| 摘要 |
Extensible support assembly for a table such as an overbed table to interconnect the top table portion and bottom stand portion thereof to change the table height, including a pair of axially overlapping upper and lower vertical support members arranged for relative axial movement therebetween, and a releasable unidirectional jamming mechanism interposed between the members having an inclined wedge surface on the upper member in opposed relation to a substantially axially extending contact surface on the lower member and forming a jamming wedge zone with the contact surface, a movable jamming roller element disposed in the jamming wedge zone, and a movable release element disposed operatively adjacent to the jamming element, such that the jamming element is movable independently of the wedge surface, contact surface and release element and is normally resiliently biased by a spring or the like independently of the release element into unidirectional jamming engagement between the wedge surface and contact surface for jamming the members against further corresponding relative movement, e.g. to decrease the table height, and furthermore such that the release element is similarly movable independently of the jamming element for releasably urging the jamming element out of such unilateral jamming engagement to permit further corresponding relative movement between the members, and preferably with antifriction guide bearing structures removably carried on the members for mounting various parts of the assembly thereat and forming corresponding removable units to facilitate assembly and disassembly of such parts. |
