Abstract:
The invention relates to a rotary control device intended, in particular, for being fixed to a handle of a remote control of a heavy-construction machine, comprising: a housing to be fastened to the handgrip in a fixed manner; a moving actuating part that rotates relative to the housing about an axis; first means for generating a rate control signal starting from the angular position of the moving actuating part, comprising a moving part driven by the actuating part and a part fixed to the housing, the moving actuating part being able to be driven by the operator in two opposite directions starting from a home position up to elastic means.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a rotary control device designed in particular to be attached to a handle of a remote control of a heavy construction machine. 
       DESCRIPTION OF THE PRIOR ART 
       [0002]    A remote control of a heavy construction machine comprises, in a known manner, a handle that can be moved according to at least one degree of freedom relative to a support, the movement of this handle allowing an operator to control at least one receiving member external to the remote control. 
         [0003]    In order to increase the number of receiving members that can be controlled or to make it possible to vary the control instructions, it is a known practice to add to the remote control devices that can be controlled by the fingers of the user, and in particular devices of the proportional type. 
         [0004]    Among these devices, it is a known practice to use rotary control devices that usually comprise: 
         [0005]    a casing designed to be fixedly attached to the handle, 
         [0006]    a movable actuation portion that can be rotated relative to the casing about an axis, 
         [0007]    means for generating a control signal based on the angular position. of the movable actuation portion comprising a movable portion and a portion fixedly attached to the casing. 
         [0008]    The means for generating a control signal, preferably of the contactless type, may comprise for example a magnet rotatably attached to the actuation portion and a Hall effect sensor. 
         [0009]    This type of control device also comprises elastic means making it possible to return the movable actuation portion to a rest position, from which the operator may move this portion in two opposite directions. 
         [0010]    Such types of devices give satisfaction for the control of receiving members in normal conditions of use. 
         [0011]    It is however desirable to provide means for protecting the control device, by ensuring the redundancy of the information. In particular, this redundancy makes it possible to identify incorrect information in the case of a short circuit between the wires conveying the signal. 
         [0012]    In addition, it is desirable to supply the information on the direction of actuation directly to a supervision module that can therefore block an “aggravating movement” that can cause the machine to overturn. 
         [0013]    It should be noted that the control devices must also comply with constraints of minimal space requirement and simplicity of installation on the remote control. 
         [0014]    The object of the present invention is to provide a solution making it possible to solve in particular the two technical problems explained above by ensuring a redundancy of the information making it possible to detect dangerous situations or malfunctions of the control, while retaining the same simplicity of installation. 
       SUMMARY OF THE INVENTION 
       [0015]    Accordingly, the subject of the present invention is a rotary control device designed in particular to be attached to a handle of a remote control of a heavy construction machine, comprising: 
         [0016]    a casing designed to be fixedly attached to the handle, 
         [0017]    a movable actuation portion that can be rotated relative to the casing about an axis, 
         [0018]    first means for generating a proportional control signal based on the angular position of the movable actuation portion, comprising a movable portion moved by the actuation portion and a portion fixedly attached to the casing, 
         [0000]    the movable actuation portion being able to be moved by the operator in two opposite directions from a rest position against elastic means, 
         [0019]    which device also comprises second means for generating at least one signal of the on/off type delivering a first signal value when the actuation portion is oriented in a first direction relative to the rest position, beyond a first threshold, and delivering a second signal value when the actuation portion is oriented in a second direction relative to the rest position, beyond a second threshold. 
         [0020]    Thanks to these arrangements, the device provides redundant information. The information on the direction of actuation of the actuation portion given by the first generation means may be compared with the information provided by the second generation means in order to detect a malfunction. 
         [0021]    In addition, to prevent aggravating movements, it is possible to block the control of a receiving member when the information provided by the second generation means indicates that the control of the receiving member is carried out in the direction of such a movement. 
         [0022]    Advantageously, the second means for generating a signal are placed on the casing of the device. 
         [0023]    According to one possibility, the second means for generating a signal comprise at least one member that is movable, particularly in translation, moved by the actuation portion against elastic return means. 
         [0024]    Advantageously, the actuation portion comprises at least one ramp or a bearing abutment designed for the movement of the movable member. 
         [0025]    Advantageously, the output signal of the second generation means consists of two individual signals on two output channels. 
         [0026]    According to one embodiment, the second means for generating a signal comprise at least one pushbutton that can be actuated during the movement of the movable member. 
         [0027]    According to another embodiment, the movable member comprises conductive elements designed to enter into contact with at least one conductive track in at least one position of the device. 
         [0028]    Advantageously, the conductive elements are in open circuit in the rest position of the device. 
         [0029]    Advantageously, the conductive elements comprise flexible brushes making an electric sliding contact with at least one electric track in at least one position of the device. 
         [0030]    According to one embodiment, the second generation means comprise first means for detecting the movement of the actuation portion in a first direction relative to the rest position and second means for detecting the movement of the actuation portion in a second direction relative to the rest position. 
         [0031]    According to one possibility, the second generation means comprise detection means of the on/off type. 
         [0032]    According to another possibility, the second generation means comprise detection means of the proportional type associated with means for comparing the value supplied by the detection means with at least one threshold. 
         [0033]    According to one embodiment, the detection means of the proportional type are common with those used by the first means for generating a proportional signal. 
         [0034]    According to another embodiment, the detection means of the proportional type are distinct from those used by the first means for generating a proportional signal. 
         [0035]    Advantageously, the means for comparing the value supplied by the detection means with at least one threshold comprise a generator of at least one threshold value and at least one comparator of the output signal of the detection means of the proportional type with this at least one threshold value. 
         [0036]    According to one embodiment, the comparators are of the single or hysteresis comparator type. 
         [0037]    Advantageously, the detection means comprise a Hall effect sensor. 
         [0038]    Advantageously, the device comprises filters for protection against electromagnetic interference. 
         [0039]    According to one embodiment, the output signals are amplified by amplification means, in particular by a transistor. 
         [0040]    Advantageously, the output signal of the second generation means consists of two individual signals on two output channels. 
         [0041]    Advantageously, each individual signal on a given output channel is equal to a determined value when the actuation portion is actuated in a first direction relative to the neutral position, based on a movement threshold value, and equal to a second value, in particular zero, when the actuation is carried out in the opposite direction or when the movement in the first direction is below the threshold. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0042]    In any case, the invention will be well understood with the aid of the following description, with reference to the appended schematic drawing, representing as a nonlimiting example several embodiments of a device according to the invention. 
           [0043]      FIG. 1  is an exploded view in perspective of a device according to a first embodiment. 
           [0044]      FIG. 2  is a view in perspective of the device of  FIG. 1  attached to a remote control handle of a heavy construction machine. 
           [0045]      FIG. 3  is a schematic view of the means for generating control signals used in the device of  FIG. 1 . 
           [0046]      FIG. 4  is a schematic view of the output characteristic of the second means for generating a control signal. 
           [0047]      FIG. 5  is a schematic view of the means for generating control signals according to a second embodiment. 
           [0048]      FIG. 6  is a schematic view of the means for generating control signals according to a third embodiment. 
           [0049]      FIG. 7  is a front view of the device according to a fourth embodiment. 
           [0050]      FIGS. 8 ,  9 ,  10  are front views of the device according to a fifth embodiment, in three different positions. 
           [0051]      FIG. 11  is a detail schematic view of the conductive tracks of the device of  FIG. 8 . 
           [0052]      FIG. 12  is a view in perspective of the traveler used in the device of  FIG. 8 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0053]    As shown in  FIGS. 1 and 2 , a rotary control device  2  according to the invention comprises: 
         [0054]    a casing  3  designed to be fixedly attached to the handle  4 , 
         [0055]    a movable actuation portion  5  that can be rotated relative to the casing  3  about an axis A, 
         [0056]    first means  6  for generating a proportional control signal S 1  based on the angular position of the movable actuation portion  5 , comprising a movable portion  7  and a portion  8  fixedly attached to the casing, consisting respectively of a magnet  7  fixedly attached rotatably to the actuation portion  5  and a first Hall effect sensor  8 . 
         [0057]    The movable actuation portion  6  may be moved by the operator in two opposite directions DA and DB from a rest position P against elastic means  9 . 
         [0058]    According to an essential feature of the invention, the device  2  also comprises second means  10  for generating at least one signal S 2  of the on/off type delivering a first signal value when the actuation portion  5  is oriented in a first direction DA relative to the rest position P, beyond a first threshold TA, and delivering a second signal value when the actuation portion  5  is oriented in a second direction DB relative to the rest position P, beyond a second threshold TB. 
         [0059]    The second means  10  for generating a signal are placed on the casing of the control device, in the form of a printed circuit or a card  12  to which is also attached the fixed portion of the first generation means  6 , comprising the first Hall effect sensor  8 . 
         [0060]    According to a first embodiment, shown in  FIG. 3 , the card  12  has three inputs: 
         [0061]    a first 5V power supply input E 1 , 
         [0062]    a second 0V potential input E 2 , 
         [0063]    a third power supply input E 3  at a potential determined at a constant value of +UV. 
         [0064]    The card  12  also has three outputs: 
         [0065]    a first output S 1  corresponding to the proportional signal generated by the first means, 
         [0066]    a second output S 2 A and a third output S 2 B that supply an output signal S 2  of the on/off type of the second generation means  10  consisting of two individual signals on the two output channels. 
         [0067]    The fixed portion of the first generation means  6  comprises, in series, and supplied between the first input E 1  and the second input E 2 : 
         [0068]    a first filter  13  designed for protection against electromagnetic interference, or an EMI filter, 
         [0069]    the Hall effect sensor  8 , and 
         [0070]    a second EMI filter  14 . 
         [0071]    The output S 1  corresponds to the output of the second EMI filter  14 . This output value is a value proportional to the movement of the actuation portion. 
         [0072]    In particular, in this embodiment, the output voltage lies between 0 and 5V, these extreme values corresponding to the values of the inputs E 1  and E 2 , a position of the actuation portion in the vicinity of the rest position P corresponding to a rest value VR of the order of 2.5V. 
         [0073]    The second generation means comprise detection means of the proportional type associated with means for comparing the value supplied by the detection means with two thresholds TA and TB. 
         [0074]    In particular, in this embodiment, the detection means of the proportional type consist of the first Hall effect sensor  8  also used by the first means  6  for generating a proportional signal. 
         [0075]    The means for comparing the value supplied by the detection means with at least one threshold comprise a generator  15  of the threshold values TA and TB and two hysteresis comparators  16  and  17  of the output signal of the detection means of the proportional type with the two threshold values TA and TB. 
         [0076]    In this embodiment, the thresholds TA and TB have the respective values 2.2 and 2.7V, these values being on either side of the 2.5V rest value VR. 
         [0077]    The generator  15  of the threshold values is supplied by the inputs E 1  and E 2 . 
         [0078]    The output signals of each of the two comparators  16  and  17  are amplified by amplification means, consisting respectively of two transistors  18  and  19 , whose supply is provided by the input E 3 . 
         [0079]    The individual amplified signals are then connected respectively to the outputs S 2 A and S 2 B. 
         [0080]    The value of each individual signal present at one of the outputs S 2 A and S 2 B is equal to a determined value corresponding substantially to the value of UV of the input signal E 3  when the actuation portion  5  is actuated in a given direction DA, DB relative to the neutral position P, based on a movement threshold value TA, TB and equal to zero when the actuation takes place in the opposite direction. 
         [0081]    The use of the thresholds TA and TB makes it possible not to generate an output signal when the actuation portion is in the vicinity of its rest position P. 
         [0082]    The output characteristic S 2  of the second generation means  10 , consisting of the characteristics on the two output channels S 2 A and S 2 B, is shown in  FIG. 4 , representing on the ordinate the output value, and on the abscissa the angular position a of the actuation portion  5  also corresponding to the voltage at the terminals of the detection means consisting of the Hall effect sensor. 
         [0083]    The characteristic of S 2 A is represented in dot-and-dash lines and that of S 2 B in continuous lines. 
         [0084]    Using the outputs S 2 A and S 2 B, the card  12  therefore makes it possible to determine the direction of actuation with an on/off signal. 
         [0085]    According to a second embodiment, a device  2  according to the invention comprises the same elements bearing the same reference numbers as in the first embodiment, as described with reference to  FIGS. 1 and 2 , and has a similar output characteristic to that described with reference to  FIG. 4 . 
         [0086]    The second means  10  for generating an on/off signal represented in  FIG. 5  use the same elements as in the first embodiment, except for the detection means of proportional type that consist of a second Hall effect sensor  20  of proportional type distinct from that used by the first means  6  for generating a proportional signal. 
         [0087]    This arrangement is advantageous because it makes it possible to provide redundancy of the measurements making it possible to detect any failure of the first sensor. 
         [0088]    According to a third embodiment, a device  2  according to the invention comprises the same elements bearing the same reference numbers as in the first embodiment, as described with reference to  FIGS. 1 and 2 , and has a similar output characteristic to that described with reference to  FIG. 4 . 
         [0089]    However, the second generation means, shown in  FIG. 6 , comprise detection means of the on/off type comprising: 
         [0090]    first means for detecting the movement of the actuation portion  5  in a first direction DA relative to the rest position P, consisting of a first Hall effect sensor  22  of the on/off type, and 
         [0091]    second means for detecting the movement of the actuation portion in a second direction DB relative to the rest position P, consisting of a second Hall effect sensor  23  of the on/off type. 
         [0092]    In this embodiment, the use of comparators and of a generator of threshold values is not necessary, the sensors delivering an output signal when the position of the actuation portion passes beyond a given threshold TA, TB. 
         [0093]    The output signal of each of the on/off type Hall effect sensors  22 ,  23  is therefore directly connected respectively to one of the transistors  18  and  19 . 
         [0094]    The card  12 , thus made with a smaller number of components, produces an output characteristic similar to that of  FIG. 4 . 
         [0095]    According to a fourth embodiment, shown in  FIG. 7 , the device  24  comprises, in a similar manner to the device of the first embodiment: 
         [0096]    a casing  3  designed to be fixedly attached to a handle of a remote control of a heavy construction machine, 
         [0097]    a movable actuation portion  5  that can be rotated relative to the casing  3  about an axis A, of which only a portion consisting of a stud is shown in  FIG. 7 , 
         [0098]    first means for generating a proportional control signal S 1  based on the angular position of the movable actuation portion, not shown in  FIG. 7 . 
         [0099]    As in the first embodiment, the movable actuation portion may be moved by the operator in two opposite directions from a rest position, against elastic means. 
         [0100]    The above elements are similar to those described in the first embodiment. 
         [0101]    The device  24  also comprises second means for generating at least one signal S 2  of the on/off type delivering a first signal value when the actuation portion  5  is oriented in a first direction DA relative to the rest position P, beyond a first threshold TA, and delivering a second signal value when the actuation portion  5  is oriented in a second direction DB relative to the rest position P, beyond a second threshold TB. 
         [0102]    The second signal generation means are placed on the casing of the control device and comprise two symmetrical arrangements  25  situated on either side of the actuation portion and comprising: 
         [0103]    a ramp  26  on the external portion of the stud  5 , 
         [0104]    a traveler  27 , a member that can be moved in translation in a sliding direction C, comprising a first end  28  designed to interact with the ramp  26 , a portion having a plane  29  inclined relative to the direction C and a second end  30  subjected to the action of a return spring  32 , 
         [0105]    a sealed elastic bellows  33 , that can be moved in a direction transversal to the direction C, and comprising a boss  34  designed to interact with the inclined plane of the traveler, 
         [0106]    a pushbutton  35 , interacting with the face  36  of the bellows  33  opposite to the boss. 
         [0107]    In the rest position, the ramps  26  of the two arrangements  25  do not interact with the travelers  27 , the latter being held in a retracted position relative to the sealed bellows by the return springs, the two pushbuttons  35  being in the “out” position. 
         [0108]    As shown in  FIG. 7 , when the actuation portion  5  is oriented in a first direction DA relative to the rest position P, beyond a first threshold TA, the ramp  26  interacts with the traveler  27  that moves against the spring  32  in the direction C away from the axis A of rotation of the actuation portion. 
         [0109]    The inclined plane  29  interacts with the boss  34  of the bellows  33 , this bellows being pushed downward against its elastic return force, the face  36  of the bellows pushing in the pushbutton  35 . 
         [0110]    In this position, the second ramp  26  is not in contact with the first traveler  27  of the second arrangement  25 , the second pushbutton  35  therefore being in the “out” position. 
         [0111]    Conversely, when the actuation portion  5  is oriented in a second direction DB relative to the rest position P, beyond a second threshold TB, a second ramp  26 , symmetrical to the first, interacts with a second traveler  27  of a second arrangement  25 , similarly pushing in a second pushbutton  35 . 
         [0112]    The first ramp  26  is no longer in contact with the first traveler of the first arrangement, the first pushbutton  35  therefore being in the “out” position. 
         [0113]    The two arrangements  25  forming the second generation means make it possible to compose an output signal S 2  of the on/off type, consisting of two individual signals at two outputs S 2 A and S 2 B representing the signal of the two pushbuttons  35 , the output characteristic therefore being similar to that of the device of the first embodiment, as shown in  FIG. 4 . 
         [0114]    The presence of the bellows makes it possible to seal the device. 
         [0115]    According to a fifth embodiment, shown in  FIGS. 8 to 12 , the device  37  comprises, in a manner similar to the device of the first embodiment: 
         [0116]    a casing  3  designed to be fixedly attached to a handle of a remote control of a heavy construction machine, 
         [0117]    a movable actuation portion  5  that can be rotated relative to the casing  3  about an axis A, of which only one portion consisting of a stud is shown in  FIGS. 8 to 10 , 
         [0118]    first means for generating a proportional control signal S 1  based on the angular position of the movable actuation portion, not shown in  FIGS. 8 to 10 . 
         [0119]    As in the first embodiment, the movable actuation portion may be moved by the operator in two opposite directions from a rest position against elastic means. 
         [0120]    The above elements are similar to those described in the first embodiment. 
         [0121]    The device  37  also comprises second means  38  for generating at least one signal S 2  of the on/off type delivering a first signal value when the actuation portion  5  is oriented in a first direction DA relative to the rest position P, beyond a first threshold value TA, and delivering a second signal value when the actuation portion  5  is oriented in a second direction DB relative to the rest position P, beyond a second threshold TB. 
         [0122]    The second means  38  for generating a signal are placed on the casing of the control device and comprise: 
         [0123]    a bearing ramp  39  on the outer portion of the stud of the actuation portion  5 , forming a bearing abutment on its front edge, 
         [0124]    a cam  40 , that can rotate relative to the casing about an axis B parallel to the axis A of rotation of the actuation portion  5 , comprising an arm designed to interact via its end  42  with the bearing ramp  39  of the stud, 
         [0125]    an elastic sealed bellows  44 , that can be moved in a direction E transverse to the axis B, and comprising a boss  45  designed to interact with a contact surface  43  of the arm of the cam  40 , by means of an intermediate metal plate  41 , in order to prevent a direct contact between the bellows and the cam that would not have a satisfactory friction coefficient, 
         [0126]    a traveler  46 , a member that can be moved in translation in the sliding direction E, comprising a first end  47  designed to interact with the face  48  of the bellows  44  opposite to the boss, a lateral portion to which is attached at least one pair of conductive brushes  49 ,  50 , electrically connected, and a second end  52  subjected to the action of a return spring  53 , 
         [0127]    at least a couple of conductive tracks  54 ,  55  attached to a wall of the casing  3  parallel to the direction E so as to be able to enter into contact respectively with the first and the second brush of the couple of brushes  49 ,  50 . 
         [0128]    The return spring  53  makes it possible to keep the traveler  46  in contact with the bellows  44 , the bellows in contact with the cam  40 . 
         [0129]    Via the end of its arm  42 , the cam is: 
         [0130]    in contact with the abutment of the bearing ramp  39  of the stud of the actuation portion  5  of the device  37 , in the rest position of the system, 
         [0131]    in contact with the bearing ramp, beyond the abutment, when the actuation portion is moved in the direction DB, beyond the threshold TB. 
         [0132]    The arm is not in contact with the bearing ramp, when the actuation portion is moved in the direction DA, beyond the threshold TA. 
         [0133]    Therefore, according to the angle α formed by the actuation portion with the rest position, the slide is moved in the direction E, and the couple of brushes  49 ,  50  attached to the traveler. In particular, according to the representation of  FIGS. 8 to 11 , when the actuation portion moves in the direction DA, the traveler  46  rises, and when the actuation portion moves in the direction DB, the traveler  46  descends. 
         [0134]    As shown in  FIG. 11 , the first track  54  is continuous and connected to a supply input E 4 . 
         [0135]    The second track is separated into two electrically insulated portions  55 A and  55 B, separated by a nonconductive strip  56 , the first portion  55 A being connected to a first output S 2 A and the second portion  55 B being connected to a second output S 2 B. 
         [0136]    The couple of brushes  49 ,  50  makes it possible, according to the position of the traveler, to connect the first track  54  to the first portion  55 A or to the second portion  55 B of the second track, or to leave the circuit open, if the second brush is in contact with the conductive strip  56 . Thus, according to these configurations, a signal will be emitted at the outputs S 2 A or S 2 B or no signal will be emitted. 
         [0137]    As shown in  FIG. 8 , in the rest position of the device  37 , the second brush  50  is at the nonconductive strip  56 , the circuit connecting the input E 4  being open, no output signal being emitted. 
         [0138]    As shown in  FIG. 9 , when the actuation portion  5  is oriented in a first direction DA relative to the rest position P, beyond a first threshold TA, the traveler rises relative to the rest position, the second brush  50  is in contact with the first portion  55 A of the second track, the input E 4  is connected to the output S 2 A, an output signal being emitted at this output. 
         [0139]    As shown in  FIG. 10 , when the actuation portion  5  is oriented in a second direction DB relative to the rest position P, beyond a second threshold TB, the traveler rises relative to the rest position, the second brush  50  is in contact with the second portion  55 B of the second track, the input E 4  is connected to the output S 2 B, an output signal being emitted at this output. 
         [0140]    The second generation means  38  make it possible to compose an output signal S 2  of the on/off type, composed by two individual signals on two output channels S 2 A and S 2 B, the output characteristic therefore being similar to that of the device of the first embodiment, as shown in  FIG. 4 . 
         [0141]    It goes without saying that the invention is not limited to the preferred embodiments described above, as a nonlimiting example; on the contrary, it covers all the variant embodiments in the context of the following claims.