GB2276181A

GB2276181A - Interlocking building blocks

Info

Publication number: GB2276181A
Application number: GB9305586A
Authority: GB
Inventors: Roger Martin Cooper; Robert Charles Nunn
Original assignee: PHI DESIGN Ltd
Current assignee: PHI DESIGN Ltd
Priority date: 1993-03-18
Filing date: 1993-03-18
Publication date: 1994-09-21
Anticipated expiration: 2013-03-18
Also published as: GB2276181B; GB9305586D0

Abstract

A building block has the top and bottom provided with a first kind of form looking male (23) and female (24) connector, and each side provided with a second kind of form locking male (15) and female (16 - 20) connector; both kinds of connector are engageable by relative motion in a direction perpendicular to the top face of a block, and only one male connector of the second kind is provided. The block may be rectangular, of plastics material, (e.g. polyproplylene), and may be used to construct chambers below ground level. <IMAGE>

Description

BUILDING BLOCK This invention relates to building blocks, particularly interlocking blocks of moulded plastic.

Utility services (gas, water, telephone, electricity, cahle t.v. etc.) are usually laid underground and a long standing problem for utility providers has been the rapid and economical construction of the below ground chambers which are required for access to the service lines. Such chambers may for example give access to valves, meters and the like.

Historically such chambers have been constructed using conventional bricks held together by mortar, and a double wall is essential to avoid crushing loads from the surrounding soil or backfill. These brick chambers are very slow to build, require large quantities of materials, cannot be adapted to new circumstances when built and require skilled labour for construction, among other disadvantages.

Another approach has been to use rectangular concrete sections which can be stacked one upon the next until a chamber of the required size is formed. The concrete sections are very heavy and may require a small crane to lift them into place. Access apertures to bring the services into and out of the chamber must be constructed.

Both of these methods suffer the disadvantage that the construction materials are heavy, and thus must usually be transported to the site by a large truck. Ouantities must be predicted in advance and much time may be lost if a return visit for additional materials is required. Several workmen are usually necessary.

Proposed legislation placing a limit on the weight a workman may lift without assistance, and the total amount a workman may lift per day will make such chambers even more expensive to construct.

More recently it has been proposed to use preformed chambers of glass reinforced plastic. These offer a solution to the problems of weight and construction time but are not readily adaptable to the different service depths which may hecome apparent only when the chamber aperture is excavated. They are also bulky to transport and have relatively poor resistance to crushing loads. A large stock of different sized chambers is required for each service provider.

Utility providers are placing more and more equipment in underground chambers and frequently now require shelves or hooks onto which equipment can be placed - this can for example protect sensitive electrical metering equipment from ground water damage. It is not easy to provide such additional facilities in chambers constructed in the conventional manner.

What is required is an economical means of constructing an underground chamber which overcomes all of the aforementioned problems whilst meeting the additional needs of utility service providers.

According to the present invention there is provided a building block having a top, a bottom and four sides, the top and bottom lying in parallel planes and the four sides being perpendicular thereto and lying in two mutually perpendicular planes, the top and bottom being provided with a first kind of form locking male and female connector, and each side being provided with a second kind of form locking male and female connector, both first and second kinds of connectors being engageable by relative motion between two blocks in a direction perpendicular to said top plane and wherein said block has only one of the male connectors of the second kind.

A number of such blocks may be connected end to end by the connectors of the second kind to form a string, and several strings may be connected one above the other by the connectors of the first kind to form a wall. Connectors of the second kind allow joining of blocks at right angles, thus permitting construction of rectangular chambers of any desired size.

An important feature of the invention is the provision of only one male connector of the second kind on each block.

This arrangement ensures that the lateral (exposed) faces of a wall or chamber have no protrusions; the chamber is thus of maximum internal size and minimum external size, and the lack of protrusions permits unobstructed backfilling, and a relatively smooth snag free internal chamber surface. It is of course very important to ensure a relatively smooth external surface so that the ground aperture is the minimum size - an increase in aperture of only a few centimetres can necessitate substantial additional soil removal. The existence of female connectors of the second kind in the lateral faces ensures however that the chamber is keyed against movement when the aperture is backfilled.

A block according to the invention may have two opposite sides which are twice as long as the other two opposite sides, the male connector of the second kind being provided on one of said other two opposite sides. Such a block is like a regular house brick and has two substantially square modules. This block can be laid in a bond for increased strength, and can be used to connect two or more walls to make a multiple skin chamber.

Preferably this block has one male connector of the second kind and five female connectors of the second kind.

The blocks may be typically based on a cube of 75 mm and moulded in a plastic material such as polypropylene. A typical (standard) block may be 75 mm wide, 150 mm long and 75 mm deep; the end faces having opposed male and female connectors of the second kind, and the side faces having two equispaced female connectors of the second kind per side.

Half blocks or double blocks are possible, as are larger mouldings constituting wall portions. A half block would for example be square and have one connector of the second kind on each face.

Such blocks are very light and can be readily assembled into a chamber of the desired size by unskilled labour and without the use of joining materials such as mortar or adhesive. It is envisaged that chambers could be constructed by one man, and all the necessary materials carried in a small van.

Because the blocks are relatively small, the chamber size can be determined on site, and variations made as required.

In a preferred embodiment the top and bottom faces are provided with male connectors of the first kind on one face only; this arrangement ensures that one of the upper and lower faces is projection free.

The male connector of the first kind may comprise upstanding projections of substantially constant section; one of said top and bottom only may be provided with male connectors of the first kind.

The male connectors of the first kind may be provided one on each opposite side and at opposite ends or in the centre or along the length of said block, female connectors of the first kind being provided at other ends of each side and at opposite ends or in the centre or along the length of said block.

The female connectors of the first kind may comprise holes on the surface having said male connectors of the first kind, and open channels on the surface not having said male connectors of the first kind, said channels being open to the side of the block. The channels may extend substantially from the bottom of a block to the top.

In a preferred embodiment male connectors of the first kind are provided on one face only and in a mirror image about a plane of symmetry perpendicular to said face.

Preferably said face includes both male and female connectors of the first kind, the symmetrical arrangement ensuring that two blocks can be engaged top to bottom and that the faces with male connectors are engageable. This arrangement ensures that both an upper and lower chamber face may be formed without projections.

Adjacent layers of standard blocks may be bonded in the manner of house bricks but this is not essential since the connectors of the first and second kind provide adequate inter-block engagement.

The symmetry of the blocks necessary to ensure interengagement has other advantages. In particular the female connectors of the second kind are vertically aligned on the side walls. C-shaped connection strips may be provided to connect adjacent vertical groups of such female connectors, the strips sliding over the blocks in a vertical direction and thereby providing additional reinforcement.

These aligned female connectors can also receive corresponding male members forming part of shelves, hooks and the like, and otherwise provide a means of attachment for equipment in the chamber.

In order to permit access for services into and out of the chamber, blocks or half blocks can be omitted; the apertures around the service pipe or cable can be sealed by one or more shutters located for relative vertical movement in the aligned female connectors of the second kind.

Furthermore since the chamber can be constructed around existing services the problem of making apertures in preformed chambers or chamber sections does not arise.

Preferably the male or female connector of the second kind provided on opposite sides of the block includes obstruction means to permit interconnection by movement in one direction only. This ensures that adjacent blocks are prevented from sliding apart under the action of gravity if supported on one side only. Accordingly an assembled chamber or wall section can be carried to the installation site without danger of the blocks sliding apart. The obstruction means is preferably adjacent one of said top and bottom faces.

The male connector of the second kind is preferably waisted in a plane parallel to the top of the block; the male connector of the second kind may have a greatest width substantially at the outer extremity thereof and a minimum width immediately adjacent the side face of the block. Said outer extremity is preferably planar.

The male connector of the second kind is preferably symmetrical about a plane perpendicular to said top and passing through the male connector of the second kind and the female connector opposite thereto.

Preferably the male connector of the second kind and the female connector of the second kind are of substantially the same shape.

In the preferred embodiment the obstruction means comprise means filling the waisted portion of the male connector of the second kind.

Partition walls may be constructed between opposite internal faces of the chamber. In this case only one end of a block string can engage in an internal chamber face, but adjacent strings of blocks can have opposite ends engaged in opposite chamber faces. This arrangement provides more than adequate resistance to compressive loads which may be exerted by material surrounding the chamber.

Additional strip like or rectangular members may be provided to bring the upper surface of the chamber to the desired level, thereby to ensure that the chamber cover is flush with the ground. Such members may be of several different thicknesses and have projections or recesses for engagement with the blocks from which the chamber is constructed. Furthermore such members may have an upper form adapted to receive a standard cover or cover frame.

Alternatively a cover may be provided which is adapted to directly engage the upper wall surface of the chamber.

Blocks according to the invention are relatively easy to pack in a small space for storage by virtue of the lack of lateral protrusions. When laid on their side the blocks slide easily and have moreover a substantially flat upper surface on which other blocks or equipment may easily slide.

One embodiment of the block will now be described with reference to the accompanying drawings in which: Fig. 1 is a side elevation of a moulded block according to the invention; Fig. 2 is a plan of the block shown in Fig. 1; Fig. 3 is a view of the underside of the block shown in Fig. 1; Figs. 3.1 and 3.2 are perspective views of the block of Fig. 1; Fig. 4 is a view of the underside of a rectangle of blocks according to the invention; Figs. 5 and 5.1 are views of the underside of other rectangles of blocks according to the invention; Fig. 6 shows a strap to hold adjacent blocks against separating forces; Fig. 7 shows an internal engagement member to hold blocks side by side; Fig. 8 shows a partial block wall having an aperture; Fig. 9 shows a pair of half shutters for the aperture of Fig. 9; and Fig. 10 is a horizontal section through one of the half shutters of Fig. 9.

With reference to the drawings a moulded polypropylene block 11 comprises two substantially rectangular chambers 12,13 separated by a wall 14; the chambers 12,13 are to reduce material content whilst the wall 14 provides support for the long sides of the block as illustrated.

The chambers 12,13 may have an additional partition wall extending parallel to the top and bottom of the block and substantially mid-way between the top and bottom. Such a wall provides additional stiffening and may also be used as the means of distributing mould material through the mould for the block.

The peripheral wall of the block includes one projection 15 and five recesses 16-20; the projection and recesses constitute male and female form locking members as will be apparent from the following description.

The projection 15 is waisted (undercut) so that the tip of the head is of larger width than the base. The recesses 16-20 are of a conforming shape and are thus adapted to receive a projection by relative sliding movement in a direction perpendicular to the top face. The projection 15 and recesses 16-20 extend from top to bottom of the block as illustrated but the waisted portion of projection 15 is closed at the upper end by ribs 21 which ensure engagement of the projection 15 with a recess 16-20 only by the lower end of the projection. The ribs 21 ensure that adjacent blocks can be engaged in one direction only, the ribs also acting as a stop to prevent sliding out of engagement except by reversal of the engagement movement.

The recesses 16-20 are relieved at their upper ends by corresponding areas 22 to ensure proper horizontal alignment of interengaged blocks.

As shown most clearly in Figs. 3.1 and 3.2, the upper surface of the block has a series of symmetrically arranged studs 23 and apertures 24. The studs 23 are substantially cylindrical and have a diameter slightly less than that of the apertures 24. As can be seen, the studs are staggered along the upper face and alternate with the apertures, the arrangement being such that when the upper faces of two blocks are pushed together, each stud 23 will engage a corresponding aperture 24. Furthermore when blocks are laid in a horizontally staggered bond, the stud half of one block will engage with the recess half of another block. It will further be apparent that blocks may be assembled face to face in vertical alignment or staggered, with studs at opposite ends. This permits an increased number of assembly arrangements.The studs 23 are hollow to reduce material content and to increase flexibility.

The block is provided with eight grooves 25 on the outer face, corresponding to the position of the studs 23 and aperture 24. The grooves at either end are open to a respective short side of the block whereas the centre grooves are open to a respective long side of the block.

The grooves have substantially parallel sides and are of the same width as the apertures 24; each groove is semicircular at its inner end to correspond with the circumference of an aperture 24 or the outer periphery of a stud 23. The ribs 26 between adjacent centre grooves are cut back as shown.

The grooves 25 constitute female openings for engagement with the studs 23 when blocks are engaged top to bottom. This arrangement enables adjacent blocks to engage top to bottom in all possible configurations and without regard to the disposition of the studs 23. Accordingly blocks may be engaged in vertical alignment, in a horizontal bond, with projections at one end or the other, and most importantly at right angles in all eight possible configurations. Thus rectangular structures with an overlapping corner bond can be constructed without regard to the direction of adjacent layers (projections 15 at right end or left end).Furthermore the orientation of adjacent layers (right way up or upside down) may be reversed whilst ensuring proper engagement of studs 23 and apertures 24; this arrangement permits both top and bottom surfaces of a structure to be projection free, the outer layers having inward facing studs 23.

The grooves 25 also serve the purpose of keeping material content low whilst stiffening the block against distortion and providing a block which is easily moulded.

Fig. 4 illustrates the underside of a rectangle of blocks according to the invention. Engagement of adjacent blocks in-line and at right angles can be clearly seen.

Fig. 5 illustrates another rectangle, one half of one block longer than the rectangle of Fig. 4. In this case a portion of block extends at opposite ends and this arrangement may advantageously key the structure into the ground. Alternatively a half block may be substituted at opposite corners to provide a rectangle free of protrusions.

Fig. 6 illustrates how 'C' shaped members 31 of constant section and appropriate length may be slipped over a junction between two blocks to reinforce the form lock provided by male members 15 and recess 18. The 'C' shaped members 31 may be of any suitable material and may be provided in long lengths to be sawn to size on site. The members 31 may extend upwardly or downwardly of the chamber to engage the chamber base or ground, and/or a cover of the chamber. The members 31 may be adapted to slide over the blocks from top or bottom, or may be snapped into place by the inherent resilience thereof; metal or plastic members 31 are envisaged.

Fig. 7 illustrates means for holding rows of adjacent blocks side by side. A member 32 or 33 or 34 of a length to suit the chamber is passed between adjacent blocks and has arms which extend outwardly to engage within opposed recesses as illustrated. Once locked together in this fashion the members cannot easily move apart. Again the members 32-34 can be of any suitable section and material; they may be of indefinite length and cut to the required size on site. The members 32-34 may be engaged vertically by sliding, or laterally by resilient deformation.

The chamber may include a preformed base and or cover having peripheral projections or recesses for engagement with the blocks.

Hooks of any convenient shape may be slid or resiliently snapped into engagement with the recesses to support equipment and or shelves and the like. The hooks may be retained in any convenient manner, for example by screwing through a flange into the wall of an adjacent block.

Fig. 8 illustrates how an aperture 36 can be created in a wall by making, for example, a half block spacing between blocks 37 and 38. The aperture is bounded at the top and bottom by blocks 39 and 40; other blocks are not shown.

The aperture may be closed for example by half shutters sliding in the channels provided by the recesses e.g. 20,19. Redundant holes may be closed by a sliding closure plate.

Fig. 9 illustrates a pair of half shutters 41,42 having semi-circular cut-outs to engage around a water pipe - the shutters move apart in the direction indicated by arrows A. Each half shutter is formed with projections 43 to engage a recess, e.g. 20. The shutters need not slide and may be adapted to be snapped into place. A closing plate can be manufactured in a similar way.

Claims

1. A building block having a top, a bottom and four sides, the top and bottom lying in parallel planes and the four sides being perpendicular thereto and lying in two mutually perpendicular planes, the top and bottom being provided with a first kind of form locking male and female connector, and each side being provided with a second kind of form locking male and female connector, both first and second kinds of connectors being engageable by relative motion between two blocks in a direction perpendicular to said top plane and wherein said block has only one of the male connectors of the second kind.

2. A block as claimed in claim 1 having two opposite sides which are twice as long as the other two opposite sides, the male connector of the second kind being provided on one of said two opposite sides.

3. A block as claimed in claim 1 or 2 provided with one male connector of the second kind and five female connectors of the second kind.

4. A block as claimed in any one of claims 1 to 3 wherein the top and bottom faces are provided with male connectors of the first kind on one face only.

5. A block as claimed in any one of claims 1 to 4 in which male connectors of the first kind are provided one on each opposite side and at opposite ends and/or in the centre of said block, with female connectors of the first kind being provided at other ends of each side and at opposite ends and/or in the centre of said block.

6. A block as claimed in any one of claims 1 to 5 wherein the female connectors of the first kind comprise holes on the face having said male connectors of the first kind and open channels on the surface not having said male connectors of the first kind, the channels being open to the side of the block.

7. A block as claimed in any one of claims 1 to 6 wherein the female connector of the second kind includes obstruction means to permit interconnection by movement in one direction only.

8. A block as claimed in any one of claims 1-7 wherein the male connector of the first kind comprises an upstanding projection of substantially constant section.

9. A block as claimed in claim 8 wherein male connectors of the first kind are provided on one face only and in a mirror image about a plane of symmetry perpendicular to said face.

10. A block as claimed in claim 9 wherein said face is provided with both male and female connectors of the first kind so that the faces of two such blocks can be engaged

11. A wall comprising a plurality of blocks as claimed in any one of claims 1 to 9 connected end to end by connectors of the second kind and on top of one another by connectors of the first kind.

12. A wall as claimed in claim 10 characterised in that the female connectors of the second kind are aligned vertically.

13. A wall as claimed in claim 11 provided with a cshaped strip to connect adjacent vertical groups of said female connectors, the strip sliding over the blocks in a vertical direction and thereby providing additional reinforcement.