Faculty of Engineering –
Department of Mechanical Engineering
B. Sc
Graduation Project
Class of 2002
Project: “Operator
Lift for Tower Cranes”
Project
No: 138
Advisor: Mr. Ram Talmor
Written By: David
Weil (I.D. No. 015852965)
Location:
Abstract
Project
Description:
This project presents the design of an elevator system to be attached to a tower crane.
The elevator shall be used by the tower crane operator in order to access the control cabin of the crane, located at the top of the mast.
Project Objectives:
This project was born out of a need to ensure the safety of the tower crane operator when traveling up or down the tower crane mast, and to allow simple and quick access to the control cabin of the crane when high rising cranes are used.
The main object of the project was to design an elevatoring system that may attach to a tower crane.
The most important goal of the design was to ensure that the elevatoring system may attach to any existing tower crane, in other words, to design a system that may be universal.
In addition, the design would need to be as simple as possible in order to keep costs down, so as to ensure the feasibility of the project.
Let it be known that until today only a handful of such elevator systems have been designed.
Guidelines for Project:
The work undertaken by myself was in the field of structural engineering.
The emphasis of my work was on the bracing design.
The design of the bracing is the most significant part of the project, as the demand that the design be universal, fitting all tower cranes, required that the bracing be changeable. In addition, connecting an elevator mast that has to be stationary, to a tower crane mast that may deflect in any direction, required the integration of some unique solutions, such as the differentiation between two types of bracings and the design of the telescopic system for the Upper Brace.
The outline for the elevator car is also presented, including the selection of the drive system, the design of the support system (The wheels) and the structural design of the elevator car itself.
In addition, the elevator mast was designed and was proven to withstand all forces present.
The Design:
With feasibility and cost in mind, the natural choice for the elevator type was the Rack and Pinion Elevatoring System.
The makeup of the mast of the tower crane, the universal nature of the design and the strict Israeli Standards (Dictated by the National Institute for Standards) left me no other choice other than to design an elevatoring system that shall run along the outer side of the tower crane mast, with an elevator mast that shall attach to the tower crane mast.
In order to allow the natural deflection of the tower crane mast, but to ensure that such deflection shall not be passed on to the elevator mast, a unique concept for the bracing system was designed. The bracing system presented is in part rigid, connected to sections of the tower crane mast where movement is negligible, and in part telescopic, allowing the limited deflection of the tower crane mast in any direction wherever such movement is possible, but at the same time preventing the movement or dynamic forces from passing on to the elevator mast.
In addition the design was kept simple, almost maintenance free and designed to be easily connected to almost any tower crane.
The Final Result:
All of the goals set out at the start of the project were met.
In general, it may be concluded that the design presented is universal – fitting almost any tower crane. The design is limited to braced tower cranes only, but with the use of such an elevatoring system being feasible on high tower cranes only (over 25 meters in height), and with all but a few high rising tower cranes being braced to adjacent structures, it may be said that there is no real limitation set here on the use of the elevator system.
The changeable brace ends (The horizontal and vertical hooks) make the design be easily adapted to fit any size or shaped tower crane mast, and make such an adaptation inexpensive and very simple.
To sum, let me say that with all objectives met, the design presented shall leave any potential investor without a doubt that this design is feasible by being maintenance free, and easily adapted to any tower crane, and that the elevator is in fact necessary in order to adapt to the growing use of high rising tower cranes by ensuring the safety of the tower crane operator.
General Specification
Elevator
Car
Max. Capacity: 2 Persons or 250 [Kg]
Dimensions (Width x Depth): 1.0 x 1.4 [m]
Internal Height: 2.0 [m]
Weight (Incl. Machinery): 1050 [Kg]
Max. Linear Velocity: 0.69 [m/s]
Drive
System
Motor Unit: 2 x Grinshpon -AC Worm
Gear Motor, 6” WHM
Max. Power Output: 12.5 HP (9.32KW)
Max. Output Speed: 147 rpm
Elevator Mast
General Dimensions: 0.7 x 0.7 [m]
Single Section Height: 1.5 [m]
Single Section Weight: 105 [Kg]
Maximum Height of Mast: 200 [m]
Bracing
Lower Brace Assembly Weight: 129 [Kg]
Upper Brace Assembly Weight: 144 [Kg]
Allowed Horizontal Deflection (of Upper Brace): 0.17 [m]
Bracing
Width: 2.0
2.3 [m]
Bracing
Height (Distance between Hooks): 1.6
1.9 [m]
The Operator Elevator for Tower Cranes