GB2085940A - Jack for supporting modular floor - Google Patents

Abstract

A Jack has a base (11), a head (14), and body rising from the base to support the head. The body (13) is a hollow tube carrying a captive nut (17) which co-operates with a stud (12) rising from the base (11), so that the body is supported in height-adjustable manner on the stud. Releaseable mechanical means of adjustment take the form of studs (22) projecting from the undersurface of the base (11). The projecting ends of the studs (22) are hardened and ground conical. Rotation of the studs (22), one of which projects from each corner of the square base (11) brings the jacking surface of the jack head (14) into a desired attitude relative to a surface on which, in use, the jack base (11) stands. Thereafter, the conical ends of the studs (22) show virtually no tendency to rotate, thus tending to maintain the jacking surface in the desired attitude until the studs (22) are positively released. <IMAGE>

Description

SPECIFICATION Jack for supporting modular floor The invention relates to jacks.

The invention is particularly, though not exclusively, applicable to jacks for use in supporting what are currently called modular floors.

Modular floors are usually interior floors comprising a large number of tiles or floor boards supported edge-adjacent to one another. The surface defined by the modular tiles or boards is intended to be as flat as possible. Such floors are currently used in rooms which house computer equipment and other electrical equipment which needs extensive cabling and ducting. To accommodate the cabling and ducting, a modular floor is supported above the original basic floor of the building in which the equipment is housed.

The cabling and ducting occupy the space created between the original basic floor and the modular floor, and the upper surface of the modular floor then constitutes the new, raised, interior floor level of the building.

Known methods of supporting modular floors consist in supporting each corner area of adjacent tiles by a single screw jack. The jack is positioned underneath the edge-abutting tiles so that its head supports the mutually adjacent corners of four individual tiles whilst the base of the jack stands on the original basic floor beneath. The jack base is usually glued to the basic floor by a suitable adhesive, so that the stresses imposed on the modular floor in use will not cause the jack to shift its position on the basic floor.

The simplest form of floor-supporting jack is screw-adjustable in overall height but has no further adjustment. The jack head has an upper surface which is flat, and which is parallel to the undersurface of the jack base.

Once the jack is glued in place on the basic floor, the angular attitude of the jack head relative to the basic floor cannot be altered.

Should the jack base be set onto a part of the basic floor which is not truly horizontal, the region of the modular floor which the jack supports will not be truly level.

An improvement on this simple type of screw-adjustable supporting jack is also known. The improved jack is again screwadjustable for height, but has a two-part head.

The two parts of the head co-operate to give the jack head a limited universal articulation relative to the base of the jack. In use, adhesive is packed between the two co-operating parts of the jack head. The adhesive sets hard, but takes a long time, typically several hours, to set. The jack is located in position beneath the tiles and adjusted to its desired height. Similar adhesive is packed beneath the base; and the jack is then left to allow the adhesive to lock together the two parts of the head, and to glue the jack base to the basic floor.

With this improved type of jack, some settling of the modular floor can take place before the head is irrevocably locked by the adhesive. For example, work on adjacent jacks and tiles can disrupt the position of the tiles supported by the first-laid jacks, whilst the adhesive is still setting. Sideways stressing of the jack will later occur if the floor is heavily used. When this happens, either the jack base breaks away from the basic floor to which it has originally been glued, in order to accommodate the movement of the modular floor which has occured; or the jack refuses to budge and the tiles themselves ride out of alignment with one another. In the first case, the floor is no longer properly supported from beneath. In the second case, the floor is no longer uniformly level. In either case, the floor becomes unsafe.

Modern modular floors, especially when used to support computer equipment, are usually formed from tiles approximately two feet (0.6 metres) square. Even a relatively small room can require many such tiles. The number of jacks supporting the modular floor is correspondingly great, and the number of jack-supported points at which the floor can become unsafe is dangerously high. The twopart design of jack-head is expensive, and because a large number of jacks is needed for even a small floor the provision of such jacks becomes an abnormally expensive exercise.

Once the two-part articulating heads are locked by the set adhesive, they (and their jacks) can only be re-used if the adhesive bond is broken so that the two parts of the head are free to articulate before being locked by new adhesive into a new position: not all adhesives lend themselves easily to this operation.

The invention arises from the need to provide angular adjustment of the jacking (i.e.

floor supporting) surface of the jack head, relative to the basic floor surface on which the jack base stands, but without the drawbacks inherent in either the articulating-head design or the simple height-adjustable fixed-head design both discussed above.

In a jack embodying the invention, releasable mechanical means of adjustment are provided, which, when operated with the jack base standing on a surface, bring the jacking surface of the jack head into a desired attitude relative to the surface on which the jack base stands; and which, thereafter, tend to maintain the jacking surface in that attitude until the mechanical means are positively released.

Preferably the releasable mechanical means of adjustment operate, not between the jack head and the jack base but, in use, between the undersurface of the base of the jack and the surface on which the base is standing.

This is cheaper and more reliable than articulating the jack head relative to the jack base.

The means of adjustment may comprise one or more rotary-action elements projecting, by selectively variable amounts, from the jack base towards the surface on which, in use, the base is standing. Such elements are easily adjusted, and lend themselves to precise operation, by hand if necessary.

The, or each rotary-action element may be constituted by a screw one end of which can be caused to project progressively from the undersurface of the jack base. Suitable screw threads are available, and combine precision of adjustment with high load-bearing capability.

The jack may be a screw jack (i.e. a jack in which the distance between the jack head and the jack base is varied by a screw-and-nut action). These are cheap, rigid and reliable.

One jack embodying the invention is illustrated, by way of example only, in the accompanying drawings. In these drawings: Figure 1 shows the jack in sectioned side elevation; Figure 2 shows the jack in plan; Figure 3 shows the jack in perspective; and Figure 4 shows an alternative head for use with the jack of Figs. 1 to 3.

All the Figures of the drawings are drawn to approximately the same scale.

The jack illustrated in Figs. 1 to 4 will now be described with reference to the drawings.

Its main parts are a base, referenced 11, from which a screw-threaded stud 1 2 is upstanding; a jack body 1 3 supported in height adjustable manner on the stud 12; and a jack head 14 which is carried on the body 1 3. The base 11 and the head 14 are both flat mild steel plates of appreciable thickness, and are square when viewed in plan (i.e. when viewed as in Fig. 2). The jack body 1 3 is a rigid elongate steel tube, again square when viewed in plan, and is welded to the underside of the jack head 14 so as to project centrally from the undersurface of the head and at right angles to the top surface of the head.

The plates 11 and 14, the tubular section 13, and the threaded stud 12, are all readily and cheaply available from stock. In particular, the components 1 2 and 1 3 can be bought as finished lengths from which the required length of tube (13) or threaded stud (12) can be cut.

The stud 1 2 is screw-threaded throughout its length. A hole, sized to accommodate the stud 12, is drilled and tapped in the centre of the base plate 11. The stud 1 2 is screwthreaded into that hole. It is then welded, on both faces of the base plate 11, into the hole, as indicated respectively by the numbers 1 5 and 1 6. The weld 1 6 on the undersurface of the base plate 11 is then ground flat so that the base plate remains substantially flat across its undersurface. The stud 12 projects at right angles from the undersurface of the base plate 11.

A square-sided steel nut 1 7 is welded into the projecting end of the jack body 1 3. The nut 1 7 is centrally drilled and tapped to cooperate with the threaded stud 1 2. As Fig. 1 shows, when the stud 1 2 is screwed into the nut 17, the jack body 1 3 and head 14 are secured in height-adjustable relationship with the base 11; and the upper surface of the head 14 is parallel with the undersurface of the base 11.

Before the stud 1 2 is threaded into the nut 17, a second nut 1 8 is threaded onto the stud 12. The nut 18 is hexagonal. As Fig. 1 shows, it acts as a locknut. When the jack body 1 3 has been set at a desired distance along the stud 12, the nut 18 is brought hard against the nut 1 7 to lock the body 1 3 in position on the stud 1 2.

Relatively hard rubber strips 1 9 are glued around the periphery of the upper surface of the jack head 14. When the jack is in use, supporting the tiles 21 (shown in chain line) of a modular floor, the strips 1 9 cushion the supported tiles.

Hexagonally-headed studs 22 co-operate with holes drilled and tapped into the base plate 11. As Fig. 2 shows, there are four such holes, each given the reference number 23, each drilled and tapped adjacent one respective corner of the base plate 11 so as to extend through the base plate at right angles to its upper and lower opposed major surfaces. The projecting end of each stud 22 is hardened and is ground conical, as shown in Fig. 1.

In use, the studs 22 are initially retracted so that their conical ends do not project beyond the undersurface of the base plate 11. The jack is positioned beneath the mutually adjacent corners of four tiles so that, as shown in Fig. 3, its head 14 supports those four corners. It is set at a desired height by rotating the body 1 3 along the stud 1 2. It is then set in a desired attitude by adjusting the screws 22. When the upper surface of the jack head 14 has been set level by using these two degrees of freedom of movement of the surface, the nut 1 8 is brought hard against the nut 1 7 to lock the body 1 3 in place. The studs 22 do not need to be locked in place, since there is virtually no tendency for them to rotate once they have been set at their appropriate individual heights.

Slow-setting adhesive is packed beneath the base plate 11. The studs 22 hold the jack in position, relative to the basic floor on which it stands, as the adhesive sets. Once the adhesive is set, the jack base is held firmly in place beneath the modular floor tiles 21. The individual tiles can subsequently be removed and replaced without disturbing the jack.

Because the jack's attitude can be precisely adjusted initially, and then held in its adjusted position whilst the adhesive sets, any ten dency of the floor tiles 21 to settle subsequently is minimised. The overall flat surface of the modular floor is thus maintained without substantial side loads being placed on the jacks which support the floor. The jack described and illustrated combines the simplicity of the basic non-articulating screw jack with the adjustment of attitude given by the twopart-head articulating jack, yet avoids the latter's two main drawbacks--expense, and lack of positive maintenance of the adjusted position whilst the adhesive is setting.

In Fig. 4, the jack head is separable from the tubular body 1 3. A spigot 1 3A is a forcefit into the open upper end of the tubular body 1 3. The body 1 3 is circular in crosssection to accommodate the circular-section spigot. A jacking head 1 4 of any desired kind can be be fitted over the spigot 1 3A and will then be supported by the body 1 3. The head 14 will normally be a sliding fit or a force-fit on the spigot 13A.

The jack described and illustrated could, if necessary, support a central region of a tile of the modular floor. Such support is sometimes needed in addition to the described support to spread the loads imposed on individual tiles by heavy equipment standing on the tiles. It may also be needed in situations where the movement of parts of certain floor-standing equipment-for example, the intermittent acceleration and deceleration of computer discs-imposes repeated stresses on the tiles of the floor.

Claims (11)

1. A jack having a base, a head, and a body rising from the base to support the head; and also having releasable mechanical means of adjustment which, when operated with the jack base standing on a surface, bring the jacking surface of the jack head into a desired attitude relative to the surface on which the jack base stands, and which, thereafter, tend to maintain the jacking surface in that attitude until the mechanical means are positively released.

2. A jack according to claim 1, in which the releasable mechanical means of adjustment act, in use, between the undersurface of the jack base and the surface on which the base is standing.

3. A jack according to claim 1 or claim 2, in which the releasable mechanical means of adjustment comprise one or more rotary-action elements projecting, by selectively variable amounts, from the jack base towards the surface on which, in use, the jack base is standing.

4. A jack according to claim 3, in which the or each rotary-action element is constituted by a screw, one end of which can be caused to project progressively from the undersurface of the jack base.

5. A jack according to claim 4, in which the projecting end of the screw is conical.

6. A jack according to claim 5, characterised by the absence of any locknut or other means on the jack for locking the or each screw in a desired projecting position.

7. A jack according to any of the preceding claims, the jack being a screw jack, and the jack body having a non-round-section external surface.

8. A jack according to any of the preceding claims, the jack being a screw jack; the jack body comprising a hollow tube containing a captive nut; and the nut co-operating, in use, with a screw rising from the jack base to provide height-adjustment of the jack head relative to the jack base.

9. A jack according to claim 8, in which the jack base and screw are initially formed separately from, and subsequently secured to, one another; and the jack body and head are also initially formed separately from, and subsequently secured to, one another.

1 0. A jack according to claim 9, in which the jack base and the jack head are both formed from plate of substantially the same gauge and have substantially the same shape and configuration as one another.

11. A jack according to any of claims 8 to 10, in which a spigot, projecting from the undersurface of the jack head, fits releasably into the end of the hollow tubular jack body remote from the jack base.

1 2. A jack according to any of the preceding claims, in which strips of resilient material extend around the peripheral region of the jacking surface to define a substantially planar extension of the jacking surface.

1 3. A jack substantially as described herein with reference to, and as illustrated in, Figs. 1 to 3 of the accompanying drawings.

1 4. A jack according to claim 13, modified substantially as described herein with reference to, and as illustrated in, Fig. 4 of the accompanying drawings.