WO1990005617A1

WO1990005617A1 - A motory system for producing a relative, incremental movement and positioning between two bodies

Info

Publication number: WO1990005617A1
Application number: PCT/DK1989/000269
Authority: WO
Inventors: Hans MØLLER
Original assignee: Moeller Hans
Priority date: 1988-11-14
Filing date: 1989-11-14
Publication date: 1990-05-31
Also published as: AU4623589A

Abstract

It is known that an accurate relative movement and positioning between two bodies (2 and 26, 28, 30) can be effected by successive depression of mutually staggered wedges (40, 42) on one of the bodies against a rectilinear tooth row (4, 6) on the other body (2). If high displacement forces are to be transferred problems occur with respect to wear of the wedge guides, and with the invention this is obviated by the wedges (40, 42) being secured on leaf springs (46), which allow the wedges to carry out the required actuation movements while the associated cross forces are transferred in a frictionless manner to the relevant carrier body (28) through the leaf springs (46). Particularly advantageous actuation means (66, 68) for the operation of the wedges are indicated, and it is also disclosed that the discussed moving and positioning principle is applicable for the production of rotary movements.

Description

A otory system for producing a relative, incremental movement and positioning between two bodies.

The present invention relates to a motory system for pro¬ ducing a relative, incremental movement and positioning between two bodies and of the type specified in the intro¬ ductory clause of claim 1.

According to the published German Patent Application No. 1,901,246 a motory system of this type has already been proposed, viz. for effecting an adjustment of a tool holder in a working machine. By the use of the said wedges, which are successively forced inwardly against the row of teeth, a mutual displacement between the bodies will occur, and by a simple counting of the actuations the displacement can proceed until a desired new position has been reached; in that position the last actuated wedge will be centered in a well defined manner in the opposed declivity in the row of teeth, such that the wedge will automatically act as an efficient means for mutually anchoring the bodies in the direction of the displacement, and also the said cen¬ tering will provide for a positioning with a high accuracy.

Despite this moving and positioning principle enabling the attainment of many noticeable advantages, it has not found extension in practice. The principle is well suited for the transfer of considerable forces, but for this it is a condition that the wedges and their moving elements be guided accurately relative the wedge carrying body it¬ self, and the larger the forces to be transferred, the larger also the associated lateral wear on the guiding means. An accurate centering of the wedge relative the row of teeth will not result in any accurate resulting posi¬ tioning if there is a lateral play between the wedge and the wedge carrying body, and it is supposed that circum¬ stances like these have made it difficult to design such systems in a suitably robust and longlasting accurate man¬ ner at a competitive price.

With the invention, however, it has been realized that this is possible anyway, viz. when the motory system is designed according to the characterizing clause of claim 1. When the wedges are united with the said plate portions the latter will be able to transfer the forces between the wedges and the wedge carrying body without the wedge movements giving rise to any friction in the system and thus neither to any wear.

While in the known proposal use is made of wedges which are connected directly with the associated moving means, such that heavy demands are made on the lateral stability of the latter, it will be appreciated^'that with the invention no such demands will be made, and with a system according to claim 2 it is achievable that almost any connection between the wedges and the moving means can be avoided, when only the latter are able to step against the wedge carrying plate portions. This in its turn enables the moving means to be highly simplified, e.g. as indicated in claim 3, and also this will contribute to the possibili¬ ty of manufac uring the system at comparatively quite low costs.

By the invention the motory system has been enriched with such qualities that it may occur as a commercial pro¬ duct, and in the same connection it is realized that such product will not be limited to show a flat tooth row, since it may operate with certain advantages with a round rack, while an essential further possibility is the use of a rack which is curved in its longitudinal direction, viz. as a toothed rim on a rotatable system; hereby it will be possible to operate e.g. spindle valves in a processing plant. Also such a motory system according to the invention may be embodied in a simple and cheap manner based on the possibilities as indicated in claims 2 and 3 of arranging the wedge carrying plate portions and the associated, outer pressure pistons, respectively, as the latter may be arranged in an uncomplicated manner in respective con¬ centric layers about the cylindrical or circular tooth rack. Furthermore, in connection with the invention, it has been realized that for the practical usability of the discussed system it is decisive that it is possible to check that the single wedges really reach their bottom positions by the successive movements and not least by the terminating movement of the last wedge during the adjust¬ ment sequence, and the matter claimed in claim 4, there¬ fore, is of high importance to the invention.

In the following the invention is described in more detail with reference to the drawings, in which:-

Fig. 1 is a schematic side view of a motory system according to the invention.

Fig. 2 is a corresponding, more detailed view.

Fig. 3 is a schematic top view of the system.

Fig. 4 is an exploded perspective view of the system,

Fig. 5 is a further exploded perspective view of the system,

Fig. 6 is a sectional view illustrating a single actuator means,

Fig. 7 is an exploded perspective view illustrating various parts of a system for producing a rotary movement,

Fig. 8 is a sectional view of the same system shown in its assembled condition,

Fig. 9 is a perspective view of a modified part thereof,

Fig. 10 is an end view thereof.

Fig. 11 is a corresponding view of the same part, further modified/ and

Figs. 12-18 are various views of further embodiments.

The system shown in Fig. 1 comprises a stationary rack 2 with transverse tooth ribs 4 forming declivities 6 between them and a block body 8 surrounding the rack 2 with slide fit and provided with protruding working cylinders 10, which are hose connected with a driving station 12 as¬ sociated with a control unit 14.

Inside the block body 8, underneath each cylinder 10, is located respective wedge heads 16,18,20 mounted at one end of respective, horizontal leaf springs 22, the other ends of which are fixed to the block. The wedge heads 16, 18,20 are individually depressable by means of respective piston rods 11 of the cylinders 10, while they will other¬ wise assume a free position lifted off from the teeth 4 by the action of the leaf springs 22.

By depressing one of the wedges, e.g. the wedge 18 in Fig. 2, this wedge is pressed to the bottom of the underlying declivity, 6 in the rack 2, and because the wedge is horizontally undisplaceable relative the block 8 due to the leaf spring 22 the block will hereby move a distance along the rack, if the wedge.did not initially assume a position exactly over-the middle of the declivity.

When one of the wedges (viz. 18) is entirely depres¬ sed into a declivity the two other wedges will assume po¬ sitions slightly offset from the middle of respective un¬ derlying teeth 4 to respective opposite sides thereof, and by a .following actuation of one of these wedges arid an associated retraction of the previously depressed wedge the block 8 will thus be moved one step forwardly or rear- wardly along the rack, the length of the step being a little less than half the distance between the teeth 4. Thus, if the wedge 16 in Fig. 2 is actuated to be depres¬ sed while the wedge 18 is allowed to return upwardly the block 8 will move a step towards the right, while it will move a step to the left if the wedge 20 is actuated.

These movements will be accurately controlable from the control unit 1 , such that a specific movement of the block 8 may be effected through a corresponding number of successive activations of the various wedges, of which there should be at least three if the movement shall be dirigible both forwardly and rearwardly.

It will be understood that the system is not just a movement or motory system, but also a positioning system, provided the toothing 4,6 on the rack 2 be equidistant with a required accuracy, the control unit 14 in a simple manner being able to account for the number of wedge actu¬ ations between consecutive stops of the block member 8.

It is possible hereby to move the block member 8 with a considerable force and also to bring it into a series of positions, in which it may be positioned with a high accuracy, the movement of the block member being stoppable abruptly by the full depression of the last wedge of the adjustment sequence. A corresponding accurate positioning in an increased number of positions will be attainable with the use of a finer tooth pitch and/or by a controlled, graduated depression of the wedges, but the latter solu¬ tion is very little attractive, while the former could be used to a certain limit; among other reasons, in view of the desirable power transfer of the movements it is unsuit¬ able to make use of a very small tooth pitch.

According to the invention it is chosen, instead, to make use of an increased number of wedges arranged with a decreased mutual operational spacing, this being illu¬ strated in Fig. 3, where five individually operable wedges 16,17,18,19 and 20 are shown. The added wedges 17 and 19 are located pitchwise halfway between the respective neighbouring wedges 16,18 and 18,20, whereby the possibi¬ lity of a terminating depressing of the wedges 17 and 19 will involve that the block 8 can be stopset in an in¬ creased number of accurate positions.

In principle many more wedges with mutually slightly staggered locations may be used, such that the number of mutually accurate positionings of the block 8 between two teeth 4 may be increased as desired, corresponding to ac¬ curacies down in the micrometer range even if the tooth pitch is more millimeters. Each and every stop position is obtained by a full depression of a wedge into a correspond¬ ing declivity, i.e. the actuation of the wedges may be quite 'coarse¹, when only the control unit 14 holds ac¬ count of the number of successive actuations of the wedges.

Each single wedge can be supplemented with more wedges located after each other in the longitudinal direc¬ tion of the rack 2 with a pitch exactly as the pitch of the teeth 4, such that the force of displacement by the pressing in of the wedge body is distributed over the flanks of more teeth 4, whereby the associated wear is reduced. This is illustrated in the following figures.

As far as the wear by the actuation of the wedges is concerned it will be noted that a certain wear may well occur on. the wedges and on the tooth flanks during the actual movements, but also that such wear will not notice¬ ably affect the accuracy of the final positionings as achieved by the associated 'last' wedge depressions into the declivities 6, as the wear can hardly extend to the respective bottom and top portions of the declivities. When many wedges are used the driving effect will occur mainly at the bottom of the declivities 6, i.e. there will be no perceivable wear at the top of the declivities, and when the wedges are dimensioned such that by their full intrusion into the declivities they will entirely fill out the width of the latter, then the accuracy of the posi¬ tioning will be practically entirely independent of any more or less advanced wear on the coacting parts.

In Fig. 4 is shown a practical example of the design of the block body 8. It consists of a bottom part 26 for guidingly receiving the rack 2, an intermediate part 28 that carries the working wedges, and a top part 30 holding the required means for actuating the wedges. The bottom part consists of a ϋ-profiled base member 32 having at each end a cross block insertion 34, the lower edge of which is shaped in conformity with the upper cross secti¬ onal shape of the rack 2, while along the opposed insides of the upright side walls of the profile 32 there are mounted longitudinal guiding members 36 for the side edges of the rack 2. The bottom part 26 will thus be ountable on the rack with slide fit about the rack. In¬ ternally in the bottom part, topwise at both ends thereof, is mounted a number of lying, U-shaped members 38, which are photosensors for the operation of the wedges, as explained further below.

The intermediate part 28 is a plate member which can be secured against the top side of the bottom part 26 and which carries at its underside a number of *wedge bodies for cooperation with the rack 2. These wedge bodies are designated 40 and are each shaped with a number of single wedges 42 placed with exactly the same pitch as the teeth of the rack 2. Each wedge body 40 is arranged on a longi¬ tudinally oriented plate strip member 44, which over a main portion is connected with a leaf spring 46 secured to the plate member 28 by a screw connection with a block member 48 depending from the plate member 28. It is indeed pos¬ sible that the block member 48 and optionally even the leaf spring 46 may be provided fully integrated with the plate member 28. By means of the leaf spring 46 the wedge body is normally held in an upper position, in which the wedges 42 will be located entirely above the teeth of the rack 2. The single wedge bodies 40 are mounted mutually slightly offset in the longitudinal direction with respect to their location relative the ^'teeth of the rack 2, as ex¬ plained above.

For the generation of a uniformly controlled movement of the block body 8 both forwardly and rearwardly along the rack 2 the intermediate part 28 should carry an un¬ even number of wedge bodies 40, and it is an unqualified coincidence that in Fig. 4 only four such wedge bodies are shown.

The top part 30 is provided with the above mentioned actuators 10 for selective depression of the single wedge bodies 40, and these actuators, which are described in more detail below, are here powered by a pressure medium through laterally projecting stubs 50, which are connected with pressure hoses 52 leading to a non-illustrated pres¬ sure station corresponding to the unit 12 of fig. 1.

The base plate strips 44 of the wedge bodies 40 have extensions 54 with reduced width and extending beyond the wedge bodies 40. By the depression of the single wedge bodies 40 also these extensions 54 will be depressed, viz. down into the respective free spaces between the ϋ-branches of the photosensors 38, such that through these it can be confirmed that each actuated wedge body is really pressed down into its bottom position, whereby such a detection may be used for^* effecting an actuation order for the next wedge body. Through wire connections not shown the photo¬ sensors 38 are connected to a multiplug 56 on the*side of the bottom part 26.

For the depressing of ^'the single wedge bodies 40 use is made of pressure pins which project downwardly from the top part 30 through holes in the intermediate plate member 28. As shown in Fig. 5 the top part consists of two double layer blocks 54 and 56 each consisting of two plate ele¬ ments 58 and 60 with an intermediate layer 62 of a rubber diaphragm material. In the lower plate element 58 is pro¬ vided some oblong holes 64, which accommodate respective, relatively thin plate members 66 that are just roughly fitting in the holes 64 and are each provided with a cen¬ tral, depending pin 68. The diaphragm 62 extends flat over this or these areas, and in the underside of the upper plate element 60 there is provided a crosswise extending groove 70, see Fig. 6, which is located just above each of these areas so as to be open downwardly towards the dia¬ phragm 62, these grooves thus being monolaterally open towards a surface portion of the plate element 60 and be- irig connected with the above mentioned, respective stubs 50 with associated hoses 52. Each pin 68 projects down¬ wardly through a hole 72 in the plate member 28 of the intermediate part so as to step upon one of the underly¬ ing wedge bodies 40.

By means of the respective leaf springs ^'46 the wedge bodies 40 are held pressed upwardly against the underside of the plate element 28, whereby the pin 68 is held pres¬ sed upwardly corresponding to a^' pressing upwards of the top plate 66 of the pin against the flat diaphragm 62. With reference to Fig. 6 it will be understood that the plate portion 66 and therewith the pin 68 will be forced down¬ wardly when a pressure medium is introduced into the groove 70 and that hereby also the wedge body 40 will be depressed so as to work out the discussed movement relative the rack 2.

The working cylinders used are of a particularly sim¬ ple design, but normally the plate pistons 66 will occupy a relatively large area, such that^' the pins 68 cannot be arranged particularly close to each other. However, a close juxtaposition is achievable with the use of the upper double layer block 56, which is designed principally equally, but with longer depending pins 68' placed offset relative the holes 64 in the bottom block 54. This block, then, is provided with extra throughlet holes 74 for the pins 68', whereby these may step upon further wedge bodies 40 through respective holes 72 in the intermediate plate member 28.

According to Fig. 4 it may be desirable that the wedge bodies be located in groups rather close to each other, and as they should ideally be centrally pressure loaded it may be difficult to arrange the pressure pins with corre¬ spondingly small mutual spacings. This problem, however, may be widely solved in that only some of the wedge bodies are actuated by centrally arranged pressure pins, while neighbouring wedge bodies are actuated not centrally, but 1 0

symmetrically by means of two concurrently actuated pres¬ sure pins cooperating with the respective front and rear ends of the wedge body, this being equivalent with the action of a single central pressure pin; hereby the pins may be arranged with generally increased spacing, e.g. such that two neighbouring piston plates 66 in one of the double layer blocks 54 or 56 operate a single wedge body in the said symmetrical manner, while a single piston plate in the other double layer block engages a neighbouring wedge body centrally. If required, one or more additional double layer blocks can be used in the top part 30, such that the number of operative pins 68 may be still further increased.

Of course, also other means may be used for actuating the wedges, and in principle there are no limits for the number of wedge bodies held by the mo ement body 8. When they are mounted with the required accurate mutual posi¬ tioning in the longitudinal direction of the rack they may be actuated sequentially for displacement and positioning of the movement body 8 with prqctically any desired accu¬ racy, even down in the μm-range, despite the use of a rela- tivele coarse and therewith mechanically stable toothing of the rack 2.

With the use of many wedge bodies 40 only a very small mutual displacement of the body 8 and the rack 2 will be effected by each wedge actuation, viz. corresponding to the desired degree of resolution or accuracy, such that for a high degree of accuracy the displacement will take place correspondingly slowly. It is possible, however, to control the operation by a selective actuation of the wedges in such a manner that during the displacing movement only such wedges are operated which per actuation can ef¬ fect the longest possible displacement between the parts, while the stepwise detailed actuation of the successive wedge bodies is not commenced until the moving body 8 ap- proaches its desired final position. It may even be achieved, e.g. with the use of a pinion engagement with the rack 2, that the body 8 (or the rack) be subjected to a very rapid intermediate transport towards the relevant final position, where then only the final positioning is effected by means of the wedge bodies 40.

In the foregoing the advancing and positioning of a movement body relative a rectilinear rack 2 has been con¬ sidered, but the invention is not correspondingly limited, ^• as it will include both an 'inverted engagement¹, i.e. whereby a moving body with a rigid, short rack member is moved along a beam provided with a longer row of actuatable wedge bodies, and a movement along curved paths. The lat¬ ter possibility is particularly interesting, as it may refer to a rotation of a shaft having teeth extending in the longitudinal direction thereof, such that an exact rotational adjustment of the shaft can be effected. More¬ over, the rack may be shaped with a round cross section for cooperation with wedge bodies 40 placed around the rack, and the toothing could then be provided in a thread- ing-like manner, which will facilitate the production of the rack. For an accurate rotation of a shaft the shaft may be connected with a wider pinion cooperating with sur¬ rounding wedge bodies 40, as examplified further below.

According to Fig. 4 the resilient leaf strips 46 con¬ sist of separate strips secured to the lower block plate 28, but these strips could be provided in an integral man¬ ner as cut out tongues of or in a lower plate member of a spring material.

This possibility - by way of example - is illustrated in Figs. 7-12, these figures being concentrated about the production of a controlled rotary movement.

In the embodiment according to Figs. 7 and 8 an actu¬ ator housing 80 cooperates with a pinion 82 on a shaft rotatably mounted in bearings 86 in the housing 80. The pinion 82 is surrounded by a cylinder member 88 having tongue portions 90, which at their free ends are provided internally with wedge bodies 92 and externally with pres¬ sure pads 94. About the cylinder member 88 is provided a cylindrical block 96 , which corresponds to the plate block 58 in Fig. 5 and is designed with an annular row of holes 98 outside the free ends of the respective tongue portions 90, these holes serving to receive piston plates 100, which are thin relative the wall thickness of the cylindrical block 96 and are provided with inwardly projecting pressure feet 102 for coacting with the pressure pads 94. About the cylindrical block 96 is mounted a rubber sleeve 104 corre¬ sponding to the rubber diaphragm 60 in Fig. 5, and this again is tightly surrounded by an interior cylindric sur¬ face 106 of an outer housing portion 108 of the actuator housing 80. In this interior cylindric surface recesses 110 are provided outside each of the holes 98, correspond¬ ing to the recess 70 in Fig. 6 and correspondingly con¬ nected to individual pressure medium connector stubs for selective actuation of the piston plates 100 for depres¬ sing the respective wedges 102 against the surface of the pinion 82 as illustrated at the bottom of Fig. 8.

The embodiment here described is so widely equivalent with Figs. 1-6 that a more detailed description of its operation is deemed unnecessary. The result is that the pinion 82 can be rotated through desired angles with very high accuracy, e.g. for accurate adjustment of a regulation valve, and it is still so that the driving force for the rotation is produced by depression of leaf spring portions 90 extending generally parallelly with the resulting move¬ ment, such that through these portions quite considerable forces can be transferred in the peripheral direction of the pinion 82, no matter to which side the movement takes place. The cylindric member 88, of course, should be held rigidly relative the actuator housing, this anchoring not being illustrated. In Fig. 9 it is shown that the periphally oriented tongue portions 90 can be replaced by cross oriented tongue por¬ tions 112 shaped with a rather broad tongue root, at which there is preferably provided a peripheral slot 114, whereby the tongue portions 112 are easy to bend despite the part- cylindrical shape of their root portions. In such an embo¬ diment the tongues do not extend in the longitudinal direction of the force acting on .the pinion, but rather crosswise thereto, and for the same reason it is empha¬ sized that these tongue portions have root areas of such a width that already hereby they will be widely stabilized against their outer ends of engagement being displaced in the peripheral direction of the pinion.

With the latter embodiment there will remain the prob¬ lem that the inner operative wedges 102 are not secured against a slight tilting of the associated tongue portions 112 about the longitudinal axes of the latter,* whereby a certain inaccuracy of the single final positions could occur. This, however, can be counteracted in a simple man¬ ner, viz. by providing on the tongues, at both sides of the respective wedges, abutment portions which will be supported on the top of the adjacent teeth in the depressed final position of the wedge. A corresponding, but parti¬ cularly attractive solution is illustrated in Fig. 10, where on each tongue 112 there is provided two wedges 92' with a mutual spacing of two teeth on the pinion, such that these wedges in a likeworthy manner will be depres- sable into declivities on either side of a central, non- used declivity, corresponding to the depression of a single wedge into just that declivity. During their depression the two wedges will meet almost exactly the same resist¬ ance, and at least it will hold true that in their fully depressed positions they will be located fully centered, here stabilizing the tongue against being twisted about its longitudinal axis. Fig. 11 shows a modified design of the spring cylinder 88, viz. entirely without specific tongue portions. The wedges 92" are mounted on suitable base means, and it will be noted that by the depression of a set of wedges there "will only occur some deformation of the cylinder 88, and the cylinder is able to transfer quite considerable forces in the peripheral direction.

The invention is not limited to the embodiments shown, as e.g. for the driving of a pinion it will be possible to use wedge bodies provided on straightlined leaf springs extending tangentially to the pinion and being held by a rigid carrier structure.

In its basic design the spring cylinder according to Figs. 9 and 11 will be well suited for cooperation with both a rotary system as in Figs. 7-8 and an axially dis- placeable system having a round rack with roundgoing teeth, when only the orientation of the wedges be properly adapted.

It has been mentioned above, see e.g. Figs. 7-11, that the wedge bodies 92 to be forced against the tooth row 82, along which the positioning movement shall take place, may be forced by means of pressure medium actuated pistons, but it is also mentioned that the actuation may of course also be effected by other means, and here electromagnetically actuated pistons may be a close to hand possibility. In the following a particularly advantageous possibility should be disclosed, viz. based on the use of permanent magnets, see Figs. 12-18.

A first embodiment is shown in Figs. 12-15, which can be compared with Fig. 8, i.e. where a controlled rotary movement between the coacting parts is to be produced. The pinion 82 is rigidly mounted on a shaft 120 constituting on main part of the system and e.g. being terminated in a pin¬ ion 122 for external transfer of movement. In the sectional view of Fig. 13 this pinion is replaced by a wheel 124 hav¬ ing an inclined front cam surface, which cooperates with a complementary cam block 126 that is non-rotatably mounted i in such a manner that a rotation of the wheel will result in an axial displacement of the block 126, i.e. such that a rotation of the shaft 120 will be transformed into an axial displacement..

The other main part of this system is a rigidly mounted cylinder 88, see also Figs. 8 and 11 of the parent application, this cylinder in Fig. 13 being shown mounted in an apparatus housing 108. Outside the periphery of the pinion 82 the cylinder is provided with inner wedge bodies 92, which by local depressions of the resilient cylinder shell 88 may engage with the pinion 82 and produce the discussed relative movements between the two main parts. According to the invention, for effecting these depressions use is made of iron members 128 mounted internally (or optionally even externally) on the cylinder 88 immediately in front of the associated wedge bodies, and coaxially with the pinion 82 a radially extending permanent magnet 130 is mounted so as to be rotatable for successive mag¬ netic attraction of the.iron members.

The magnet 130 is mounted in a holder 132 protruding from a shaft bush 134, which is axially connected^' with a planetary gear 136 driven by a control motor 138. The shaft bush 134 is freely rotatable on a projecting end of the pinion shaft 120, while it has a limited free rotata- bility of e.g. 45 with the connector shaft 140 to the planetary gear 136.

When the magnet is in a position adjacent one of the iron members 128 this member, as shown in Fig. 14, will be attracted inwardly such that the cylinder 88 will here be deformed for depressing the associated wedge body 92 against the periphery of the pinion 82 for producing the desired effect. The parts are dimensioned such that the wedge body reaching its pinion engaging position the iron member 128 will be prevented from effectively or material¬ ly abutting the magnet 130, i.e. it will be ensured that between these parts there will remain a narrow air gap 142. Mechanically, therefore, the magnet will thus still be freely rotatable, though it will of course be held magnet¬ ically by its attraction to the iron member 128, which could even - for increasing the attraction effect - be con¬ stituted by a counter polarized permanentmagnet. The at¬ traction engagement may be very strong with the use of modern magnetic materials, however without a corresponding¬ ly strong holding force against a lateral retraction of the magnet 130 from the engagement, i.e. the magnet can be turned away by applying a relatively modest momentum from the shaft 140, which may thus be driven by a relatively weak motor 138 through the planetary transmission 136. By this turning away the attraction engagement with the iron or magnet member 128 will be released, whereby the cylin¬ der 88 at the relevant place will straighten resiliently so as to remove the wedge body from its engagement with the pinion 82.

However, the turning away of the magnet will be fol¬ lowed immediately by a turning in of the magnet underneath the neighbouring iron or magnet member 128, which will thereby be attracted for effecting the next step of the desired movement, confer the parent application. The said partly free rotatability of the magnet relative its driving shaft 140 is of importance for securing that the magnet may be attracted by and pivot towards the next iron member 128 very rapidly after its driven retraction from the former holding engagement, such that the pinion 82 is not in the meantime entirely out of connection with either of the wedge bodies 92.

It will be appreciated that by the movements here dis¬ cussed there will occur no wear whatsoever between the ac¬ tuation system including the magnet 130 and the moving or motory system represented by the iron or magnet members 128 cooperating with the magnet, and that these members will be actuated with a very ideal characteristic, as their applied force and therewith their ability to move and finally positioning the pinion 82 will be increasing the closer they come to the attraction magnet 130.

In principle the motor 138 may be controlled as a step motor for stepwise rotation of the magnet 130 in one direction or the other, but it is possible to use a quite cheap and conventional, reversible motor, partly because the driving shaft 134,140 of the magnet may be driven through a low gear ratio and partly because in this shaft connection there is a certain inner rotatability which makes it acceptable that the motor does not stop quite abruptly.

Thus it will be clear that a rotary motion of the permanent magnet 130 - or a corresponding movement of an iron member cooperating with an annular row of permanent magnet members 128 on the cylinder 88 - can produce a con¬ siderable down-geared and very accurate incremental turning of the output shaft 120 relative the cylinder 88. It will be understood, however, that the successive actuations of the various wedge bodies 92 may be utilized for alternative¬ ly producing an axially oriented positioning movement when the wedge bodies are arranged to cooperate with an axially movable part having cross oriented teeth.

If such an axial movement shall proceed over relative¬ ly long distances it may be chosen to remove the magnetic movement system from the central area of the main system and instead arrange it in a circumferential manner as illu¬ strated in Fig. 16. Here the cylinder 88 surrounds a cross toothed rod (not shown) and is designed with cut tongue portions 112 corresponding to the tongues 112 of the Fig. 9 of the parent application. At the interior sides of and the outer ends of these tongue portions is provided wedge bodies 92 for cooperation with the cross oriented teeth on a throughgoing rod. Hereby the task will be to control the depression of the tongue ends in a sequentially con- 1 8

trolled manner, and in the embodiment shown this is ob¬ tained by arranging on the outside of the tongue ends out¬ wardly projecting and angularly bent portions 144, while about this system there is provided a rotatable cylinder 148, which is spotwise provided with inwardly projecting carrier portions 150 at an innermost end an iron or magnet member 152, which by a rotation of the outer cylinder 148 can be turned into positions underneath the iron or magnet ^•members 146 on the holder portions 144, such that these will hereby be pulled inwardly for forcing the respective wedge bodies 92 against the cross toothing of the central rod, see also Fig. 17.

As mentioned, an extra strong attraction effect may be achieved with the use of interacting permanent magnetic means on both one and the other of the main parts of the system, but with the use of magnetic members on both main parts it will also be achievable that strong engagement forces are obtainable by the ability of such magnetic mem¬ bers to be repelled from or by each other. Thus, in Fig. 18 it is illustrated that a rack 156 may cooperate with wedge bodies 158, which may be selectively forced against the rack in carrying magnet members 160 that can be depressed by the repelling force of an overlying permanent magnet 162, which is moved to and fro by means of a control cylinder 164, the magnet 162 being mounted in a holder 166, which by means of rollers 168 is supported against an outer rigid pressure surface 170. Thus the rack 156 may be moved forwardly or rearwardly all according to the magnet holder 166 being moved forwardly or rearwardly between the central or the left or the right hand repelling magnet 160, respec¬ tively.

It should be noted that in Fig. 16 the cylinder ton¬ gues 112 are shown to be tapering in such a manner that when they project alternatingly to opposite sides it is possible to utilize a very large part of the area of the cylinder body 148.

In general the dimension of the actuator magnet in its own peripheral direction or its direction of movement should be big enough to avoid any slip in the successive actuation of the armature members 128,146, whereby it will also with the present system be achievable that the motory system will be self-locking against the occurrance of a free relative movement, as a wedge body will not be moved free of the toothing before the next wedge body has been brought into initial engagement therewith.

Also in the present connection it should be ensured that the motor 138 cannot be actuated until it has been detected that preceding actuation has resulted in a total depression of the relevant wedge body. It is shown in Fig. 13 that for this detection it is suitable to make use of Reed switches 129, which are mounted such that they do not react to the free magnetic field of the magnet 130 itself, but only be the field deformation produced when the iron member 128 reaches its bottom position.

It is a possibility that the wedge bodies may be pro¬ vided fully integrally with the material of the carrier cylinder, by die pressing and a following tempering there¬ of, such that the cylinder appears as a spring steel member.

Finally it should be remarked that for the function of the system it is immateriel which means are used for turning the shaft 140.

Claims

C L A I M S :

1. A motory system for producing a relative incremental movement and positioning between two bodies, comprising on one body a row of teeth ond on the other body a number of wedges, which are movable towards and away from the teeth perpendicularly to the tooth row and are operable, when forced against a tooth flank, to produce a relative displacement of the .tooth row and to be brought into a bottom position centered in the V-shaped declivity between two neighbouring teeth, the wedges being mounted with such mutual spacings that by successive actuations by means of controlled actuator means they can produce a forthgoing mutual movement of the two bodies, characterized in that the wedges are provided on respective strip or plate por¬ tions, which extend generally in a plane perpendicular to the direction of the operative movement of the associated wedges and are secured to the wedge carrying body in a flexible manner.

2. A system according to claim 1, characterized in that the plate portions are mounted so as to be swingable into said bottom position with an associated building up of a spring bias, by means of which they are retractable from said position, and in that the associated actuation means are constituted by e.g. piston actuated pressure pins, which step against the plate portions at or adjacent the respective wedges without otherwise being connected with the plate portions.

3. A system according to claim 2, characterized in that the piston actuated pressure pins are mounted on pressure plates located and loosely guided in respective guiding openings in a thicker holding plate, outside which there is provided a resilient diaphragm covered by an outer plate, in the inner side of which there is provided reces¬ ses adjacent the respective guiding openings, these reces- ses in mutually separated manner being individually con¬ nected to a pressure medium source through successively actuatable valves.

4. A system according to claim 1, characterized in that the wedge carrying body is provided with sensors arranged to detect a completed actuation of the respective wedges.

5. A system according to claim 1, characterized in that the wedge carrying plate portions are provided as cut tongue portions in a common, unitary plate element.

6. A system according to claim 1, characterized in that the tooth carrying body is a cylindrical, relatively axial¬ ly displaceable rod with roundgoing teeth.

7. A system according to claim 1, characterized in that the tooth carrying body is a body of revolution having axially extending tooth profiles.

8. A system according to claim 7, characterized in that the wedge carrying plate portions of the other body, which surrounds the body of revolution, extends with substantial width, in the axial direction between their free, wedge carrying ends and their ends of connection with the sur¬ rounding body, the plate portions optionally being con¬ stituted by integral plate areas of an unbroken cylinder shell body.

9. A system according to claim 8, characterized in that the wedge carrying, free ends of the plate portions of the second body are provided with opposed abutment areas located adjacent the opposed edges of the plate portion and facing the tooth row, said abutment areas in the bottom position of the relevant wedge or wedges engaging against a tooth top area of the tooth row at both sides of the wedge engagement area.

10. A system according to claim 8, characterized in that permanent magnet means are provided for actuating the wedges.