Abstract:
A shift mechanism for motor vehicle transmissions having a selector lever ( 14 ) supported in bearings in a housing ( 10 ) that can be pivoted about a transverse axle ( 24 ) in longitudinal direction and about a longitudinal axle ( 50 ) in the transverse direction. At the selector lever ( 14 ) or at components ( 26, 82 ) moving with the selector lever ( 14 ) on the one hand and on components ( 96, 100 ) fixed to the housing on the other hand, position indicating elements ( 128, 130 ) or sensors ( 102-114, 120-126 ) are arranged in such a way that the sensors ( 102-114, 120-126 ) respond upon the approach to position indicating elements ( 128, 130 ) and transmit signals to a transmission control arrangement corresponding to the pivoted position of the selector lever ( 14 ). In order to make possible an automatic detection of the position of the selector lever ( 14 ) during any desired movement in the longitudinal and transverse directions, the position indicating elements ( 128, 130 ) and the sensors ( 102-114, 120-126 ) are arranged essentially in planes that are approximately parallel to the planes established by the pivoting path of the selector lever in the longitudinal direction and by the pivoting path of the selector lever in the transverse direction.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     The invention concerns a shift mechanism for motor vehicle transmissions with a selector lever supported in bearings in a housing, that can be pivoted about a longitudinal axle in the transverse direction and about a transverse axle in the longitudinal direction. Position indicating elements or sensors are arranged at the selector lever or at components moving with the selector lever on the one hand, and at components fixed to the housing on the other hand, in such a way that the sensors respond upon the approach to position indicating elements and transmit signals to a transmission control corresponding to the pivoted position of the selector lever. 
     U.S. Pat. No. 5,406,860 describes a transmission selector lever arrangement with a lever supported in bearings in a housing which can be pivoted in longitudinal and transverse direction within a guide slot, that is provided with a main slot and three subordinate slots parallel to the main slot and connected by transverse slots with the main slot. A sector component is supported in bearings, free to pivot, between a housing wall and the lever and is forced by a spring into a central position. By pivoting the lever within a transverse slot in the direction of a subordinate slot, the lever can be brought into engagement with the sector component so that both can be pivoted together in the longitudinal direction, as long as the particular subordinate slot permits. The lever and the sector component each carry a magnet. Hall effect sensors are arranged at the housing wall in such a way that when the lever is pivoted within a subordinate slot and upon the approach of the magnets to the Hall effect sensors, signals are generated that in each case correspond to the position of the lever. The sensor signals, in particular, can be used to determine in which subordinate slot the lever is located and which position it occupies within the subordinate slot. The known arrangement of the magnets and sensors, however, does not permit the detection of varying lever positions within any configuration of guide slots. 
     The object of the invention is seen as that of defining a shift mechanism of the aforementioned type that permits an automatic detection of the position of the selector lever in the longitudinal and transverse direction during any desired movement of the selector lever in the longitudinal or transverse direction. 
     According to the invention, the position indicating elements and the sensors are arranged in essentially two planes that are oriented approximately parallel to the planes that are defined, on the one hand by the pivoting path in the longitudinal direction, and on the other hand by the pivoting path in the transverse direction. This makes it possible to detect the position of the selector lever in the longitudinal direction as well as in the transverse direction. By a corresponding arrangement of position indicating elements on the one hand, and of sensors on the other hand, any desired position of the selector lever can be selected for a detection of the position in both directions of movement. 
     A preferred embodiment of the invention provides for the provision in the housing of a pivoting component that can be pivoted longitudinally about a transverse axle fixed to the housing. The pivoting component, in turn, contains a longitudinal axle about which the selector lever can be pivoted. Thereby the selector lever can be pivoted together with the pivoting component in the longitudinal direction and be pivoted relative to the pivoting component in the transverse direction. 
     Since thereby the pivoting component moves within a fixed pivoting path, that is defined by the transverse axle, a spacing from a housing wall extending perpendicular to the transverse axle remains constant. Thereby a constant spacing between the plane of the position indicating elements and the plane of the sensors can be maintained. Here there is a particular advantage in fastening at least one magnet to the pivoting component and to arrange at least one sensor in the region of the opposite housing wall in such a way that upon pivoting the pivoting component, the magnet enters the detection region of the sensor. The sensors applied here are preferably Hall effect sensors. In principle it would also be possible to fasten the Hall effect sensors to the pivoting component and the magnets as stationary parts to the housing, however, the routing of electrical lines to the stationary Hall effect sensors is simpler. 
     In order to be able to continuously detect the rotational position of the selector lever in the longitudinal direction, a preferred further development of the invention proposes that the rotational position of the selector lever be transmitted to a rotational transmitter. This can be performed, for example, by fastening a gear or a gear segment to the pivoting component which interacts with a further gear or gear segment, where the further gear or gear segment is connected by a shaft to a rotational transmitter. By appropriate dimensioning of the pitch circles of the gears a desired transmission ratio between the selector lever and the rotational transmitter can be achieved. 
     The application of a rotational transmitter is particularly advantageous if the shift mechanism is to be employed to transmit control signals for a vehicle drive with an infinitely variable transmission. Here, for example, the transmission ratio of the drive can be provided as input analogous to the position of the selector lever  14 , which is detected by the rotational transmitter. 
     Preferably the rotational transmitter employed may be a non-contacting transmission, for example, a continuous rotational sensor with Hall effect element such as is offered, for example, by the company AB Electronics. 
     It is desirable that the operator feel at what point certain lever positions are reached or passed while the selector lever is being pivoted. For this purpose a preferred embodiment of the invention suggests that the pivoting components or the selector lever carry detent means that interact with detent elements formed fixed to the housing or on the pivoting component, in order to define detent positions during the pivoting of the selector lever in the longitudinal direction or in the transverse direction. 
     There is a particular advantage in the shift mechanism that can be applied to various applications, for example, for selector levers guided in different guide slots, where in any case minor, simple compliance measures must be taken. This permits the manufacture of shift mechanisms in relatively large volume and permits a reduction in manufacturing cost and a rational supply system. In order to attain these goals a preferred embodiment of the invention proposes that the detent elements fixed to the housing and/or the detent elements arranged on the pivoting component be configured on components that can be fastened to or interchanged with the housing or the pivoting component. Such components may, for example, be interchangeable plates with a detent scheme, for example, with one or more recesses in which a ball of the detent means engages. By means of the interchangeable longitudinal and transverse detents, a universally useful shift mechanism, also called shift unit, can be attained. 
     The detent means is preferably a ball pressure element, whose ball interacts with a detent element configured as a cam surface that may, for example, contain recesses and/or projections. The ball pressure element contains a spring-loaded ball, that can be depressed. 
     According to a preferred further embodiment of the invention, the housing contains a support component supported in bearings that can be pivoted about a longitudinal axle fixed to the housing which participates in the transverse pivoting movement of the selector lever relative to a driver. The support component carries at least one position indicating element, in particular a magnet, which intrudes during the pivoting of the support component into the detection region of at least one sensor fixed to the housing, preferably a Hall effect sensor. 
     A simple, preferred configuration of the driver is provided by a fork-shaped receptacle on the support component that engages a strap of the selector lever extending in the direction of the transverse axle which can be slid within the receptacle. This permits a pivoting of the selector lever in the longitudinal direction in which the strap is shifted in longitudinal direction within the fork-shaped receptacle, without any pivoting motion of the support component. However, if the selector lever is moved in transverse direction, the strap transmits the pivoting motion to the support component, and pivots this along with the selector lever. 
     A further particularly preferred embodiment of the invention, that makes it possible for the shift mechanism to comply with different applications, provides for at least one adapter element, that can be fastened to the housing and is interchangeable, on which at least one sensor is arranged, in particular a Hall effect sensor. For the particular applications in each case adapter elements can be employed, that are equipped variously, with differing sensor arrangements. The adapter elements can be mounted very simply on the housing, for example, by bolting or by engaging detents, and are easily interchangeable. 
     Preferably the adapter element may be configured as a circuit board or an integrated circuit, that carries further electrical components in addition to the sensors, for example, for the processing of sensor signals. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawing shows an embodiment of the invention on the basis of which the invention as well as further advantages and advantageous further developments and embodiments of the invention shall be explained and described in greater detail in the following. 
     FIG. 1 shows a perspective view of a shift mechanism according to the invention, in which housing, guiding gate and shift knob are illustrated separately. 
     FIG. 2 shows an exploded view of a shift mechanism according to FIG.  1 . 
     FIG. 3 shows a circuit board with Hall effect sensors for the detection of the shift lever position in the longitudinal direction. 
     FIG. 4 shows a circuit board with Hall effect sensors for the detection of the shift lever position in the transverse direction. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The shift mechanism shown in FIGS. 1 and 2 generally contains a housing  10 , a guide gate  12  that covers the top of the housing and a selector lever  14  at whose free end extending upward through the guide gate  12 , out of the housing  10 , a shift knob  16  is fastened that can be operated by an operator and includes a control head  17 , not explained here in any greater detail. The housing  10  contains a base housing  18  and a side cover plate  20 , (shown in FIG. 2) that can be bolted to the base housing  18  and through which the base housing  18  can be closed at the side. A transverse axle  24  is supported in bearings on an end face wall  21  of the base housing  18  and on the side cover plate  20  located opposite at a bearing location  22 . A pivoting component  26 , also called a quadrant, is supported in bearings, free to pivot on the transverse axle  24 . On the transverse, axle  24 , between the pivoting component  26  and the end face wall  21  of the base housing  18 , two steel disks  28 ,  30  and a friction disk  32 , located between them, are arranged. These represent a friction clutch that restricts the pivoting motion of the pivoting component  26  in the longitudinal direction, so that the pivoting component  26 , and with it the selector lever  14 , remains in its immediate longitudinal position as long as no force is applied to move it. 
     A first gear segment  34  is fastened to the pivoting component  26 , its axis of rotation coincides with the transverse axle  24 . The first gear segment  34  meshes with a second gear segment  36 , which is connected, fixed against rotation, to the input shaft  38  of a rotational transmitter  40 . Thereby the pivoting motion of the pivoting component  26  is transmitted to the rotational transmitter  40 . The rotational transmitter  40  is a non-contacting rotational transmitter that rotates continuously and contains Hall effect sensors. The rotational transmitter signals correspond to the immediate pivoted position of the selector lever  14  in the longitudinal direction and are transmitted to a transmission control arrangement, not shown in any greater detail. 
     A recess of the pivoted component  26 , not shown in any greater detail, engages a detent means that consists of a ball pressure element  60  and is oriented parallel to the transverse axle  24 . The ball pressure element  60  generally contains a sleeve within which a compression spring is arranged which forces a ball axially outward. Opposite the ball an interchangeable detent plate  62  is fastened to the end face wall  21  of the base housing  18 , which in the present embodiment is provided with only one detent bore  64 . At a certain pivoted position of the selector lever  14  in the longitudinal direction (and with it the pivoted component  26 ) the ball of the ball pressure element  60  engages the detent bore  64  and forms a detent position, that can be felt by the operator during the pivoting of the selector lever  14 . By the use of differing detent plates  62 , with differing numbers and positions of detent bores, various differing detent positions for the longitudinal pivoting movement of the selector lever  14  can be established, without significant cost. 
     The lower region of the selector lever  14 , that extends away from the shift knob  16 , extends in two legs  42 ,  44  spaced at a distance from each other, whose lower, free ends are connected to each other by a strap  46  or a fork. When the shift mechanism is installed, the pivoting component  26  is located in the region between the two legs  42 ,  44 . A longitudinal bore  48  of the pivoting component  26  engages a longitudinal axle  50 , whose both ends engage bores  52 ,  54  in the two legs  42 ,  44 , so that the selector lever  14  is supported on the pivoting component  26  and can be pivoted in the transverse direction with respect to the pivoting component  26 . Furthermore two helical springs  56 ,  58  are provided that force the pivoting component  26  to the left when viewed looking forward, that is, into its park position. 
     A detent in the form of a ball pressure element  68  is inserted into an axial bore  66  of the selector lever  14 , the detent is configured similar to the ball pressure element  60  previously described. The ball of the ball pressure element  68  projects into the space between the two legs  42 ,  44  and interacts with a detent surface  70  of the pivoting component  26 . A detent projection  72  projecting upward, shown as a line, oriented parallel to the longitudinal axle  50  extends over the detent surface  70 . For the ball pressure element  68  the detent projection  72  forms an obstacle that can be overcome, through which the operator feels during the pivoting of the selector lever  14  in the transverse direction when a certain lever position is traversed. This simplifies the operation of the selector lever  14 . The detent surface  70  is developed on an interchangeable component that is fastened to the pivoting component  26 . By the use of various interchangeable components, with variously configured transverse directed detent projections, raised contours, humps, ramps or recesses, various tactile obstacles can be provided by very simple means. Thereby it is possible to conform to any desired requirement that can be provided, this can be accomplished without any particular expense and without the necessity of a fundamental modification of the shift unit. 
     In a side wall  74  and in an intermediate wall  76  of the base housing  18 , bearing locations  78 ,  80  are provided in which a support component  82  with its rotational axle  84 , fixed to the housing, is supported in bearing, free to pivot. The support component  82  is provided with a fork-shaped receptacle  86  that is open upward and extends in the transverse direction, which engages the strap  46  of the selector lever  14 . During the pivoting of the selector lever  14  in the transverse direction about the longitudinal axle  50 , the pivoting movement is transmitted over the strap  46  and the receptacle  86  to the support component  82 , so that this is pivoted about the longitudinal axle  84 , fixed to the housing. When the selector lever  14  is pivoted in the longitudinal direction about the transverse axle  24 , the strap  46  slides in its longitudinal direction within the receptacle  86  without pivoting the support component  82 . 
     The guide gate  12  shown in FIG. 1 contains a slot in which the selector lever  14  is guided. The slot contains a neutral channel extending in the transverse direction that connects a neutral position N with a park position P. From the neutral channel, a first forward channel F 1  extending in longitudinal direction branches off. Offset from the first forward channel and in the opposite direction from the neutral channel, a reverse channel R branches off and extends in the longitudinal direction. The first forward channel F 1  jogs into a second forward channel F 2  offset therefrom and also extending in the longitudinal direction. When the selector lever  14  is moved within the forward channels F 1  and F 2  and the reverse channel R, the rotational transmitter  40  is rotated and transmits corresponding signals to a transmission control arrangement in order to control the vehicle speed corresponding to the position of the selector lever. 
     An opening  94  in the side wall  74  of the base housing  18  can be closed by a first integrated circuit  96 . An opening  98  in the cover plate  20  can be closed by a second integrated circuit  100 . FIGS. 3 and 4 show the two integrated circuits  96 ,  100  from the interior of the housing. As can be seen in FIG. 3, on the second integrated circuit  100  seven Hall effect sensors  102 ,  104 ,  106 ,  108 ,  110 ,  112 ,  114  are arranged in an arc. Two fastening holes  116 ,  118  are used for the mounting on the cover plate  20 . According to FIG. 4, on the first integrated circuit  96  four Hall effect sensors  120 ,  122 ,  124 ,  126  are arranged in an arc. Here too, two fastening holes  127 ,  129  are provided that are used for the fastening on the side wall  74 . Both integrated circuits  96 ,  100  are equipped with further electrical components that are indicated in FIGS. 3 and 4 as rectangles, but are not described in any further detail. These are resistors, voltage regulators, integrated electronic components and the like which are used for signal processing for the Hall effect sensors  102 - 114  and  120 - 126 . 
     The support component  82  carries an extension arm  88  that extends generally upward at whose upper end a position indicating element such as a permanent magnet  128  is fastened. When the support component  82  is pivoted, the permanent magnet  128  moves parallel to the surface of the first integrated circuit  96  along an arc on which the Hall effect sensors  120 ,  122 ,  124 ,  126  of the first integrated circuit  96  are arranged. When the selector lever  14  is pivoted in the transverse direction, the magnetic field of the permanent magnet  128  is detected successively in each case by one of the Hall effect sensors  120 ,  122 ,  124 ,  126  so that these transmit control signals to a transmission control arrangement corresponding to the position of the selector lever  14 . When the selector lever  14  is in the neutral position N the Hall effect sensor  120  responds to the magnetic field of the permanent magnet  128 , when the reverse channel R is reached the Hall effect sensor  122  responds, when the first forward channel F 1  is reached the Hall effect sensor  124  responds and when the selector lever is in the park position P then the Hall effect sensor  126  responds. 
     The pivoting component  26  also carries a position indicating element such as a permanent magnet  130  in its upper region. When the pivoting component  26  is pivoted the permanent magnet  130  moves parallel to the surface of the second integrated circuit  100  along an arc on which the Hall effect sensors  102 ,  104 ,  106 ,  108 ,  110 ,  112 ,  114  of the second integrated circuit  100  are arranged. When the selector lever  14  is pivoted in the longitudinal direction, the magnetic field of the permanent magnet  130  is detected successively in each case by one or more of the Hall effect sensors  102 ,  104 ,  106 ,  108 ,  110 ,  112 ,  114  so that these transmit control signals to a transmission control arrangement corresponding to the position of the selector lever  14 . The control signals of the Hall effect sensors  102 ,  104 ,  106 ,  108 ,  110 ,  112 ,  114  reveal, for example, whether the selector lever  14  is located in the end position of the reverse channel R, the park position P, the neutral channel, the neutral position N, in the transition region between the first and the second forward channels F 1  and F 2  or the end position of the second forward channel F 2 . 
     A micro-switch can be mounted at the location  132  of the cover plate  20 , whose trigger element lies in the pivoting path of the selector lever  14  and responds when the park position P is reached. Furthermore a micro-switch can be mounted at the location  134  of the base housing  18 , whose trigger element also lies in the pivoting path of the selector lever  14  and responds when the neutral position N is reached. The signals of the micro-switches are transmitted to a transmission control arrangement, not shown, and evaluated there. 
     The shift unit shown with the integrated shift elements for the pre-selection of the vehicle speed as well as an actuation device for manual throttle control (rotational transmitter  40 ), is a group of components for the manual, infinitely variable shifting of an infinitely variable transmission under load in agricultural tractors. 
     Although the invention has been described in terms of only one embodiment, anyone skilled in the art will perceive many varied alternatives, modifications and variations in the light of the above description as well as the drawing all of which fall under the present invention.