EP0941407B1 - Linear drive mechanism - Google Patents

Description

The invention relates to a linear drive according to the features the preamble of claim 1.

Linear drives are mainly used in assembly and handling technology used and go for example from EP 0 219 439 A1. In the known case, one is due to the application of fluid drivable to an axial linear movement Stripping section provided in a front section of a housing lying storage area from a storage facility includes and thereby under lateral support in Is guided displaceably in the longitudinal direction. To the stripping section to be able to position in a predetermined axial position, is a position specification element protruding to the side of the driven part provided that runs along a threaded rod, which are arranged in a side next to the stripping section Position specification space is arranged. In the position specification space there are also several on the position specification element responsive sensors with one of the Interact with the threaded rod assigned brake device. Will the position setting element during the axial movement of the Output part in the vicinity of one of the sensors, the braking device controlled with a brake signal so that the Threaded rod fixed non-rotatably and a further axial movement of the position specification element and with this connected stripping section is prevented.

The section of the driven part protruding from the housing is very often subject to high lateral forces during operation. For example the output part is provided with a gripper, who has to carry heavy loads. You can also use other linear drives be attached to a multi-axis handling device to obtain. It is therefore necessary that Output part relative to the housing over a proportionate long storage area and support in the transverse direction. This results in a correspondingly large overall length of the Housing.

In a linear drive known from EP-A-0 472 778 a storage device is provided, which extends over only a partial circumference of the stripping section, so that position setting elements arranged on the driven part axially immerse in the storage area. The Storage facility is within a closed Profile trained housing.

It is the object of the present invention to provide a linear drive of the type mentioned at the beginning, which is more reliable Storage of the positionable stripping section over has a compact overall length.

To solve this problem, the characteristics of the characteristic Part of claim 1 provided.

In this way, there is a linear drive in which the for the position setting element usable axial displacement distance reaches into the storage area. The axial movement of the Position specification element is not due to the beginning of the storage area limited. The position specification space in which the Position specification element protrudes and along it this position setting element during the linear movement of the driven part shifted, is at least partly also to the Extended storage area by the storage facility provided there over only part of the circumference of the stripping section extends and the driven part along an im Travel of the circumferential section located position setting element is exposed, so that in the storage area there is a free space from the position setting element is freely accessible. For this purpose, the Housing at least in the storage area via a storage device load-bearing, approximately L-shaped in cross section Basic body, the one facing away from the two L-legs Circumferential area of the stripping section forms the free space. The position setting element can thus on the effective storage device move past into the storage area become. There is therefore the possibility of a axially relatively long storage area to choose, without this to have to increase the overall length of the housing excessively, because the position specification space and the storage facility can overlap axially without mutual interference.

Advantageous developments of the invention result from the subclaims out.

The free space is expediently one with the base body connected lid body covered, which also the position specification space limited.

The housing of the linear drive is expediently designed such that that it has a rectangular-like outer contour in cross-section Has.

If the storage facility runs along its entire length extends over only a partial circumference of the stripping section, can increase the overall length of the position specification space Free space should be provided for the entire length of the storage area occupies.

The storage device is preferably of at least two diametrically opposite, for example, cassette-like built-up storage units formed on with respect the longitudinal axis of the driven part diametrically opposite Pages with the outer circumference of the stripping section to the Working together storage. Several such pairs of storage units can be distributed in the longitudinal direction of the stripping section be fixed to the housing.

The storage device expediently serves at the same time Anti-rotation device of the driven part. Are diametrically opposite arranged storage units available the stripping part expediently in the corresponding areas each via a longitudinal guide groove, in which engages the respective associated storage unit in a form-fitting manner.

In order to make optimal use of the construction volume, it is advantageous if the free space accessible by the position-setting element placed so with respect to the transverse and vertical axes of the housing is that it has an oblique orientation, whereby it obliquely to the side and at the same time points up or down.

The position setting element is in an expedient embodiment formed as a stop that with at least a counter-stroke works together, the component a position setting device arranged in the position setting space is. The stop runs to specify the position to a counterstop arranged in its relocation path on.

The existing counter stops are expediently on one in the position specification space parallel to the longitudinal axis of the driven part extending support rod arranged.

The counter stops are expedient in the longitudinal direction adjustable to different position requirements as required to be able to make. To ensure that force is applied as centrally as possible to obtain, the stop is preferably designed so that he at least partially and preferably the support rod grips like a fork.

A change in the position specification can be done without axial Adjust the counter stops if the position setting device about at least one counterstop has the intermediary of an associated switching device between one in the stroke of the stop outstanding effective position and one outside the travel path the inactive position of the stop switchable is. The switching device expediently works with the handrail carrying the counter stops, the positioning of a respective counter-stop by rotating the handrail around its longitudinal axis becomes. The support rod can be conveniently in positioned at least two different rotational angle positions become. The number of positionable angular positions depends largely on the number of switchable Counter-stops. Should be in addition to two predefined end positions if necessary, a single intermediate position, For example, a middle position can be specified, so suffice a counter stop and two positionable angular positions, around the counterstop either in the effective or to spend the ineffective position. To a bigger one To be able to specify the number of intermediate positions is one correspondingly larger number of counter-stops are provided, which is achieved by gradually positioning the handrail can optionally shift into the effective position.

The load on the individual components of the linear drive to reduce and in particular to avoid hard impacts the position setting device expediently with a Shock absorber device equipped with at least one Movable attenuator with which the support rod is motion-coupled. The handrail can be moved in this way stored that they along a predetermined damping distance is limited axially movable. In this case one takes the setting of the counterstops appropriately in such a way that they then take up their position specification, if the handrail at one end of the damping section arrives at a predetermined end position. The damping section is then defined by the distance that that of counter-attack acted upon until it is reached the end position mentioned. This way regardless of which counterstop is effective, one reliable shock absorption, not every counter stop own shock absorber device must be assigned, but a single one interacting with the handrail Shock absorber device is sufficient.

The shock absorber device expediently has only two shock absorbers, each in one stroke direction are effective and particularly in the area of the two axial end regions of the support rod. Thus are for Positioning in two or more positions preferably only two shock absorbers required.

Figur 1:

eine bevorzugte Ausgestaltung des erfindungsgemäßen Linearantriebes in Seitenansicht und teilweise geschnitten bzw. aufgebrochen,

Figur 2:

die beiden Endabschnitte des Linearantriebes aus Figur 1 in vergrößerter Darstellung,

Figur 3:

den Linearantrieb aus Figuren 1 und 2 im Querschnitt gemäß Schnittlinie III-III,

Figur 4:

den Linearantrieb aus Figuren 1 und 2 im Querschnitt gemäß Schnittlinie IV - IV,

Figur 5:

eine perspektivische Teilansicht des Linearantriebes, wobei der Lagerbereich ersichtlich ist und die Positionsvorgabeeinrichtung nicht näher gezeigt ist,

Figur 6:

eine Einzeldarstellung des bei dem Linearantrieb zur Anwendung kommenden, als Anschlag ausgebildeten Positionsvorgabeelementes,

Figur 7:

den in Figur 2 markierten Bereich VII in vergrößerter Darstellung zur Verdeutlichung der Wirkung der Stoßdämpfereinrichtung, wobei die Haltestange in ihrer Grundstellung gezeigt ist,

Figur 8:

die Anordnung aus Figur 7 bei von der Haltestange nach dem Zurücklegen der Dämpfungsstrecke eingenommener Endposition,

Figur 9:

einen Teilquerschnitt durch den Linearantrieb im Bereich der in Figuren 1 und 2 nur strichpunktiert schematisch angedeuteten Umschalteinrichtung gemäß Schnittlinie IX - IX, wobei die Haltestange eine erste Drehwinkelstellung einnimmt,

Figur 10:

die in Figur 9 gezeigte Umschalteinrichtung im betätigten Zustand, wobei die Haltestange in einer zweiten Drehwinkelstellung positioniert ist,

Figur 11:

einen Teilquerschnitt durch den Linearantrieb im Bereich eines in Figuren 1 und 2 lediglich schematisch und strickpunktiert angedeuteten umschaltbaren Gegenanschlages gemäß Schnittlinie XI - XI, wobei der Gegenanschlag eine der ersten Drehwinkelstellung aus Figur 9 entsprechende unwirksame Stellung einnimmt,

Figur 12:

die Anordnung aus Figur 11 bei von dem Gegenanschlag eingenommener wirksamer Stellung, die der in Figur 10 gezeigten zweiten Drehwinkelstellung der Haltestange entspricht, und

Figur 13:

eine der Figur 9 entsprechende schematische Darstellung einer weiteren Ausführungsform einer Umschalteinrichtung, die ein schrittweises Positionieren der Haltestange in mehr als zwei unterschiedlichen Drehwinkelstellungen ermöglicht.

The invention is explained in more detail below with reference to the accompanying drawing. In this show:

Figure 1:

a preferred embodiment of the linear drive according to the invention in side view and partially cut or broken,

Figure 2:

the two end sections of the linear drive from Figure 1 in an enlarged view,

Figure 3:

the linear drive from Figures 1 and 2 in cross section according to section line III-III,

Figure 4:

the linear drive from Figures 1 and 2 in cross section according to section line IV - IV,

Figure 5:

2 shows a perspective partial view of the linear drive, the bearing area being visible and the position setting device not being shown in more detail,

Figure 6:

an individual representation of the position setting element used as a stop and used in the linear drive,

Figure 7:

area VII marked in FIG. 2 in an enlarged representation to illustrate the effect of the shock absorber device, the holding rod being shown in its basic position,

Figure 8:

7 shows the arrangement from FIG. 7 with the end position assumed by the holding rod after the damping section has been covered,

Figure 9:

2 shows a partial cross section through the linear drive in the area of the switching device according to section line IX - IX, which is only schematically indicated by dash-dotted lines, the holding rod assuming a first rotational angle position,

Figure 10:

9 the switching device shown in FIG. 9 in the actuated state, the holding rod being positioned in a second angular position,

Figure 11:

3 shows a partial cross section through the linear drive in the area of a switchable counterstop according to section line XI-XI, which is indicated only schematically and in dot-dash lines, the counterstop assuming an ineffective position corresponding to the first angle of rotation position from FIG. 9,

Figure 12:

11 shows the arrangement from FIG. 11 in the effective position assumed by the counterstop, which corresponds to the second rotational angle position of the holding rod shown in FIG. 10, and

Figure 13:

a schematic representation of a further embodiment of a switching device corresponding to FIG. 9, which enables the holding rod to be positioned step by step in more than two different rotational angle positions.

The linear drive according to the example has a housing 1, the one extending in the longitudinal direction, in cross section 4 has an approximately L-shaped base body 2, on the in the limited by the two L-legs Area a lid body with a L-shaped cross section 5 is releasably attached so that there is a cross section in results in a substantially rectangular outer contour of the housing 1. The housing 1 is on both ends by a front (6) or rear (7) end wall closed, whereby the end walls 6, 7 via fasteners 8 on the Base body 2 are fixed and the lid body 5 in turn removable with the base body 2 and the two end walls 6, 7 is connected.

The linear drive has a housing 1 axially displaceable output part 12, which is a rod-shaped Has shape and is tubular, for example. The stripping section 12 extends partially inside the Housing 1, wherein there is a predetermined storage area in the housing 1 13 and the front end wall 6 penetrates and protrudes from the housing 1 with an outer longitudinal section 14. The storage area 13 is preferably located in the front section assigned to the front end wall 6 the housing 1.

In the storage area 13 is a housing-fixed storage device 15 arranged which cooperates with the outer circumference of the driven part, whereby it supports the driven part 12 laterally and at the same time leads axially displaceable. The storage facility 15 expediently also serves to prevent rotation Fixing the stripping section 12 to twist it around its To prevent longitudinal axis 16 with respect to the housing 1. Outdoors End of the outer length section 14 is on the driven part 12 a force tapping element 17 arranged with a component to be moved can be connected. The anti-rotation device guarantees an always unchanged angular alignment of the power output element 17, so that the linear drive especially for use in assembly and handling technology is suitable where, among other things, objects are transported and must be positioned correctly.

The output part 12 is a fluid-operated drive device 18 assigned, with the help of the driven part 12 through Fluid force for a reciprocating axial linear movement is drivable in the direction of its longitudinal axis 16. This Drive device 18 is preferably inside the housing 1 housed.

The drive device 18 is preferably an independent one fluid-operated cylinder 22 is formed. This has a rear on the rear end wall 7 of the housing 1 of the linear drive fixed axially immovable Cylinder housing 21 that is parallel to the driven part 12 is aligned. The housing is attached expediently with the mediation of a rear end body 24 on which the rear end of a cylinder tube 23 is attached and this in turn is dash-dotted indicated screw connection 25 or another Connection type set on the rear end wall 7 is.

At its front is the cylinder tube 23 of the cylinder housing 21 closed by a front end body 26, which penetrates under seal by a piston rod 27 is, the inner end of one in the interior of the cylinder tube 23 axially displaceably guided piston 28 fixed is. The piston 28 divides the interior of the cylinder tube 23 in two volume-changing work rooms 32, 33, those on the opposite axial side of the assigned one End bodies 24, 26 are tightly limited.

The axial length of the working cylinder 22 is less than that of the housing 1. The facing the front end wall 6 Front of the cylinder housing 21 ends axially inside the front end wall 6 and, for example, in the Storage area 13.

The tubular output part 12 according to the example is related the cylinder housing 21 and the entire working cylinder 22 executed as a separate component. It is coaxial with the cylinder barrel 23 arranged and axially from the front pushed onto this so that it over the cylinder tube 23 encloses at least part of its overall length on the outside. there is the driven part 12 arranged relative to the housing Cylinder housing 21 axially displaceable, depending on it from its axial position more or less far beyond protrudes the front of the cylinder housing 21 and accordingly also the length of the outer length section 14 of the Output part 12 varies. The front end wall 6 out of the front end body 26 of the working cylinder 22 emerging piston rod 27 protrudes into the cylinder housing 21 axially upstream interior 34 of the tubular driven part 12 in and extends forward to in the proximity of the force tapping element 17 on which they are common is attached to the driven part 12.

Each working space 32, 33 of the working cylinder 22 communicates with a connection opening 35, 36 assigned to it, via the if necessary, a fluid pressure medium, especially compressed air, fed into and out of the working spaces 32, 33 can be dissipated. Depending on which work area 32, 33 is pressurized with pressure medium, the piston 28 is in the axially shifted in one direction or another, being its movement via the piston rod 27 to that firmly connected to it Output part 12 is transmitted. With the resulting Axial displacement of the driven part 12 is this for example, exclusively from the storage facility 15 led. In particular, there is no transverse support of the Output part 12 on which the cylinder tube 23 and the two end bodies 24, 26 composing cylinder housing 21. For example, lies radially between the cylinder housing 21 and the longitudinal section of this enclosing tubular output part 12 a the length of the aforementioned Longitudinal section having a cylindrical annular gap 37 in front. This has the advantage that the cylinder tube 23rd can be done very thin-walled because there are no managerial duties has to take over. The working cylinder 22 is practically with its rear end body 24 and its unsupported piston rod 27 on the front suspended between the housing 1 and the driven part 12 and does not need to absorb lateral forces.

The connection area between the rear end of the working cylinder 22 and the rear end wall 7 can if necessary, limited flexibility and / or with a pivoting option be carried out for manufacturing or assembly-related reasons Misalignment with respect to the longitudinal axes of the working cylinder 22 and the output part 12 to compensate automatically. In Figure 1, this is shown schematically by a dash-dotted line indicated pivot axis 38 indicated.

Since the cylinder tube 23 on the part of the driven part 12 none When subjected to transverse loads, it can advantageously for fluid transmission for the operation of the working cylinder 22 required printing medium can be used. To do this extends itself inside the cylinder tube 23 in its longitudinal direction a connecting channel 42 in the area of the back of the cylinder tube 22 with a first connection channel 43 communicated, which the rear end body 24th penetrates and leads to the first connection opening 35. At the the connecting channel is at the front end of the cylinder tube 23 42 with a formed in the front end body 26 Transition channel 45 in connection, which in turn in the neighboring front working space 33 opens. In this way can the front work space 33 over the assigned first Connection opening 35 from the rear of the housing 1 through Purely static connection channels are pressurized with compressed air or be vented. Since the circumference of the working cylinder 22nd therefore no disruptive pressure medium lines required are, overall, very compact transverse dimensions of the Achieve linear drive.

The second connection opening 36 is expediently located in the vicinity of the first connection opening 35 and in particular on the rear end wall 7. It communicates with a rear body 24 also pulling through second connection channel 44, which in the immediate adjacent rear work space 32 opens out. To this The fluidic control of the linear drive is by possible from a central location.

In order to realize the thinnest possible cylinder tube 23 can and still have the largest possible flow cross-section in the connecting channel 42, the connection channel 42 is exemplary as with respect to the Interior 32, 33 of the cylinder tube 23 arranged concentrically Ring channel 46 executed, the ring-shaped according to Figure 4 Cross section. The radial dimensions of this Ring channel 46 can be carried out minimally, because by the large circumferential extent a sufficiently large flow cross-section results.

The ring channel 46 is expediently realized by that one from the cylinder tube 23 as in the embodiment an inner tube 47 of smaller diameter and one the inner tube with radial space enclosing on all sides, Outer tube 48 arranged coaxially to the inner tube 47. The inner tube 47 delimits the working spaces 32, 33 and forms the tread for the piston 28 and the circumferential Gap between the two tubes 47, 48 represents the Ring channel 46 represents. The concentric alignment of the two Tubes 47, 48 are made by appropriate attachment to concentric offset mounting sections 51, 52 of the two End body 24, 26 so that it is in the interior of the ring channel 46 no flow obstacles.

The linear drive is expediently provided with a position setting device 53 equipped, which is in the housing 1 laterally next to the driven part 12 or the working cylinder 22 extends. It works with a position specification element 54 together, which in a region of the driven part 12 this is co-movable, which is independent of the axial position of the driven part 12 axially within the Housing 1 is located. For example, it is at an axial distance to both front ends of the driven part 12 on The outer circumference of the driven part 12 is arranged. Conveniently, it is near the inner end of the Output part 12. It projects laterally from the output part 12 away and in one next to the driven part 12 and the working cylinder 22 provided, hereinafter as a position specification space 55 designated receiving space, in which also the position setting device 53 is housed. Will the stripping section 12 axially displaced, the position setting element shifts 54 according to double arrow 56 in the longitudinal direction of the Position specification space 55.

By interacting with the position setting element 54, the position setting device 53 is able to specify different axial positions of the driven part 12. In this way, the driven part 12 can be positioned as required in predetermined positions during its operation.
In order to enable simple and at the same time reliable positioning, the position setting element 54 is designed, for example, as a stop body projecting in the transverse direction from the driven part 12, hereinafter referred to as stop 57. He is able to work with one or more counter stops 58, which are part of the position setting device 53 defined on the housing side. If the stop 57 runs onto one of the counter stops 58 positioned in its travel path 56, the driven part 12 is stopped in its movement.

To ensure a large positioning range and simultaneous stable storage of the stripping section 12 a to obtain the smallest possible overall length of the housing 1 the example arrangement made so that the position specification space 55 in which the stop 57 runs along from the rear of the housing 1 into the storage area 13 stretched axially into it. This allows the stop 57 to move freely run past the storage facilities 15. The range of motion of the stop 57 and the storage area 13 thus overlap in the axial direction, so that a shortened Overall length is possible.

This is made possible by the fact that the storage facility 15 at least along their section of their overall length and preferably - as in the exemplary embodiment - along the entire length Length of the storage area 13, only over part of the circumference of the stripping section 12 extends. The stripping section 12 is thus not completely enclosed by the bearing device 15, it there is only storage in some areas. In the embodiment is the bearing on two diametrically opposite, seen in cross-sectional view rather selective Areas of the outer circumference of the driven part 12 are limited. The corresponding storage areas are shown in FIGS. 4 and 5 marked by reference numerals 62. The bearing device 15 comprises here two successively in the longitudinal direction of the driven part 12 arranged pairs of diametrically opposite each other especially cassette-like storage units 63, 64, which in the storage areas 62 on the outer surface of the Output part 12 abut so that it is axially displaceable is guided and supported in the transverse direction at the same time. By doing the two pairs of bearing units 63, 64 with an axial distance are arranged to each other, one results over a large length distributed cross support, resulting in a very precise and resilient guidance of the driven part 12 results.

The number of storage units 63, 64 is basically arbitrary. For example, there could already be a pair of storage units 63, 64 are sufficient if this has a suitable Length. The storage units 63, 64 can be used as required as a plain bearing or as a roller bearing, the latter in particular in ball or roller circulation technology.

The bearing device 15 expediently forms at the same time an anti-rotation device for the driven part 12. For this purpose, it is provided, for example, that the driven part 12 in its storage areas 62 in each case in its outer circumference introduced, longitudinal guide groove 61, into which the associated bearing units 63, 64 form-fit intervention. The latter can be seen clearly from FIG. 4.

The bearing units 63, 64 each only extend over a partial circumference of the driven part 12. This results two peripheral portions 65, 66 of the driven part 12, which are not cooperate with the storage device 15. Along one this peripheral portions 65 is the driven part 12 in the Storage area 13 exposed, so that laterally next to the Output part 12 a in the longitudinal direction and at the same time results in the circumferentially extending free space 67. This is aligned so that it is in the travel 56 of the stop 57 and is therefore part of the position specification space 55 forms. Its extent extends for example in the range of 180 ° and is due to the width of the bearing units 63, 64, slightly less than 180 °.

If the stripping part 12 in the one shown in Figures 1 and 2 retracted position in which it is the Working cylinder 22 expediently over its entire length encloses, the stop 57 is located inside the housing 1 axially spaced from the storage area 13. However, it is able to extend the driven part 12 in the mentioned Retract clearance 67, being the storage facility 15 happened on the side. In Figure 5 is dash-dotted at 68 the stop 57 retracted into the free space 67 is indicated.

The width of the housing 1 is in the by the stripping section 12 and the position setting space 55 passing through Plane measured direction larger than in the direction perpendicular to this Direction. The corresponding orientation is therefore as vertical axis 72, the right-angled orientation referred to as transverse axis 73. To this cross-sectional shape to make the best possible use of the free space 67, the free space 67 is expediently based on the Placed transverse and vertical axes 73, 72 so that it is aligned obliquely , the exposed peripheral portion 65 of the Output part 12 obliquely sideways in the transverse direction and at the same time points up or down in the height direction. Around To realize the design, the base body 2 has, for example at least in the storage area 62 the L-like already mentioned above Cross-sectional shape, being with its two L-legs 3, 4 the one peripheral section 66 of the driven part 12 covers - expediently without managerial tasks themselves to take over - and an exposed peripheral section 65 remains, to which the free space 67 is assigned.

The free space 67, like the rest of the position setting space 55, could basically be open on the side. To injuries to avoid, however, expediently one Cover by the lid body 5 already mentioned.

The position setting device provided in the exemplary embodiment 53 extends over almost the entire length of the housing between the front and the rear end wall 6, 7. It has two adjacent to the end walls 6, 7 arranged holder 74, 75 on the base body 2 in particular on the inner surface of the longer L-leg 3 are set. For attachment, the base body 2 can have at least one longitudinal anchoring groove 76, on the holder 74, 75 using commercially available sliding blocks are anchored axially adjustable.

The two holders 74, 75 carry one extending between them and parallel to the longitudinal axis 16 of the stripping section 12 extending support rod 77. On the support rod 77 are several of the already mentioned counter stops 58 with axial Spacing from each other held in rotation. Are exemplary two each in the neighborhood of one of the two holders 74, 75 arranged end counter-stops 58 'and one at a distance to these two end counter-stops 58 ' Between counter-stop 58 '' provided. The stop 57 protrudes towards the support rod 77, which it at least partially encompasses, what can be seen for example from Figures 11 and 12 is. The stop 57 protrudes into the axial space between the two end counter-stops 58 ', which are such are arranged and designed so that they are always in Travel 56 of the stop 57 are. They serve as a default the end positions of the driven part 12, the stop 57 with the retracted end position according to FIG. 1 to the rear End counter-stop 58 'and when extended, not shown End position on the front end counter stop 58 ' has accrued.

The end counter stops 58 'are on the support rod 77 in Longitudinally adjustable and lockable so that a particularly infinitely variable setting for the End positions. For this purpose, the holding rod 77 can be used as a threaded rod be carried out on the counter stops 58 with a complementary internal thread 78 are screwed on, so that they screw axially and when the desired one is reached Fix position releasably by means of a lock nut 83 to let.

The intermediate counterstop additionally provided in the exemplary embodiment 58 '' allows in addition to the two end positions the requirement of an intermediate position of the Output part 12. This intermediate position can be in advance adjust as required by using the intermediate counterstop 58 '' for example comparable to the end counter stops 58 'in Axial direction is adjustable.

In contrast to the end counter stops 58, 58 ', which are essentially are disc-shaped and coaxial the support rod 77, the intermediate counter-stop 58 ″ via a with respect to the longitudinal axis 85 of the holding rod 77 asymmetrical and in particular not rotationally symmetrical Shaping. An exemplary embodiment is shown in figures 11 and 12. This shape makes it possible to use the intermediate counterstop 58 '' between one in the travel path 56 of the stop 57 projecting effective position (Figure 12) and one located outside the travel path 56 of the stop 57 switch inactive position (Figure 11). The switching process is, for example, by a switching device 84 caused, which cooperates with the support rod 77 and is able to move it about its longitudinal axis 85 in to rotate and position the preselected angular positions. Depending on the switching position, the Stop 57 the intermediate counter-stop 58, 58 '' unhindered happen or is stopped by this, so that the driven part 12 stops in an intermediate position.

In the exemplary embodiment, the intermediate counter-stop 58 '' plugged coaxially onto the holding rod 77, but deviates from a circular or rotationally symmetrical contouring from. For example, it has two diametrically opposed, on a common imaginary radius 87 lying counter-stop parts 86, in particular wing-like protrude radially outwards. The on the radius 87 between the intermediate areas 88 lying opposite the counter-stop parts 86 are free.

In adaptation to this shape, the stop 57 is on his the support rod 77 partially encompassing section two each other with respect to the longitudinal axis 85 of the support rod 77 also diametrically opposite stop parts 89 provided, which are concentric with respect to the longitudinal axis 85 Perimeter 87 protrude. The rest of the area around 87 Intermediate areas between the stop parts 89 are free. The stop parts 89 are preferably located in the Area of the free end of one around the support rod 77 fork-like section of the stop 57.

The intermediate counterstop is in the inactive position 58 '' in such a rotating position that its counterstop parts 86 according to Figure 11 outside the axial Travel of the stop parts 89 are. To be effective To get a position, the intermediate counterstop 58, 58 '' rotated so far by means of the switching device 84, until its counterstop parts 86 according to FIG axial travel of the stop parts provided on the stop 57 89 lie.

By the counter-stop parts 86 and the stop parts 89 with respect to the longitudinal axis 85 of the support rod 77 to each other diametrically are arranged opposite, results in Impact a centric force transmission on the handrail 77, which benefits the life of the individual components.

A reliable, non-rotatable fixation of the intermediate counterstop 58, 58 'on the support rod 77, can be a modification of the above-mentioned embodiment special type of attachment may be provided. So, according to example the holding rod 77 designed as a threaded rod via a square from FIGS. 11 and 12 Cross section, with only the corner areas with threads are provided so that the end counter-stops 58 ' and easily screw on the lock nuts 83 assigned to them to let. On the other hand, the intermediate counter-stop has 58 '' over a central, cross-sectional shape of the handrail 77 corresponding square opening 90, with the axial slidably and at the same time rotatably on the support rod 77 can be postponed. Axially on both sides of the intermediate counterstop 58, 58 'is then expedient in each case a mounting nut 92 is provided so that the intermediate counter-stop 58 '' axially immobile at the desired point can be tightened.

In the described embodiment, the handrail can 77 by the switching device 84 in two different Position the angular positions that the effective and ineffective position of the intermediate counterstop 58, 58 'correspond. A suitable one for this Switching device 84 is schematic in FIGS. 9 and 10 indicated. It comprises a holding body 82, via which it is attached the base body 2 of the housing 1, for example on the anchoring groove 76, is attached. On the holding body 82 is one Actuation device 97 with an application element 93 arranged with a rotatable with the support rod 77 connected pawl 94 cooperates. By a Spring device 95 is the pawl 94 in an initial position biased, in which the support rod 77 one of the ineffective position takes the corresponding rotational angle position (Figure 9). By actuating the loading element 93, the pawl 94 against the force of the spring device twisted until it is the one shown in FIG assumes the actuated position in which the holding rod 77 in one of the effective position of the intermediate counterstop 58, 58 '' corresponding angle of rotation position is shifted. For adjustable Specification of the actuated position of the ratchet 94 is expediently an example of a screw formed adjusting element 96 is provided. With subsequent Deactivation of the loading element 93 is the Pawl 94 by the spring device 95 in the starting position pivoted back.

The loading element 93 is in the exemplary embodiment Part of a fluid-operated application device, for example a working cylinder. But here would be too any other type of actuation is conceivable, for example an electrical one Activity. Also could work without a return spring by double-acting actuation of the loading element 93 provides.

It would be readily possible to have several on the support rod 77 To provide intermediate counter-stops 58, 58 '', each of which a counterstop if necessary in the effective position is switchable to a larger number of intermediate positions pretend. It would be an advantage here, the switching device 84, for example corresponding to that shown in FIG Design to run as a stepper drive with the the holding rod 77 by gradually turning it into more than two predetermined rotational angle positions can be positioned.

The switchover device 84 according to FIG an application device provided with an application element 93 97 provided with one of the handrails 77 associated pawl 94 cooperates. Again, the pawl 94 is shown by a not shown Spring device 95 in the illustrated starting position biased. In contrast to the design according to figures 9 and 10, the pawl 94 is freely rotatable the support rod 77 arranged and with at least one or several movable pawls 98 provided with in the circumferential direction Rest areas arranged in a star-like pattern 99 of a switching body connected in a rotationally fixed manner to the holding rod 77 100 can work together. If the pawl 94 deflected into their actuated position, the latches reach 98 in a snap connection with the circumferential direction next rest section 99, so that in the starting position reversing pawl 94 of the switching body 100 together clocked with the support rod 77 by a rotation step becomes.

A stop 57 of a preferred embodiment is shown in FIG Individual representation shown. You can see the fork-like section 102 with the two attachment parts provided on it 89. The fork-like stop 102 at a distance from the front End counter-stop 58, 58 'upstream is expedient another fork section 103 is provided. Upon reaching the stop 57 runs in the inner end position of driven part 12 with the rear fork-like portion 102 on the inner End counterstop 58, 58 'on while reaching the outer end position with the fork section 103 on the front End counter stop 58, 58 'collides. It is now possible to a single existing intermediate counterstop 58 '' by placing it close to the front End counter stop 58, 58 'is screwed. The attack 57 is then able with its fork section 103 continue to run onto the front end counter stop 58, 58 ', the intermediate counter-stop 58, 58 ″ ineffective immersed in the fork mounts. The slot-like space 104 facilitates the accessibility of one fastening nut 92 when the stop 58 on for adjustment purposes the intermediate counterstop 58 '' was created.

For the impact of the stop 57 on the counter stops 58 to dampen, the position setting device 53 is preferred equipped with a shock absorber device 105. she comprises at least one and, for example, two movable Attenuators 106, 106 'with which the support rod 77 is axially coupled. The shock absorber device 105 is assigned to all counter-stops 58 together with which she works together on the support rod 77.

In detail, the support rod 77 is a damping section s designated distance limited axially movable suspended on the housing 1 via the shock absorber device 105. This is achieved, for example, in that the Both ends of the support rod are conveniently piston-like trained guide members 107, 107 'are provided via which provided the support rod 77 in on the holders 74, 75 Guides 108, 108 'is axially displaceably guided. A respective guide member 107, 107 'forms at the same time a stop element, which with one of the damping section s corresponding distance a arranged on the associated holder 74, 75 Stroke limiting section 109, 109 'axially opposite.

Normally, the holding rod 77 takes a basic position a, in which their guide members 107, 107 'to both stroke limiting parts 109. 109 'spaced by the damping distance s are. This is shown in Figures 1, 2 and 7. stabilized is this basic position by those already mentioned Attenuators 106, 106 'of two fluid shock absorbers 110, the axially on both sides of the support rod 77 in extension are arranged to this. They are with their damper housing 111 fixed on the relevant holder 74, 75 in such a way that its attenuator 106, 106 'facing the support rod 77 is and this is applied under resilient pretension. As a result, the holding rod 77 is in its basic position axially stabilized. The preload is not one caused spring device shown in the associated damper housing 111 is housed. The attenuators 106, 106 'are from the damper housing 111 outstanding bumpers formed on those in the damper housing 111 a damping piston is arranged, with a respective attenuator 106, 106 'while displacing a Shift damping fluids towards damper housing 111 leaves. Shock absorbers of this type, be they gas dampers, hydraulic ones Shock absorbers or mixed mode shock absorbers, are known as such, so that a closer look then unnecessary at this point.

Strikes the handrail 77 in the basic position Stop 57 on one of the counter stops 58 (this moment is shown in Figure 7), then the counterstop in question 58 together with the holding rod 77 through the force of the impact by the damping distance s until the in the direction of movement front guide member 107 on the associated Stroke limitation section 109 runs up and the handrail 77 thereby reached an end position. Because this assigned attenuator 106 is displaced, one finds Shock absorption takes place at which the impact energy is down to one tolerable measure is reduced.

The individual counter stops 58 are expediently Set so that they have the desired position specifications take exactly when the handrail 77 has reached the end position at the end of the damping process.

In order to be able to adjust the damping intensity variably without the end position of the holding rod 77 and thus the position default positions the counterstops is to be influenced the damping distance s is expediently given unchangeably. The stroke limitation sections 109, 109 'are separate from the respective shock absorber 110 arranged on the associated holder 74, 75. The shock absorbers 110, however, are in the longitudinal direction the holding rod 77 is adjustable on the associated holder 74, 75 attached, the axial distance between the damper housing 111 variable to the assigned stroke limitation section 109, 109 ' can be adjusted. The setting option is preferred guaranteed by a screw connection. According to the example the damper housings 111 are provided with an external thread 112, through which they are screwed into an internal thread Retaining recess 113 with variable screw-in depth can be screwed in are. A lock nut can be used to fix the position 114 serve.

To detect certain axial positions of the support rod To enable 77 is expediently at least one guide member 107 'provided with an actuating element 118, for example with a permanent magnet, at least one Sensor 119 is assigned, which is in the area of the outer circumference the associated guide 108 '.

Claims (29)

1. Linear drive with a rod-like drive part (12) secured against rotation and guided for axial movement relative to the housing (1) by means of a bearing device (15) acting together with its external circumference and located in a bearing area (13) of a housing (1), at least one laterally projecting position setting element (54) being provided, which is displaced along a position setting space (55) extending adjacent to the drive part (12) during the axial movement of the drive part (12), the bearing device (15) extending only over part of the circumference of the drive part (12) for at least a section of its overall length and the drive part (12) being exposed in the bearing area (13) along a circumferential section not acting together with the bearing device (15), so that there is a free space (67) in the bearing area (13) at the side of the drive part (12) extending in its longitudinal and circumferential directions, to form a part of the position setting space (55) along which the position setting element (54) can travel, characterised in that the housing (1) has a base body (2) with a cross-section resembling an L to support the bearing device (15) at least in the bearing area (13).
2. Linear drive according to claim 1, characterised in that a top body (5) with a cross-section resembling an L is mounted on the base body (2) with a cross-section resembling an L, resulting in a external contour of the housing (1) with a substantially rectangular cross-section.
3. Linear drive according to claim 1 or 2, characterised in that the free space (67) extends at least approximately over the whole length of the bearing area (13).
4. Linear drive according to any of claims 1 to 3, characterised in that the circumferential extension of the free space lies in the area of 180 degrees, being expediently somewhat less than 180 degrees.
5. Linear drive according to any of claims 1 to 4, characterised in that the bearing device (15) comprises at least two bearing units (63,64), each extending only over part of the circumference of the drive part (12), which act together with the external circumference of the drive part (12) on diametrically opposite sides.
6. Linear drive according to claim 5, characterised in that the bearing device (15) comprises several pairs of diametrically opposed bearing units (63, 64) axially aligned and arranged consecutively.
7. Linear drive according to any of claims 1 to 6, characterised in that the bearing device (15) simultaneously forms a device securing the drive part (12) against rotation.
8. Linear drive according to claim 7 in conjunction with claim 5or 6, characterised in that the drive part (12) is, in the areas (62) of its external circumference which act together with the bearing units (63, 64), provided with at least one longitudinal guide groove (61) engaging the associated bearing unit (63, 64) to secure the drive part (12) against rotation.
9. Linear drive according to any of claims 1 to 8, characterised in that the free space (67) is so placed relative to the lateral and vertical axes (73, 72) of the housing (1) as seen in cross-section, that it is inclined, the exposed circumferential section (65) of the drive part (12) extending obliquely sideways and in the vertical direction.
10. Linear drive according to any of claims 1 to 9, characterised in that the drive part (12) emerges from the housing (1) at at least one of its end faces, the bearing area (13) being located in the end section of the housing (1) associated with the end face in question.
11. Linear drive according to any of claims 1 to 10, characterised in that the drive part (12) is tubular in shape.
12. Linear drive according to any of claims 1 to 11, characterised in that the position setting element (54) is located on the external circumference of the drive part (12) at an axial distance from the two ends of the drive part (12).
13. Linear drive according to any of claims 1 to 12, characterised in that the position setting element (54) acts together with a position setting device (53) located in the position setting space (55).
14. Linear drive according to claim 13, characterised in that the position setting element (54) is designed as a stop (57) moving with the drive part (12), at least one counter-stop (58) of the position setting device (53) being provided in its traversing path (56) in the area of the position setting space (55).
15. Linear drive according to claim 14, characterised in that a retaining bar (77) of the position setting device (53) supporting the at least one counter-stop (58), in particular for adjustment in the longitudinal direction, is located adjacent to the drive part (12) in the position setting space (55).
16. Linear drive according to claim 15, characterised in that the stop (57) provided on the drive part (12) at least partially encompasses the retaining bar (77) of the position setting device (53).
17. Linear drive according to claim 16, characterised in that the retaining bar (77) is partially encompassed by at least one forked section (102) of the stop (57).
18. Linear drive according to any of claims 14 to 17, characterised in that the position setting device (53) is provided with at least one counter-stop (58) capable of being switched between an active position in which it projects into the traversing path of the stop (57) and an inactive position outside the traversing path of the stop (57) by means of an associated changeover device (84).
19. Linear drive according to claim 18 in conjunction with any of claims 15 to 17, characterised in that the at least one counter-stop (58) is secured against rotation on the retaining bar (77), the changeover device (84) acting together with the retaining bar (77) and rotating it about its longitudinal axis (85) for switching the at least one counter-stop (58).
20. Linear drive according to claim 19, characterised in that the retaining bar (77) can be switched to at least two different rotary angle positions by the changeover device (84).
21. Linear drive according to claim 20, characterised in that the changeover device (84) is designed as a stepper drive for switching the retaining bar (77), by step-wise rotation, to preferably more than two preset rotary angle positions.
22. Linear drive according to any of claims 18 to 21, characterised in that the position setting device (53) is provided with two external end counter-stops (58, 58') setting the end-of-stroke positions of the drive part (12) and designed to adopt their active positions independent of the rotary angle position of the retaining bar (77), at least one switchable intermediate counter-stop (58, 58") being provided between these end counter-stops (58, 58').
23. Linear drive according to any of claims 18 to 22, characterised in that the switchable counter-stop (58) is provided with counter-stop sections (86) acting together with the stop (57) and projecting in the manner of wings.
24. Linear drive according to any of claims 15 to 23, characterised in that the position setting device (53) is provided with a shock absorbing device (105) comprising at least one movable damping element (106, 106') coupled for movement to the axially movable retaining bar (77).
25. Linear drive according to claim 24, characterised in that the retaining bar (77) is, starting from a basic position, capable of being displaced in at least one axial direction by a preset damping distance (s) until reaching a preset end position while displacing the at least one damping element (106, 106').
26. Linear drive according to claim 25, characterised in that the end position of the retaining bar (77) is fixed independent of the maximum possible damping stroke of the damping element (106, 106') of the shock absorbing device (105).
27. Linear drive according to any of claims 24 to 26, characterised in that the shock absorbing device (105) is provided with two shock absorbers (110) fitted with the damping elements (106, 106'), their damping actions axially opposing each other relative to the retaining bar (77).
28. Linear drive according to claim 27, characterised in that the two shock absorbers (110) are assigned to axially opposite end areas of the retaining bar (77), expediently arranged as axial extensions of the retaining bar (77), each being secured, in particular, to a retainer (74, 75) fixed on the housing.
29. Linear drive according to any of claims 24 to 28, characterised in that the retaining bar (77) is guided for movement by means of, in particular piston-like, guide elements (107, 107'), whereby at least one guide element (107, 107') can be provided with an actuating element (118) acting together with a position sensor (119).

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