GB2172029A

GB2172029A - Improvements to trench shoring equipment

Info

Publication number: GB2172029A
Application number: GB08601474A
Authority: GB
Inventors: Nigel Thompson
Original assignee: SHORCO TRENCH SYSTEMS Ltd
Current assignee: SHORCO TRENCH SYSTEMS Ltd
Priority date: 1985-01-22
Filing date: 1986-01-22
Publication date: 1986-09-10
Also published as: GB8501531D0; GB8601474D0

Abstract

Improved trench shoring apparatus comprises pairs of support posts 1 separated by transverse struts 4. Outer shoring panels 5 and inner shoring panels 7 are accommodated in stepped overlapping relationship within guide channels 2, 3 in the support post 1. Rollers 9, 12 are provided on each corner of each panel to bear against a corresponding surface of the support post 1 to ensure easy removal of the panels from the support posts 1. <IMAGE>

Description

SPECIFICATION Improvements to trench shoring equipment The present invention relates to improvements to trench shoring equipment using supports and slid ing panels.

Apparatus for supporting the walls of a trench or other excavation is described in Published Interna tional Patent Application No PCT/EP83/00198. This apparatus comprises pairs of support posts which are arranged in pairs opposite each other and which are separated by struts spanning the width of the trench. Each post has oppositely facing guide chan nels for accommodating the edges of inner and outer shoring panels, which are arranged in stepped overlapping relationship.

In operation, a trench is excavated to the required depth. A pair of support posts is lowered into one end of the trench, and each post is then pushed down until it is firmly embedded. An outer shoring panel is slid down to the bottom of the excavated trench on each side of the trench, guided in the guide channels of the support posts. A second pair of support posts and associated struts is then lowered over the free ends of the outer shoring panels. The trench excavation is then continued, pressing the support posts and panels down further as excava tion proceeds, until the tops of the panels are at ground level. Inner panels are then inserted into the guide channels in order to give support to the walls during subsequent excavation.

Further excavation is then carried out, the inner panels and posts being pushed down until the trench has been fully excavated, when the tops of the posts may be at substantially the same level as the tops of the outer panels. The upper portion of the inner panels overlap the lower portions of the outer panels, so that a depth of trench is shored which is greater than the depth of the individual panels.

When work within the trench has been completed and back filling has commenced, the panels are withdrawn using either a crane or excavator attached to the panels with chains to pull the panels vertically through the guide channels in the support posts.

A disadvantage of this system is that as the panels are withdrawn, they often tilt so that the upper edge of the panel departs from the horizontal causing diagonally opposite corners of the panel to dig into the guide channels, thus preventing easy removal of the panels from the support posts.

According to the present invention there is pro vided apparatus for shoring the walls of a trench, comprising inner and outer pairs of shoring panels whose lateral edges are slidably guided by opposite ly aligned support posts held in a spaced apart relationship by struts, each support post having on each side thereof a guide channel to accommodate the edges of the inner and outer shoring panels in stepped overlapping relationship to shore a trench greater than the depth of a single panel, there being at least one roller mounted so that there is provided a rolling surface contact between the or each panel and its associated support posts.

Preferably a roller is mounted on the or each panel so as to bear against an associated support post.

Preferably a roller is mounted at each of the four corners of the panel.

Preferably rollers are mounted at each of the four corners of all panels inserted between the support posts.

Preferably each roller is mounted on a stub axle within a recess in the panel, the longitudinal axis of the stub axle being substantially parallel to the longitudinal axis of the struts separating the pairs of support posts.

An embodiment of the present invention will now be described and contrasted with the currently known apparatus by way of example only with reference to the accompanying drawings in which: Figure lisa plan view of the currently known apparatus; Figure 2 is a plan view of the apparatus in accordance with the present invention; and Figure 3 is a perspective view of apparatus in accordance with the present invention.

With reference to Figure 1,the currently known apparatus as described in PCT/EP83/00198, comprises a support post 1 having guide channels 2,3 the support post 1 being linked to an identical support post on the other side of the trench by a transverse strut 4. Outer shoring panels 5 and inner shoring panels 7 each have flanges 8 extending along the depth of the panel such that both panels 5 and 7 can be slotted side by side into the guide channels 2, 3 of the support post 1.

With reference to Figure 2, apparatus in accordance with the present invention has the same components as the currently known apparatus described above with reference to Figure 1, the same reference numerals having being used for the same components in Figures 1 and 2, but also includes a roller 9 mounted centrally at an edge of an outer panel 5 on a fixed stub axle 9a within a recess 10 of the outer panel 5, the longitudinal axis of the stub axle 9a being parallel to the longitudinal axis of the transverse strut 4. The edge of the roller 9 bears against the surface 11 of the support post 1.

An identical roller 12 is similarly mounted at one side of an inner panel 7 on a fixed stub axle 12a within a recess 13, the longitudinal axis of the stub axle 12a being parallel to the plane defined by the edge of the inner panel 7. The edge of the roller 12 bears against the surface 14 of the support post 1.

Identical arrangements are present at each end of each inner and outer shoring panel.

With reference to Figure 3, two rollers 15 and 16 are mounted at each edge of every shoring panel inserted between the support posts, the rollers 15 and 16 being mounted close to the upper edge 17 and the lower edge 18 respectively of each panel.

When the shoring panels are removed the rollers roll along the guide channels 2,3 in the support post 1 and thus prevent the corners of the panels jamming against the support rails as a result of the tilting of the panel.

Claims

1. Apparatus for shoring walls of a trench, comprising inner and outer pairs of shoring panels whose lateral edges are slidably guided by oppositely aligned support posts held in a spaced apart relationship by struts, each support post having on each side thereof a guide channel to accommodate the edges of the inner and outer shoring panels in stepped overlapping relationship, to shore a trench greater than the depth of a single panel, there being at least one roller mounted so that there is provided a rolling surface contact between the or each panel and its associated support post.

2. Apparatus according to Claim 1 in which a roller is mounted on the or each panel so as to bear against an associated post.

3. Apparatus according to Claim 1 or Claim 2 in which a roller is mounted at or near each of the four corners of a panel.

4. Apparatus according to any of the preceding claims in which rollers are mounted at or near each of the four corners of all panels inserted between the support posts.

5. Apparatus according to any of the preceding claims in which each roller is mounted on a stub axle within a recess in the panel, the longitudinal axis of the stub axle being substantially parallel to the longitudinal axis of the strut separating the pairs of support posts.

6. Apparatus according to Claim 1 and substantially as herein described.

7. Apparatus for shoring the walls of a trench substantially as herein described with reference to Figures 2 and 3 of the accompanying drawings.