Material or article handling – Vertically swinging load support – Grab
Patent
1983-01-10
1985-07-30
Spar, Robert J.
Material or article handling
Vertically swinging load support
Grab
414 7, 901 21, 901 22, 74479, B66C 100
Patent
active
045318859
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a device for robot manipulators of the kind which has a multiple articulated manipulator arm rotatably mounted in a swivelling base, and wherein a front portion of the manipulator arm is rotatably connected, via a three-point connection, to a portion of the manipulator arm situated at the back so that the front portion of the manipulator arm can be turned, up to a certain angle, in all possible directions in relation to the rear portion of the manipulator arm by means of two longitudinally displaceable, substantially parallel stays, one end of which is rotatably secured to the front portion of the manipulator arm and form two of the points in said three-point connection, the third point consisting of a universal joint, and wherein the manipulator arm with a tool holder is controlled by a system with hydraulic servo-cylinders. Such robot manipulators have their movement pattern programmed in that a person takes hold of the manipulator arm and guides it in the required movement pattern which the robot manipulator arm can then repeat automatically.
One great disadvantage of the known robot manipulators of this kind is that it is difficult for a person to move the manipulator arm by hand with the required precision during the programming. This is due partly to the fact that the manipulator arm is comparatively heavy because hydraulic servo-cylinders for movements of the manipulator arm are mounted in its various arm portions and it is due partly to a comparatively great friction between the piston rods and the piston rod packing in the hydraulic servo-cylinders of the robot manipulator.
An attempt has previously been made to remedy the above-mentioned disadvantage by a separate passive programming arm with little mass and friction. Since the movements of the programming arm are stored on a so-called disc or corresponding magnetic storage medium, the robot manipulator can execute the same movements when it is controlled by the same disc.
A disadvantage of the separate programming arm, however, is the increased cost of the robot manipulator which the separate programming arm involves. Another disadvantage of the separate programming arm is that it necessarily requires like placing of the tool on the manipulator arm and the programming arm and this has proved to involve difficulties in practice.
Another disadvantage of the known robot manipulators of this kind is that the decomposition of the position measuring system in the various servo systems which control the rotary movements of the robot manipulator cannot be transmitted proportionally to the working range of the manipulator arm because the linear movement of the hydraulic servo-cylinders have to be converted into rotary movement, which leads to a less precise repetition of the programmed movement pattern.
Yet another disadvantage of the known robot manipulators of this kind is that the connections between the front portion of the manipulator arm and the piston rods of the hydraulic servo-cylinders which move the front portion in relation to the rear portion of the manipulator arm, are ball-and-socket joint connections which are expensive and difficult to make sufficiently accurate for this purpose, while at the same time the movement amplitudes in a ball-and-socket joint are limited.
Another disadvantage of the known robot manipulators of this kind is a less effective means to prevent the above-mentioned piston rods from twisting in relation to one another during displacement.
A disadvantage which follows from the fact that hydraulic servo-cylinders are placed in the manipulator arm in the known robot manipulators of this kind is that drops of oil from the hydraulic system can be most undesirable in individual cases, for example when handling edible material.
The object of the invention is to provide a robot manipulator of the above-mentioned kind without a separate programming arm and wherein the other above-mentioned disadvantages are eliminated, so that a person can easily move the manipulator arm by hand with the requir
REFERENCES:
patent: 4259876 (1981-04-01), Belyanin
patent: 4300362 (1981-11-01), Lande et al.
patent: 4378959 (1983-04-01), Susnjara
Graco Robotics Inc.
Sjoquist Paul L.
Spar Robert J.
Underwood Donald W.
LandOfFree
Device for robot manipulator does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device for robot manipulator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for robot manipulator will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2370278