DE3308474A1 - Mechanism for moving objects while retaining a certain alignment - Google Patents

Abstract

The mechanism for moving objects, such as for example workpieces or working tools, while retaining a certain alignment is intended in particular for loading and unloading objects stacked in rows on pallets. It comprises a base frame (10), on which a three-part articulated arm (12, 22, 41) is rotatably mounted about a first basic axis (11). The two outer parts (22, 41) of the articulated arm are pivotal about a second and third basic axis (20, 40) respectively, which both lie parallel and at right angles to the first basic axis (11). A holding means for the objects to be moved is to be attached to the free end of the articulated arm by means of two hand axes (58, 63), arranged at right angles to each other. The first hand part (60), mounted on the first hand axis (58), is connected by a first transmission to the first arm part (12) and is thereby held in a rotationally fixed manner with respect to the first hand axis (58). The second hand part (62), mounted on the second hand axis (63), is connected by a transmission (74-94) to the base frame (10) and is held in a rotationally fixed manner in relation to the second hand axis (63). <IMAGE>

Description

Patent attorneys Dipl.-Ing. W.Beyer Dipl.-Wirtsch.-Ing. B. Jochem

Frankfurt / Main Staufenstrasse

Note 5

Norbert Schlimm
Angerburger Allee 4c

1000 BERLIN 19th

Patent and utility model auxiliary application

Title: WORK EQUIPMENT FOR MOVING OBJECTS WHILE MAINTAINING A CERTAIN ORIENTATION

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WORK EQUIPMENT FOR MOVING OBJECTS WHILE MAINTAINING A CERTAIN ORIENTATION

The invention relates to an implement for moving objects, e.g. workpieces or work tools, while maintaining a certain orientation, especially for handling and unloading of articles stacked in rows on pallets, consisting of a base frame, one around one first arm part rotatably mounted on the first base axis, and a second arm part arranged thereon at right angles to the first A second arm part rotatably mounted on the base axis, one on it rotatably mounted about a third base axis parallel to the second third arm part, one on it rotatably mounted about a first hand axis parallel to the second and third basic axis first hand part and one thereon rotatably mounted about a second hand axis parallel to the first basic axis second hand part, which is connected to a holder for the objects to be moved.

Such work devices can, for example, work machines that carry tools se'in their tools, for example cutting, shaping or welding tools, on certain parallel paths to be guided and to be raised and lowered relative to these, or handling devices, with the help of which e.g. Workpieces or finished products are to be picked up and / or deposited in parallel rows in an orderly manner.

In such a case, it is advisable to use tools whose parts can be moved along guideways, which are arranged according to Cartesian spatial coordinates. Then the guideways can be arranged in a row align the objects or the parallel movement paths and you only need three controllable drives for movements in the direction of the three coordinate axes. Gantry cranes can be mentioned as an example of such work equipment. Basically they have the disadvantage that their guide railways take up a lot of space and precede supporting parts that are difficult to move

SL 9253 HG / February 21, 1983

set so that the accelerations and working speeds to be achieved are correspondingly low and the ratio of Dead weight to payload is unfavorable.

Working equipment of the type mentioned at the beginning with an articulated arm that can be moved in a circle (see e.g. that from VEB-Verlag Technik Berlin 1981 published book "Industrieroboter", page 92) require less contact area, but set apart from the stationary frame, at least five relatively rotatable parts ahead. In known working devices resulted from this the need for five controllable drives with the further disadvantageous consequences that the large number of controllable motors and the associated gear and torque-transmitting organs increased the masses to be moved and together with the necessary 5-axis control led to relatively high costs.

The invention is therefore based on the object of creating an implement of the type mentioned at the outset which is structurally and is simpler, lighter and faster in use than the previously known such devices.

The above object is achieved according to the invention in that the first hand part connected to the first arm part by a first transmission and with respect to the first hand axis is held in a rotationally fixed manner, and that the second handle is connected to the stationary frame by a second transmission and is held non-rotatably with respect to the second wrist axis.

The invention ensures that no controllable drive motors are needed for the two wrist axes, which otherwise contribute significantly to the control effort of the implement and due to their mass and unfavorable Position at the extreme end of the articulated arm reduce the load capacity and working speed. The alternative proposed In contrast, transmissions are simpler, cheaper and more reliable and also simplify operation during programming by means of the "teach-in" process.

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330847A

The said transmissions, through which the arm movements are counteracted on the wrist axes, thus the predetermined Maintain constant alignment of the gripper or other holder for the objects to be moved are preferably chain or belt drives. If necessary, however, other transmissions, such as e.g. Rods moved by cranks or transmission shafts connected by gear drives come into question.

The invention is explained in more detail below with reference to an exemplary embodiment shown in the drawing. Show it:

1 shows a simplified perspective illustration, partly in section, of an implement according to the invention;

FIG. 2 also shows the device according to FIG. 1 in perspective, seen from the other side.

The implement shown has a base frame 10 which can be firmly anchored to the ground. On the base frame is a first arm part 12 rotatably mounted about a central vertical axis of the base frame. There is a first one for this turning movement Drive motor 14 mounted on the base frame 10, which via a so-called cyclocross gear and a pinion 16 rotatably with the arm part 12 connected gear 18 drives.

A second arm part 22 is mounted on a shaft 20 on the first arm part 12. With this is a coaxially arranged Connect wheel 24 so that it cannot rotate. Also are on the axis two further wheels 26 and 28 are freely rotatable. A chain can extend around most of the circumference of the wheel 24 30, which is attached with its outer end to the circumference of the wheel 24. The opposite end of the chain is connected via / a swivel joint 32 to a rack 34 into which the output pinion 36 of a second drive motor 38 intervenes with the attached Cyclo gear. The toothed rack 34 is moved up and down by means of the motor-gear unit 38.

SL 9253 HG / February 21, 1983

It takes the chain 30 with it via the swivel joint 32, and since its outer end partially around the circumference of the wheel 24 placed and also attached there, the linear movement of the rack 34 is in a rotary movement of the .Rads 24 and the second arm part 22 connected to it.

The outer end of the second arm part 22 carries an axis 40 on which a third arm part 41, which is fixed with Wheels 42, 44 is connected, is stored. Chains 46 and 48, e.g. so-called leaf chains, as used in forklifts find are fixed with their outer ends on the circumference of the wheels 42 and 44, over part of the Umfar.gs these wheels out, placed on the freely rotatable wheels 26 and 28 seated on the axis 20 and immediately next to them the vertical axis of rotation of the first arm part 12 guided from above into the base frame 10, where they have a Rotary joint 50 are fixedly connected in the longitudinal direction to one or two toothed racks 52, in which an output pinion 54 a third drive motor 56 which is also connected to a cyclo transmission engages. By means of this engine and the The transmission formed by the racks 52 and chains 46, 48, the third arm part 41 can pivot about the axis 40 will.

It can be seen that all drive motors 14, 38 and 56 for the movements of the three arm parts 12, 22 and 41 are stationary are stored and therefore neither strain the arm nor adversely affect the acceleration values of the arm movements.

At the free end of the third arm part 41 is a first hand axis 58, which is parallel to the two axes 20 and 40, so in the example is arranged horizontally. A first hand part 60 is rotatable relative to the arm part 41 on the Axis 58 mounted. A second handle 62 is on the first handle 60 relative to this about an indicated vertical axis

SL 9253 HG / February 21, 1983

63 rotatably mounted. A gripper, not shown, for workpieces, for example, can be connected to the second hand part 62.

When using the working device shown, objects are deposited in rows or objects aligned in this way are to be recorded, the drives for the first and second hand parts 60, 62 movements of the arm parts compensate for rotational movements of the hand parts about the hand axes 58 and 62 relative to the first arm part 12 and the Avoid base frame 10. Instead of appropriately controlled drives, which are usually at the outer end of the articulated arm would have to be assembled, the tool shown has light transmissions, which have the same purpose with simpler ones Achieve means.

The guidance of the first handle 60 can be seen from FIG. 1. As shown there, a Ra-ä- 64 is seated on the second basic axis designated by 20 and is held so as to be non-rotatable relative to the first arm part 12. On the third basic axis

40 two wheels 66 are mounted, which are firmly connected to one another. Between the wheel '64 and one of the two Wheels 66 extend into a self-contained chain 68. Another wheel 70 sits on the first hand axis 58 and is connected to the first hand part 60 in a non-rotatable manner. Another self-contained chain 72 runs over the other of the two wheels 66 and wheel 70. The translation of the chain drive 64-72 is a total of 1: 1, so that regardless of pivoting movements of the second arm part 22 to the second basic axis 20 and the third arm part 41 about the third basic axis 40 the first handle part 60 with reference to the Axis 58 is held non-rotatably. In the example, the first handle 60 retains in all positions of the pivot arm 12, 22,

41 the position in which the second hand axis is parallel to the first basic axis, i.e. to the axis of rotation of the first Arm part 12, is vertical.

To rotational movements of the first arm part 12 by the indicated at 11 to compensate for the first basic axis on the second handpiece 62,

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SL 9253 HG / 2T.2.1983 ^Γ

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• S- is according to FIG. 2 between the latter and the base frame 10 arranged a further transmission. This consists of a non-rotatably fixed on the base frame 10 gear 74, a toothed belt or a chain 76, which the gear 74 with a on the first arm part 12 about a to the base axis 11 parallel Axis rotatably mounted gear 78 connects, a non-rotatably connected to the latter worm 80, which with a corresponding worm wheel 82 is in engagement, which is rotatably mounted on the second base axis 20 and rotatably is connected to a P-ad 84, which in turn via a belt or chain 86 to one of two wheels 88 mounted next to one another on the third basic axis 40 and connected non-rotatably to one another. That the other of the two wheels 88 is via a belt or a chain with one mounted on the first wrist axis 58 Wheel 92 in connection, the rotational movement of which is about a bevel gear pair 94 is transmitted to the second handle 62. If the translation of the aforementioned transmission between the gear 74 and the second handle 62 is a total of 1: 1, the fixedly anchored gear 74 also holds the second hand part 62 relative to the second hand axis 63 non-rotatably fixed, so that a connected to the second hand part 62 Gripper or other holder in all positions of the articulated arm 12, 22, 41 its orientation with respect to the Retains base frame 10 and experiences only a parallel displacement with respect to this.

The transmissions described above for the drives of the second and third arm parts as well as the hand parts can be toothed belt or chain drives, with self-contained, endless toothed belts or chains over toothed belt pulleys or Gears are guided and are positively engaged with these by means of the teeth. Alternatively, toothless belts or Chain drives are used in which finite belt or chain strands with their ends, e.g. by means of screws or rivets, are set on the periphery of the driving and driven wheels. This possibility exists because in most cases only a rotation angle of less than 36o is required are, among those in the illustrated embodiment

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Given conditions, only the wheel 78 needs to be a normal toothed belt pulley or a gear on which the Toothed belt 76 or a chain may not be fixed because only this wheel 78 has to rotate more than 36o.

In order to be able to use the mentioned type of transmission with belt or chain strands fixed at the ends on the circumference of wheels To transmit torques in both directions of rotation, two strands of belts or chains are arranged next to each other, the ends of which are looped in the opposite direction around a double-wide wheel or two non-rotatably connected wheels. In order to Depending on the wrap angle, angles of rotation of up to almost 3 6o can be achieved in both directions of rotation. Most of the time, however, are enough 27o. At angles of rotation up to about 18o could also be closed, endless belts or chains are used, each at a point on the circumference of the driving and on the one hand on the other hand, the driven wheel are set.

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Claims (1)

PATENT CLAIMS Work device for moving objects, e.g. workpieces or work tools, while maintaining a specific orientation, especially for loading and unloading items stacked in rows on pallets, consisting of a base frame, a first arm part rotatably mounted on it about a first base axis, a second one rotatably mounted thereon about a second basic axis arranged at right angles to the first Arm part, one thereon rotatably mounted about a third arm part parallel to the second, third basic axis, one on it around a parallel to the second and third basic axis first hand axis rotatably mounted first hand part and one thereon about a parallel to the first basic axis second hand axis rotatably mounted second hand part, which with a holder for the objects to be moved is connected, characterized in that the first hand part (60) through a first transmission (64-72) to the first arm part (12) is connected and held non-rotatably with respect to the first hand axis (58), and that the second hand part (62) connected to the base frame (10) by a second transmission (74-94) and with respect to the second hand axis (63) is held non-rotatably. Tool according to Claim 1, characterized in that that the first transmission (64-72) consists of a rotationally fixed to the first arm part (12) connected, on the second base axis (20) arranged first wheel (64), one rotationally fixed to the first handle (60) connected, on the first hand axis (58) arranged second wheel (70) and one via intermediate wheels (66) on the third basic axis (40) guided chain or belt drive (68, 72) with a transmission ratio of 1: 1 between the first and second wheels (64, 70). SL 9253 HG / 21.2. Tool according to Claim 1 or 2, characterized in that the second transmission (74-94) from a rotatably connected to the base frame (10), arranged on the first base axis (11) third wheel (74), a non-rotatably connected to the second hand part (62), on the second hand axis (63) arranged fourth wheel (94) and one via angle drives (80, 82; 94) and intermediate wheels (88) on the second and chain or belt drive (76, 86, 90) guided by a third basic axis (20, 40) with a transmission ratio of 1: 1 between the third and fourth wheels (74, 94). SL 9253 HG / February 21, 1983