Thames Water – Expanding Beam
A unique issue was posed to us from one of our largest customers, regarding a low headroom travelling beam installation at one of their sites. This site contained two universal beams running parallel, close to the top of the ceiling of the enclosure (1). Headroom was too limited to install a travelling beam above or below the beams, therefore an expanding beam (2) was conceived to fit inside the flanges of the beams
Design requirements:
- 250kg WLL
- Total height < 150mm
- Fit through a gap 1150mm long, and expand to 1220mm
- 325mm of beam trolley travel (3)
- Stub axle bearings to sit inside beam flange (4)
This design has a simple premise, yet getting the expanding mechanism to fit in such a small space required several unique design considerations. Due to the geometry, bevel gears were required to allow the operator to expand the beam once in place, the expansion mechanism driven by a square thread which was chosen due to them requiring less resistance, as well as the large pitch allowing significantly less turns to open up the beam.
Combining these bespoke components within the expansion mechanism with the stub axle bearings and small captive beam trolley into a headroom of less than 150mm was a technical challenge, however the result was a compact expanding beam that satisfied all criteria and worked faultlessly.