Abstract: A telescopic position adjustment mechanism allows for a telescoping element to be indexed by fixed increments toward a more telescopically collapsed position, relative to its base. The telescopic position adjustment mechanism uses a stepping reservoir that can, in a stepping configuration, selectively receive a predetermined volume of fluid from a support reservoir that supports the telescoping element against the base, enabling the telescoping element to collapse toward the base by a distance corresponding to the predetermined volume of fluid. In a locking configuration, the volume of fluid in the support reservoir is constant and the telescopic position is fixed, and in a free movement configuration fluid can flow freely between the support reservoir and a sink reservoir to permit free telescopic movement. A rotation resistance mechanism uses a locking key that is biased into engagement with a locking channel to inhibit rotation of the telescoping element relative to the base.

Abstract: A telescopic position adjustment mechanism allows for a telescoping element to be indexed by fixed increments toward a more telescopically collapsed position, relative to its base. The telescopic position adjustment mechanism uses a stepping reservoir that can, in a stepping configuration, selectively receive a predetermined volume of fluid from a support reservoir that supports the telescoping element against the base, enabling the telescoping element to collapse toward the base by a distance corresponding to the predetermined volume of fluid. In a locking configuration, the volume of fluid in the support reservoir is constant and the telescopic position is fixed, and in a free movement configuration fluid can flow freely between the support reservoir and a sink reservoir to permit free telescopic movement. A rotation resistance mechanism uses a locking key that is biased into engagement with a locking channel to inhibit rotation of the telescoping element relative to the base.

Abstract: A telescopic position adjustment mechanism allows for a telescoping element to be indexed by fixed increments toward a more telescopically collapsed position, relative to its base. The telescopic position adjustment mechanism uses a stepping reservoir that can, in a stepping configuration, selectively receive a predetermined volume of fluid from a support reservoir that supports the telescoping element against the base, enabling the telescoping element to collapse toward the base by a distance corresponding to the predetermined volume of fluid. In a locking configuration, the volume of fluid in the support reservoir is constant and the telescopic position is fixed, and in a free movement configuration fluid can flow freely between the support reservoir and a sink reservoir to permit free telescopic movement. A rotation resistance mechanism uses a locking key that is biased into engagement with a locking channel to inhibit rotation of the telescoping element relative to the base.

Abstract: A telescopic position adjustment mechanism allows for a telescoping element to be indexed by fixed increments toward a more telescopically collapsed position, relative to its base. The telescopic position adjustment mechanism uses a stepping reservoir that can, in a stepping configuration, selectively receive a predetermined volume of fluid from a support reservoir that supports the telescoping element against the base, enabling the telescoping element to collapse toward the base by a distance corresponding to the predetermined volume of fluid. In a locking configuration, the volume of fluid in the support reservoir is constant and the telescopic position is fixed, and in a free movement configuration fluid can flow freely between the support reservoir and a sink reservoir to permit free telescopic movement. A rotation resistance mechanism uses a locking key that is biased into engagement with a locking channel to inhibit rotation of the telescoping element relative to the base.