Portable handheld work apparatus

A portable handheld work apparatus has a drive motor as well as an adjusting element for controlling the drive motor. The work apparatus has at least one actuating element. A movement of the actuating element is transmitted to the adjusting element via a transmitting unit. A good operator control is achieved when at least one transmitting characteristic (49, 50; 89, 90; 309, 310) of the transmitting unit runs nonlinearly as a function of the actuating displacement (s) of the actuating element.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority of German patent application no. 10 2006 050 430.5 filed Oct. 26, 2006, the entire content of which is incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a portable handheld work apparatus having a drive motor and an adjusting element for controlling the drive motor. The work apparatus has at least one actuating element and a movement of the actuating element is transmitted to the adjusting element via a transmitting unit.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 6,666,187 discloses a motor-driven work apparatus having an actuating element which is pivotally supported. The actuating element lies against a resiliently biased stop. The pretension of the spring force is adjustable and the actuating force is adjustable in this way.

When actuating a drive motor, especially an internal combustion engine, a fine adjustment is desirable in some ranges of the actuation; whereas, in other ranges of actuation only a coarse adjustment is needed. In known transmitting units, the transmitting characteristic can, however, be adjusted at most for the entire actuating path. In this way, an inadequate operating comfort results.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a portable handheld work apparatus of the kind described above wherein the comfort for the operator is increased.

The portable handheld work apparatus of the invention includes: a drive motor; an adjusting element operatively connected to the drive motor for controlling the drive motor; a movable actuating device displaceable through an actuating displacement (s); a transmitting unit for transmitting a movement of the actuating device to the adjusting element; and, the transmitting unit defining a transmitting characteristic which is a nonlinear function of the actuating displacement (s).

The nonlinear course of the transmitting characteristic makes possible that a precise adjustment of the adjusting path is possible in the ranges of the actuating path wherein a precise adjustment is required; whereas, in ranges where a precise adjustment of the adjusting element is not needed, a simple and quick operator control via a coarse adjustment of the position of the adjusting element is made possible. In this way, a higher level of comfort in operation is achieved.

Advantageously, the transmitting unit has a first transmitting characteristic in a first range and a second transmitting characteristic in a second range of the actuating path. Especially when the drive motor is an internal combustion engine and the adjusting element is a throttle flap, a precise capability of adjustment is necessary at low rpms of the engine; whereas, at high rpms, a coarse positioning of the throttle flap is sufficient. This can be achieved in that the transmitting characteristic at low rpm distinguishes from the transmitting characteristic at high rpms. In both ranges, respective linear courses of the transmitting characteristic can be provided. Advantageously, the transmitting unit has a stop which is actuated after passing through the first operating range of the actuating path. The position of the stop is especially adjustable so that the operator can adjust up to which actuating path the first range should extend, that is, up to which actuating path a fine adjustment is wanted.

To prevent an unintended movement out of the first range, an adjustable latch device is provided which, in a first latched position, blocks a further actuation of the actuating element after passing through the first range of the actuating path and which, in a second released position, permits a further actuation of the actuating element. In order to completely actuate the actuating element, the operator must thereby first shift the latch device in the second actuated position.

Advantageously, a transmitting characteristic, which does not run linearly, is the actuating force. In this way, the operator can make a coarse adjustment in a range with low actuating force. In the second range, a higher actuating force is needed so that a fine adjustment of the actuating element can take place. The user receives feedback via the spring as to which range of actuation the operator is in. In this way, the operation by the user is simplified. The transmitting unit practically includes a spring which opposes the movement of the actuating element in one of the ranges of the actuating path.

It can, however, also be provided that a transmitting characteristic, which does not run linearly, is the positioning path of the actuating element. In one of the ranges, a long actuating path is needed for a pregiven displacement path; whereas, in the other range, a considerably smaller actuating path is needed for the same displacement path. In this way, in the first range, a fine adjustment of the adjusting element takes place while in the second range, a rapid actuation is possible. This is especially advantageous when the actuating element is a throttle flap. Because of the geometry, a displacement of the throttle flap out of the closed position effects a large change of the flow cross section. A displacement by a corresponding angle with an almost completely open throttle flap has only a slight influence on the flow cross section. A nonlinearly running adjusting path thereby permits an adaptation of the actuating path to the change of the flow cross section. In this way, with the displacement of the actuating element by an actuating path, independent of the position of the throttle flap, the same or almost the same change of the free flow cross section results.

Advantageously, the transmitting unit includes a transmitting element. The actuating element acts upon the transmitting element via an intermediate lever. It is provided that the transmitting element is fixed to an attachment point on the intermediate lever. In this way, the nonlinear transmitting characteristic can be adjusted via the intermediate lever.

It is provided that the actuating element is pivotally supported about a first pivot axis on the intermediate lever and that the intermediate lever is pivotally supported on the housing of the work apparatus about a second pivot axis. The second pivot axis has a different distance to the attachment point of the transmitting element measured perpendicularly to the actuating direction of the transmitting element than the first pivot axis. The first pivot axis as well as the second pivot axis has a distance to the attachment point which is greater than zero. The lever arms for the actuation of the transmitting element are of different size in the two ranges. For this reason, different adjusting paths result for the same actuating path. In this way, and in a simple manner, a nonlinear transmitting characteristic is achieved. The nonlinearity of the transmitting unit is constructively pregiven because of the two pivot axes spaced from each other. In the first range of the actuating path, the actuating element pivots about the first pivot axis and, in the second range of the actuating path, the actuating element and the intermediate lever pivot together about the second pivot axis.

It can, however, also be provided that the actuating element is pivotally supported about a first pivot axis on the housing and that the intermediate lever is pivotally supported about a second pivot axis on the actuating element. Advantageously, the intermediate lever moves along a cam contour relative to the housing. The form of the cam contour determines the transmitting characteristic between actuating element and adjusting element. It can also be provided that the actuating element is pivotable about a first axis in the housing and that the intermediate lever is guided to be displaceable in the housing. The intermediate lever is especially actuated by the actuating element via a cam contour. Advantageously, the position of the cam contour is adjustable via an adjusting device. In this way, the position of the first and second ranges and therefore the transmitting characteristic of the transmitting unit can be adjusted.

It can also be provided that the actuating element is pivotally supported about a first pivot axis on the housing and that the intermediate lever is pivotally supported about a second pivot axis on the housing. Advantageously, the actuating element acts on a cam contour of the intermediate lever when pivoting about the first pivot axis and pivots the intermediate lever about the second pivot axis. The transmitting characteristic can be influenced by the arrangement of the pivot axes and the configuration of the cam contour.

It can also be provided that the transmitting element is fixed on the actuating element. It is advantageous when the actuating element is pivotally supported about a first pivot axis and about a second pivot axis. The actuating element pivots about the first pivot axis in the first range of the actuating path and pivots about the second pivot axis in the second range of the actuating path. With the two different pivot axes, there result different transmitting characteristics in the first and second ranges which are determined by the position of the pivot axes. In order to achieve a nonlinear transmitting characteristic, it can also be provided that the transmitting element is held on an attachment pin on the actuating element. The position of the attachment pin on the actuating element changes in dependence upon the actuating path of the actuating element. If the position of the attachment pin on the actuating element changes continuously, for example, by guidance in a slot, a continuous change of the transmitting characteristic can be achieved thereby. The position change takes place especially not perpendicularly to the actuating direction of the transmitting element.

The transmitting unit has a deflecting cam which is at a distance to the transmitting element in a first range of the actuating path and which, in a second range of the actuating element between an attachment point of the transmitting element and the adjusting element, acts on the transmitting element and deflects the transmitting element. The deflecting cam effects an additional actuation of the transmitting element and therewith of the adjusting element. When the deflecting cam is not in engagement, the transmitting element is moved only by the movement of the actuating element. As soon as the deflecting cam comes into engagement with the transmitting element, the actuating element as well as the deflecting cam effect an actuation of the transmitting element. In this way, a nonlinear transmitting characteristic is achieved.

It can also be provided that a first actuating element is provided for the actuation in a first range of the actuating path and a second actuating element is provided for the actuation in a second range of the actuating path. The two actuating elements thereby determine different transmitting characteristics. It is provided that the transmitting element is fixed to an attachment point on the first actuating element and that the second actuating element acts on the transmitting element between the attachment point of the transmitting element and the adjusting element. The two actuating elements thereby operate substantially independently of each other on the transmitting element. Also, the simultaneous actuation of both actuating elements is possible. It can, however, also be provided that the transmitting element is fixed on the first actuating element and that the second actuating element acts on the first actuating element. With a corresponding geometric arrangement of the actuating elements, different transmitting characteristics are achieved when actuating the first and second actuating elements, respectively.

A substantially free configuration of the transmitting characteristic can be achieved when the actuating path of the actuating element is transferred electrically to the adjusting element. Advantageously, the actuating element actuates an electric adjusting device which generates an electrical signal corresponding to the actuating path. It is provided that the electrical signal is the input signal of a control which generates an output signal in dependence upon a wanted transmitting characteristic which output signal determines the position of the adjusting element. The transmitting characteristic stored in the control can be freely selected and can be matched to the work apparatus. For different transmitting characteristics in different work apparatus, only the transmitting characteristic, which is stored in the control, need be adapted. A constructive adaptation of the transmitting unit is not necessary.

Advantageously, the work apparatus has a switch element with which a unit for generating the nonlinear transmitting characteristic can be switched into an inactive state. In this way, the operator can select whether a nonlinear transmitting characteristic is wanted in at least one range. Should the user want a linear transmitting characteristic for specific cases of use, then this can be set by the switch element. Especially, the course of the nonlinear transmitting characteristic can also be influenced or set via the switch element.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

FIG. 1shows a schematic of a blower apparatus1which is configured as a backpack blower apparatus. The blower apparatus1has a housing2which is mounted on a back carrier10. An internal combustion engine3is mounted in the housing2and drives a blower wheel (not shown). The blower wheel moves an airflow through a blower tube9. A handle11is fixedly mounted on the blower tube9and has a throttle lever12, a throttle lever lock13as well as an off switch14. The throttle lever12actuates a transmitting element8which can, for example, be a bowden cable. The transmitting element8is connected to a throttle element7pivotally journalled in an intake channel4of the internal combustion engine3. When actuating the throttle lever12, the actuating movement is transmitted via the transmitting element8to the throttle element7. The throttle element7is spring biased in the direction toward its completely closed position by a spring28. The throttle element7is mounted in a carburetor5which is mounted in flow direction between an air filter6and the internal combustion engine3. The throttle element7is especially a throttle flap. The internal combustion engine3can, for example, be a two-stroke motor or a four-stroke engine.

For a slightly open position of the throttle flap7, a slight actuation of the transmitting element8already effects a large change of the quantity of air inducted. In contrast, for a substantially open throttle flap, a slight actuation of the transmitting element8effects only a very slight change of the inducted airflow. For this reason, it is desirable not to transfer the movement of the throttle lever12linearly to the movement of the throttle element7.

InFIG. 2, an embodiment of a transmitting unit is shown with which the movement of the throttle lever12is nonlinearly transmitted to the transmitting element8. The throttle lever12is pivotally supported on a first pivot axis16on an intermediate lever15. The intermediate lever15is pivotally supported on a second pivot axis17in a housing18of the handle11. The transmitting element8is, for example, a bowden cable and is attached to an attachment point19on the throttle lever12. The throttle lever lock13is pivotally supported in the housing18about a pivot axis21. A hook20is provided on the throttle lever lock13and this hook blocks the throttle lever12in the unactuated position of the throttle lever lock13. If the throttle lever lock13is actuated, then the hook20pivots away from the throttle lever12and the throttle lever12can be actuated. Because of the spring28on the throttle element7, the throttle lever12and the intermediate lever15are pulled into the unactuated position shown inFIG. 2when the throttle lever12is not actuated.

To actuate the throttle element7, the throttle lever lock13is first actuated so that the hook20pivots away from the throttle lever12. Thereafter, the throttle lever12can be actuated. The throttle lever12first pivots about the first pivot axis16. The first pivot axis16is at a first distance23to the attachment point19measured perpendicularly to the actuating direction34of the transmitting element8. This first distance23determines the lever arm with which the transmitting element8is actuated. In the unactuated position, the intermediate lever15rests against a stop22on the housing18. The intermediate lever15has a stop25.

In the throttle lever12, a sleeve51is mounted which can be adjusted via an adjusting screw26in the direction toward the stop25. The sleeve51coacts with the stop25as soon as the throttle lever12has pivoted by a corresponding angle about the first pivot axis16. As soon as the sleeve51lies against the intermediate lever15, no further pivoting of the throttle lever12relative to the intermediate lever15can take place with a further actuation of the throttle lever12. With a further actuation of the throttle lever12, the throttle lever12and the intermediate lever15pivot together about the second pivot axis17. The second pivot axis17is at a second distance24to the attachment point19and this distance is likewise measured perpendicularly to the actuating direction34and defines the lever arm with which the transmitting element8is actuated. The second distance24is considerably longer than the first distance23.

As long as the sleeve51has not yet come into contact engagement on the stop25, a pivoting of the throttle lever12by a pregiven amount effects an actuation of the transmitting element8by a pregiven path displacement. As soon as the sleeve51comes to lie against the stop25and the throttle lever12together with the intermediate lever15is pivoted about the second pivot axis17, a pivoting of the throttle lever12through the pregiven angle effects a shift of the transmitting element8by a considerably greater adjusting displacement which is dependent upon the ratio of the two distances (23,24) which can amount to, for example, twice the adjusted displacement which results when there is a pivoting of the throttle lever about the first pivot axis16.

The embodiment ofFIG. 3corresponds essentially to the embodiment ofFIG. 2. The same reference numerals identify the same components. In the transmitting unit shown inFIG. 3, a lever27coacts with the stop25on the intermediate lever15. The lever27is pivotally supported in the throttle lever12. In this way, an adjustment can be made starting at which actuating displacement of the throttle lever12, the throttle lever12and the intermediate lever15pivot together about the second pivot axis17.

FIG. 4shows a transmitting unit for another work apparatus having a handle31. The transmitting unit shown inFIG. 4can, for example, be provided for a hedge clipper. The handle31has a housing38wherein an intermediate lever35is pivotally journalled about a pivot axis37. A throttle lever32is pivotally supported about a pivot axis36on the intermediate lever35. The pivot axis36of the throttle lever32is at a distance43to an attachment point39of the transmitting element8with this distance being measured perpendicularly to the actuating direction34and being less than a distance44of the pivot axis37to the attachment point39of the transmitting element8.

The intermediate lever35is provided with a stop45which is configured on a band47. The band47can, for example, be a metal band. The band47is fixed to a slider46guided on the housing38. By actuating the slider46, the position of the stop45on the intermediate lever35can be shifted. The band47is guided on the intermediate lever35with a guide48so as to be longitudinally displaceable.

In the housing38, a throttle lever lock33is pivotally supported about a pivot axis41. The throttle lever lock33has a stop42against which the intermediate lever35rests. Furthermore, the throttle lever lock33has a hook40which blocks the throttle lever32in the unactuated position of the throttle lever lock33. To actuate the transmitting element8, the throttle lever lock33must first be pivoted about the pivot axis41. The hook40is pivoted away from the throttle lever32and the stop42from the intermediate lever35. When actuating the throttle lever32, the throttle lever32first pivots about the pivot axis36until the throttle lever32comes in contact with the stop45. Thereafter, the throttle lever32and the intermediate lever35pivot together about the pivot axis37. When pivoting about the pivot axis36, a lever arm is active which corresponds to the distance43. When pivoting about the pivot axis37, a lever arm results which corresponds to the longer distance44so that, in the range wherein the throttle lever42and the intermediate lever35pivot together about the pivot axis37, the transmitting element8is actuated with greater intensity. In this way, a nonlinear course results of the transmitting characteristic of the actuating displacement of the throttle lever32to the adjusting displacement of the throttle element7.

The transmitting unit shown inFIG. 5corresponds essentially to the transmitting unit ofFIG. 4. The same reference numerals identify the same components. The intermediate lever35of the transmitting unit shown inFIG. 5has a stop55which is configured on a set screw54. By screwing in or screwing out the set screw54, the position of the stop55can be changed and, in this way, the transmitting characteristic of the transmitting unit is influenced.

In the embodiment shown inFIG. 6, a stop60is provided on the intermediate lever35which stop is configured as a cam contour on an adjusting wheel59. By rotating the adjusting wheel59, the stop60can be adjusted and the transmitting characteristic influenced.

In the embodiment ofFIG. 7, a slider64is mounted on the intermediate lever35and this slider has a stop65. The slider64has teeth66which mesh with teeth69on the adjusting wheel68. A rotation of the adjusting wheel68effects a longitudinal displacement of the slider64and therefore an adjustment of the stop65. The slider64is supported by a guide67on the intermediate lever35.

In the embodiment shown inFIG. 8, a stop70is provided on a cam71. The cam71is fixed on a toothed wheel73which coacts with a toothed rack72. The toothed rack72is held on the intermediate lever35and meshes with gear teeth69on the adjusting wheel68. Setting the adjusting wheel68effects a longitudinal displacement of the toothed rack72and therefore a rotation of the gear wheel73. In this way, the position of the stop70can be shifted on the cam71.

The embodiment shown inFIG. 9corresponds essentially to the embodiment ofFIG. 2. The intermediate lever15lies between the stop22and a band76which is supported on a counter holder77on the housing18. In this way, the intermediate lever15cannot be actuated. A lock slider75is mounted on the band76. With an actuation of the lock slider75, the band76is pulled away from the counter holder77so that the intermediate lever15can be pivoted. The band76can, for example, be a metal band.

In the embodiment shown inFIG. 10, a lock slider80is provided as a lock device for the intermediate lever15. The lock slider can be actuated in the direction of the pivot axes16and17. As shown inFIG. 11, the lock slider80blocks the intermediate lever15in the locked position shown inFIG. 11so that an actuation of the intermediate lever15is not possible. When the lock slider80is pushed into the position shown inFIG. 12, then the intermediate lever15is released and an actuation of the intermediate lever15is possible.

In the embodiments shown inFIGS. 9 and 10, the throttle lever12can accordingly be actuated until the throttle lever12lies against the stop25of the intermediate lever15. A further actuation is not possible when the lock device is locked. If the lock device is released, then the intermediate lever15can also be pivoted. With a further actuation of the throttle lever12, throttle lever12and intermediate lever15pivot together about the pivot axis17.

A further embodiment of a lock device is shown inFIG. 13. Here, a lock slider85is provided which blocks a movement of the intermediate lever15. When the lock slider85is pulled outwardly from the housing18, then the intermediate lever15pivots in common with the throttle lever12about the pivot axis17.

InFIG. 14, a course of the adjusting displacement (a) on the throttle element7is shown as a function of the actuating displacement (s) of the throttle lever12. In a first range29of the actuating displacement (s), a first transmitting characteristic49to the adjusting displacement (a) is given which runs linearly. In this first region, the throttle lever12does not yet lie against the intermediate lever15. The throttle lever12pivots about the pivot axis16. In order to obtain a pregiven adjusting displacement (a) on the throttle element7, the throttle lever12must be pivoted through a comparatively large actuating displacement (s). In a second range30, a second transmitting characteristic50is given which likewise runs linearly. The second transmitting characteristic50has a steeper slope than the first transmitting characteristic49so that a nonlinear course of the transmitting characteristic results over the entire adjusting displacement (a). The slope of the curve, which reflects the transmitting characteristic, does not run continuously. In the first region29, a first slope is given and, in a second region30, a second steeper slope is given. In the second range30, the throttle lever12lies against the intermediate lever15and the two levers pivot about the pivot axis17. Because of the longer lever arm, only a comparatively slight actuating displacement (s) is needed for a pregiven adjusting movement on the throttle element7.

InFIG. 15, a further embodiment of a transmitting unit is shown which is mounted in a housing38. The transmitting unit has a throttle lever92which is pivotally supported about a first pivot axis101in the housing38. The first pivot axis101is formed on a pin which is guided in a slot100on the housing38. A tension spring98acts on the pin which presses the pin into the position shown inFIG. 15. The transmitting element8is fixed at an attachment point99on the throttle lever92. The pivot axis101is at a distance83to the attachment point99of the transmitting element8and this distance83is measured perpendicularly to the actuating direction34.

In the housing38, a throttle lever lock93is journalled which forms a stop94for the throttle lever92and blocks the throttle lever92in the unactuated position. In the housing38, a set screw96is mounted wherein a stop screw97is mounted. The stop screw97is so supported within the set screw96that it cannot rotate about the rotational axis of the set screw96. If the set screw96is rotated, then the stop screw97is displaced in its longitudinal direction in the housing38. A stop95is formed on the set screw96for the throttle lever92.

The throttle lever lock93is first actuated for actuating the throttle lever92. Thereafter, the throttle lever92can be actuated. The throttle lever92pivots about the first pivot axis101until the throttle lever92comes to lie against the stop95. With further actuation of the throttle lever92, a pivoting about the first pivot axis101is no longer possible because of the stop95. The stop95forms a second pivot axis which is at a distance84to the attachment point99and this distance84is greater than the distance83. For further actuation, the throttle lever92is pivoted about the stop95. The pin on which the throttle lever92is supported in the housing38moves in the slot100. The actuation of the throttle lever92takes place against the force of the tension spring98.

The transmitting characteristic of the transmitting unit ofFIG. 15is shown inFIG. 16. In a first range29of the actuating displacement (s), in which the throttle lever92pivots about the first pivot axis101, there results a first transmitting characteristic89having a flat course. In an adjoining second range30, the throttle lever92pivots about the pivot axis defined by the stop95. In this range, the lever arm for actuating the transmitting element8is greater so that a transmitting characteristic90having a steeper course results. In the second range, the lever arm is defined by the distance84.

In the embodiment of a transmitting unit shown inFIG. 17, a throttle lever102is pivotally supported about a pivot axis106on a housing18. An intermediate lever105is pivotally supported about a pivot axis107on the throttle lever102. In the housing18, a throttle lever lock103is supported which has a hook104and this hook blocks the throttle lever102in the unactuated position of the throttle lever lock103. The pivot axis107is arranged on the intermediate lever105between an attachment point109for the transmitting element8and a support roller108. A cam contour is formed on the housing18on which the support roller108slides during operation. The cam contour is formed by a first support surface110which runs evenly as well as a second cam contour111which likewise runs evenly but is at an angle to the first cam contour110. The cam contour111is formed on a wedge112. The wedge112can be displaced by a set screw113in the housing18so that the position of the cam contour111is adjustable.

During operation, the throttle lever lock103must first be actuated. Thereafter, the throttle lever102can be actuated. The intermediate lever105is displaced in its longitudinal direction when the throttle lever102is actuated. Because of the contact engagement of the support roller108on the first cam contour110, the longitudinal displacement of the intermediate lever105effects a displacement of the support roller108on the cam contour110which effects an actuation of the transmitting element8in the actuating direction34. Since the first cam contour110extends as a flat, a flat course of the transmitting characteristic results. As soon as the support roller108lies against the second cam contour111, there results a steeper course of the transmitting characteristic because the second cam contour111pivots the intermediate lever105to a greater extent about the pivot axis107.

In the embodiment shown inFIG. 18, an intermediate lever125is supported on the housing18and is displaceable on a guide127in its longitudinal direction. The intermediate lever125has a support roller128which coacts with a cam contour of a throttle lever122. The throttle lever122is pivotally supported about a pivot axis126in the housing18. On the throttle lever122, a first cam contour130as well as a second cam contour131are formed with the second cam contour131running inclined to the first cam contour130. The second cam contour131is formed on a wedge132which can be displaced relative to the throttle lever122via a set screw133. For this purpose, the set screw133is connected to the wedge132by a band135, especially, a metal band. The intermediate lever125is spring biased in its longitudinal direction relative to the housing18by a pressure spring134.

In addition, a throttle lever lock123is mounted on the housing18and has a hook124. The hook124blocks the intermediate lever125. The transmitting element8is fixed on an attachment point129on the intermediate lever125. The intermediate lever125has a support roller128which first slides on the first cam contour130when the throttle lever122is actuated with a released throttle lever lock123. The first cam contour130effects a displacement of the intermediate lever125inFIG. 18upwardly and therefore an actuation of the transmitting element8. In the region of the first cam contour130, a shift of the throttle lever122effects only a slight actuation of the throttle element7. As soon as the support roller128lies in contact engagement with the second cam contour131, the actuating element is actuated with intensity with this second cam contour131running considerably steeper. In this range, a slight displacement of the throttle lever122is sufficient for a large adjusting displacement of the transmitting element8.

InFIG. 19, an embodiment of a transmitting unit is shown which has a throttle lever142and a throttle lever lock143. The throttle lever lock143has a hook144which blocks the throttle lever142. The throttle lever142is pivotally supported about a pivot axis146in the housing18. An intermediate lever145is pivotally supported about a pivot axis147on the throttle lever142. The position of the pivot axis147can be changed via a set screw156. The transmitting element8is fixed at an attachment point149on the end of the intermediate lever145lying opposite the pivot axis147. The intermediate lever145has a cam contour157with which it slides on a support roller148when the throttle lever142is actuated. The support roller148is mounted at a fixed location on the housing18. Because of the geometry of the cam contour157, an actuation of the throttle lever142first effects only a slight actuation of the throttle element. With a further actuation of the throttle lever142, the path increases which the actuating point149passes through in the actuating direction34. After a pregiven actuating displacement, the intermediate lever145impacts a spring biased stop150. The stop150is resiliently biased by a pressure spring155in the direction toward the intermediate lever145and is fixed on the housing18. The stop150is mounted on a pin151which is held in a guide152so as to be displaceable in its longitudinal direction. The guide152is threadably engaged in a sleeve154. The sleeve154is fixed to an adjusting wheel153. When rotating the adjusting wheel153, the guide152screws into the sleeve154because the guide152is held so as to be non-rotatable relative to the housing18.

In the transmitting unit shown inFIG. 19and in view of the above, a nonlinear course of the adjusting displacement results as a function of the actuating displacement as well as a nonlinear course of the actuating force as a function of the actuating displacement. The slope of the curve, which shows the course of the actuating displacement, runs continuously while the slope of the curve, which indicates the course of the actuating force, does not run continuously.

In the embodiment of a transmitting unit shown inFIG. 20, a throttle lever162is supported about a pivot axis166in a housing18. The transmitting unit has a throttle lever lock163having a hook164which blocks the throttle lever162. The throttle lever162has a support roller168which acts on an arm of an intermediate lever165. The intermediate lever165is pivotally supported in the housing18about a pivot axis167. The transmitting element8is fixedly attached at an attachment point169on the arm of the intermediate lever165which lies opposite the support roller168. When pivoting the throttle lever162, the support roller168rolls off on a cam contour176on the intermediate lever165. In the embodiment, the cam contour176is configured to be even. However, the cam contour176can assume any desirable form in order to achieve another transmitting characteristic.

In the housing18, a stop170is supported which is held on a toothed rack171. The stop170is resiliently biased with a pressure spring175opposite a guide174. The toothed rack171meshes with teeth173of an adjusting cam172. The adjusting cam172lies against the transmitting element8.

During operation, the throttle lever lock163is first actuated. Thereafter, the throttle lever162can be pivoted. The intermediate lever165is pivoted about the pivot axis167and the transmitting element8is actuated. As soon as the intermediate lever165lies against the stop170, a further actuation of the throttle lever162effects, in addition to an actuation of the transmitting element8on the attachment point169, also a movement of the toothed rack171and therewith a movement of the adjusting cam172. The adjusting cam172deflects the transmitting element8transversely to the actuating direction34of the transmitting element8and effects thereby an additional actuation. In this way, a nonlinear course of the transmitting characteristic of the actuating displacement and the actuating force of the throttle lever results.

In the embodiment shown inFIG. 21, the throttle lever162acts via a cam contour178on a cam contour176of the intermediate lever165. The intermediate lever165is pivotally supported about a pivot axis167. The cam contour176of the intermediate lever165is mounted between the pivot axis167and the attachment point169of the transmitting element8on the lever165. The arm of the intermediate lever165lies facing away from the pivot axis167. A stop180acts on this arm of the intermediate lever165starting at a pregiven actuating displacement with this stop being configured as a pressure spring. The pressure spring is guided on the housing18on a guide pin179. The actuating force increases as soon as the intermediate lever165lies against the stop180. A desired nonlinear transmitting characteristic can be adjusted via the configuration of the cam contours178and176.

The embodiment ofFIG. 22corresponds essentially to the embodiment ofFIG. 21. However, the pivot axis167is mounted between the cam contour176and the attachment point169. The stop180engages between the attachment point169and the pivot axis167. The transmitting element8is redirected on two direction-changing elements181.

A further embodiment of a transmitting unit is shown inFIG. 23. The configuration of the transmitting unit shown inFIG. 23is similar to the transmitting unit ofFIG. 19. The same reference numerals identify the same components. The transmitting element8is mounted on an attachment point189on the intermediate lever145. The attachment point189is configured on a pin which is guided in a guide path188in a guide piece184. The guide piece184is movably mounted in the housing18on a guide183. To adjust the position of the guide piece184, an adjusting wheel186with teeth187is provided which meshes with teeth185on the guide piece184. The guide path188has a first section which has a slight slope and a second section having a steep slope. When actuating the throttle lever142, the pin moves first in the first range on the attachment point189. The transmitting element8is only slightly actuated. As soon as the pin reaches the second region of the guide path188, the transmitting element8is strongly actuated in the same actuation of the throttle lever142. Other configurations of the guide path188can be provided.

In the embodiment shown inFIG. 24, a second intermediate lever195is mounted on the intermediate lever145. The second intermediate lever195is pivotally supported on a pivot axis193on the intermediate lever145. The second intermediate lever195is guided with a first guide pin199in a first guide path197and with a second guide pin200in a second guide path198. The two guide paths197and198are formed in a guide piece194. The position of the guide piece194in the housing18can be shifted via an adjusting wheel186. The transmitting element8is fixed on the second intermediate lever195at an attachment point189and is guided via a direction-changing roller196in the housing. The length of the first guide path197parallel to the actuating direction at the attachment point189is shorter than the length of the second guide path198. The second guide path198runs in a second section along a circular arc about the end point of the first guide path197. In this way, an amplified actuation of the transmitting element8is achieved. Other configurations of the guide paths197and198can be provided.

In the embodiment shown inFIG. 25, a throttle lever202is pivotally supported about a pivot axis206in the housing18. A throttle lever lock143blocks the throttle lever202with a hook144in the unactuated position. The transmitting element8is fixed to an attachment pin209on the throttle lever202. The attachment pin209is guided in a guide path210in the throttle lever202and a second guide path211on the housing18. The two guide paths210and211lie at an angle to each other so that, with an actuation of the throttle lever202, a forced guidance of the attachment pin209results. The guide paths210and211run in an arc. In this way, there results a nonlinear course of the transmitting characteristic of the actuating displacement of the throttle lever202to the movement of the transmitting element8. The attachment pin209moves with an actuation of the throttle lever202in the guide paths210and211. In this way, the transmitting element8is actuated in the actuating direction34. The throttle lever202is spring supported via a spring203. The spring203is configured as a leaf spring and is fixed at an adjustment element204. The adjustment element204has teeth205which mesh with teeth207on an adjusting wheel208. By rotating the adjusting wheel208, the position of the adjusting element204is shifted and therefore the pretension of the leaf spring203is shifted. For this reason, the actuating force can be adjusted via the adjusting wheel208. With a corresponding configuration of the two guide paths210and211, a desired nonlinear transmitting characteristic of the actuating movement of the throttle lever202on the adjusting movement of the adjustment element is realized.

In the embodiment shown inFIG. 26, a throttle lever272is supported in a housing18on a pivot axis276. A transmitting element8is fixed on an attachment point271on the throttle lever272. A set screw304is mounted on the throttle lever272and, via this set screw, the position of a sleeve308can be adjusted. The sleeve308coacts with a stop305. The stop305is fixedly connected to an actuating rod303and the actuating rod303can be displaced via a lock lever302. The stop305is resiliently biased by a pressure spring306in a direction toward the locked position which is shown inFIG. 26. The stop305is guided on a guide307fixed on the housing.

A throttle lever lock273is fixed on the housing18and this throttle lever lock blocks the throttle lever272with a hook274. The throttle lever lock273is first actuated to actuate the throttle lever272. Thereafter, the throttle lever272can be actuated until the sleeve308lies against the stop305. For further actuation, the lock lever302must first be actuated against the force of the spring306so that the stop305moves outside of the region of the sleeve308and a further actuation of the throttle lever272is possible.

On the throttle lever272, a deflection cam301is mounted which comes into engagement with the transmitting element8with a further actuation of the throttle lever272and the transmitting element8is deflected in a direction perpendicular to the actuation direction34. In this way, an actuation of the transmitting element8takes place. As soon as the deflection cam301comes into engagement with the transmitting element8, a stronger actuation of the throttle element7results thereby. In this way, a nonlinear transmitting characteristic is achieved.

FIGS. 27 to 31show embodiments of actuating units wherein two actuating elements are provided for a transmitting element8.

In the embodiment shown inFIG. 27, a first throttle lever212is pivotally supported on the housing18about a pivot axis216. The first throttle lever212has a set screw215via which a sleeve225can be displaced. The sleeve225coacts with a stop223fixed on the housing. In this way, the adjusting displacement of the first throttle lever212is limited. The transmitting unit further includes a second throttle lever217which can be actuated in the conventional manner by the index finger of the operator. The second throttle lever217is pivotally supported about a pivot axis221in the housing18and lies, in the unactuated position, against a stop222on the housing18. The transmitting element8is fixed to an attachment point219on the second throttle lever217. The second throttle lever217has an entraining element220which lies against the first throttle lever212. Next to the transmitting element8and in the unactuated position (FIG. 27) of the throttle levers212and217, a deflecting cam224is mounted at a distance to the transmitting element8on the housing18. The transmitting unit includes a throttle lever lock213, a first hook214for the first throttle lever212and a second hook218for the second throttle lever217.

To actuate the throttle levers212and217, the throttle lever lock213must first be actuated so that the hooks214and218release the throttle levers212and217. The first throttle lever212is actuated for a fine adjustment of the adjusting displacement. The first throttle lever212acts via the entraining element220on the second throttle lever217and pivots the second throttle lever217about the pivot axis221. In this way, the transmitting element8is actuated slightly. If the transmitting element8is to be actuated strongly, then the second throttle lever217is actuated. This effects a comparatively large pivot displacement and therewith a strong actuation of the transmitting element8. As soon as the transmitting element8lies against the deflecting cam224, an additional deflection of the transmitting element8in a direction perpendicular to the actuating direction34is achieved which effects an additional actuation of the throttle element7. In this way, a nonlinear transmitting characteristic is achieved.

In the embodiment shown inFIG. 28, a first throttle lever212and a second throttle lever217are likewise provided. The first throttle lever212has an actuator226which deflects the transmitting element8in a direction perpendicular to the actuating direction34and presses the transmitting element8against a housing-fixed deflection cam224. In this way, only a slight actuation of the transmitting element8is achieved when actuating the first throttle lever212. With actuation, the second throttle lever217pivots about a pivot axis221and, in this way, actuates the transmitting element8fixed on the attachment point219. On the second throttle lever217, a slider228is provided which coacts with a stop227on the housing18. The slider228fixes the end position of the second throttle lever217. The slider228in this way makes possible a displacement of the end position of the second throttle lever217.

The transmitting unit shown inFIG. 29has a first throttle lever232which is pivotally supported about a pivot axis236on the housing18. A sleeve231is mounted on the first throttle lever232and this sleeve coacts with a stop244fixed on the housing. The position of the sleeve231can be changed via a set screw245. The transmitting element8is fixed on the first throttle lever232at an attachment point239. In the unactuated position, the throttle lever232lies against a stop246fixed on the housing. In the housing, the transmitting element8is guided via: a first direction-changing roller242fixedly mounted on the housing; a second direction-changing roller238mounted on a second throttle lever237; and, a third direction-changing roller243fixedly mounted to the housing.

The transmitting unit includes a throttle lever lock233having a hook234which blocks the throttle lever232in the unactuated position of the throttle lever lock233. With a slight actuation of the transmitting element8, the first throttle lever232is actuated after releasing the throttle lever lock233. In order to provide a large adjusting displacement, the second throttle lever237is provided which is pivotally supported about a pivot axis241in the housing18. The second throttle lever237deflects the transmitting element8transversely to the longitudinal direction of the transmitting element8via a movement of the direction-changing roller238and thereby effects a large adjusting movement at the adjusting element. The second throttle lever237has a latch projection240which coacts with a latch hook235fixed to the housing so that the second throttle lever237can be blocked in the completely actuated position.

The embodiment shown inFIGS. 30 and 31corresponds functionally essentially to the embodiment ofFIG. 29. In the embodiment ofFIGS. 30 and 31, the second throttle lever237is pivotally supported about a pivot axis241which is perpendicular to the pivot axis236of the throttle lever232. As shown inFIG. 31, the second throttle lever237acts via an intermediate lever247on a deflecting lever248. The intermediate lever247pivots the deflecting lever248about a pivot axis249which is parallel to the pivot axis236of the first throttle lever232. A deflecting roller250is mounted on the deflecting lever248and this deflecting roller acts on the transmitting element8transversely to the actuating direction34. The transmitting element8is pressed against a direction-changing roller243fixed on the housing. The actuation of the throttle lever232thereby provides another transmitting characteristic than the actuation of the second throttle lever237so that, overall, a nonlinear transmitting characteristic results.

Embodiments of transmitting units are shown inFIGS. 32 and 33wherein the transmission of the adjusting movement of a throttle lever252on a throttle element7takes place electrically. For this purpose, both transmitting units include electrical adjusting devices257. An electrical adjusting device can, for example, be a potentiometer or the like having a voltage divider circuit. A throttle lever lock253is provided in each embodiment which blocks the throttle lever252with a hook254in an unactuated position of the throttle lever lock253.

In the embodiment ofFIG. 32, a sleeve251is mounted on the throttle lever252which sleeve coacts with a stop258fixed to the housing and the position of the sleeve can be changed via a set screw255. The sleeve251delimits the maximum actuating displacement of the throttle lever252. The throttle lever252is pivotally supported about a pivot axis256in whose region the electric adjusting device257is mounted. The electric adjusting device257is grounded with a ground line259. A positive line260is provided which supplies an input voltage. A control line261supplies a control signal which corresponds to the position of the throttle lever252. This control signal is supplied to a control262and is converted into an output signal based on a pregiven transfer characteristic270and, based on this output signal, an actuator266for the throttle element7is actuated. The actuator266can, for example, be a positioning motor.

In the embodiment ofFIG. 33, the control line261is connected to a control and an actuator. The positive line260is connected to the adjusting device257via a switch263and a control slider265. The switch263is configured as an interrupt switch and is activated when actuating the throttle lever lock253so that only with an actuated throttle lever lock253, a current can flow to the electric adjusting device257. The control slider265permits an adjustment of the voltage supplied to the electric adjusting device257. An interrupt switch264is arranged in the control line261and when the switch264is actuated, no signal is conducted any longer via the control line261to the control262.

Additional control elements or switching elements can be provided for an electric transmission.

In the embodiments ofFIGS. 34 to 37, the actuating force referred to the actuating displacement is not constant. The transmitting unit shown inFIG. 34is similar to the functional configuration of the transmitting unit ofFIG. 26. In the transmitting unit shown inFIG. 34, an elongated slot opening278is provided on the throttle lever272wherein an end of a tension spring277is mounted. The second end of the tension spring277is mounted in an elongated slot281provided fixedly in the housing. The position of the housing-fixed elongated slot281can be adjusted via an adjusting wheel280. A stop275is formed on the elongated slot281. As soon as the throttle lever272has gone through a pregiven actuating displacement, the spring277lies on the stop275. With a further actuation, the force of the spring277must be overcome. In this way, a slight actuating force first results which increases greatly as soon as the spring277comes into engagement.

In the embodiment shown inFIG. 35, a throttle lever282is pivotally supported about a pivot axis286in a housing38. The transmitting element8is fixed at an attachment point289on the throttle lever282. A deflecting cam288is mounted on the throttle lever282via a set of teeth287. The transmitting unit has a throttle lever lock283which forms a stop284for the throttle lever282. On the housing38, in the region of the deflecting cam288, a stop285is provided which is resiliently biased via a spring297relative to the housing. The transmitting element8lies on the longitudinal side, which lies opposite the deflecting cam288, on a direction-changing pin290. After actuation of the throttle lever lock283, the throttle lever282can be actuated and is pivoted about the pivot axis286. The deflecting cam288is pivoted via the teeth287. As soon as the deflecting cam288comes into engagement with the stop285, the force of the spring297must be overcome for further actuation of the throttle lever282so that the actuating force increases. At the same time, the deflecting cam288actuates the transmitting element8in a direction perpendicular to the actuating direction34and effects an additional actuation of the transmitting element8. In this way, an increasing actuating force as well as an increasing adjusting displacement at the throttle element7is achieved.

A torsion spring291is mounted on the housing18in the embodiment shown inFIG. 36. A first end295of the torsion spring291is mounted in a guide slot293in the throttle lever272. This is also shown inFIG. 37. A second end296of the torsion spring291lies on a stop294(FIG. 37) which is configured so as to be fixed to the housing. The stop294can also be displaceably configured relative to the housing18. When actuating the throttle lever272, the first end295of the torsion spring291first slides in the guide slot293, until it comes into engagement with a stop300formed at the end of the guide slot293. For further actuation of the throttle lever272, the force of the torsion spring291must be overcome. In this way, the actuating force increases greatly.

The course of the actuating force (f) as a function of the actuating displacement (s) is shown inFIG. 38. In a first range29, wherein the spring is not yet actuated, there results a first transmitting characteristic309. In a second range30, the force of the spring must be overcome so that a steeper slope of the characteristic line results. A second transmitting characteristic310results.

FIGS. 39 to 43show an improvement of the embodiment ofFIG. 4. The same reference numerals identify corresponding components. InFIGS. 39 to 43, the position of the slider46is shown schematically in plan view above the section view of the handle31.

In the embodiment ofFIGS. 39 to 43, the slider46has the positions which are assigned to different positions of the stop45wherein the throttle lever32can impact against stop45. In addition, the slider46has an inactive position shown inFIGS. 39 and 40. InFIG. 39, the throttle lever32is unactuated. The slider46is disposed in a position wherein the stop45is inactive. When actuating the throttle lever lock33and the throttle lever32, the throttle lever32pivots about its pivot axis36into the completely actuated position shown inFIG. 40. The throttle lever32pivots past stop45. The intermediate lever35is not actuated. The actuation of the transmitting element8takes place in accordance with an essentially linear transmission characteristic.

InFIGS. 41 to 43, the slider46is shown in a position whereat the stop45is active.FIG. 41shows the throttle lever32in the unactuated position. The slider46is disposed in a center position wherein the stop45comes into engagement with the throttle lever32. If the throttle lever32and the throttle lever lock33are actuated, then the throttle lever32first pivots about the pivot axis36until the stop45lies against the throttle lever32. If the throttle lever32is actuated further out of the half-throttle position shown inFIG. 42, then the throttle lever32comes to lie against stop45and pivots together with the intermediate lever35about the pivot axis37of the intermediate lever35into the full load position shown inFIG. 43. In this position of the slider46, a nonlinear transmission characteristic of the actuating displacement results. With the slider46, the intermediate lever35with the stop45, which effects the nonlinearity of the transmission characteristic, can be shifted into an inactive state. In addition, the nonlinearity can be adjusted via the position of the stop45with the slider46.

In the further embodiments shown, a switch element can also be provided with which the unit, which effects the nonlinearity of the transmitting characteristic, can be switched into an inactive state. A switch element of this kind can especially be provided also with an electric transmission.