Fire escape – ladder – or scaffold – Platform with elevating or lowering means – Suspended
Reexamination Certificate
2000-09-14
2001-11-06
Lev, Bruce A. (Department: 3634)
Fire escape, ladder, or scaffold
Platform with elevating or lowering means
Suspended
C182S082000, C182S141000, C074S465000
Reexamination Certificate
active
06311800
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a raising system for a scaffolding platform, an elevator cage and the like.
BACKGROUND OF THE INVENTION
It has been known for a long time to use a rack and pinion system for raising scaffolding work platforms or elevator cages. Due to the frictional contact of the pinion teeth with the rack teeth, it is necessary to grease the teeth from time to time. Such a greasing operation is time-consuming and difficult to perform on the rack of an outside scaffolding assembly. Such rack is normally secured to a tower which may rise several stories. Falling particles may often adhere to the greased teeth and cause malfunctioning of the raising system because of poor meshing engagement of the pinion with the rack.
OBJECTS OF THE INVENTION
It is therefore the main objective of the present invention to provide a rack and pinion system which have use for elevators and scaffoldings and which obviates the above noted disadvantages.
Another object of the present invention is to provide a rack and pinion system into which the pinion has a friction free engagement with the rack teeth so as to eliminate any necessity of applying grease to the rack teeth and to the pinion.
Another object to the present invention is to provide a rack and pinion raising system which is capable of raising important loads of one thousand pounds or more.
SUMMARY OF THE INVENTION
The present invention is directed to a raising system for scaffolding platforms, elevator cages and the like comprising an upright stationary beam member, a series of equally spaced similar rack teeth secured to said beam member and laterally projecting from the same, each rack tooth having a substantially horizontal, straight top face, a tip and an under face, and a framework guided for vertical up and down movement along said beam member, a pinion device mounted on said framework and meshing with said rack teeth, said pinion including a power driven shaft rotatably supported by said framework, spaced from, normal to and extending across said beam member, a pair of spaced parallel radial supports secured to said power driven shaft and a series of parallel idle shafts extending between said supports, equally spaced from one another and equally radially spaced from said power driven shaft, and a cylindrical roller assembly rotatably mounted on each idle shaft, said cylindrical roller assemblies equal diameter and of a length slightly less than the distance between said two supports, said roller assemblies freely rotatable on their respective idle shafts, clearing said under faces and bearing on and rolling over the top faces of said rack teeth upon said power driven shaft rotating in one direction to raise said framework along said upright beam member or in the other direction to lower said framework along said beam member.
The diameter of said roller assemblies is smaller than the vertical distance between the top face of an underlying tooth and the under face of an overlying adjacent tooth so that a gap is left between the under face of said overlying tooth and a roller assembly in rolling contact with the top face of said underlying tooth.
Preferably, said under face is downwardly sloping in a direction away from said tip.
Preferably needle bearings are interposed between said idle shafts and said roller assemblies.
Preferably said under face is downwardly sloping in a direction away from said tip.
Preferably, each roller assembly includes several rollers disposed side by side.
Preferably a sleeve is tightly fitted around said several rollers.
Preferably, the spacing between adjacent roller assemblies and their radial spacing from said power driven shaft are such that adjacent roller assemblies successively roll over the top faces of adjacent teeth.
Preferably, said power driven shaft has two opposite ends, each protruding from said framework and further including a pair of hydraulic motors respectively drivingly connected to said opposite ends.
The present invention is also directed to the combination of the above defined raising system with a scaffolding including a multi-sided tower, a sleeve member mounted around said tower for guided up and down movement and a work platform supported by said sleeve member, said stationary beam member secured to one side of a said tower, said framework secured to and outwardly protruding from said sleeve member at said one side of said tower, and further including a safety lever pivoted to said framework and counterweighted to ride over said teeth tips and automatically pivot over each adjacent rack tooth during said upward movement of said sleeve member.
REFERENCES:
patent: 1159486 (1915-11-01), Froelich
patent: 1289508 (1918-12-01), Melcher
patent: 3071205 (1963-01-01), Beck, Jr.
patent: 4282777 (1981-08-01), Ryffel et al.
patent: 4293054 (1981-10-01), Pieri
patent: 4294332 (1981-10-01), Ready
patent: 4541297 (1985-09-01), Fujita
patent: 4664226 (1987-05-01), Centanne
patent: 4887694 (1989-12-01), Ho
patent: 4967733 (1990-11-01), Rousseau
patent: 4974700 (1990-12-01), Gates
patent: 5310018 (1994-05-01), Lahaie
patent: 5368125 (1994-11-01), St-Germain
patent: 5381704 (1995-01-01), Knotts
patent: 5392878 (1995-02-01), Bennett et al.
patent: 5487446 (1996-01-01), Patnode et al.
patent: 5540111 (1996-07-01), Barnett et al.
patent: 5579865 (1996-12-01), Butler et al.
patent: 5636705 (1997-06-01), St-Germain
patent: 5644950 (1997-07-01), Parsons
patent: 5704248 (1998-01-01), Knotts
patent: 5746290 (1998-05-01), St-Germain et al.
patent: 6095285 (2000-08-01), St-Germain
St-Germain Andre
Tessier Luc
LandOfFree
Raising system for scaffolding and the like does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Raising system for scaffolding and the like, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Raising system for scaffolding and the like will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2582945