the invention exemplary embodiments of the invention will now be described with reference to the accompanying drawings in which fig1 is a pictorial view of a fork lift truck to which is attached a swivel bearing unit that embodies the invention fig2 is a corresponding view to fig1 showing some of the components of the bearing unit fig3 is a cross sectioned side elevation of the bearing unit fig4 is a pictorial view showing a stage of assembly of the bearing unit fig5 is a sectioned side elevation corresponding to fig3 of another bearing unit fig6 is a sectioned side elevation corresponding to fig3 of a further bearing unit fig7 is a sectioned side elevation corresponding to fig3 of another bearing unit the apparatuses shown in the accompanying drawings and described below are examples which embody the invention it should be noted that the scope of the invention is defined by the accompanying claims and not necessarily by specific features of exemplary embodiments fig1 shows a fork lift truck 20 having a carriage 23 which is raisable on a mast 24 a backplate 25 is adapted to be fixed onto the carriage 23 a turntable 26 is arranged to rotate in the manner as shown the rotation being powered by a hydraulic motor and gearbox 27 various conventional kinds of attachments clamps etc can be bolted to the turntable 26 which are suitable as required for picking up a load and for turning the load over as shown a fork plate 28 is carried by the turntable 26 forks attached thereto are used for engaging with appropriate pockets on pallets to enable the pallets to be picked up and turned over the components.