GB2086448A - Jack strut assembly - Google Patents

Abstract

A strut assembly has a pair of spaced longitudinally extending surfaces formed respectively on back-to-back channel members 3, and jack means 10 at one end thereof arranged to act longitudinally of the assembly. <IMAGE>

Description

SPECIFICATION Jack strut assembly This invention relates to a strut assembly for use primarily in the civil engineering industry for such purposes as the underpinning of building structures during erection. An object of the invention is to provide a strut assembly of simple and robust construction and which is relatively flexible in application as compared with some conventional struts.

According to the invention, a strut assembly comprises a strut element having a pair of elongate channel-shaped members arranged in base-to-base relationship and jack means secured to one end of the strut element and arranged to act longitudinally of the strut.

In one convenient arrangement, the jackis incorporated in a separate base to which the strut element is secured to form the strut assembly. Alternatively, the jack may be incorporated in the strut element and may extend between the bases of said channelshaped elements.

The invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure lisa perspective part-fragmentary view of one form of the strut assembly of the invention; Figure 2 is a perspective part-fragmentary view of an alternative form of the strut assembly of the invention; Figure 3 is a part-fragmentary side elevation of another alternative form of the strut assembly of the invention; Figure 4 is a cross-section along the line IV-IV of Figure 3; Figures 5 and 6 show respectively alternative arrangements of the strut assembly of the invention used as a shoring strut; Figure 7 shows a further alternative arrangement of the strut assembly of the invention used as a shoring strut; Figure 8 is an enlarged cross-sectional view along the line 2-2 of Figure 7;; Figure 9 is a cross-section along the line 3-3 of Figure 7, and Figure 10 is a plan view of a still further alternative arrangement of the strut assembly of the invention used as a shoring strut.

Referring to Figure 1 of the drawings, this shows a strut assembly including a base 1 upon which are securely mounted three strut elements 2, one of which is omitted for eash of illustration. Each strut element 2 is conveniently, but not essentially, in the form of a standard soldier composed of a pair of channel members 3 arranged back-to-back and connected together at their upper and lower ends by end plates 4, of which only the lower ones are illustrated.

The bases 5 ofthe channels extend in generally parallel relationship and are provided with a series of circular apertures 6, the apertures in one of the members 3 being aligned with the respective corresponding apertures in the other member. The three soldiers are arranged symmetrically on the base 1 with three respective sides thereof closely adjacent near to the centre of the base. The soldiers thus form a generally star-shaped configuration, being angularly spaced about said plate centre, in this embodiment by 1200, although any otherconve- nient angular disposition may be used.

Ajacking device, indicated generally at 7 has a cylindrical body 8 from which extend radial support ing webs 9, the body and webs being rigidly secured to the base 1, as by welding for example. The body 8 contains a jack screw 10 projecting outwardly and downwardly therefrom, the free lower end of the screw 10 being attached to a supporting foot 11 indicated as a square plate but which may be of any convenient form. A nut member 12 is engaged with the screw 10 and provided with handles 13 for the application of torque thereto. The nut 12 bears against the underside of the body 8 and rotation of the nut in one direction or the other will cause a corresponding lengthening or shortening of the strut assembly.

The base 1 is provided on some or all of its sides with connecting means shown as lengths oftube 14 of such dimensions as to co-operate with couplers 15, permitting the connection to the strut assembly of bracing members 16. The connecting members may take various alternative forms in place of the tubes 14 and the coupling members may be used to connect the bracing members 16 in fixed or pivotal manner and in various orientations, as described more fully in our co-pending Patent Application entitled "Strut Assembly with Bracing Connection". The facility for the connection of bracing members is particularly useful when the strut assembly is to be used side-by-side with other similar assemblies, since the bracing members can be used to connect the assemblies together and provide additional rigidity to the structure.

In the alternative embodiment shown in Figure 2, a single strut 2 is used, together with a jacking device similar to that of Figure 1. In this arrangement, the jacking screw 10 extends into the space between the channel shaped elements 3 of the strut, for which purpose the bases 17 of the strut elements are deformed outwardly at 18 as shown, if necessary, in order to accommodate the screw.

In the alternative embodiment illustrated in Figures 3 and 4, the strut member 2 is constituted by a pair of standard soldiers 19, each similar to one of the soldiers 2 illustrated in Figure 1. In this embodiment the jack screw 8 is arranged within the space 20 between the opposed adjacent soldiers 19, the inner end portion of the jack screw 10 being supported by a slide 21 having flanges 22 which engage adjacent surfaces of the soldiers so as to afford guidance for the jack screw during relative movement between the strut elements and screw. The strut assembly of Figure 3 is shown provided with tubes 14 for the connection of bracing members by way of appropriate couplers and these may be arranged in any convenient manner and take any convenient form, as described above.

The strut assembly of the invention may be provided at one or both of its ends with a plurality of jacks, instead of the single jack as illustrated. It can be convenient to provide a three jack arrangement at one or both ends of the strut assembly and for this purpose, the base of the strut element may be provided with three generally radial legs, preferably angularly spaced by 1209 each leg being provided with a screw or hydraulic jack.

When the jacking devices are of the screw type as shown, the screw arrangement may be different to that described above. Instead of the nut member 12 being free to rotate relative to the jack body 8 and to the screw 10, the nut member may be secured, as by welding, to the body 8 and the screw 10 freely rotatable in the foot 11. Adjustment is then effected by turning the screw relative to the base and foot, conveniently by way of a bar inserted through a radial hole (not shown) in the screw for example. In another alternative arrangement, with a jacking device at each end of the strut assembly, the respective jack screws have threads of opposite hand and, with the nut members again secured to the body 8, lengthening or shortening of the strut assembly may be effected by rotating the strut element relative to the screws.

Figure 5 shows an embodiment of the strut assembly adapted for use in an inclined manner as a shoring element. The strut element 2 is provided at each end with a jacking device 7 having a cylindrical body 8 and radial supporting webs 9, the body 8 containing respective jacking screws 10A and 10B. In the arrangement shown, the strut assembly is used to support a standard vertical soldier 25, the lower end of which would normally be firmly secured to a base, as of concrete for example. The jack screw 10A is pivotally connected to a bracket 26 projecting from a plate 27 firmly secured to the soldier 25 by way of bolts 28 co-operating with clamping devices 29 which, in the example shown, co-act with the edges of the solider apertures 6. The jack screw lOB is pivotally connected to a supporting foot 30.The respective threads of the jack screws 1 0A and 10B are of opposite hand and engaged with corresponding threads formed within the bodies 8. Thus, the length of the strut assembly may be varied by rotating the strut element 2 relative to the jack screws.

In Figure 6, a strut assembly similar to that shown in Figure 5 is shown shoring a horizontal soldier 31.

The jack screw 10A is again pivotally secured to a support plate 27 which, in this embodiment, is in turn secured by clamping devices 29 to the horizontal soldier 31 which would be arranged, for example, to bridge and be rigidly secured to atleasttwoverti- cal soldiers (not shown).

Figures 7 to 9 show a further embodiment of the strut assembly arranged for use as a shoring element. The strut assembly, which is particularly useful in high load applications, includes a strut element 100 which comprises a pair of channel members 101A, 101B arranged in back-to-back relationship and secured together by end plates 101 C (Figure 7).

Each channel member has a series of apertures 101D spaced longitudinally therealong, the apertures of the respective members being arranged in aligned pairs. The strut element 100 has jacking devices 7 similar to the devices 7 of Figure 5 secured to its respective ends, the jacking devices having respective jack screws 10Aand 10B extending longitudinally of the element 1. The jack screw lOB is pivotally connected to a supporting foot 30 secured to the ground by any convenient means. The jack screw 10A has a plain end portion 40 which is received within a socket 41 of a connecting member indicated generally at 42 and retained therein by suitable means shown as a pin 43 passed through the socket and end portion 40.The connecting member 42 is constituted, in this embodiment, by a tube 44, to the free end of which is secured, as by welding, an eye member in the form of a block 45 having a circular aperture 46 therethrough.

The strut assembly illustrated is used to support a standard vertical soldier 25, the lower end of which is firmly secured to the ground, conveniently to a base of concrete for example. As will be seen more clearly from Figure 8, the soldier is of similar construction to the strut element 1 and includes a pair of channel section members 103 disposed in back-toback relationship and secured together by end plates 104 (Figure 7). Each member 103 is provided with a series of apertures 105 arranged in similar mannerto the apertures 1 D of the strut element 1.

The tube 44 is connected to the soldier 25 by aligning the eye member 45 with a pair of apertures 105 and passing through the apertures and eye member a connecting sleeve 47 of which the outer diameter is slightly less than that of the holes in the solider and eye member respectively. The sleeve 47 is provided with a cross bar 48 arranged approximately diametrically across one end thereof and secured thereto, as by welding. The ends 49 of the cross bar are bent inwardly at right angles to the cross bar to form abutments which contact inner surface portions 50 of the adjacent channel member 103. The length of the portions 49 is chosen so as to ensure that the cross bar contacts the channel member 103 solely by way of the portions 49 and a clearance is maintained between the remainder of the cross bar and the adjacent surface ofthe channel.The sleeve is retained in position by a rod or similar device passed through opposed holes 51 in the sleeve 47.

The respective threads of the jack screws 1 0A and 10B are of opposite hand and engaged with corresponding threads formed within the base 7. The length ofthe strut assembly can consequently be varied by rotating the strut element 1 relative to the jack screws.

It will be appreciated that the strut assembly of the invention may be elongated by placing the strut elements in end-to-end relationship and such composite structures may incorporate connecting means between the adjacent strut ends for the connection thereto of bracing members, as more fully described in our co-pending Patent Application No. 8010379 entitled "Strut Assembly With Bracing Connections".

For relatively low load applications, the strut assembly of Figure 10 may be employed, arranged as previously in inclined relationship with a vertical soldier 25. This assembly is essentially similar to that of Figure 7, except for the manner of connecting the strut assembly to the soldier 25. In the Figure 10 arrangement, the tube 42 is provided at its free end with a pair of opposed jaws 201, 202, each having a cross bar 203 and a pair of flanges 204. A bolt 25 is secured axially to the tube 52 and extends freely through both of the cross bars 203.Adjusting nuts 206 set the spacing of the cross bars and by moving the nuts inwardly, the separation of the jaws may be made such as to permit the jaws to be passed laterally through a pair of aligned holes 105 of the soldier and adjusted outwardly into contact with the edges of the holes 25, as shown, to lock the strut assembly to the soldier. A head 207 of the bolt 205 retains the jaws on the bolt when not clamped in their operative positions.

In its preferred forms as illustrated, the strut assembly of the invention provides the considerable advantage that the strut elements employed are standard soldiers already used on building sites for a variety of supporting purposes. Thus, once a contractor has acquired a number of jacking devices, he has the facility to construct strut assemblies to form supporting structures from standard equipment already in his possession. It will be appreciated that any of the strut assemblies of the present invention may be elongated by placing strut elements in endto-end relationship and such composite structures may incorporate connecting means between the adjacent strut ends for the connection thereto of bracing members, as more fully described in our co-pending Application entitled "Strut Assembly with Bracing Connections". Afurther advantage is that a given structure, such as a gantry, may be made up relatively rapidly from a plurality of strut assemblies of the invention with appropriate bracing connections and rapidly dismantled after use.

The strut assembly of the invention is generally of use in transmitting load, ether in tension or compression, between opposed surfaces. It may be used vertically for supporting a building in the course of construction; it may also be horizontally disposed for supporting the sides of a trench for example, or inclined to the vertical and/or horizontal.

Claims (14)

1. A strut assembly comprising a strut element having a pair of elongate channel-shaped members arranged in base-to-base relationship and jack means secured to one end of the strut element and arranged to act longitudinally of the strut.

2. A strut assembly according to Claim 1 wherein the jack is incorporated in a separate base to which the strut element is secured to form the strut assembly.

3. A strut assembly according to Claim 1 wherein the jack is incorporated in the strut element.

4. A strut assembly according to Claim 3 wherein the jack extends between the bases of the channelshaped elements.

5. A strut assembly according to Claim 4 wherein the jack is a screw jack and a portion of the screw extends between said bases of the elements, said screw portion being supported by a slide engaging adjacent surfaces ofthe elements.

6. A strut assembly according to any one of the preceding claims provided at one end thereof with means operable to form a connection with an element to be supported.

7. A strut assembly according to Claim 6 wherein said connection-forming means provides a pivotal connection with the element to be supported.

8. A strut assembly according to Claim 7 wherein the connection-forming means is a plate adapted to be rigidly secured to the element to be supported, the plate having a lug apertured to receive a pivot pin passing through the jack to form said pivotal connection.

9. A strut assembly according to Claim 7 wherein the pivotal connection is formed by a connector passing through a pair of aligned openings formed respectively in said channel elements.

10. A strut assembly according to Claim 9 wherein the connector is in the form of a sleeve which is passed through an eye in the end portion of the jack inserted between the channel elements.

11. A strut assembly according to Claim 10 wherein the sleeve is provided at one end thereof with a transverse element which has abutments limiting the extent of insertion of the sleeve within the openings.

12. A strut assembly according to Claim 6 wherein the connection is formed by way of a pair of jaws secured to the jack and of which the axial spacing is adjustable, each jaw being adapted to bridge between the aligned openings of the channel elements so that the jack may be clamped to the channel elements by increasing the spacing of the jaws.

13. A strut assembly according to any one ofthe preceding claims having a jack at each end thereof.

14. A strut assembly substantially as hereinbefore described with reference to Figure 1, Figure 2, Figures 3 and 4, FigureS, Figure 6, Figures 7 to 9 or Figures 10 and 11 of the accompanying drawings.