Lift-positioning system

A system for establishing a height for a platform of a scissors-lift, said system comprising

• (a) a microprocessor
• (b) a position-marking element attached to a rollable lower leg of said scissors-lift, wherein said position-marking element is a metal plate, said plate bearing a plurality of first position markers,
• (c) a first sensing device fixed close to said plate so that said first sensing device can sense a passage of each of said plurality of first position markers,
• (d) a connection between said first sensing device and said microprocessor such that said first sensing device can send notice of said passage to said microprocessor,
• wherein said microprocessor is programmed to contain information regarding how said platform ascends and descends as a function of time and of payload, said information based in part on a known correlation between each said passage of one of said plurality of first position markers past said first sensing device and in part on a time-keeping function of said microprocessor.

A method for inexpensively and precisely establishing a vertical position for a lift platform using a microprocessor, an incremental sensing device, and a position-marking element having a position-marking-element position bearing a one-to-one relationship to said vertical position, wherein said position-marking element contains a plurality of position markers, said method comprising:

• a) electronically connecting said incremental sensing device to said accumulator so as to allow said sensing device to transmit pulses to said accumulating controller as said sensing device detects a passage of said position markers as said position-marking element moves;
• b) calibrating said accumulator by raising and lowering said payload positioning system under known load conditions whereby information of rates of ascent and descent of said platform as a function of load are stored within said accumulator;
• c) providing said accumulator with an input device that allows a lift operator to input any desired value for said vertical position;
• d) configuring said accumulator with a through a time-keeping function of said accumulator and said, said accumulator is able to use an elapsed time to establish said platform at said desired value for said vertical position,
• e) entering said desired value into said accumulator.

A method of establishing a vertical position of a platform of a lift, using an accumulating controller, an incremental sensing device, and a position-marking element having a plurality of position markers, said method comprising the steps of:

• a) electronically connecting said incremental sensing device to said accumulating controller so as to allow said sensing device to transmit pulses to said accumulating controller as said sensing device detects said position marks from said position-marking element;
• b) raising and lowering said payload positioning system under known load conditions to calibrate said accumulating controller;
• and
• c) entering a weight of a payload into said accumulating controller by means of a weight sensing device;
• d) determining a precise position of said platform device at any one mark of said plurality of position marks;
• and
• e) estimating a position of said payload positioning device between any two of said plurality of position marks.