Abstract:
An intermittent driving apparatus for a rotary window cleaner comprises a first wiper ( 2 ) which is connected to a rotating shaft ( 10 ) of a first motor ( 8 ) and is rotatably disposed on a front window ( 1 ), a second wiper ( 3 ) which is connected to a rotating shaft ( 11 ) of a second motor ( 9 ) and is rotatably disposed on a front window ( 1 ) adjacently to the first wiper ( 2 ), and an electronic control circuit having brush boards ( 18, 20 ) of two motors connected to each other so that the second motor ( 9 ) is rotated at a predetermined time after the first motor ( 8 ) is rotated. The electronic control circuit includes a signal generating circuit ( 30 ) for repeatedly sending signals to the brush board ( 18 ) of the first motor ( 8 ) at fixed time intervals, and a brake mechanism for stopping the two wipers at the start position for a predetermined time every one rotation.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an intermittent driving apparatus for a rotary window cleaner used for an automobile and other vehicles, a railroad car, a ship, an airplane, and the like. More particularly, it relates to an intermittent driving apparatus for a rotary window cleaner in which a rotary wiper is driven intermittently while being stopped at a fixed position for a predetermined time every one rotation. 
     A rotary window cleaner is used to wipe rainwater put on a front window by rotating a wiper, and is known from U.S. Pat. Nos. 3649990, 4701972, 4773117, and 5210900. These well-known rotary window cleaners somewhat rotate because a motor has inertia even when a power source for the motor for rotating the wiper is turned off. Therefore, it is difficult for the known rotary window cleaner to always stop the wiper at a fixed position every one rotation, so that merely a low-speed operation and a high-speed operation are performed, and the known rotary window cleaner is not provided with an intermittent driving mechanism for performing an intermittent operation. 
     At the time of rainfall of a very small amount or a small amount, like a reciprocating window cleaner, the rotary window cleaner is required to be provided with an intermittent driving apparatus for performing an intermittent operation which less hinders the field of view on the front window. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide an intermittent driving apparatus for a rotary window cleaner in which a predetermined time after one of two rotating wipers disposed on a front window so as to be close to each other is started, the other is started, and the rotating wipers are intermittently driven while being stopped at the start position for a predetermined time every one rotation. 
     An intermittent driving apparatus for a rotary window cleaner in accordance with the present invention comprises a first wiper which is connected to a rotating shaft of a first motor and is rotatably disposed on a front window, a second wiper which is connected to a rotating shaft of a second motor and is rotatably disposed on the front window adjacently to the first wiper, and an electronic control circuit having brush boards of two motors connected to each other so that the second motor is rotated at a predetermined time after the first motor is rotated. The electronic control circuit includes a signal generating circuit for repeatedly sending signals to the brush board of the first motor at predetermined time intervals, and a brake mechanism for stopping the two wipers at the start position for a predetermined time every one rotation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a back face view showing a state in which a rotary window cleaner having an intermittent driving apparatus in accordance with the present invention is attached to an automotive front window; 
     FIG. 2 is a block diagram of an electronic control circuit of an intermittent driving apparatus for a rotary window cleaner in accordance with the present invention; 
     FIG. 3 is a circuit diagram of a start and brake mechanism of a first motor of an intermittent driving apparatus for a rotary window cleaner in accordance with the present invention; 
     FIG. 4 is a circuit diagram of a start and brake mechanism of a second motor of an intermittent driving apparatus for a rotary window cleaner in accordance with the present invention; 
     FIG. 5 is a circuit diagram of a brake mechanism of an intermittent driving apparatus for a rotary window cleaner in accordance with the present invention; and 
     FIG. 6 is a circuit diagram of a signal generating circuit of an intermittent driving apparatus for a rotary window cleaner in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a state in which a rotary window cleaner having an intermittent driving apparatus in accordance with the present invention is attached to a front window  1 . On the front window  1 , there are disposed two wipers  2  and  3  so that they are close to each other. The wiper  2 ,  3  is supported by a support cylinder  6 ,  7  so as to be rotatable around a rotating shaft  4 ,  5 , and the support cylinder  6 ,  7  is provided therein with a transmitting mechanism such as a toothed belt or a chain for transmitting the rotation of a motor  8 ,  9  to the rotating shaft  4 ,  5  of the wiper  2 ,  3 . The support cylinder  6 ,  7  is pivotably supported on a support shaft  16 ,  17  of a motor gear  14 ,  15  engaging with a worm  12 ,  13  formed on a driving shaft  10 ,  11  (see FIG. 2) of the motor  8 ,  9 . The rotation of the motor gear  14 ,  15  is transmitted to the rotating shaft  4 ,  5  of the rotating wiper  2 ,  3  through the transmitting mechanism which is engaged with the support shaft  16 ,  17  and the rotating shaft  4 ,  5  and which is provided in the support cylinder  6 ,  7 , and the wiper  2 ,  3  is rotated by the rotating shaft  4 ,  5 . 
     A brush board  18  for the first motor  8  is connected to a first wiring board  19  as shown in FIG. 3, and a brush board  20  for the second motor  9  is connected to a second wiring board  21  as shown in FIG.  4 . The brush board  18  of the first motor  8  and the brush board  20  of the second motor  9  are connected to each other through an electronic control circuit of the first wiring board  19  and the second wiring board  21  connected to each other. The first motor gear  14  for decreasing the rotational speed of the first motor  8  is provided with an operation cam  22 , and the first wiring board  19  is connected to a first motor brake sensor  23 , which are disposed in a gear box of the motor gear  14 , so that the operation cam  22  is engaged with the first motor brake sensor  23  by the rotation of the motor gear  14 . The motor gear  15  for decreasing the rotational speed of the second motor  9  is provided with an operation cam  25 , and the second wiring board  21  is connected to a brake sensor  26 , which is disposed in a gear box of the motor gear  15 , so that the operation cam  25  is engaged with the brake sensor  26  by the rotation of the motor gear  15 . 
     As shown in FIG. 3, the first wiring board  19  of the electronic control circuit is connected to the brush board  18  of the first motor  8  and the brake sensor  23  disposed in the gear box of the motor gear  14 , and has a normal rotation relay (a), a reverse rotation relay (b), and a time relay (c). The normal rotation relay (a) of the first wiring board  19  is connected to a signal generating circuit  30  and the brush board  18  of the first motor  8  so as to send a signal generated from the signal generating circuit  30  to the brush board  18  and turn on the first motor  8  to rotate the wiper  2 . The time relay (c) is connected to the brake sensor  23 , the normal rotation relay (a), and the reverse rotation relay (b) so as to turn on the reverse rotation relay (b) and turn off the normal rotation relay (a) when the operation cam  22  is engaged with the brake sensor  23  by the rotation of the motor gear  14 . The reverse rotation relay (b) is connected to the time relay (c) and the brush board  18  so as to send a brake signal from the time relay (c) to the brush board  18  to stop the first motor  8  at the start position. 
     A second motor start sensor  24 , which is disposed in the gear box of the motor gear  14  of the first motor  8 , is connected to the second wiring board  21  connected to the brush board  20  of the second motor  9 . The operation cam  22  is also engaged with the second motor start sensor  24  as well as the first motor brake sensor  23  by the rotation of the motor gear  14 . 
     As shown in FIG. 4, the second wiring board  21  of the electronic control circuit is connected to the brush board  20  of the second motor  9  and the brake sensor  26  disposed in the gear box of the motor gear  15 , and has a normal rotation relay (a), a reverse rotation relay (b), and a time relay (c). The normal rotation relay (a) is connected to the second motor start sensor  24 , which is disposed in the gear box of the motor gear  14  of the first motor  8 , and the brush board  20  of the second motor  9  so as to send a start signal of the second motor start sensor  24  to the brush board  20  to rotate the second motor  9  at a predetermined time after the first motor  8  is rotated, that is, when the operation cam  22  is engaged with the second motor start sensor  24  by the rotation of the motor gear  14 . The time relay (c) is connected to the brake sensor  26 , the normal rotation relay (a), and the reverse rotation relay (b) so as to turn on the reverse rotation relay (b) and turn off the normal rotation relay (a) when the operation cam  15  is engaged with the brake sensor  26  by the rotation of the motor gear  15 . The reverse rotation relay (b) is connected to the time relay (c) and the brush board  20  so as to send a brake signal from the time relay (c) to the brush board  20  to stop the second motor  9  at the start position. 
     The electronic control circuit has a brake circuit  27  shown in FIG.  5 . The brake circuit  27  is connected to the signal generating circuit  30  via a charging relay  28 , and is connected to the time relay (c) of the first wiring board  19  and the time relay (c) of the second wiring board  21  via the brake sensor  23  of the motor gear  14  and the brake sensor  26  of the motor gear  15 . It also has a first relay  29 , a capacitor  31 , and a second relay  32 , which are connected in parallel to each other. The first relay  29  is connected to the signal generating circuit  30  through the charging relay  28 . The second relay  32  is connected by the two parallel points to the brake sensor  23  of the first motor, which is connected to the time relay (c) of the first wiring board  19  and the brake sensor  26  of the second motor, which is connected to the time relay (c) of the second wiring board  21 . The capacitor  31  is disposed between the first relay  29  and the second relay  32 . 
     As shown in FIG. 6, the signal generating circuit  30  of the electronic control circuit is connected to the first wiring board  19 , which is connected to the brush board  18  of the first motor  8 , and the brake circuit  27 , which is connected to the first wiring board  19  and the second wiring board  21  through the brake sensor  23 ,  26  of the motor gear  14 ,  15 . Also, it is connected to a power source via an operation switch, and has a first relay  33 , a capacitor  34 , and a second relay  35 , which are connected in parallel to each other. The first relay  33  of the signal generating circuit  30  is connected to the first relay  29  of the brake circuit  27 , the second relay  35  is connected to the normal rotation relay (a) of the first wiring board  19 , which is connected to the brush board  18  of the first motor  8 , and the capacitor  34  is disposed between the first relay  33  and the second relay  35 . 
     When a signal for rotating the first motor  8  is transmitted by the operation switch, the first relay  33  of the signal generating circuit  30  is turned on, whereby the capacitor  34  is charged. When the first relay  33  and the second relay  35  are turned on at the same time, the capacitor  34  is turned on, and the signal generating circuit  30  is turned on. By the turning on of the signal generating circuit  30 , the first relay  33  sends a brake signal to the brake circuit  27 , and the second relay  35  sends a start signal to the normal rotation relay (a) of the first wiring board  19  connected to the brush board  18  of the first motor  8 , to rotate the first motor  8 . The capacitor  34  is used to perform an intermittent operation of the first motor  8  at intervals of about  5  seconds. The capacitor  34  can regulate the time interval of about  5  seconds by the volume. 
     The brake circuit  27 , the brake sensors  23  and  26 , and the time relays (c) and the reverse rotation relays (b) of the first wiring board  19  and the second wiring board  21  constitute a brake mechanism. When a brake signal is sent to the brake circuit  27  simultaneously with a start signal for rotating the first motor  8 , the first relay  29  of the brake circuit  27  is turned on, by which the capacitor  31  is charged. When the first relay  29  and the second relay  32  are turned on at the same time, the capacitor  31  is turned on, and the brake circuit  27  is turned on. By the turning on of the second relay  32 , the. electric power is supplied to the brake sensor  23 ,  26  of the motor gear  14 ,  15  from two parallel points of the second relay  32 , and thus the brake circuit  27  and the brake sensor  23 ,  26  wait in an energized state. When the operation cam  22 ,  25  is engaged with the brake sensor  23 ,  26  by the rotation of the motor gear  14 ,  15 , the brake circuit  27  and the time relays (c) of the first wiring board  19  and the second wiring board  21  are energized. The normal rotation relay (a) is turned off, and the reverse rotation relay (b) is turned on, by which the motor and the motor gear are stopped, and the wiper  2 ,  3  is stopped at the start position. The capacitor  31  is provided so that the brake circuit  27  has an electric current corresponding to the time for which the wiper  2 ,  3  rotates more than one turn on the front window  1 . The capacitor  31  causes an electric current to flow for about 1.5 seconds, and the wiper  2 ,  3  can always be stopped at the start position even if the rotation of the wiper  2 ,  3  is stopped at any position by switching the operation switch. 
     The following is a description of the operation of the intermittent driving apparatus for a rotary window cleaner. When the drive of the rotary window cleaner is switched to the intermittent driving position by the operation switch disposed close to a steering wheel of a vehicle, the signal generating circuit  30  of the electronic control circuit sends a signal having intervals of about 5 seconds to the brush board  18  through the normal rotation relay (a) of the first wiring board  19 . Thereby, the first motor  8  is rotated, and a brake signal from the signal generating circuit  30  is sent to the brake circuit  27 . The capacitor  31  is charged, and the brake circuit  27  and the brake sensor  23 ,  26  wait in an energized state. When the first motor  8  is rotated, the motor gear  14  meshing with the driving shaft  10  thereof rotates in the arrow-marked direction, by. which the wiper  2  is rotated around the rotating shaft  4  through the transmitting mechanism in the support cylinder  6 . 
     When the operation cam  22  attached to the motor gear  14  is engaged with the second motor start sensor  24  at a predetermined time after the first wiper  2  is rotated, a second motor start signal is sent to the brush board  20  through the normal rotation relay (a) of the second wiring board  21 . When the second motor  9  is rotated, the motor gear  15  meshing with the driving shaft  11  thereof rotates in the arrow-marked direction opposite to the rotating direction of the motor gear  14 , by which the second wiper  3  is rotated in the direction opposite to the first wiper  2  around the rotating shaft  5  through the transmitting mechanism in the support cylinder  7 . 
     When the first wiper  2  has rotated one turn and the motor gear  14  has come to the start position, the operation cam  22  is engaged with the brake sensor  23 . The brake sensor  23  electrically connected to the brake circuit  27 , which has already been turned on, sends a brake signal to the time relay (c) of the first wiring board  19 , so that the time relay (c) turns off the normal rotation relay (a) of the first wiring board  19 , and turns on the reverse rotation relay (b). Thereby, the first motor  8  is stopped, and the motor gear  14  and the first wiper  2  are stopped at the start position. Subsequently, when the second wiper  3  has rotated one turn and the motor gear  15  has come to the start position, the operation cam  25  is engaged with the brake sensor  26 . The brake sensor  26  electrically connected to the brake circuit  27 , which has already been turned on, sends a brake signal to the time relay (c) of the second wiring board  21 , so that the time relay (c) turns off the normal rotation relay (a), and turns on the reverse rotation relay (b). Thereby, the second motor  9  is stopped, and the motor gear  14  and the second wiper  3  are sopped at the start position. After a predetermined time, that is, after  5  seconds the next signal is sent from the signal generating circuit  30 , by which the above operation is repeated at time set intervals. Subsequently, the signal generating circuit  30  performs repeated operations of first signal, second signal, and so on. 
     According to the intermittent driving apparatus in accordance with the present invention, at the time of rainfall of a very small amount or a small amount, it is possible to perform easily an intermittent operation even on the rotary window cleaner like the reciprocating window cleaner in such manner that after one wiper is rotated, the other wiper is rotated, and the two wipers do rotate one turn at the start position, and stopped at the start position for a predetermined time every one rotation. Also, the hindrance of the field of view on the front window can be reduced to the utmost on the rotary window cleaner. Further, in the intermittent operation of the two wipers, after one wiper is rotated, the other wiper is rotated in the opposite direction, by which the two wipers are rotated by forming lag angle between the two wipers. Therefore, the interference of the two wipers disposed close to each other can be avoided.