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Multiple Position Extended Range Z Axis for the Ibm 7540 Robot

IP.com Disclosure Number: IPCOM000036129D
Original Publication Date: 1989-Sep-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 4 page(s) / 150K

Publishing Venue

IBM

Related People

Bolde, L: AUTHOR

Abstract

This article describes a new and unique Z axis assembly for use with the basic pneumatic Z drive of the Model 7540 robot (tool). The disclosed assembly design will increase the existing range and number of Z positions available to the tool while maintaining its +/- 0.0005- inch positional accuracy and repeatability. (Image Omitted)

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Multiple Position Extended Range Z Axis for the Ibm 7540 Robot

This article describes a new and unique Z axis assembly for use with the basic pneumatic Z drive of the Model 7540 robot (tool). The disclosed assembly design will increase the existing range and number of Z positions available to the tool while maintaining its +/- 0.0005- inch positional accuracy and repeatability.

(Image Omitted)

The original Model 7540 robot is equipped with a Z axis assembly having a range (stroke) of 3.9 inches and two position (max. up or max. down) function. The improved design (which replaces the original Z axis assembly) provides a longer range (0 to 20 inches) as well as multiple positions within that range. This is accomplished by incorporating a combination of switches, valves, fluid/air containers and a software program so that the machine moves pneumatically but is stopped hydraulically to obtain greater accuracy and speed control.

Fig. 1 shows a model 7540 robot with the extended range multiple range Z axis assembly installed. The main components of that assembly are:

1) The bearing housing 1 supports a THK bearing assembly similar to the original unit but with a longer Z shaft 3. The assembly mounts directly to the "theta" 2 arm of the robot by utilizing existing mounting holes and locating pins. The original timing gear 2 is utilized with the THK bearing assembly to drive the roll action of the Z shaft 3.

2) A 20" stroke Festo Rodless Hydraulic cylinder 4 is mounted to the vertical bracket 5, which is attached to the bearing assembly. The cylinder 4 is used to apply motion to the Z shaft.

3) Telemecanique 2-way stop valves 7 are mounted on each feed port of cylinder 4. By their use, fluid flow to and from the cylinder can be stopped.

4) A yoke bracket 6 links the Festo cylinder 4 to the Z shaft 3.

5) Reed switches 8 are mounted to a bracket that extends the length of the cylinder 4. Two are dedicated for Z-up and Z-down motion, but as many as 20 can be added and their locations independently adjusted. These switches are connected to the robot controller inputs and are used to acknowledge the position of the Z shaft.

6) A solenoid valve 9 utilizes an output from the robot controller to activate or deactivate the Telemecanique stop valves 7.

7)Air/oil tanks (not shown) contain the fluid supply for the cylinder 4.

Refer to Fig. 2 for a descri...