Handling: hand and hoist-line implements – Grapple – Pivoted jaws
Patent
1987-01-06
1988-11-15
Marbert, James B.
Handling: hand and hoist-line implements
Grapple
Pivoted jaws
414735, 414751, 414744A, B66C 100
Patent
active
047844221
DESCRIPTION:
BRIEF SUMMARY
This invention relates to a gripper for a robotic arm and to a wrist joint for a robotic arm. The aims of the invention are to provide a gripper and a wrist joint which facilitate accurate control by microprocessor.
In accordance with a first aspect of the present invention there is provided a gripper for a robotic arm, characterised in that it comprises a pair of gripper jaws, a pivot connecting the jaws for pivotal movement relative to each other about a pivot axis, each jaw having a V-like gripping section, and a gripper tip mounted on the free end of the jaw for limited angular movement about an axis parallel to said pivot axis, the jaws being substantially symmetrical with respect to a predetermined plane containing said pivot axis, and adjusting means coupled to the jaws for pivoting the jaws about the pivot axis while maintaining the jaws symmetrical relative to said predetermined plane.
In a preferred embodiment of the invention the gripper includes a housing, and guide means provided on the housing guides the pivot for linear displacement during adjustment of the gripper jaws. In particular, the pivot includes a pivot pin and the guide means comprises a slot in which an end of the pivot pin is slidably engaged. The adjusting means conveniently comprises a threaded rod journalled in the housing for rotation about a fixed axis perpendicular to the plane of symmetry, each jaw being coupled to the rod through a screw-threaded connection. These preferred features enable simple and accurate control of the gripper, the jaws being always positioned symmetrically with respect to the centre line of the gripper.
In the preferred construction the gripper is also adapted for handling objects of widely varying shapes and sizes. The V-like sections of the jaws themselves can be used for holding larger objects. Each gripper tip is preferably formed to define a substantially flat gripping face, for cooperating with plane-sided objects. In addition, a notch can be provided in the grippping face, the notch being parallel to the axis about which the tip is pivotable and spaced forwardly therefrom in the direction away from the pivot axis of the jaws. Such notches in the tips facilitate the gripping of, for example, small cylindrical objects. Notches at 90.degree. to the pivot axis may be provided also. The angular displacement of each gripper tip is conveniently limited in both directions by abutment of the tip with stop surfaces provided on the jaw carrying the tip, and the grasping of objects is facilitated if the tips are each biased by spring means, such a torsion spring, into a limit position against one of the stop faces.
In accordance with a second aspect provides a wrist joint for a robotic arm, comprising first and second bevel gears journalled in a housing for rotation about a given axis, respective drive mechanisms for rotating the first and second bevel gears, and an output bevel gear meshing with the first and second bevel gears and carried on a shaft having an axis perpendicular to said given axis, characterised in that the first and second bevel gears are combined gears, the drive mechanism for each of the first and second gears comprises a driving pinion meshing therewith, and an adjustment means is coupled to the shaft and is adjustable relative to the shaft to urge the output gear into firm meshing engagement with the first and second gears and thereby to urge the first and second gears into firm meshing engagement with the driving pinions.
The adjustment means facilitates assembly of the wrist joint be enabling backlash to be conveniently eliminated, which in turn permits accurate control of the wrist joint.
In a preferred construction the adjustment means comprises a nut having screw threaded connection on the shaft. The nut can be arranged to cooperate with abutment means on a bearing housing accommodating a bearing for the shaft.
A gripper and wrist joint assembly embodying the invention will now be described in more detail, with reference being made to the accompanying drawings in which:
FIG. 1
REFERENCES:
patent: 3261479 (1966-07-01), Baker et al.
patent: 3572807 (1971-03-01), Haaker et al.
patent: 3984009 (1976-10-01), Holroyd
patent: 4368913 (1983-01-01), Brockmann et al.
patent: 4484775 (1984-11-01), Norkus
patent: 4557661 (1985-10-01), Fischer et al.
Duke Brian R.
Jones Timothy J.
Burton Ralph M.
Marbert James B.
Universal Machine Intelligence Ltd.
LandOfFree
Gripper and wrist joint for a robotic arm does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Gripper and wrist joint for a robotic arm, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gripper and wrist joint for a robotic arm will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1099864