| 摘要 |
<p>A beam supporter has an upper outer cylinder (1), a lower outer cylinder (2), a gearbox (3) connecting these cylinders (1,2) up and down to each other, and drive and driven bevels (4,5) mating one another within the gearbox (3). A sleeve (7) built in the gearbox (3) has an outer periphery integral with the driven bevel (5), a female-threaded inner periphery (6), and a threaded rod (8) is in mesh with the female thread and extends through the inner periphery (6). A horizontal shaft (4a) of the drive bevel (4) protrudes from the gearbox to provide an operable protrusion (4b). A sliding inner cylinder (9) is secured to the rod (8) up and down, so that an upper end of this cylinder (9) slidably protrudes from an upper opening of the upper cylinder (1). A ring-shaped bearing (26) may be disposed around the threaded rod (8) and vertically slidable above the gearbox (3). A cap (20) is attached to the threaded rod (8), so that guide sticks (27) depending through the cap hold the bearing (26) freely slidable up and down but always on or above the feet of the guide sticks (27). Upper ends of the guide sticks have a stopper (27a) above an upper face of the cap (20) so that the sticks (27) are prevented from dropping off the cap (20). <IMAGE></p> |
