EP0617446B1 - Control apparatus, particularly power control apparatus for electric heating apparatus - Google Patents

Description

The invention relates to a control device according to the preamble of claim 1. It is useful for adjustment electrical and / or similar power consumers different operating levels. For this purpose, a Actuator directly and / or via an intermediate gear or the like. indirectly by hand at different performance levels or the like can be adjustable, at least one possibly largest part of the associated travel is essentially one infinitely variable or almost continuous adjustment enables.

Such a control device can e.g. according to EP-A-0 057 460 be trained and approximately parallel protruding as well as in have substantially firmly connected arms, of which one runs on an actuator of the actuator and the other carries at least one movable switch contact, elongated control heating or the like until perpendicular to these arms and how these are adjacent to the The scope of the control element can be. The tax heating or the like. But can also after the European patent application EP-A-0 268 098 and EP-A-0 194 512 approximately parallel to the arms, on their side facing away from the control element and / or on the side of the actuator facing away from the arm lie.

A second, also from the actuator for all-pole shutdown contact to be actuated or its switching arm can be in Area of the side of the actuator facing away from it in parallel or according to the German patent application DE-A-2 625 716 lie obliquely to the first mentioned arms. The control heating with associated work expansion rod can instead of strip or plate-shaped, also in accordance with DE-A-2 422 686 can be rod-shaped. Instead of the control unit to control at least one heating resistor use that for heating a relatively high thermal capacity, such as an electric hot plate, one Oven heating or the like. Is provided, the control unit according to European patent application EP-A-0 339 269 also for the operation of devices with much less Capacity or essentially capacity-free devices, such as microwave heating or the like.

Instead of, or in addition to, power control Control device also designed according to DE-A-3 844 472 as a controller be the one with a hydraulic if necessary Expansion system belonging sensor operating values of the consumer records and with the actuator to different Operating values can be limited, the actuator if necessary, in addition to the rotary movement, an axial adjusting movement executes. A similar training is also shown by DE-A-3 619 243. The control device can furthermore accordingly EP-A-0 177 811 only for actuating one Signal device or the like. Directly on the actuator electrical Have conductor tracks with a sliding contact interact or it can be designed as a switch be, if necessary, on the outside of the housing of a control unit to arrange for the operating states and with it Actuator must be coupled at the same time. The control unit can also according to DE-A-4 124 668 essentially free of Supply lines and / or breakers or one Interconnection between two separate switching devices or similar units, if necessary with associated coupling connection form for actuators. The actuator can be used as Slider and / or control shaft may be provided, its actuating movement due to stop limitation only back and forth is possible or in the same direction of movement over the entire operating range can be continued like that the case with an actuator that can be rotated through more than 360 ° is. On the features and effects of the above writings is incorporated by reference into the present invention taken.

With such control units, the respective intermediate position can because of the infinitely variable adjustability, mostly only on the basis of determined on a scale associated with the actuating handle become cumbersome and lead to reading errors can. US-A-3 083 282 shows a control device in which the various intermediate positions by snapping the Snap devices are marked marked, but all have snap recesses provided on the same circumference are the same To form. This also applies to the control unit according to the FR-A-2 597 997.

DE-A-3 702 819 shows a control device with notches, the flanks of each notch and all notches same pitch angle but different heights. The control unit is a rotary switch for a program circuit, which can only be turned in one direction.

US-A-2 813 173 shows a control device in which also the cam recesses and the cam followers are symmetrical have mutually flanks with the same slopes.

The invention has for its object to a control unit create the disadvantages of known training or of the type described are avoided and in particular a simple determination of the size of each adjustment travel and / or preferred intermediate positions enables, if necessary with structurally simple training and high functional reliability.

To solve this problem, the features of the claim 1 suitable. Means can be provided with which when reaching, overflowing or leaving one or more Intermediate positions by the operator without a look emitted perceptible signal on the actuating handle is, which is preferably independent of the movement or Standstill of the operating handle is very short. Instead of an optical, acoustic or similar signal or In addition, at least one signal is useful the operator perceivable by tactile signal that Appropriately on the operating handle on this touching hand of the operator is transferred. Thereby the operator can, despite the fact that the setting is basically infinitely variable determine on the basis of signal pulses how many intermediate positions they have during an adjustment process reached, left or run over and what setting thereafter available.

The signal could go back and forth across the actuating direction Hereby, possibly axial, movement of the actuating handle or a snap impulse corresponding to the handle be, however, it is advantageous if the handle with regard to the information provided by the reporting device Signals in this transverse direction and at least during this setting rigidly mounted, or essentially is kept free of play and the signal pulse in and / or acts in the opposite direction, e.g. by a corresponding one Snap pulse. This can be used for reaching, leaving or Passing the respective intermediate position an increase or a reduction in the counteracting activity Moment of resistance, by a factor of two up to six times, in particular about four times, larger than this Moment of resistance is. Appropriately differ the signals for the three processes, possibly by changing the Sign of the change in section modulus at Reaching and leaving an intermediate position and when Driving over the intermediate position in that two signal pulses of the last-mentioned type directly to one another are then combined into an alternating signal.

In particular if the signaling device in the manner of a rest or Snap device works, it is appropriate if the Snap force is so low that the actuator not moving even if it is very minor is outside the associated intermediate position and the snap links, possibly over inclined surfaces, are already in one another to grab. This means that there is also one in this area stepless adjustment and a secure self-retention in the set state possible, although e.g. at a rotatable actuator the arrangement can also be provided can that when approaching the exact intermediate position a few degrees of an automatic transfer of the actuator into this exact intermediate position by the snap or locking force.

The pulse generator of the signaling device is suitably within a housing of the control unit, which with the Actuator or the operating handle moving working member this pulse generator rigid with the actuator and / or the handle can be connected. This working member can by a pulse cam, but in general Course essentially increasing cam curve to Power control or the like. Be formed while doing so cooperating further working member by the on this Curved runner is formed, which is the desired one Taps performance level and adjusting to one Power contact or the like. This cam curve can be one Sheath and / or forehead curve, the pulse cams so are trained that they have no on the power setting or at most have a negligible influence. In addition or instead, the first-mentioned working member can but also immediately afterwards or at a distance provided adjacent to the control curve for the operating states and in the manner described on the basis of this control curve be provided with pulse cams.

It is particularly advantageous if the signaling device directly as an actuator for another Switching function of the control device is provided, e.g. to the Opening and closing a contact pair for the all-pole Shutdown. This switching function is useful by Reaching, leaving or overflowing the respective intermediate position unaffected. In a certain intermediate position however, especially in the off position of the Control unit, can at least here via the reporting device a switching process are triggered, then the signaling device a snap fixing due to the spring catch the control cam or the control element for the operating states causes that even through his runner or the like. is not exposed to an immediate rest, but from this position in both opposite directions could be moved out without rest. In an intermediate position, which immediately follows this off position and e.g. setting to the lowest power level represents, however, the control element both immediately by his runner and additionally by the reporting device to rest. The signal when reaching, leaving and / or passing over the off position or the like appropriate from the corresponding signal at least one other intermediate position, being advantageous the change in the section modulus associated with this signal larger than at least one other intermediate position is. This makes the off-intermediate position with regard to the Signals compared to the other intermediate positions highlighted, and it can only be based on the signal as Reference basis for setting processes can be used.

The respective cam of the control element or with this moving working member of the reporting device can by a depression and / or an elevation may be formed. To the Pre-assemble the respective runner on the base body and only then the working element, the control element or the To be able to mount the actuator essentially unhindered, expediently a cam, especially the off position or the like. Associated cams up to one lying transversely to it End face through which he has a possibly inclined insertion surface forms to the associated runner during assembly to bring into engagement with this cam that the Runner against its spring force against the cam is pushed back automatically.

At least one cam flank of one or most of preferably a total of four to eighteen, in particular approximately seven intermediate positions is very flat or at a large obtuse angle of more than 90 or 100 to 150 or 170 ° in the subsequent, essentially resting or slope-free curve sections over, this slope to the apex of the respective locking cam expediently towards zero decreases, e.g. due to arcuate curvature. This allows the adjusting the actuator by the signaling device acting force even below the counteracting Frictional force can be maintained when the runner of the signaling device is already engaged with such a flank. The apex height of the respective cam can be below one or half a millimeter Cam width compared to the cam depth or cam height 4- to 6 times bigger. In contrast, it is the off position associated cam height advantageously significantly or repeatedly, e.g. 8 to 15 times larger. Also one or both flank angles this cam are compared to those of the other intermediate positions steeper. The flank that has an intermediate position belonging directly to the off-cam can under one smaller or larger angle than flanks of the rest Intermediate positions and in relation to these also over a increase greater or lesser height, so that even when Transfer from the last intermediate position to the off position a different signal is given.

Fig. 1

einen Ausschnitt eines erfindungsgemäßen Steuergerätes in perspektivischer Darstellung,

Fig. 2

das Steuergerät gemäß Fig. 1 in einer weiteren perspektivischen Ansicht und geringfügig abgewandelter Ausbildung,

Fig. 3

einen Ausschnitt der Fig. 2 im Schnitt,

Fig. 4

das Stellglied des Steuergerätes gemäß den Figuren 1 bis 3 in teilweise geschnittener Ansicht,

Fig. 5

das Stellglied gemäß Fig. 3 in Ansicht von unten,

Fig. 6

das Stellglied gemäß Fig. 3 in Ansicht von oben,

Fig. 7

einen Ausschnitt der Meldeeinrichtung gemäß Fig. 1 in Axialansicht und

Fig. 8

das Schaltbild des Steuergerätes gemäß den Figuren 1 bis 7.

These and further features emerge from the claims and also from the description and the drawings, the individual features being implemented individually or in groups in the form of sub-combinations in one embodiment of the invention and in other fields, and being advantageous and protectable per se Can represent designs for which protection is claimed. An embodiment of the invention is shown in the drawings and is explained in more detail below. The drawings show:

Fig. 1

a section of a control device according to the invention in a perspective view,

Fig. 2

1 in a further perspective view and a slightly modified design,

Fig. 3

a section of Fig. 2 in section,

Fig. 4

the actuator of the control device according to Figures 1 to 3 in a partially sectioned view,

Fig. 5

3 in bottom view,

Fig. 6

3 in top view,

Fig. 7

a section of the signaling device according to FIG. 1 in axial view and

Fig. 8

the circuit diagram of the control device according to Figures 1 to 7.

The control unit 1 has a housing-shaped base body 2 with an approximately rectangular housing shell 3 and two approximately parallel end walls 4, 5, of which one wall 4 as a separate plate-shaped cover or as a mounting plate for essentially all functional parts of the control unit is trained. 2 can be used as the mounting board but also a one-piece with the housing shell 3 Wall 4 may be provided. To one to the end walls 4, 5 transverse actuator axis is essentially within of the housing lying actuator 6 with two bearing or Spigot 7, 8 rotatably mounted in the bearing openings of the Engage end walls 4, 5. The end wall 5 is with fasteners for fastening the control unit to the Provide the inside of a device board so that over its The front of a stub shaft 9 protrudes into an opening the associated plug pin 8 or the actuator 6 is used in a rotationally locking manner and also in a rotationally locking manner Attachment of an outside of the housing Handle 11 in the form of a rotary knob lying in the axis 10 serves. Over the other plug 7 is a the outside of the associated end wall 4 protruding Coupling member 12 for rotational connection with a Connection shaft, which e.g. an actuator one to the Base body 2 to be flanged connection or additional device can form that also accommodate a notification device can.

That essentially or at least except for the stub shaft 9 with a non-metallic material on the outer surfaces good sliding properties, e.g. Plastic, existing actuator 6 forms immediately following the plug-in pin 8 or on the inside of the end wall 5 an actuator 13 in Form of a slope curve on which a on the base body 2 separately mounted rotor 14 under resilient contact pressure is led. The arranged around the axis 10 and on this Axis 10 related curve of the actuator 13 has a highest cam 15 and following its two flanks each have a cam 16, 17 and between them over the most of its circumference is a stepless incline 18 on. This determines the by adjusting the rotor 14 respective operating level of a control device, e.g. one Circuit breaker 20, an area adjacent to the Depression the recess 16 the lowest and the Locking recess 17 determines the highest operating level, while the cam 15 the shutdown of the consumer to be connected causes.

A movable contact of the trained as a snap switch Circuit breaker 20 is fixed on the end wall 4 arranged switch base 19 mounted and one also correspondingly arranged fixed contact assigned. When the control unit 1 is in the on position Circuit breaker 20 via a working bimetal 21 and one Control heating 22 controlled clocked, the relative Duty cycle depending on the position of the control element 13 changes in that with the working bimetal 21st about an axis approximately parallel to axis 10 on end wall 4 stored rotor 14 a transfer member of the thermoplastic Link 21 or the like. More or less against one Spring arm of the movable contact presses and this thereby more or less close to its switching point.

On the side of the actuator facing away from the circuit breaker 20 6 are contact arrangements of an isolating contact 23 for a second lead or the like. and a signal contact 24 provided that e.g. to control a signaling device or the like. The movable contact of the signal contact 24 is a driver 25 of the movable contact of the Disconnect contact 23 taken away, which in turn via one of the Actuator 13 separate control curve is controlled so that he like the signal contact 24 when all curve sections are effective 16 to 18 in its one, e.g. closed Operational position is while he is effective Curve section 15 in its other operating position stands. The movable contact of the isolating contact 23 is similar to the movable contact of the signal contact 24 via a movable support member attached to the end wall 4 Base 26 stored. The base 26 has an additional one Transmission part in the form of a spring 27, an arm or the like., which is moved with the support member and the Driver 25 moves. Relating to an outside of the Housing shell 3 is parallel to the axial plane 28 of the axis 10 the control arrangement including switch 20 one side and the contacts 23, 24 including Control arrangement on the other hand. The above Sockets 19, 26 and further sockets are each in through openings the end wall 4 used so she sat on the outside of which connecting members 29, e.g. Tabs, form for device and supply lines.

With the contact arrangement for the isolating contact 23 is one Integrated reporting device 30, the signals on the Actuator 6 and the plug pin 7 in the direction of rotation on the Handle 11 act mechanically in the manner of snap pulses. The notification device 30 has two continuously Spring elements in engagement with each other 31, 32, namely a rigid or one-piece with the adjusting element 13 formed working member 31 in the form of a control curve and a working member mounted separately on the end wall 4 thereof 32 in the form of a sliding on curve 31 Runner 32, which is spring-loaded against the axis 10.

The working member 31 is about the same as the common one Corresponding arc angles of the curve sections 16 to 18 Arc angle essentially as gradient-free or cylindrical Circumferential curve 33 formed, which, however, of essentially same intermediate cam 34 is interrupted and connects at its ends to limit cams 36, between which a resting cam 35 lies. The ones that act in the manner of micro-catches Cams 34, 36 are depressions here, while the rotor 32 is a corresponding lead, but could also both associated snap or locking members each have the negative form of the form shown. The same rest cam 35 formed as a recess has an essential greater cam depth than the other cams and therefore determines a rest position that can only be overcome by much higher force. The working member 31 can with the actuator 6 each position rotated in both opposite directions be so that both flanks of each cam the runner 32 can overflow.

The respective intermediate cam 34 is curved or part-circular and extends opposite to its axis of curvature over an arc angle of less than 90 ° or between 70 ° and 80 °. Each of the intermediate cams of the same design 34 borders on both sides of its deepest apex 37 lying flanks 38 at a sharp angle to the Circumferential curve 33, their blunt in the transition area Flank slope 53 larger than this circumferential curve 33 than 120 ° or 130 °. The obtuse flank angle 54 between their two flanks 38 also lie approximately in this Order of magnitude, with the intermediate cam 34 being approximately symmetrical is the median plane going to its apex 37. Thereby the intermediate cams 34 form flat, cow-shaped depressions, where the rotor 32 each across the entire cam width over the whole area or up to the transitions into the circumferential curve 33 can apply.

The flanks 43, 44 adjacent to the resting cam 35 are around the Axis 10 is significantly longer than the flanks 38, the Edge 43 associated limit cam 36 the highest operating level and the limit cam 36 associated with edge 44 is the lowest Operation level determined. The slope of the to Circumferential curve 33 adjacent flank of the limit cam 36 as well their crown formation also corresponds to that of Intermediate cam 34. The slope 56 of the boundary edge 44 is about 150 ° flatter than that of the flank 38, while the corresponding slope of the shorter one Boundary flank 43 at its extreme end opposite the respective one Flank 38, 44 can be smaller. The on axis 10 related, approximately equal flank height of the boundary flanks 43, 44 is greater than the cam height of the circumferential curve 33, wherein the boundary edge 43 with the associated edge 41 and the Boundary flank 44 with the associated flank 42 of the resting cam 35 an approximately acute-angled cam bump 39 and 40, respectively limited.

The flanks 41, 43 go over an approximately pointed cusp apex 45 and the flanks 42, 44 over a more rounded Cusp crest 46 into each other, both of them Hump crests 45, 46 roughly the same and opposite the circumferential curve 33 have higher cams. The on the cusp parting 46 adjacent slope 55 of the degressively increasing Flank 42 is steeper than that of the degressively rising Edge 41, the progressively rising edge 38 or 43 and the approximately linearly rising edge 44, the Flank slopes of the two flanks 41, 43 are approximately the same size could be. As a result, the cams 35, 36 and the cam bumps 39, 40 in contrast to the intermediate cams 34 each formed asymmetrically to their apex or median plane.

The flank angle 57 of the cam bump 39, 40 is below 90 ° in a range between 65 ° and 80 °, with a cam bump 39 be more acute than the other cam bump 40 can. The smallest flank angle of the limit cam 36 can be smaller or larger than the flank angle 54 and so on both sides of the resting cam 35 e.g. distinguish by that the flank angle belonging to the cam hump 39 Limit cam 36 is smaller than the flank angle of at least one Intermediate cam 34 and the other limit cam 36; corresponding also applies to the largest flank angle of the Rest cam 35. Its cam apex is including the subsequent flank sections similar to that of Intermediate cam 34 formed, whereby the flank 41, 42nd between this cam apex and the cusp apex 45, 46 Is S-shaped. In the direction of adjustment is that Distance between the cam bumps 45, 46 corresponding effective width of the cam 35 at least two or three to four times larger than the cam width of cam 34. Die corresponding cam widths of the cams 36 are about the Half smaller than that of the cam 35, but about one Third larger than the cam 34, the one to the flank 43 belonging cam 36 is narrower than the other limit cam 36.

The rotor 32 has a close to the cam apex and one or both adjoining flanks 38, convex or partly circular tread and is marked by a approximately U-shaped from a strip-shaped swivel or Signal arm 50 protrusion formed transversely to the strip plane formed, the U-legs less than a quarter circle curved in one piece in the adjoining arm section pass over. Both arm sections form together or Independently acting or movable spiral springs, one of which extends from the base 26 to the rotor 32 and serves to press it while the other of the rotor 32 extends to the isolating contact 23 and for the resilient contact pressure from its movable contact. The runner 32 leading arm section can thereby opposite the isolating contact 23 leading arm section despite otherwise about same cross sections or length a much larger Have spring force that is essentially rigid or over a resilient intermediate member is supported on the spring 27, e.g. in the area in which this spring 27 on the driver 25th works.

7 is the cam bump 45, 46 with the smallest gap distance immediately adjacent to associated flat side of how the runner 32 from one resilient metal existing signal arm 50 and to the concave transition surfaces to the runner 32. Due to the different Formation of the flanks 41, 42 can either effective different lever length of the signal arm 50 so be taken into account that when adjusting movements in both Setting directions about the same signal pulse is emitted or different signal pulses can be provided for this be. For example, is from the rest or off position a smaller travel range with a higher section modulus to reach the cusp crest 46 than to reach of the cusp apex 45 required. Overcoming the cusp crest 45 gives a stronger snap than that of the apex 46. When moving to the off position the respective limit cam 36 needs to be overcome Border 44 of a larger travel range with approximately constant less moment of resistance than overcoming the Boundary edge 43, which causes an increasing section modulus.

As soon as the rotor 32 has the respective cusp apex 45, 46 has overflowed, it resiliently presses against the associated one Flank 41, 42 that the actuator 6 in its exact off position rotated and held in the adjustment direction without play becomes. When the rotor 32 is in the limit cam of the Cam hump 40 suitably lies approximately in the runner 14 Locking cam 16 while engaging the rotor crown in the Cusp crest 46 of the runners 14 expediently on the associated one Start of the slope-free section of the off cam 15 lies. When the rotor 32 is in the other limit cam 36 in contrast, the rotor 14 can already be adjacent to the cam 17 the incline 18 lie while sliding along the Runner 32 is passed through the cam 17 on the flank 41, so that this cam 17 is not a locking cam. After overflowing the cusp apex 45, 46 to the on position becomes the actuator 6 automatically under the effective spring forces adjusted until the rotor 32 the cam base of the Limit cam has reached 36.

The runner 14 carrying, essentially in operation spring-stiff and only by the spring arms of switch 20 engages against the actuator 13 spring-loaded arm 51 on the side facing away from the end wall 4 Contact base of the switch 20, the base 26 and / or the Signal arm 50, so that there is a very compact design. The spring arms of the switch 20, the switch base 19 and the Runner 32 or the signal arm 50, which is in a compared to the Actuator 13 to the end wall 4 axially offset plane are overlapped by the control element 13. Between this and the smaller working member with the largest diameter 31, the actuator 6 forms an intermediate section 52, the half the diameter is smaller than the smallest radial extent of the actuator 13 and larger than the largest radial extent of the working member 31.

The plug directly adjoining the working member 31 7 has compared to the smallest radial extent of the Working member 31 in the area of the intermediate cam 34 a smaller half a diameter, so that between all mentioned sections each have an approximately annular Forehead shoulder results. This is between the cam humps 39, 40 interrupted by an axial insertion surface 47, which is practically an approximately axial continuation of the resting cam 35 forms and to the face away from the working member 31 49 of the plug pin 7 in an inclined insertion surface 48 passes in axial view to the associated end of the Actuator 6 is exposed. When axially approaching the Actuator 6 against the end wall 4 initially runs the insertion surface 48 on the rotor 32 and presses it against its spring force radially backwards so that this slides onto the insertion surface 47 until the actuating element 13 in the area of the cam 15 with its end face on the Runner 14 runs up, runner 32 already having a first one Section of the resting cam 35 may have reached. By a small rotary movement of the actuator 6 against the restoring force of the engaging rotor 32, the cam 16 in brought the area of the rotor 14 and thereby the actuator 6 completely transferred to its axial operating position become. This allows assembly in a simple manner with a Handling machines are carried out, the actuator 6 according to the contact arrangements and the reporting device 30 is mounted.

The training according to the invention enables a very precise and between the limit cams 36 on the circumferential curve 33 in essentially continuous adjustment, the contacts 23, 24 approximately between half the height of the flanks 41, 42 and over the peak 45, 46 as well as over all the others Circumferential sections 33, 34, 36 of the working member 31 in their if necessary, closed, operating position transferred and uninterrupted are held in this position. When going through the Intermediate positions 34 on the handle 11 are lighter and 36 stronger snapshots when crossing the limit positions palpable.

According to the invention, the control device is particularly suitable for thermal relatively low-mass consumers 58, such as radiant heaters intended. The tax heating is according to Fig. 8 parallel to the consumer 58, or between the fixed contact the isolating contact 23 and the spring arm of the switch 20, namely via the actuator 21, switched and actuates the switch 20 between opening and closing clocking. Instead of several heating circuits, the consumer has 58 preferably only a single heating circuit or heating resistor on.

It is also possible to have several of the same or different types Control units combined to form a control unit assembly be, of which at least one each no reporting device may have, while separately operable control devices have different or the same signaling devices can.

Claims (10)

1. A control apparatus, more particularly a power control apparatus (1) for electrical heaters, including a base body (2), with regard to which a positioning member (6) actuatable over a positioning travel and intermediate positions in a positioning direction against the moment of resistance of a snap-action means (30) is movably mounted, said snap-action means (30) comprising working members (31, 32) interengaging in each intermediate position, one of which comprises snap-action flanks (41, 42; 43, 38; 44, 38) having flank sections ensuring in common the intermediate position and dictating slope angles, characterized in that said flank sections of said two snap-action flanks (41, 42; 43, 38; 44, 38) assuring said intermediate position comprise differing gradients.
2. The control apparatus as set forth in claim 1, characterized in that said manually actuatable positioning member (6) is substantially infinitely variable in opposing directions as well as at least over a partial travel and said snap-action means (30) is provided as the signal generator of a signalling means for signalling said intermediate positions of said positioning member (6) substantially without a scale by positioning signals, more particularly several snap-action members (34 to 36) being configured for outputting position signals distinguishable from each other and preferably said snap-action members (34 to 36) being configured for outputting tactile position signals at an operator control (11) by a sudden change in said actuating moment of resistance acting against said actuation of said positioning member (6).
3. The control apparatus as set forth in claim 2, characterized in that said snap-action members (34 to 36) are configured so that said positioning signal results in a reduction in said moment of resistance when said positioning member (6) approaches one of said intermediate positions or an increase in said moment of resistance when said positioning member (6) leaves an intermediate position, more particularly as regards at least one intermediate position said change in said moment of resistance corresponding to maximally two to four times and preferably said snap-action means (30) presenting said positioning member (6) in at least one intermediate position a more or less equal moment of resistance in both opposing positioning directions.
4. The control apparatus as set forth in any of said preceding claims, characterized in that said snap-action means (30) as a latching means assures at least one intermediate position of said positioning member (6) self-centering, more particularly said snap-action members (32, 34 to 36), such as recesses on a control curve (31) as well as a follower (32) guided thereon are urged into interengagement by spring pressure, and preferably said follower (32) is provided on a working member (50) for actuating at least one pair of contacts (23, 24), said follower (32) being movable in one of its latched intermediate positions relative to another of its intermediate positions against a greater moment of resistance.
5. The control apparatus as set forth in claim 4, characterized in that said working member (50) carrying said follower (32) mounts a movable contact of said contact pair (23) and is configured as a spring, arm, or the like, more particularly said follower (32) being configured integrally with said corresponding working member (50), and preferably for controlling the power at a positioning lever (51) a positioning element (13) engaging said positioning member (6) being provided, said positioning element (14) surrounding said working member (50) without contact.
6. The control apparatus as set forth in any of the preceding claims, characterized in that said snap-action member (34 to 36) of said snap-action means (30) mounted manually rotatable on said base body (2) comprises an inclined assembly surface area (48) for guiding-in said snap-action member (32) engaging it, more particularly said guide-in surface area (48) being formed by a substantially continual elongation of said snap-action flanks (41, 42) for a position of said snap-action means (30) associated with the OFF position of said control apparatus (1) and preferably said guide-in surface area (48) being offset in said positioning direction relative to at least one further snap-action member (34, 36) of said snap-action means (30).
7. The control apparatus as set forth in any of the preceding claims, characterized in that said snap-action member (6) comprises adjacent to said adjoining snap-action member (34 to 36) a positioning element (13) for substantially infinitely variable power control, between which and said snap-action member (34 to 36) an intermediate section (52) is provided, more particularly said positioning member (6) being configured as a positioning shaft to be connected to said operator control (11) and preferably said positioning member (6) consisting of a non-metallic material and forming two journals (7, 8), said snap-action member (34 to 36) directly adjoining one journal (7) and said positioning element (13) directly adjoining the other journal (8).
8. The control apparatus as set forth in claim 7, characterized in that said positioning element (13 ) is located nearer to said operator control (11) than said snap-action member (34 to 36), more particularly said guide-in surface area (48) as viewed axially being exposed at one end of said positioning member (6) and preferably a coupling member (12) for a connecting shaft protruding beyond said floating journal (7) facing away from said operator control (11).
9. The control apparatus as set forth in any of the preceding claims, characterized in that said snap-action flanks (41, 42) are recess flanks provided at cam humps (39, 40) translating via near acutely angled hump crests (45, 46) of said cam humps (39, 40) into further snap-action flanks (43, 44), more particularly the flank angle (57) of at least one of said cam humps (39, 40) being 90° and preferably said hump crests (45, 46) being differingly acutely angled.
10. The control apparatus as set forth in claim 9, characterized in that said snap-action flank (41, 42) of said snap-action member (35) translates via said corresponding hump crest (45, 46) directly into said further snap-action flank (43, 44) of a further snap-action member (36), more particularly both hump crests (45, 46) being adjoined by snap-action flanks (43, 44) of further snap-action members (36), of which one is shorter and preferably said two further snap-action members (36) engaging said follower (32) in the highest and lowest operating stage of said control apparatus (1) respectively.

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