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US 5,579,865 AGranted
Scaffold
OwnerJ. Frank Butler, Robert J. Leachinventors
Life of this patent
Estimating the term…
Abstract
A modular scaffolding assembly in which the platform may move up or down in a continuous motion. A platform carriage is engaged with a tower by spring loaded friction blocks and climbs or descends the tower along a pair of stepped racks. Platform modules may be removably connected to the platform carriage.
Claims13
A scaffold, comprising:
- a tower connected to a base;
- a platform engaged with said tower, said platform comprising a platform carriage adapted to be slidably engaged with said tower;
- means for moving said platform relative to said tower in at least one direction up or down in a continuous motion comprising first and second spaced apart hydraulic cylinder actuators supported on said carriage and each including boot means engageable with spaced apart steps on said tower;
- and
- control means for causing one of said cylinder actuators engaged with one of said steps to move said platform relative to said tower while causing the other of said cylinder actuators to disengage from another step.
2 more elements
A scaffold, comprising:
- a tower connected to a base, said tower comprising a plurality of tower modules;
- a platform engaged with said tower, said platform comprising a platform carriage adapted to be slidably engaged with said tower, said platform carriage comprising a plurality of friction block assemblies for engagement with said tower;
- means for moving said platform up or down relative to said tower comprising a yoke assembly mounted to said platform carriage, said yoke assembly comprising first and second hydraulic cylinder assemblies each including means for systematically engaging a pair of racks connected to said tower, said racks including spaced apart steps formed thereon;
- and
- control means for actuating one of said cylinder assemblies engaged with a step to move said platform with respect to said tower and causing the other of said cylinder assemblies to disengage from another step in a predetermined manner to move said platform substantially continuously up or down relative to said tower.
2 more elements
A method for raising a scaffold platform, comprising the steps of:
- (a) engaging said platform with a tower, said tower comprising a pair of racks for systematic engagement with an upper cylinder and a lower cylinder connected to said platform;
- (b) engaging said lower cylinder with a first step of said racks and extending said lower cylinder while simultaneously retracting said upper cylinder;
- (c) engaging said upper cylinder with a second step of said racks for a time interval while said lower cylinder is engaged with said first step and thereafter extending said upper cylinder while simultaneously retracting said lower cylinder;
- and
- (d) repeating steps (b) and (c) until said scaffold platform is raised to a desired height.
2 more elements
A method for lowering a scaffold platform, comprising the steps of:
- (a) engaging said platform with a tower, said tower comprising rack means having spaced apart steps for systematic engagement with an upper cylinder and a lower cylinder connected to said platform;
- (b) retracting said upper cylinder while engaged with said rack means to lower said platform;
- (c) disengaging said lower cylinder from a first step and thereafter extending said lower cylinder and engaging said lower cylinder with a second step;
- (d) retracting said lower cylinder while engaged with said second step to lower said platform;
- (e) disengaging said upper cylinder from said rack means and thereafter extending said upper cylinder and reengaging said upper cylinder with a third step;
- and
- (f) repeating steps (b), (c), (d), and (e) until said scaffold platform is lowered to a desired height.
4 more elements
A scaffold, comprising:
- a generally vertically extending tower including vertically spaced apart steps supported thereon;
- a platform including a platform carriage adapted to be engaged with said tower for movement generally up and down relative to said tower;
- first and second vertically spaced apart hydraulic cylinder actuators supported on said carriage, each of said actuators including boot means engageable with respective ones of said steps;
- and
- a hydraulic control circuit connected to said first and second cylinder actuators, respectively, and operable for causing said cylinder actuators to move said platform up or down with respect to said tower.
2 more elements
Dependencies are inferred from the claim text.