The metal bearing bracket (18) incorporates a vertical bore which may incorporate a supporting bolt. The bolt has an e.g. hexagonal head (5) with a flange (54) and a smooth shaft (6) there is a flange at the bottom of the smooth shaft above a threaded portion (40). The flange at the top of the bolt may rest on a flange (37) on top of a sleeve (25) of smaller diameter than the bore. The top portion of the bore is enlarged and is filled with a flexible e.g. rubber bush (10) which extends downward into the narrower diameter portion of the bore in the bracket.
