed in claim 12 or claim 13, wherein the internal thread of the reinforcing insert is a multi-start screw thread.

15. A panel as claimed in any of claims I to 11, wherein the reinforcing insert is hollow and provides an internal passage having a shoulder beneath which a projection on the lifting implement can be positively engaged by turning the lifting implement in relation to the reinforcing insert.

16. A panel as claimed in any of claims I to 15, wherein the said outer rim of the reinforcing insert is in the form of an outwardly projecting peripheral lip.

17. A panel as claimed in any of claims I to 16, wherein the panel is moulded and the reinforcing insert moulded into the panel.

18. A panel as claimed in any of claims I to 16, wherein the reinforcing insert is inserted in a hole in the panel.

19. A panel as claimed in claim 18, wherein the hole is in the form of a "blind" hole or a through-hole.

20. A panel as claimed in claim 18 or claim 19, wherein the hole has a countersunk mouth 5 within which the outer rim fits.

21. A panel as claimed in any of claims 18 to 20, wherein the hole is provided with an adhesive for use in holding the reinforcing insert within the body of the panel.

22. A panel, substantially as hereinbefore described with reference to or as illustrated in Figures 1 to 5 of the accompanying drawings.

23. A method of providing a panel that is removable from a position in which it is held by gravity in an aperture defined by a floor, wall or ground surface where the exposed surface of the panel is Rush with the surrounding surface, including providing the panel with a reinforcing insert having an outer rim defining an opening, inserting the said reinforcing insert in the body of the said panel such the reinforcing insert is held in the body of the panel and the said outer rim is flush with that surface of the said panel which is exposed in use.

24. A method as claimed in claim 23, including locating the reinforcing insert in a position which is offset from the centre of the panel.

25. A method as claimed in claim 24, wherein the position of the reinforcing insert is adjacent an edge of the panel.

26. A method as claimed in any of claims 23 to 25, including providing the opening of the reinforcing insert with an internal dimension which is such as to guard against the insert being a health and safety hazard.

27. A method as claimed in any of claims 23 to 26, including providing the reinforcing insert with a sleeve having said outer rim and said opening at one end and another opening at its other end.

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28. A method as claimed in any of claims 23 to 26, including providing the reinforcing insert with a sleeve having said outer rim and said opening at one end and its other end closed.

29. A method as claimed in any of claims 23 to 28, including providing the reinforcing insert with means for holding the reinforcing insert within the body of the panel.

30. A method as claimed in claim 29, wherein the holding means is an external thread.

3 1. A method as claimed in claim 28, wherein the holding means is a coarse external screw thread.

3 2. A method as claimed in any of claims 23 to 3 1, including providing the reinforcing insert with a frusto-conical external shape.

33. A method as claimed in any of claims 23 to 32, wherein the reinforcing insert is hollow and cylindrical with an internal wall of cylindrical shape, and the method includes providing the internal wall with a internal thread which is engageable by a complimentary external thread on the lifting implement.

34. A method as claimed in claim 33, wherein the internal thread of the reinforcing insert is a coarse screw thread.

35. A method as claimed in claim 33 or claim 34, wherein the internal thread of the reinforcing 25 insert is a multi-start screw thread.

36. A method as claimed in any of claims 23 to 32, wherein the reinforcing insert is hollow, and the method includes providing an internal passage in the reinforcing insert having a shoulder beneath which is positively engageable with a projection on the lifting implement by 30 turning the lifting implement in relation to the reinforcing insert.

37. A method as claimed in any of claims 23 to 36, including forming the outer rim of the 22 reinforcing insert with an outwardly projecting peripheral lip.

38. A method as claimed in any of claims 23 to 37, including moulding the panel and moulding the reinforcing insert into the panel.

39. A method as claimed in any of claims 23 to 37, including forming a hole in the panel into which the reinforcing insert can be inserted.

40. A method as claimed in claim 39, wherein the hole is a "blind" hole or a through-hole.

4 1. A method as claimed in claim 3 9 or claim 40, including forming the opening in the hole with a countersunk mouth and fitting the outer rim in said mouth.

42. A method as claimed in any of claims 3 9 to 4 1, wherein the hole is drilled into the panel.

43. A method as claimed in any of claims 39 to 42, including providing the hole with an adhesive for use in holding the reinforcing insert within the body of the panel.

44. A method of providing a panel, substantially as hereinbefore described with reference to or as illustrated in Figures I to 5 of the accompanying drawings.

45. A kit of parts for use in removing a panel from a position in which it is held by gravity in an aperture defined by a floor, wall or ground surface where the exposed surface of the panel is flush with the surrounding surface, said kit of parts including a reinforcing insert having an outer rim defining an opening and being adapted to be held within the body of such a panel such that the outer rim is flush with that surface of the panel which is exposed in use, and a lifting implement which is engageable within the said insert.

46. A kit of parts as claimed in claim 45, and further including the said panel.

47. A kit of parts as claimed in claim 45 or claim 46, wherein the internal dimensions of the opening of the reinforcing insert are such as to guard against the reinforcing insert being a 23 health and safety hazard.

48. A kit of parts as claimed in any of claims 45 to 47, wherein the internal dimension of the opening of the reinforcing insert is between 8mm and 10mm.

49. A kit of parts as claimed in any of claims 45 to 48, wherein the reinforcing insert is in the form of a sleeve having said outer rim and said opening at one end and another opening at its other end.

50. A kit of parts as claimed in any of claims 45 to 48, wherein the reinforcing insert is in the form of a sleeve having said outer rim and said opening at one end and its other end closed.

1. A kit of parts as claimed in any of claims 45 to 50, wherein the reinforcing insert is provided with means for holding the reinforcing insert within the body of the panel.

52. A kit of parts as claimed in claim 5 1, wherein the holding means is an external thread.

3. A kit of parts as claimed in claim 5 1, wherein the holding means is a coarse external screw thread.

54. A kit of parts as claimed in any of claims 45 to 53, wherein the reinforcing insert is of frusto-conical external shape.

55. A kit of parts as claimed in any of claims 45 to 54, wherein the reinforcing insert is hollow and has an internal wall of cylindrical shape which is internally threaded to be engageable by a complimentary external thread on the lifting implement.

56. A kit of parts as claimed in claim 55, wherein the internal thread of the reinforcing insert is a coarse screw thread.

57. A kit of parts as claimed in claim 55 or claim 56, wherein the internal thread of the reinforcing insert is a multi-start screw thread.

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58. A kit of parts panel as claimed in any of claims 45 to 54, wherein the reinforcing insert is hollow and provides an internal passage having a shoulder beneath which a projection on the lifting implement can be positively engaged by turning the lifting implement in relation to the 5 reinforcing insert.

59. A kit of parts as claimed in any of claims 45 to 58, wherein the said outer rim of the reinforcing insert is in the form of an outwardly projecting peripheral lip.

60. A kit of parts as claimed in any of claims 45 to 59, wherein the said lifting implement comprises a handle terminating in an engagement member, and wherein the said engagement member is receivable through the opening of, and engageable within, the reinforcing insert of the panel. 15

61. A kit of parts as claimed in claim 60 as appended to claim 55, wherein the engagement member is provided with an external thread which is engageable with the internal thread of the reinforcing insert.

62. A kit of parts as claimed in claim 60 as appended to claim 58, wherein the engagement 20 member is provided with an outwardly extending projection such that the engagement member is insertable in a passage in the reinforcing insert which terminates in a cavity that provides a shoulder beneath which the projection on the lifting implement can be positively engaged by turning the lifting implement in relation to the reinforcing insert. 25

63. A kit of parts as claimed in any of claims 60 to 62, wherein the lifting implement is provided with a surface that is located between the handle and the engagement member and which abuts against the exposed surface of the panel to act as a stop and to prevent bending of the engagement member during the removal of the panel from the aperture. 30

64. A kit of parts as claimed in any of claims 60 to 63, wherein the handle of the lifting implement is connected to the engagement member by pivotable means for enabling the handle to move relative to the engagement member during the removal of the panel from the aperture.

65. A kit of parts as claimed in claim 64, wherein the said pivotable means is a hinge or a universal joint.

66. A kit of parts as claimed in claim 64 or claim 65, wherein the lifting implement includes restricting means which is movable between a position in which movement of the pivotable means is prevented and permitted respectively.

67. A kit of parts as claimed in claim 66, wherein the restricting means comprises a sleeve 10 which normally covers the pivotable means to prevent the said movement of the handle relative to the engagement means and which is moveable to uncover the pivotable means to permit the said relative movement of the handle.

68. A kit of parts as claimed in claim 67, wherein biasing means is provided to urge the 15 restricting means into the position in which the relative movement of the handle is prevented.

69. A kit of parts as claimed in claim 68, wherein the biasing means is a compression spring.

70. A kit of parts as claimed in claim 68 or claim 69, wherein the pivotable means is connected 20 to the handle via a shaft which is telescopically mounted within a tubular member that is rigid with the sleeve at one end and a gripping member at its other end, with the said biasing means acting between the handle and the gripping member such that movement of the gripping member towards the said handle moves the sleeve and uncovers the pivotable means to permit movement of the handle relative to the engagement member. 25

71. A kit of parts as claimed in claim 70, wherein the biasing means urges the sleeve against a stop to delimit the amount of covering movement of the sleeve.

72. A kit of parts, substantially as hereinbefore described with reference to or as illustrated in 30 Figures 4, 5 and 6 of the accompanying drawings.

73. A kit of parts, substantially as hereinbefore described with reference to or as illustrated in 26 Figures 4, 5 and 7 of the accompanying drawings.

74. A kit of parts, substantially as hereinbefore described with reference to or as illustrated in Figures 4, 5, 8, 9 and 10 of the accompanying drawings.

75. A kit of parts, substantially as hereinbefore described with reference to or as illustrated in Figures I to 6 of the accompanying drawings.

76. A kit of parts, substantially as hereinbefore described with reference to or as illustrated in 10 Figures 1 to 5 and 7 of the accompanying drawings.

77. A kit of parts, substantially as hereinbefore described with reference to or as illustrated in Figures I to 5 and Figures 8 to 10 of the accompanying drawings.

78. A lifting implement for removing a panel as claimed in any of claims I to 22 from a position in which it is held by gravity in an aperture defined by a surrounding floor, wall or ground surface where the exposed surface of the panel is flush with the surrounding surface, the said lifting implement comprising a handle terminating in an engagement member, wherein the said engagement member is receivable through the opening of, and is engageable in, the 20 reinforcing insert of the panel.

79. A lifting implement as claimed in claim 78, wherein the lifting implement is provided with a surface that is located between the handle and the engagement member and which abuts against the exposed surface of the panel to act as a stop and to prevent bending of the 25 engagement member during the removal of the panel from the aperture.

80. A lifting implement as claimed in claim 78 or claim 79, wherein the handle of the lifting implement is connected to the engagement member by pivotable means for enabling the handle to move relative to the engagement member during the removal of the panel from the aperture.

8 1. A lifting implement as claimed in claim 80, wherein the said pivotable means is a hinge or a universal joint.

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82. A lifting implement as claimed in claim 80 or claim 81, wherein the lifting implement includes restricting means which is moveable between a position in which movement of the pivotable means is prevented and permitted respectively.

83. A lifting implement as claimed in claim 82, wherein the restricting means comprises a sleeve which normally covers the pivotable means to prevent the said movement of the handle relative to the engagement means and which is moveable to uncover the pivotable means to permit the said relative movement of the handle.

84. A lifting implement as claimed in claim 83, wherein biasing means is provided to urge the restricting means into the position in which the relative movement of the handle is prevented.

85. A lifting implement as claimed in claim 84, wherein the biasing means is a compression spring.

86. A lifting implement as claimed in claim 84 or claim 85, wherein the pivotable means is connected to the handle via a shaft which is telescopically mounted within a tubular member that is rigid with the sleeve at one end and a gripping member at its other end, with the said biasing means acting between the handle and the gripping member such that movement of the gripping member towards the said handle moves the sleeve and uncovers the pivotable means to permit movement of the handle relative to the engagement member.

87. A lifting implement as claimed in claim 86, wherein the biasing means urge a sleeve against a stop to delimit the amount of covering movement of the sleeve.

88. A lifting implement as claimed in claim 86, wherein the engagement member is provided with an external thread which is engageable with the internal thread of the reinforcing insert.

89. A lifting implement as claimed in claim 86, wherein the engagement member is provided with an outwardly extending projection such that the engagement member is insertable in a or the passage in the reinforcing insert that provides a shoulder beneath which the projection on 28 the lifting implement can be positively engaged by turning the lifting implement in relation to the reinforcing insert.

90. A lifting implement as claimed in claim 87, wherein the engagement member is provided with at least one engagement element that is movable between a first position in which the said at least one engagement element permits entry of the engagement member through the opening of the reinforcing insert and into a passage defined by the reinforcing insert and a second position in which the said at least one engagement element is actuated to hold the engagement member within the reinforcing insert.

91. A lifting implement as claimed in claim 90, wherein an actuating member is provided which acts in use upon the said at least one engagement element when the engagement member reaches the bottom of the passage to move the said at least one engagement element between the first and second positions.

92. A modification of the lifting implement as claimed in claim 91 as appendant to any of claims 80 to 87, wherein the actuating member is constituted by the said pivotable means such that the actuating member is actuated when the said pivotable means is operated.

93. A lifting implement as claimed in any of claims 90 to 92, wherein the said at least one engagement element takes the form of a plurality of balls or movable gripping lugs which are supported by the engagement member and are inoperable in the said first position and which project ftom the engagement member into an annular recess in the wall of the passage in the said second position to hold the engagement member within the reinforcing insert. 25

94. A lifting implement, substantially as hereiribefore described with reference to or as illustrated in Figure 6 of the accompanying drawings.

95. A lifting implement, substantially as hereiribefore described with reference to or as 30 illustrated in Figure 7 of the accompanying drawings.

96. A lifting implement, substantially as hereiribefore described with reference to or as illustrated in Figures 8 to 10 of the accompanying drawings.

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97. A method of removing a panel as claimed in any of claims I to 22 from a position in which it is held by gravity in an aperture defined by a surrounding floor or ground surface where the exposed surface of the panel is flush with the surrounding surface, including providing the panel with a reinforcing insert held in the body of the panel, engaging a lifting implement as claimed in any of claims 78 to 96 in the said reinforcing insert and operating the said lifting implement to remove the panel from the aperture.

98. A method as claimed in claim 97 as appended to claim 79, wherein the lifting implement is 10 turned to engage the engagement member in the reinforcing insert.

99. A method as claimed in claim 98, wherein the lifting implement is turned until the said abutment surface abuts the exposed surface of the panel.

100. A method as claimed in any of claims 97 to 99, wherein the panel is lifted onto an edge of the aperture by raising the engaged lifting implement.

101. A method as claimed in any of claims 97 to 100 as appendant to any of claims 80 to 96, wherein the handle is pivoted in relation to the engagement member and the lifting implement 20 is pulled with a sliding motion to remove the panel from the aperture.

102. A method as claimed in any of claims 97 to 101 as appendant to any of claims 82 to 96, wherein the gripping member is moved against the biasing means to release the restricting means and the handle is pivoted in relation to the engagement member such that the panel can 25 be pulled from the aperture and slid along the surrounding surface.

103. A method of removing a panel from a position in which it is held by gravity in an aperture defined by a surrounding floor or ground surface where the exposed surface of the panel is flush with the surrounding surface, substantially as hereiribefore described with reference to or 30 as illustrated in Figures I to 6 of the accompanying drawings.

104. A method of removing a panel from a position in which it is held by gravity in an aperture defined by a surrounding floor or ground surface where the exposed surface of the panel is flush with the surrounding surface substantially as hereinbefore described with reference to or as illustrated in Figures I to 5 and Figure 7 of the accompanying drawings.

105. A method of removing a panel from a position in which it is held by gravity in an aperture defined by a surrounding floor or ground surface where the exposed surface of the panel is flush with the surrounding surface substantially as hereinbefore described with reference to or as illustrated in Figures I to 5 and Figures 8 to 10 of the accompanying drawings.

106. A method of removing a panel from a position in which it is held by gravity in an aperture defined by a surrounding floor or ground surface where the exposed surface of the panel is flush with the surrounding surface substantially as hereinbefore described with reference to or as illustrated in Figure 6 of the accompanying drawings.

107. A method of removing a panel from a position in which it is held by gravity in an aperture defined by a surrounding floor or ground surface where the exposed surface of the panel is flush with the surrounding surface, substantially as hereinbefore described with reference to or as illustrated in Figure 7 of the accompanying drawings.

108. A method of removing a panel from a position in which it is held by gravity in an aperture defined by a surrounding floor or ground surface where the exposed surface of the panel is flush with the surrounding surface, substantially as hereinbefore described with reference to or as illustrated in Figures 8 to 10 of the accompanying drawings.

109. A method of removing a panel from a position in which it is held by gravity in an aperture defined by a surrounding floor or ground surface where the exposed surface of the panel is flush with the surrounding surface, substantially as hereinbefore described with reference to or as illustrated in Figures 11 to 14 of the accompanying drawings.

110. A floor comprising at least one panel as claimed in any one of claims I to 22, wherein the panel is an access panel for a services duct.

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111. A floor as claimed in claim 110 and substantially as hereinbefore described with reference to or as illustrated in Figure 2 of the accompanying drawings.

112. A floor comprising a plurality of panels as claimed in any one of claims I to 22 supported 5 above a subfloor by supporting means.

113. A floor as claimed in claim 112, wherein the supporting means comprises at least one adjustable prop such as a screw jack.

114. A floor as claimed in either claim 112 or claim 113 and substantially as hereinbefore described with reference to or as illustrated in Figure 2a of the accompanying drawings.