DE8902325U1 - Grippers for robots or handling devices - Google Patents

Description

Patent Attorney Dipl.-Ing. R. Beyer, Am DiclMibach·», D-4<Ö0 RaÜngcn 6 Grippers for robots or handling devices

Description Genus

The innovation relates to a gripper for robots or handling devices with at least two gripping jaws that can be moved relative to one another in a one-piece housing, wherein a cylinder is arranged in the housing, in which a piston that is alternately acted upon by pressure medium pressure on both sides is arranged in a longitudinally displaceable and sealing manner, which drives a wedge gear.

State of the art

^ll/ DE-OS 35 44 130 discloses a gripper for handling devices, which consists of a clamping device with at least two clamping fingers that are movable relative to one another and are held on a housing, as well as a clamping finger actuating device provided in the housing and consisting of a cylinder-piston arrangement. The clamping finger actuating device has at least

Patent Attorney DipL-Ing! R. Beyer, Am tficltelSbacirS/D-^O Ratingen 6

two cylinder-piston units arranged coaxially one behind the other, which are coupled in a force-locking manner and can be pressurized in opposite directions with pressure medium. For the force-locking coupling, a central piston attachment passes through a cylinder cross-partition in a sealing manner and rests against the piston on the clamping finger side.

This previously known design essentially has the following disadvantages:

a) The gripping forces are only transmitted linearly.

b) When retracted, the maximum guide length is significantly less than 50% of the housing length.

c) The gripping force gear is not protected against dirt.

From DE-OS 33 06 526 a gripping device for workpieces or other handling parts is already known, with a working piston that can be actuated by pressure medium in a housing, is longitudinally displaceable and sealed in a cylinder, and is connected to a bolt in the drive

Patent Attorney &ugr;&idiagr;&rgr;&Igr;.-lng. K. Heyer, Ani UlcKelSbach*8,*U-403ö Katingen 6

connected to which gripping fingers are assigned, whereby the working cylinder with the working piston is arranged directly below the plane of movement of the bolts, whereby channels are arranged on the sides and/or front of the housing and at least the upper housing part, in which the bolts can be moved radially to the longitudinal axis of the housing and to the working cylinder, is designed to be pressure-tight to the outside. The housing is designed as a flat, one-piece housing block in which the connection channels that are not required are closed off by blind plugs or the like.

This gripping device has the following disadvantages:

a) The lateral stability is severely limited with long gripping fingers despite the guide ^bolts .

b) The tipping force is not reduced with long gripping fingers, but rather increased due to the system.

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Patent Attorney Dipi.-Ing. R. Beyer, An! uickdsbHch'»,*D-<iö3ö Ratingen 6

c) When gripping in holes, only a very unfavorable guide ratio is effective, which consumes a large part of the gripping force in the form of friction.

DE-OS 36 40 7ÖÜ describes a gripper for a robot with a pneumatic pressure cylinder for driving gripper fingers that can be moved in a straight line against each other, whereby the central axis of the pressure cylinder runs parallel or coaxially to the longitudinal axis of the gripper and the gripper fingers can be attached to radially movable sliding pieces by means of a gear. Angle levers are provided between the pressure cylinder and the sliding pieces, which are provided at their ends like forks with open sliding slots into which the drive pins of the pressure cylinder and sliding pieces engage. Roller bushings are placed on the drive pins and are guided in the sliding slots of the short angle levers. This design has the following disadvantages:

a) Due to its design, the gripper is very high.

b) The gripping forces are transmitted linearly.

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FBtentanwait Dipi.-ing. R. Beyer, Am DicUcisbach=8,D-4830 Ratingen 6

c) Ee no component is generated that reduces the tipping force,

d) The housing has screwed-on guideways which do not have the maximum possible guide length.

A gripper with two gripping jaws that are relatively movable relative to one another is already known from EP-OS 0 293 153 (88 304 652.6), which essentially has the following disadvantages:

a) Although the gripping jaws are guided smoothly by balls, the force is only transmitted at specific points, which causes high levels of wear.

b) The power transmission gear is not protected against dirt.

c) The gripping force is not reduced with long gripping fingers, but is increased due to the system.

PaieiianwBlt Dipl.-ing. R. Be"&ldquor;*r, Ani uicVeisbacliif, B-ASSI) Rniingen 6

Task

The innovation is based on the task of creating a gripper that eliminates the disadvantages of the state of the art while providing a relatively high gripping force.

Solution

The problem is solved by the features set out in claim 1.

Some advantages

When designed in accordance with the innovation, a gripper for robots or handling devices is created which not only applies a relatively high gripping force and is therefore not only suitable for handling heavy and long workpieces, but whose gripping jaws also have great lateral stability.

A further advantage is that the tilting force friction of the gripper jaw guides is reduced with long gripper jaws.

Patent Attorney Dipl.-Ing. R. Beyer, Am iMckelsibach*, D-4eJ0 Ratingen 6

Another notable advantage is that all transmission forces are not transmitted point-like or line-like, but rather over surfaces.

In addition, the gripping force gear must be encapsulated to protect it from dust and dirt.

All of these advantages are achieved with a compact design, whereby the height in particular is quite low, so that the entire construction is flat and can also be manufactured inexpensively.

Long gripper jaw guides also allow an overall better guide ratio to be achieved, which is required for long attachment gripper jaws, for example.

The drawing shows the innovation - partly schematically using an example of implementation. It shows:

Fig. 1 a gripper for robots or handling devices, partly in section, partly in elevation;

Patent Attorney Dipl.-Ing. R. Beyer, Am Dickeisbach 8, P '^3D RaVngenti

I 1 c I

Fig. 2 a partial section along the line II - Fig. 2 of Fig. 1 - partly shown in the view and

Fig. 3 is a partial view in the direction of arrow X in Fig. 1, partly broken away.

The reference number 1 designates a one-piece housing made of a metallic material, for example steel, which has a cylinder 2 at one end, in which a piston 3, which is alternately pressurized on both sides with pressure medium (pneumatically or hydraulically), is arranged so that it can move longitudinally and seals in the axial direction of the cylinder 2. The piston 3 is sealed in a pressure-tight manner by a sealing element 4 on the cylinder 2 and has a piston rod 5 which drives a wedge gear 6 of known design and arrangement to actuate the gripping jaws 7 and 8, whereby the gripping jaws 7 and 8 can be moved back and forth synchronously orthogonally to the longitudinal axis 9 of the piston rod 5 and the piston 3 arranged coaxially therewith.

Patent Attorney Dipl.-Ing. R. Beyer, Am Dickeisbach 8, D-%ÖO Rjftingen-tf

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Threaded connection bores 10 and 11 are arranged on the housing 1, to which hoses or lines (not shown) are to be connected, through which the pressure medium can be supplied in a controlled manner to one or the other side of the piston 3 under the predetermined pressure medium pressure.

Each of the gripping jaws 7 and 8 is connected to an attachment gripping jaw by means of screws, of which only the attachment gripping jaw 12 is shown in Fig. 1. The diametrically opposite attachment gripping jaw is designed in the same way. A workpiece is gripped between them, which is only schematically indicated in Fig. 1 with dot-dash lines and has been provided with the reference number 13. The fastening screws for the attachment gripping jaw 12 are designated with the reference numbers 14 and .

In Fig. 1 the guide length is indicated by F and in Fig. 2 the length of the housing is indicated by L.

When gripping heavy loads, the surface 16, which is only indicated schematically, is relieved.

Patent Attorney Dipl.-Ing. R. Beyer, Am Dickeisbach 8, D-^lt) Kdtingen'tf · · · · ' ·.

The forces are transmitted over the area of the wedge gear, whereby only the surfaces 17, 18 and 19 are shown in Fig. 2. The diametrically opposite surfaces of the wedge gear are designed in the same way (Fig. 2).

The cylinder 2 is sealed against dust and pressure by a cover 20.

At 21, the assumed pivot point for the moment occurring when gripping loads is schematically shown for one fastening jaw 7.

From Fig. 3 it can be seen that the cover 22 is detachably attached to the housing 1 by several screws, of which only the screw 23 can be seen in Fig. 3.

Fig. 3 shows that the tipping stability has been increased by the guidance of the gripping jaw 7 - the gripping jaw 8 is arranged, designed and mounted in the same way - by the surface guides on the surfaces 24, 25, 26, 27, 28 and 29. The guidance on the surfaces 28 and 29 increases the lateral stability of the gripping jaws 7 and 8.

Patent Attorney »Inl.-Inu. R. Beyer. Am Dlckelabach 8. D-4tf3l) lUtlngen'd

It can be clearly seen from Fig. 1 that each gripping jaw 7 and 8 is supported on 50% of the housing length L in the retracted state. All transmission forces are diverted via surfaces. The gripping force transmission gear 6 causes an axial and a radial force transmission. The force transmission is the same as the

Surface 16 with long jaw attachments and increasing tilting force. The plate 22 protects the gripping force gear against the ingress of dirt and dust.

The gripper bridge guides are advantageously T-slot-shaped.

The features set out in the protection claims and in the description and in the drawing can be essential for the realization of the spatial form concept of the innovation, both individually and in any combination.

Patent Attorney Dlpl.-Ing. R. Beyer, Am Dlckelsbach 8, D^üiO Ratlnaerf &bgr;

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bibliography

EP-OS O 293 153 (88 304 652.6) DE-QS 36 40 IQQ DE-OS 33 06 526 DE-OS 35 44 130

Patent Attorney Dipl.-Ing. IL Beyer. Am Dickeisbach 8, D'-46iO Ritingen 6

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Reference cells

1 Housing 2 3 Pistons 4 Sealing element 5 Piston rod 6 Wedge gear 7 Geifbacke 8th M 9 Longitudinal axis 10 Connection hole 11 The 12 Attachment gripping jaw 13 workpiece 14 Fixing screw 15 The 16 Area 1? H 18 It 19 11 20 Lid

Patent Attorney Dlpl.-Ing. R. Beyer, Am Dlckelsbach 8, D-4050 Ratlngen* &bgr; " "

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21 pivot point 22 Lid 23 screw 24 Area 25 M 25 It 27 ti 28 The 29 F Leading length L Housing length X View direction

Claims (1)

Patent Attorney Dipl.-Ing. R. Beyer, Am'Dic&elsbacir8,*D-40ä0 Ratingen 6 Claim for protection Gripper for robots or handling devices with at least two gripping jaws (7, 8) that can be displaced relative to one another in a one-piece housing (1), wherein a cylinder (2) is arranged in the housing (1), in which a piston (3) that is alternately acted upon by pressure medium pressure on both sides is arranged in a longitudinally displaceable and sealing manner, which drives a wedge gear (6), characterized in that a) each of the gripping jaws (7, 8) is supported on 50% of the housing length (L) in the retracted state; b) all transmission forces are redirected via surfaces (17, 18, 19, 24, 25, 26, 27, 28, 29); c) the wedge gear (6) produces a component that reduces the tilting friction and relieves the load on the guide surfaces (·6); Patent Attorney Dipl.-Ing. R. Beyer, Am t)idMSbach-8, D °30 Ratingen 6 d) the wedge gear (6) is protected against the ingress of dirt and dust by means of a plate (22); e) the gripper jaw guides are T-slot-shaped and have wide guide surfaces (24, 25, 26, 27).