Liquid supplying device for endoscope

A liquid supplying device has a housing with a connecting portion to which a connector of an endoscope is connected. A lamp, an air pump and a liquid supply tank are arranged in the housing. The pump is connected to the connecting portion and the tank through a pipe. The tank is connected to the connecting portion through a pipe. A switching mechanism is connected to the pipes. A selector valve is connected to the pipe at a position between the pump and the tank. A control circuit is connected to the lamp and pump, and a light source switch is connected to the control circuit. When the switch is closed, the circuit drives the lamp and pump and switches the selector valve to a first position for blocking the pipe, thereby preventing supply of the liquid to the endoscope. When the switch is open, the circuit switches the selector valve to a second position for communicating the pipe. If the switching mechanism is operated under this condition, the liquid is supplied to the endoscope through the pipe.

BACKGROUND OF THE INVENTION 
The present invention relates to a liquid supplying device for supplying a 
liquid in an air supply channel of an endoscope so as to clean this air 
supply channel. 
In order to prevent infection from an endoscope, a liquid supplying device 
is provided which can easily clean an air supply channel of an endoscope 
after use. This device is assembled in a light source of the endoscope. In 
this device, a switching mechanism is operated to selectively supply a 
liquid held in a liquid supply tank to an air supply channel of an 
endoscope. However, if the switching mechanism is accidentally operated 
during diagnosis with the endoscope connected thereto, a liquid, such as 
an infusion solution harmful to the human body, may be supplied to a 
patient undergoing diagnosis. 
In order to prevent this, another liquid supply device has been proposed. 
According to this device, a light source connector and a liquid supply 
connector are arranged independently of each other. Therefore, even if a 
switching mechanism is accidentally operated during diagnosis with an 
endoscope connected thereto, a liquid will not be erroneously supplied to 
the patient. However, this device has a complex structure and its 
operation is difficult. 
SUMMARY OF THE INVENTION 
The present invention has been made in consideration of this and has as its 
object to provide a liquid supplying device in which a liquid cannot be 
supplied while an illuminating light source lamp is ON so as to guarantee 
the safety of a patient and which is easy to operate. 
According to an aspect of the present invention, there is provided a liquid 
supplying device which comprises a housing with a connecting portion to 
which the connector of the endoscope is connected; air and liquid 
supplying means, arranged inside the housing, for supplying liquid and air 
into the air supply channel from the other end of the air supply channel; 
a light source which is arranged inside the housing and which emits light 
which becomes incident on the light guide from that end of the light guide 
which is near the connector; and regulating means for preventing the air 
and liquid supplying means from supplying liquid while said light source 
is ON.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The preferred embodiments of the present invention will now be described 
sequentially with reference to the accompanying drawings. 
FIGS. 1 to 3 show the first embodiment of the present invention. Referring 
to FIG. 1, reference numeral 1 denotes an endoscope which has a control 
section 2 and an insertion section 3 extending from the section 2. One end 
of a universal cord 4 is connected to the control section 2 and the other 
end is connected to a connector 6 to be connected to a liquid supplying 
device 5. An air supply channel 7 and a light guide 10 extend within the 
endoscope 1 and the universal cord 4. One end of the air supply channel 7 
opens to the distal end of a connecting mouthpiece 8 of the connector 6, 
as shown in FIG. 2. The other end of the air supply channel 7 is connected 
to a nozzle 9 arranged at the distal end of the insertion section 3. The 
liquid supplying device 5 to which the connector 6 is to be connected has 
the construction as shown in FIG. 2. More specifically, the device 5 has a 
housing 11 and a light source 12 arranged therein. Light emitted from the 
light source 12 is converged by a lens 13 and becomes incident on the 
light guide 10 inside a light guide mouthpiece 14 formed at the end face 
of the connector 6. The light guide 10 extends through the universal cord 
4, the control section 2, and the insertion section 3 to reach the distal 
end of the insertion section 3. An air pump 16 is also arranged in the 
housing 11. A check valve 17 is connected to the delivery side of the pump 
16. Pipes 22 and 23 are connected to the check valve 17. The pipe 22 is 
connected to a receptacle 18 which is fixed to the housing 11 and which 
receives the connecting mouthpiece 8 of the connector 6. The pipe 23 is 
connected to a cylinder 24 of a switching mechanism 19 described below. 
The switching mechanism 19 has a cylinder 24 fixed to the housing 11, a 
piston 26 which is slidably inserted in the cylinder 24 and has at one end 
thereof a control button 25 extending outside the housing 11, and a spring 
27 for biasing the piston 26 in the direction projecting from the cylinder 
24. An annular groove 28 is formed in the outer surface of the piston 26. 
O-rings 29 are arranged on the outer surface of the piston 26 to provide a 
good hermetic seal between the piston 26 and the cylinder 24. The spring 
27 normally biases the piston 26 to a first position (standby position) 
shown in FIG. 2. The pipe 23 is connected to the side wall of the cylinder 
24 so as to communicate with the interior of the cylinder 24 when the 
piston 26 is at the first position. One end of a lifting pipe 31 is 
connected to the cylinder 24 to communicate with the annular groove 28. 
The other end of the lifting pipe 31 is hermetically inserted inside a 
liquid supply tank 32 holding a liquid therein. Therefore, when the piston 
26 is at the first position, it blocks communication between the pipe 23 
and the lifting pipe 31. However, when the piston 26 is pushed to a second 
position, it allows communication between the pipe 23 and the lifting pipe 
31 through the annular groove 28. 
Another air pump 33 for liquid supply (may also be referred to as a liquid 
supply pump 33 hereinafter) is also arranged inside the housing 11. The 
air pump 33 communicates with the upper space inside the liquid supply 
tank 32 through a pipe 34 so as to supply compressed air thereinto. A 
relief valve 35 is arranged at an intermediate position of the pipe 34. 
A control circuit 36 is assembled in the liquid supplying device 5. The 
control circuit 36 controls the light source 12 and the pumps 16 and 33. A 
lamp switch 37 is connected to the control circuit 36 and can be 
externally operated. 
FIG. 3 shows a circuit diagram of the liquid supplying device. The pump 16 
is controlled by an air pump driver 38, the light source 12 is controlled 
by a lamp driver 39, and the liquid supply pump 33 is controlled by a 
liquid supply pump driver 41. Inputs are supplied to the drivers 38, 39 
and 41 through the lamp switch 37, an air supply switch 42, and a liquid 
supply switch 43, respectively. These drivers 38, 39 and 41 are connected 
to a power supply through a power switch 44. 
The various operation modes of the liquid supplying device having the 
construction as described above will now be described. When diagnosis is 
to be performed, the lamp switch 37 is turned on. Then, the air supply 
switch 42 is turned on. When the power switch 44 is turned on, the light 
source 12 is turned on, and the air pump 16 is actuated. Then, diagnosis 
with the endoscope 1 can be performed. During diagnosis, the liquid supply 
switch 43 is kept open, and air is not supplied. 
In order to clean or disinfect the air supply channel 7 after using the 
endoscope 1, only the power switch 44 is turned on. Then, since only the 
liquid supply switch 42 is normally closed, only the liquid supply pump 33 
is actuated. The liquid supply pump 33 supplies compressed air to the 
liquid supply tank 32 so as to decompress the liquid in the liquid supply 
tank 32 and to supply it to the lifting pipe 31. Note that the light 
source 12 is OFF during this operation. When the control button 25 of the 
switching mechanism 19 is pressed such that the piston 26 reaches the 
second position, the lifting pipe 31 and the pipes 22 and 23 communicate 
through the annular groove 28. Then, the liquid is supplied to the air 
supply channel 7 of the endoscope 1 through the receptacle 18, thereby 
cleaning and disinfecting the channel 7. When the lamp switch 37 is closed 
after this cleaning operation, the state before the diagnosis is 
established. The air pump 16 is then actuated to supply air into the 
channel 7 to dry it. 
Therefore, when the light source 12 is ON in the device of the above 
construction, the liquid supply switch 43 is always open. In other words, 
the liquid supply tank 32 is not decompressed in this state. For this 
reason, even if the switching mechanism 19 is switched to the liquid 
supplying side or the second position, liquid is not supplied to the 
channel 7. 
In the embodiment described above, the air pump 16 is directly connected to 
the receptacle 18. However, as shown in FIG. 4, the air pump 16 can be 
connected to the space inside the cylinder 24 through a pipe 21. Then, the 
check valve 17 can be omitted. Note that reference numeral 45 denotes a 
relief valve. Furthermore, as shown in FIG. 5, the air supply switch 42 
can be omitted, and the power switch 44 can be directly connected to the 
air pump driver 38. 
FIGS. 6 to 8 show a second embodiment of the present invention. The device 
of this embodiment has only one air pump 16. The air pump 16 is connected 
to a liquid supply tank 32 through a pipe 52. A selector valve 53 is 
arranged at an intermediate position along the pipe 52. The pipe 52 is 
also connected to a cylinder 24 of a switching mechanism 19. The valve 53 
has a construction as shown in FIG. 7. Referring to FIG. 7, the valve 53 
has a cylinder 54 and a piston 55 arranged inside the cylinder 54. The 
piston 55 is actuated by a solenoid 56. The piston 55 is biased by a 
spring 57 to a first position (standby position) shown in FIG. 7. When the 
solenoid 56 is energized, it attracts the piston 55 by a given distance. 
When the piston 55 is at the first position, it blocks the pipe 52. When 
the solenoid 56 is energized and the piston 55 moves, the pipe 52 is 
communicated through an annular groove 58 formed in the outer surface of 
the piston 55. 
In a control circuit 36 of this embodiment, a switch 59 for allowing 
communication between the selector valve 53 and the solenoid 56 operates 
in an opposite manner, as shown in FIG. 8 to the lamp switch 37. More 
specifically, when the lamp switch 37 is open, the switch 59 is closed, 
and when the lamp switch 39 is closed, the switch 59 is open. 
The lamp switch 37 is operated by a sliding button 61. The air pump 16 is 
directly connected to a power switch 44. 
When diagnosis is to be performed according to this embodiment, the lamp 
switch 37 is closed by operating the sliding button 61. Then, the switch 
59 of the selector valve 53 is opened, and the valve 53 is kept closed. 
Therefore, no compressed air is supplied to the liquid supply tank 32 by 
the air pump 16. For this reason, even if the switching mechanism 19 is 
accidentally set to the liquid supplying side during diagnosis, liquid 
will not be supplied to the air supply channel 7 through a lifting pipe 
31. 
In order to clean the air supply channel 7, the lamp switch 37 is opened. 
Then, in synchronism with this, the switch 59 is closed and the solenoid 
56 of the valve 53 is energized. Then, the piston 55 is attracted to the 
solenoid 56, so that the valve 53 is opened, and the pipe 52 is 
comunicated. Since the air pump 16 is actuated, compressed air from the 
pump is supplied to the liquid supply tank 32 to allow supply of a liquid 
held therein. When the switching mechanism 19 is operated in this state, 
the liquid in the tank 32 flows into the air supply channel 7 to clean it. 
In order to dry the channel 7, the lamp switch 37 is turned on. Then, the 
compressed air in the air pump 16 is supplied to the air supply channel 7 
through the cylinder 24 of the switching mechanism 19. At this time, the 
valve 53 is closed. During this drying process, air can also be supplied 
when the lamp switch 37 is open. Therefore, the piston 25 of the switching 
mechanism 19 can be switched to the first position when the lamp switch 37 
is open. 
FIG. 9 shows a third embodiment of the present invention. In this 
embodiment, the selector valve 53 of the second embodiment is arranged at 
an intermediate position of the lifting pipe 31 between the switching 
mechanism 19 and the liquid supply tank 32. Other details of the 
construction of the third embodiment remain the same as those of the 
second embodiment. The device of the third embodiment operates in the same 
manner as the second embodiment. 
FIGS. 10 and 11 show a fourth embodiment of the present invention. The 
fourth embodiment has substantially the same construction as that of the 
third embodiment and is different therefrom only in that a manual selector 
valve 62 is arranged at an intermediate position of the lifting pipe 31 in 
place of the valve 53 of the third embodiment. The valve 62 engages with 
the sliding button 61 for operating the lamp switch 37 through a lever 63 
and is opened/closed in synchronism with the sliding button 61. As shown 
in FIG. 11, the valve 62 has a cylindrical valve body 64 and a valve plug 
65 rotatably arranged therein. The valve plug 65 has a channel 66 for 
allowing communication with the lifting pipe 31. The lever 63 extends from 
the valve plug 65 outside the valve body 64. The channel 66 is 
opened/closed by rotating the valve plug 65 by means of the lever 63. An 
elastic member 67 for providing a hermetic seal is arranged around the 
valve plug 65. When the sliding button 61 is operated and the lamp switch 
37 is closed, the selector valve 62 is closed through the lever 63 coupled 
to the sliding button 61. The valve 62 is opened as the lamp switch 37 is 
opened. Other details of the operation of this embodiment are the same as 
those of the second embodiment. Note that the selector valve 62 can be 
inserted at an intermediate position of the pipe 52. 
FIG. 12 is a fifth embodiment of the present invention. This embodiment 
does not have a selector valve 53 or 62 but has a locking mechanism for 
locking the piston 26 of the switching mechanism 19 by means of the 
sliding button 61. This locking mechanism has a stopper pin 64 formed on 
the sliding button 61, and a stopper groove 65 formed on the outer surface 
of the piston 26 of the switching mechanism 19. When the sliding button 61 
is operated while the piston 26 is at the first position, the stopper pin 
64 is fitted in the stopper groove 65 so as to lock the piston 26 at the 
first position and the lamp switch 37 is closed. Thus, if the lamp switch 
37 is closed, the switching mechanism 19 is locked and liquid cannot be 
supplied. However, when the lamp switch 37 is open, that is, when the 
sliding button 61 is not being operated, the switching mechanism 19 can be 
operated and the air pump 16 is operative. Therefore, liquid can be 
supplied to clean the air supply channel 7. 
FIG. 13 shows a sixth embodiment of the present invention. In this 
embodiment, instead of operating the stopper pin 64 by means of the 
sliding button 61, the stopper pin 64 is operated by a solenoid 66. The 
solenoid 66 is energized by the control circuit 36 to project the stopper 
pin 64, as needed. Thus, when the lamp switch 37 is closed, the solenoid 
66 is energized. Other details of this embodiment remain the same as those 
of the fifth embodiment. 
A selector valve 67 as shown in FIGS. 14 and 15 can be used as the 
switching mechanism 19. The valve 67 has a cylinder 68, a piston 69 
slidably inserted in the cylinder 68, a spring 71 for biasing the piston 
69 from a second position shown in FIG. 14 to a first position shown in 
FIG. 15, and a solenoid 72 for attracting the piston 69 to the second 
position. When the lamp switch 37 is open, that is, when the light source 
12 is not ON, the solenoid 72 is energized and the piston 69 is attracted 
to the second position. Then, the lifting pipe 31 communicates through an 
annular groove 73 formed in the outer surface of the piston 69. However, 
when the lamp switch 37 is closed, the solenoid 72 is not energized. Thus, 
the piston 69 is at the first position and allows communication of the air 
supply pipe 52. In this state, liquid cannot be supplied. 
FIGS. 16 to 22 show a seventh embodiment of the present invention. In this 
embodiment, two types of liquid supply tanks 81 and 82 are arranged. An 
infusion solution or a disinfectant is held in the tank 81, and water is 
held in the tank 82. The air pump 16 and the receptacle 18 are coupled 
through an air supply pipe 84. A first electromagnetic valve 85 is 
arranged at an intermediate position of the air supply pipe 84. Lifting 
pipes 86 and 87 are respectively connected to the liquid supply tanks 81 
and 82. The pipes 86 and 87 are connected to the receptacle 18 through a 
second electromagnetic valve 88 and a liquid supply pipe 89. The tanks 81 
and 82 also communicate with the air supply pump 16 and are supplied with 
compressed air to thereby supply the liquids. 
The first electromagnetic valve 85 has the construction as shown in FIGS. 
17 and 18. More specifically, a piston 92 is slidably inserted inside a 
cylinder 91 connected to the air supply pipe 84. The piston 92 is driven 
by a solenoid 93. The piston 92 is also biased by a spring 94 from a 
second position shown in FIG. 18 to a first position shown in FIG. 17. 
When the solenoid 93 is not energized, the piston 92 is at the first 
position and the air supply pipe 84 is allowed to communicate through an 
annular groove 95 formed in the outer surface of the piston 92. When the 
solenoid 93 is energized it attracts the piston 92 against the biasing 
force of the spring 94. Then the piston 92 blocks the air supply pipe 84. 
The second electromagnetic valve 88 has the construction as shown in FIGS. 
19 and 20. The valve 88 has a cylinder 96 which is connected to the 
lifting pipes 86 and 87 and to a liquid supply pipe 89, and a piston 97 
which is slidably inserted in the cylinder 96. The piston 97 is moved by a 
solenoid 98 and a spring 99. When the solenoid 98 is not energized, the 
piston 97 is biased by the spring 99 to a first position (standby 
position) shown in FIG. 19. When the solenoid 98 is energized, the piston 
97 is attracted by the solenoid 98 against the biasing force of the spring 
99 and is moved to a second position shown in FIG. 20. When the piston 97 
is at the first position, the lifting pipe 86 communicates with the liquid 
supply pipe 89 through an annular groove 101 formed in the outer surface 
of the piston 97, while the lifting pipe 87 is blocked by the outer 
surface of the piston 97. When the piston 97 is at the second position, 
the lifting pipe 87 communicates with the liquid supply pipe 89 through 
the annular groove 101 of the piston 97 while the lifting pipe 86 is 
blocked. 
The air pump 16, the first and second electromagnetic valves 85 and 88 and 
the light source 12 are connected in a control circuit 102, a circuit 
diagram of which is shown in FIG. 21. Various switches for controlling the 
control circuit 102 are arranged at the front side of the housing 11. In 
the control circuit 102, a drive voltage Vcc is applied to the series 
circuit of the air pump 16 and a first electromagnetic contactor 103 
through a normally closed main stop switch 104 and a normally open main 
switch 105. A contact 103a of the contactor 103 is connected in parallel 
with the main switch 105. The drive voltage Vcc is applied to a series 
circuit of the light source 12 and a second electromagnetic contactor 106 
through the main stop switch 104, the main switch 105, a normally closed 
lamp stop switch 107 and a normally open lamp switch 108. A contact 106a 
of the contactor 106 is connected in parallel with the lamp switch 108. 
The drive voltave Vcc is also applied to a series circuit of the first 
electromagnetic valve 85, a third electromagnetic contactor 109 and a 
contact 106b of the contactor 106 through the main stop switch 104, the 
main switch 105, a normally closed cleaning stop switch 111, and a 
normally open liquid supply switch 112. A contact 109a of the contactor 
109 is conneced in parallel with the liquid supply switch 112. A series 
circuit of the second electromagnetic valve 88, a fourth electromagnetic 
contactor 113 and a contact 106c of the contactor 106 is connected through 
a normally open switch 114 to a node between the switch 112 and the 
contactor 109. A contact 113a of the contactor 113 is connected in 
parallel with the switch 114. 
The operation of this embodiment is performed in accordance with the timing 
chart shown in FIGS. 22A to 22L. When the main switch 105 is closed, the 
drive voltage Vcc is applied to the air pump 16 which starts operating. 
Then, the first electromagnetic contactor 103 is energized to close its 
contact 103a. Thus, the operation of the air pump 16 is continued. The 
delivery pressure of the air pump 16 is applied to the liquid supply tanks 
81 and 82 to decompress the liquids held therein. However, since the first 
and second electromagnetic valves 85 and 88 are closed, the liquids will 
not be supplied from these tanks 81 and 82. 
A case for cleaning the air supply channel 7 of the endoscope 1 will now be 
described. First, when the liquid supply switch 112 is closed, the third 
electromagnetic contactor 109 is energized and its contact 109a is closed. 
Then, the first electromagnetic valve 85 is energized, and the piston 92 
moves to the second position shown in FIG. 18 to block the air supply pipe 
84. Thus, supply of air to the air supply channel 7 is not performed. 
Since the piston 97 of the second electromagnetic valve 88 is at the first 
position shown in FIG. 19, the lifting pipe 86 communicating with the tank 
81 holding the infusion solution therein communicates with the liquid 
supply pipe 89. However, the lifting pipe 87 is blocked. Therefore, only 
the infusion solution is supplied to the air supply channel 7. 
When the switch 114 is operated and closed, the fourth electromagnetic 
contactor 113 is energized and its contact 113a is closed. Then, the valve 
88 is energized, and the piston 97 moves to the second position shown in 
FIG. 20. The lifting pipe 87 communicates with the liquid supply pipe 89, 
and the lifting pipe 86 is blocked by the piston 97. Therefore, only the 
water in the tank 32 is supplied to the air supply channel 7 of the 
endoscope 1, thus cleaning it with water. 
When the cleaning stop switch 111 is despressed, the whole cleaning 
operation is stopped. More specifically, the valve 85 is returned to the 
first position shown in FIG. 17 and the second valve 88 is returned to the 
first position shown in FIG. 19. No liquid is supplied in this state. 
Meanwhile, when the piston 92 of the first electromagnetic valve 85 returns 
to the first position, air is supplied to dry the air supply channel 7. 
The main stop switch 104 is then depressed to stop conduction of the first 
electromagnetic contactor 103 and to open its contact 103a. Then, the air 
pump 83 is deactivated, and the supply of air is stopped. 
When diagnosis is to be performed with the endoscope 1, the main switch 105 
and the lamp switch 108 are turned on. In this case, the second 
electromagnetic contactor 106 is energized and its contact 106a is closed. 
Power is supplied to turn on the light source 12. When the contact 106a of 
the contactor 106 is closed, the light source 102 is kept ON. However, at 
the same time, contacts 106b and 106c are opened. Therefore, the solenoids 
93 and 98 for the first and second electromagnetic valves 85 and 88 are 
not energized. That is, when the light source 12 is ON, the valves 85 and 
88 are OFF and erroneous supply of liquid is prevented. 
The means for detecting the ON/OFF state of the light source can be a 
current detector for detecting a current flowing to the light source or a 
photosensor for detecting light emitted from the light source according to 
the present invention. 
The receptacle 18 can have a check valve 117, as shown in FIG. 23. A valve 
plug 118 is biased by a spring 119. When the connecting mouthpiece 8 of 
the connector 6 is not inserted, a channel 120 can be blocked. When the 
connecting mouthpiece 8 is inserted in the receptacle 18, the valve plug 
118 is pressed through the mouthpiece to communicate the channel 120. 
Then, even if liquid is supplied while the connector 6 is removed, leakage 
of the liquid through the receptacle 18 is prevented. 
As described above in detail, according to the present invention, 
accidental supply of an infusion solution or the like which may be harmful 
to the human body into a body cavity of a patient during diagnosis with an 
endoscope can be prevented. A liquid supplying device of the present 
invention does not require switching of connectors and the like and is 
easy to handle.