abstract |
A carriage 1 which is slidably mounted on a track 2, which track comprises an elongate upwardly open channel formed with at least one longitudinally extending lip 6, 7 has guide means 12 engageable with the track and a screw clamp 12 engageable with the lip of the track. The clamp (see Fig 8) comprises a headed member 42 engaging under the tips of the track. The track also has widened nominally circular locations 8 to allow for introduction and removal of the heads 42. The head is attached to a threaded shaft 37 which extends through the carriage to an internally threaded cap 36, rotation of which causes the head to clamp to the underside of the lips. Item 11 Fig. 1 in a retractable stud bolt (Figs. 5, 6, not shown) which fits the circular openings to lock the carriage in a chosen position on the track. <IMAGE> |