The invention relates to a robot manipulator comprising a base and at least two parallelogram mechanisms supported by the base, wherein each parallelogram mechanism is formed with legs, wherein each of such legs of such parallelogram mechanism is with pivots connected to other legs of the same parallelogram mechanism, and wherein said at least two parallelogram mechanisms are linked to each other so as to provide for a concerted movement of the respective legs of the at least two parallelogram mechanisms .

Such a construction wherein multiple parallelogram mechanisms are present is disclosed by US 9, 060, 092. The manipulator according to this citation is intended to manipulate an instrument for minimally invasive surgery.

The preamble of the main claim is known from WO2017/167349 and from the article by the current inventor Van der Wij k, Volkert : "The grand 4R four-bar based inherently balanced linkage architecture for synthesis of shaking force balanced and gravity force balanced mechanisms", MECHANISM AND MACHINE THEORY,

PERGAMON, AMSTERDAM, NL 150, 20 April 2020, XP086148031,

ISSN : 0094-114X, DOI : 10 . 1016/J.MEXHMACHTHEORY. 2020 . 103815 .

The prior art mentioned in the previous paragraph relates to pantographs, which are distant from the robot manipulator of the invention, as will become apparent from the following disclosure .

The robot manipulator of the invention is intended for highspeed operation to perform pick and place motions . It is an object of the invention to provide such a robot manipulator which is essentially free from vibrations so as to make the manipulator particularly suitable for application in the semiconductor industry wherein fast pick and place operations of chips are required. It is further intended to provide a robot manipulator which is of low complexity, exhibits high stiffness and low mass, and exhibits low inertia to make highspeed operations feasible .

The robot manipulator of the invention is therefore embodied with the features of one or more of the appended claims .

Essentially the robot manipulator of the invention has the features of claim 1, to note that the base of the manipulator comprises a base pivot, which base pivot is common to the at least two parallelogram mechanisms by arranging that the base pivot coincides with respective pivots of the at least two parallelogram mechanisms, the base pivot thus forming a joint for two legs of each parallelogram mechanism connected to the base pivot, wherein the respective two legs of a first parallelogram mechanism that are joined at the base pivot are rigidly connected to the respective two legs of a second parallelogram mechanism that are joined at the base pivot, and wherein a virtual axis through the base pivot and at least one of the pivots distant from the base pivot delimits a first side from a second side of the manipulator, and the respective two legs of the first parallelogram mechanism are rigidly connected to the respective two legs of the second parallelogram mechanism that are on the same side with reference to said virtual axis through the base pivot and the at least one of the pivots that is distant from the base pivot, so as to arrange that a motion of a first pivot or tip of the first parallelogram mechanism that is distant from the base pivot, towards or away from said base pivot, results into an opposite motion of a second pivot that is distant from the base pivot, said second pivot being part of the second parallelogram mechanism connected to the base pivot . The arrangement of the invention provides a low and in particular a constant inertia to the robot manipulator making it especially suitable for highspeed and dynamically balanced operations at the first pivot or tip, which pivot or tip can be provided with a gripping hand or other tool .

In one embodiment the at least two parallelogram mechanisms are planar and in the same plane . This is however not essential, since it is also possible that the at least two parallelogram mechanisms are planar and in parallel planes . In both situations the robot manipulator has the required low and constant inertia with reference to the base pivot , The latter arrangement with the parallelogram mechanisms in parallel planes may be beneficial when the amount of space that the robot manipulator occupies needs to remain restricted.

Preferably a motor or motors are provided to directly or indirectly actuate the legs of the first and second parallelogram mechanisms at or near their connection with the base pivot . There are many options for this drive arrangement . In some embodiments the motor or motors drive an arm mechanism that connect to the rigidly connected legs of the respective parallelogram mechanisms . It is however also possible to locate the motor or motors at or near the base pivot, or to apply linear motors between the base and the parallelogram mechanisms, or by any other feasible way including an external transmission system.

Beneficially the arm mechanism together with the at least two parallelogram mechanisms are dynamically balanced.

In some embodiments it is preferred that the motor or motors drive a counterrotating element or counterrotating elements, as will be further explained hereinafter. The accompanying drawing, which is incorporated into and forms a part of the specification, illustrates several embodiments of the present invention and, together with the description, serves to explain the principles of the invention. The drawing is only for the purpose of illustrating the invention and is not to be construed as limiting the invention.

In the drawings :

Figures 1 and 2 show two poses of a robot manipulator according to the invention;

Figure 3 shows a mechanical scheme representing the embodiment shown in figures 1 and 2; Figure 4 shows another embodiment of coupled planar parallelogram mechanisms;

Figures 5-9 depict a more complete representation of one embodiment of the robot manipulator of the invention; and Figures 10-17 show several variations to the construction of the invention with reference to illustrative schemes representative for mechanical constructions within the scope of the invention.

Whenever in the figures the same reference numerals are applied, these numerals refer to the same parts .

Figures 1 and 2 show two poses of what can be said to be the essence of a robot manipulator 1 according to the invention, which in more complete form is shown in figures 5 and 6.

The robot manipulator 1 of the invention comprises a base 2 and at least two parallelogram mechanisms 3, 4 supported by the base 2, wherein each parallelogram mechanism 3, 4 is formed with legs 5.1-5.8, wherein each of such legs 5.1-5.8 of such parallelogram mechanism 3, 4 is with pivots 6.1-6.8 connected to other legs of the same parallelogram mechanism, and wherein said at least two parallelogram mechanisms 3, 4 are linked to each other so as to provide for a concerted movement of the respective legs 5.1-5.8 of the at least two parallelogram mechanisms 3, 4.

The base 2 of the manipulator comprises a base pivot 0, which base pivot 0 is common to the at least two parallelogram mechanisms 3, 4 by arranging that the base pivot 0 coincides with respective pivots 6.1, 6.8 of the at least two parallelogram mechanisms 3, 4, the base pivot 0 thus forming a joint for two legs 5.1, 5.6 and 5.2, 5.5 of each parallelogram mechanism 3, 4 connected to the base pivot 0, wherein the respective two legs 5.1, 5.6 of a first parallelogram mechanism 3 that are joined at the base pivot 0 are rigidly connected to the respective two legs 5.2, 5.5 of a second parallelogram mechanism 4 that are joined at the base pivot 0. Different from the construction of a pantograph, this connection of legs of the first parallelogram mechanism to the legs of the second parallelogram mechanism can be explained as follows . Imagine a virtual axis through the base pivot 0 and at least one of the pivots 6.3; 6.6 distant from the base pivot 0. This vertical axis delimits a first side from a second side of the manipulator 1, with sides adjoin each other. According to the invention the respective two legs 5.1 and 5.6 of the first parallelogram mechanism 3 are to be rigidly connected to the respective two legs 5.2 and 5.5 of the second parallelogram mechanism 4 that are on the same side with reference to said virtual axis through the base pivot 0 and the at least one of the pivots 6.3; 6.6 that is distant from the base pivot 0. To be precise with reference to figures 1 and 2 : the leg 5.1 of the first parallelogram mechanism 3 rigidly connects to leg 5.2 of the second parallelogram mechanism 4, and leg 5.6 of the first parallelogram mechanism 3 rigidly connects to leg 5.5 of the second parallelogram mechanism 4. This construction arranges that a motion of a first pivot 6.6 or tip of the first parallelogram mechanism 3 that is distant from the base pivot 0 towards or away from said base pivot 0 results into an opposite motion of a second pivot 6.3 that is distant from the base pivot, said second pivot 6.3 being part of the second parallelogram mechanism 4 connected to the base pivot 0. As mentioned figures 1 and 2 show two different poses of what can be considered to be the core of the robot manipulator 1 of the invention.

Figure 3 shows a mechanical scheme representing the embodiment shown in figures 1 and 2 so as to provide a skilled person easy access to the principles of the construction according to the invention. Figure 3 provides a scheme representative for the construction of figures 1 and 2, and must be seen in combination with figure 4 which shows a scheme representative of another embodiment of the invention. Where figures 1, 2 and 3 depict that the at least two parallelogram mechanisms 3, 4 are planar and in the same plane without intersecting/overlapping elements, it is figure 4 that shows that the at least two parallelogram mechanisms 3, 4 can also be planar and in parallel planes . Also the legs of a particular parallelogram mechanism may be in separate parallel planes .

Figure 4 shows coupled planar parallelogram mechanisms which are based on the essence of the invention, to note that a motion of a first pivot or tip of the first parallelogram mechanism that is through two legs connected to the base pivot (0) , which motion is towards or away from said base pivot (0) results into an opposite motion of a second pivot that is through two legs connected to the base pivot (0) , said second pivot being part of the second parallelogram mechanism connected to the base pivot . The shown coupled planar parallelogram mechanisms are provided with solely revolute joints for two poses, in general with all sides of the parallelogram mechanisms of a different length, rotating about a central joint 0 with 2 degrees-of- freedom θ1 and θ2 with respect to the surroundings, which means one internal/relative degree-of-freedom. Both triangular elements include the same angle γ as indicated in figure 4. Each triangular element can have a generally located center of mass, as indicated with the center-of-mass symbol, and has an inertia . For specific conditions on the mass distributions and the size of the triangular elements which can be selected by the skilled person without undue burden, the inertia of the complete mechanism about joint 0 is equal for all poses . When one parallelogram mechanism moves outwards the other parallelogram mechanism moves inwards, and vice versa . For specific conditions on the mass distributions and the size of the elements which can be selected by the skilled person without undue burden, the mechanism is also shaking force balanced or gravity balanced with respect to joint 0.

Turning now to figures 5-9, it is shown that the robot manipulator 1 preferably comprises a motor or motors 8 that are provided in the shown embodiment to indirectly actuate the legs

5.1, 5.6 and 5.2, 5.5 of the first and second parallelogram mechanisms 3, 4 at or near their connection with the base pivot

0. One of the motors 8 drives an arm mechanism 9.1, 9.2 that connects to the rigidly connected legs 5.1 and 5.2 of the respective parallelogram mechanisms 3, 4 , wherein the arm 9.2 of arm mechanism 9.1 , 9.2 rigidly connects to the legs 5.1 and

5.2. The other motor 8 drives an arm mechanism 10.1, 10.2 that connects to the rigidly connected legs 5.5 and 5.6 of the respective parallelogram mechanisms 3, 4 , wherein the arm 10.2 of arm mechanism 10.1, 10.2 rigidly connects to the legs 5.5 and 5.6. As already indicated above it is preferred that the arm mechanisms 9.1, 9.2 and 10.1, 10.2 together with the at least two parallelogram mechanisms 3, 4 are dynamically balanced.

The robot of figures 5 and 6 is shown with two revolute motors 8 located at joints of the base 2 for actuation, however the mechanism can also be actuated in multiple other ways such as :

( 1) with revolute motors in the central base joint 0; (2 ) with linear motors connected between the base 2 and the parallelogram mechanisms; (3) by internal actuators within the parallelogram or arm mechanisms; ( 4 ) by external transmissions from e . g. other systems . Particularly with reference to figure 9 showing a scheme representative of the embodiment of figures 5-8 , it will be clear for the artisan that the constant inertia mechanism of the invention can be applied in multiple ways to obtain a 2-DoF fully dynamically balanced robot manipulator mechanism with the tip or pivot 6.6 as the position to place an end-effector. Figure 9 shows the configuration corresponding to Figure 3 when it is fully symmetric (angle γ=90 degrees, all sides of each parallelogram of equal length) , however this is not essential . Reference 0 again represents a revolute joint with the base 2. To each triangular element two additional links are connected with another revolute base joint, such that on both sides A and B they form an inverted parallelogram linkage with the two pairs of opposite links of equal length. This is the required geometric condition for full dynamic balance, in addition to a certain mass distribution and size of the elements which can be selected by the artisan without undue burden.

When for instance a grasper device is mounted in or on the tip or pivot 6.6, its mass and inertia can be accounted for in the mass and inertia of the legs of the parallelogram mechanisms for constant inertia and for dynamic balance .

The remainder of the following description concerning the figures 10-17 relate to several variations to the construction of the invention, which for sake of simplicity are referred to with reference to illustrative schemes representative of mechanical constructions within the scope of the invention.

Figure 10 shows a 2-DoF dynamically balanced manipulator mechanism with constant inertia mechanism as in Figure 9 (fully symmetric, however this is not essential) wherein to each triangular element two additional links are connected with another revolute base joint, such that on both sides A and B they form a kite shape as illustrated in figure 10 with dashed lines . This provides the required geometric condition for full dynamic balance, in addition to a certain mass distribution and size of the elements , which can be selected by the skilled person without undue burden.

Figure 11 shows a 2-DoF balanced manipulator mechanism with the constant inertia parallelogram mechanisms as in Figure 9 (fully symmetric, however this is not essential) wherein to each triangular element two additional links are connected with another revolute base joint, such that on both sides A and B they form a kite shape as illustrated with the dashed lines . This kite shape is different from the kite shape in Figure 10. This is the required geometric condition for full dynamic balance, in addition to a certain mass distribution and size of the elements, which can be selected by the skilled person without undue burden.

Figure 12 shows a 2-DoF dynamically balanced manipulator mechanism with a constant inertia mechanism of Figure 3, with joint 0 as a revolute joint with the base and with two counterrotating elements with their own revolute joint with the base . This embodiment has the advantages of a much smaller footprint, fewer parts, and a simpler construction. The counterrotating elements are connected to and driven by the triangular elements by means of e . g. ( 1) friction or (2) toothed gears or ( 3) an inverted belt-drive .

Figure 13 shows a 2-DoF dynamically balanced manipulator mechanism with the constant inertia parallelogram mechanisms of Figure 3, with joint 0 as a revolute joint with the base and with a separate reaction wheel (rotating element) with a revolute joint with the base . The reaction wheel is driven by a separate actuator that is controlled such that all the reaction moments on the base are eliminated. This embodiment has the advantages of an even smaller footprint, fewer parts, simpler construction, and adaptive moment balance due to the control of the additional actuator.

It is also possible to combine the embodiments of Figures 12 and 13. Then the two counterrotating elements of Figure 12 mainly serve as the motors that drive the constant inertia mechanism to provide some moment balance, and the counterrotating element of Figure 13 then provides the remaining (adaptive) moment balance so that the two counterrotating elements of Figure 12 can remain relatively small .

Figure 14 shows a 2-DoF dynamically balanced manipulator mechanism with the constant inertia parallelogram mechanisms of Figure 3 (drawn with full symmetry as in Figure 9, however this is not essential) , with joint 0 as a revolute joint with the base and with two counterrotating elements with a revolute joint in the triangular elements . In the version on the left of figure 14, the counterrotating elements are driven by belt transmissions with belt wheels that are fixed with the base . In the version on the right of figure 14 , the counterrotation elements are driven by gearwheels fixed with the base and intermediate gearwheels with revolute joints in the triangular elements . The embodiments of figure 14 have the advantages of applying only one base pivot and an efficient use of the counter mass (for shaking force balance) which also serves as a counterrotating inertia element (for shaking moment balance) which arranges for a relatively low total mass and inertia of the manipulator.

The constant inertia parallelogram mechanisms of Figures 3 and 4 can be combined in various ways to result in extended constant inertia mechanisms . Figure 15 shows a 3-Dof constant inertia mechanism constructed of two 2-DoF constant inertia mechanisms, each with a different value for angle γ as illustrated, with a common central element with four joints. It shows that to the parallelogram mechanisms of Figure 3 another parallelogram mechanism is added to the right side, actuated with 63, with a (coupled) counter parallelogram at the top. The two triangular elements and the quadrilateral element are all connected with a revolute joint in 0. In addition there are two tip elements which form a parallelogram as illustrated. These tip elements can move with 3 degrees-of-freedom (vertical and horizontal translation and rotation) with respect to the surroundings, which means two internal/relative degrees-of-freedom.

Each element in figure 15 can have a generally located center of mass, as indicated with the center-of-mass symbol, and has an inertia. For specific conditions on the mass distributions and the size of the elements which can be selected by the skilled person without undue burden, the inertia of the complete mechanism about joint 0 is equal for all poses. For specific conditions on the mass distributions and the size of the elements the mechanism is also shaking force balanced or gravity balanced with respect to joint 0.

With respect to Figure 16, in the left of the figure the tip elements are connected with generally located revolute joints in the connecting links. In the right of the figure also the parallelogram indicated with θ3 is generally integrated with a separate revolute joint in the central pentagonal element which now has 5 revolute joints in total. One of the tip elements is connected to an additional link which runs parallel to the parallelogram indicated with θ1 and θ2.

Finally figure 17 provides an illustration of a 3-DoF inherently dynamically balanced manipulator mechanism. The 3-DoF constant inertia parallelogram mechanisms of the invention can be applied in multiple ways to obtain a 3-DoF fully dynamically balanced manipulator mechanism with the two tip elements as location for the end-effectors . Figure 17 corresponds to the mechanism of Figure 15 where 0 is a revolute joint with the base . To each of the three elements connected in 0 the solution for dynamic balance as presented in Figure 9 is applied, forming three inverted parallelogram linkages with the two pairs of opposite links of equal length and with a revolute joint with the base .

Additionally it is remarked that a 3-DoF dynamically balanced manipulator mechanisms can also be obtained by combining the 3- DoF constant inertia mechanism of Figure 15 with the additional elements for dynamic balance as presented in Figures 10, 11, 12, 13, and 14.

The illustrated dynamically balanced parallelogram mechanisms in the respective figures are all planar, moving within a single plane or in multiple parallel planes . By combination of two or more planar parallelogram mechanisms that are spatially separated such that the mechanisms are in differently orientated planes, it is possible to provide spatial dynamically balanced parallelogram mechanisms .

Embodiments of the present invention can include every combination of features that are disclosed herein independently from each other. Although the invention has been discussed in the foregoing with reference to an exemplary embodiment of the invention, the invention is not restricted to this particular embodiment which can be varied in many ways without departing from the invention. The discussed exemplary embodiment shall therefore not be used to construe the appended claims strictly in accordance therewith. On the contrary the embodiment is merely intended to explain the wording of the appended claims without intent to limit the claims to this exemplary embodiment . The scope of protection of the invention shall therefore be construed in accordance with the appended claims only, wherein a possible ambiguity in the wording of the claims shall be resolved using this exemplary embodiment .

Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents . The entire disclosures of all references, applications, patents, and publications cited above are hereby incorporated by reference . Unless specifically stated as being "essential" above , none of the various components or the interrelationship thereof are essential to the operation of the invention. Rather, desirable results can be achieved by substituting various components and/or reconfiguration of their relationships with one another.