WO1982004003A1

WO1982004003A1 - Positioning tool

Info

Publication number: WO1982004003A1
Application number: PCT/SE1982/000171
Authority: WO
Inventors: Bo Nordgren
Original assignee: Bo Nordgren
Priority date: 1981-05-13
Filing date: 1982-05-13
Publication date: 1982-11-25
Also published as: GB2112900B; GB8300856D0; GB2112900A; SE8103011L

Abstract

A positioning tool of the kind in which a support member, a revolving tool table, for instance, is rotatable with respect to a base to support an equipment which is to be rotated about an axis of rotation, the support member comprising a worm wheel (5), which, to rotate the support member, meshes with drive worms. To make possible not only a revolving motion of the support member but a motion thereof in a direction perpendicular to the rotational axis thereof, the worm wheel (5) thereof is, in accordance with the invention, meshing with two mutually parallel and axially non-displacable drive shafts (9 and 10, resp.), provided with screw threads (8) corresponding to the teeth (7) of the worm wheel arranged on each one side of the worm wheel and acting as drive worms, the screw threads of said shafts having a length at least corresponding to the length of an intended motion of the support member in a direction parallel to the direction of the two drive shafts.

Description

Positioning tool

This invention relates to a positioning tool for applying to an article a translatory and rotatory movement.

For a plurality of purposes there is, in practice, a demand for a tool to accurately adjust the position of an article within a specific working range in a plane along a limited linear path determined by the length of the working range of the tool, under a translatory, straight motion of the article, and to rotate the article at a selected position within said path to turn it about an axis perpendicular to said plane.

The object of the present invention is to provide a position adjusting tool of this kind in which the translatory and rotatory positioning of a table constituting the support for an article is provided for by aid of common position adjusting means cooperating to apply to the table a translatory as well as a rotatory motion, and which tool makes possible a simplified construction of the tool as compared with prior art tools for the same purpose.

A positioning tool according to the invention may be used for a plurality of applications within the work shop industry, for instance as support table for many purposes in which a work piece to be machined is mounted on a table which can be exposed to a revolving motion and, simultaneously or alternately, can be exposed to a translatory motion either while revolving or within intervals between revolving movements. Other applications are within the field of material handling, such as within the machine contracting business, where it is a question of applying to a working tool a revolving motion about the axis and a translatory motion of said axis within a specific working range.

Further, the invention is applicable within instrument and other similar technique, in which a rapid and accurate adjustment of instrument or other equipment is desired.

A positioning tool according to the invention is of the kind in which a revolving table, which is rotatable with respect to a base and constitutes the support for an equipment to be exposed to a rotational movement about an axis, is provided with a ring gear constituting a worm weei, the center axis of which is common to the axis of rotation of the table, and in which said worm wheel to be exposed to a rotational movement

OMPI meshes with worm gears, said positioning tool for providing a translatory movement of the axis of rotation of the support table in a direction being, in accordance with the invention, characterized by said worm wheel being in mesh with two mutually parallel, axialiy non-dϊsplacable drive shafts, each provided with screw threads corresponding to the teeth of the worm wheel and acting as worm gears, said screw threads having a length at least corresponding to the length of an intended translatory motion of the support table, the rotatable support table with the worm wheel attached thereto being displaceable relative to the base in a direction parallel to the two driving shafts.

In dependence of the application of which it is a question in the specific case, the base may be. the base of a machine tool, the chassis of a hoisting crane or other equipment for managing materials, a base plate of a fixture table, or a device for accurate adjustment of instruments of different kind into a desired position.

The invention will be more closely illustrated by the following description of an embodiment thereof for securing a work piece on a support in form of a revolving feed table, an indexing table for instance, having a base plate as support, with reference to the accompanying drawing, on which fig. 1 is a schematic plan view of the tool according to the invention and^* fig. 2 is a cross sectional view of the same taken on the line II— II of figure 1.

In this embodiment the positioning tool according to the invention comprises a base plate 1 provided with holes 2 to fasten the tool on a tool machine, for instance. The base plate carries a revolving table 3 provided with a worm wheel 5 attached to a stud 4.

In conventional revolving table tools, whether being stationary or adjustable in one or more directions perpendicular to the rotational axis of the revolving table, the revolving table proper is as such journalied in its base plate and is exclusively arranged for executing a rotational motion relative to the base plate, driven by one or more worms for rotation. A cross-section of such conventional tool may, generally, look the same as the one shown in fig. 2, the hub of the revolving table thus being journalied in a radial bearing, while axial forces are taken up by suitable axial bearing surfaces.

In a positioning tool according to the invention, however, the revolving table 3 is arranged within a straight ditch 6, in the longitudinal direction of which it is movable, supported by surfaces or bearings taking up the axial forces and allowing for a rotation of the revolving table in all its

OMPI possible positions along the ditch. To drive the revolving table, the tool comprises on each side of the worm wheel 5 and the ditch 6, a drive shaft 9 and 10, respectively, extending parallel to the ditch and having a screw thread 8 corresponding to the teeth 7 of the worm wheel, said two drive shafts being axially non-displaceably journalied in the base plate 1, the screw threads 8 having a length in the axial direction at least corresponding to the length of the translatory motion of the revolving table along the ditch 6 for which the tool is designed.

In the embodiment illustrated by the figures, each drive shaft comprises a crank 9a and 10a, respectively, with which the drive shafts may be rotated independently of each other. Obviously, any desired controllable drive means could be used for individual or, as the case may be, common drive of the two shafts.

As will easily be seen, a rotation of the two drive shafts in the same sense, that is, with the same direction of rotation, and with the same rotational speed, the shafts will act on the worm wheel such that it, and the revolving table therewith, without being rotated will move in the longitudinal direction of the ditch 6. If, on the other hand, the drive shafts are rotated with the same speed of rotation and with mutually opposite directions of rotation, the table will be exposed to a rotational movement without the rotational axis of the table changing position. If, in each case, either only a translatory or only a rotating motion is to be executed, a drive means for the shaft 9a and 10a may comprise a gear box with can be switched between a positon in which both drive shafts are rotated with the same speed and the same direction of rotation for a translatory displacement of the revolving table, and a position, in which the two drive shafts are driven with the same velocity, however in opposite rotational directions, to apply to the revolving table a rotation about a stationary axis.

Between said two limit values for the motion to which the revolving table may be exposed, combinations of rotational and translatory motions of the revolving table are, obviously attainable by choice of rotational speed of the two drive shafts in correspondence to a preselected program.

As shown by the figures, the stud 4 of the revolving table provided with a pivot 11 underneath the worm wheel 5, said pivot being guided laterally by a groove 12 in the base plate 1, thereby laterally guiding and, as the case may be, supporting the revolving table. When making use of this invention it is obviously a matter of choice in dependence of the purpose for which the tool is to be used, how the axial journalling of the table is to be effected.

The embodiment illustrated by the drawing, a pitch dividing table, the table at an upper plane 13 thereof is provided with T-grooves 14 for attaching bolts of conventional type.

Claims

CLAIMS 1. A positioning tool for translationally moving and rotating an article, comprising an article support table (3) which is rotatable relative to a base (1) and is provided with a ring gear (7) constituting a worm wheel (5), the centre axis of which is common to the axis of rotation of the support table, and which meshes with each one of two worm gears, each comprising screw threads (8) corresponding to the teeth of the worm wheel (5), said worm gears being located on each one side of the worm wheel, axially non-displacably journalied in the base by means of drive shafts (9 and 10, resp.) and are rotatable about mutually parallel axes, characterized by the fact that the support table (3) together with the worm wheel (5) attached thereto, is displaceable relative to the base in the direction of the axis directions of the worm gears (9 and 10), and that the screw threads (8) of the worm gears have a length at least corresponding to the length of an intended translatory motion of the support table.

2. A positioning tool according to claim 1, characterized by the fact that the drive shafts (9, 10) are rotatable independently of each other.

3. A positioning tool according to claim 1, characterized by means for simultaneous driving of the drive shafts in the same or in opposite senses at choice.

4. A positioning tool according to anyone of the previous claims, characterized by means for simultaneous driving of the shafts (9, 10) with the same or with different rotational speed at choice.