GB2168398A - A wheelchair incorporating a flush toilet - Google Patents

Abstract

A wheelchair incorporates a flush toilet consisting of a water tank, toilet bowl, excrement tank, a motor which operates a mixer for breaking excrement, and a pump for removing said excrement. A mechanism is provided whereby the toilet seat may be automatically covered by a subseat. The wheelchair is also provided with a reclining facility and an automatic moving and driving device.

Description

SPECIFICATION A multi-function wheelchair This invention is concerned with a kind of wheelchair with multi-functions which can be moved forward, backward, to the left or to the right automatically by electricity or by hand, and also be available for sitting, lying or relieving nature.

More particularly, this invention is concerned with a multi-function wheelchair, which can help those who have difficulty in walking or moving, such as the maimed, the crippled, the sick or the old. The structure of a conventional wheelchair 1, as shown in Figure 1, comprises a chair 10, a pair of front wheels 13,14 and a pair of rear wheels 11,12 with a bigger diameter than the front wheels.

At the outside of rear wheels, there are respectively sub-wheels 110,120 (sub-wheel 120 is not shown in the figure because of its viewing angle) connected with the same shaft as said rear wheels 11,12, which the user may turn with his hands to move the wheelchair. Said front wheels 13,14 can be constructed to control the moving direction with cooperation of the action of said rear wheels 11,12.

At the front of said wheelchair are a pair of foot rests and at the back 15 of the chair 10 are a couple of handles provided for manually pushing the wheelchair. This kind of wheelchair has been used for a long time, having really rendered a great contribution to mankind, but it only serves as a mobile chair for those who cannot walk.

Persons with physical defects, senile people, especially hemiplegic patients, who need to be taken care of all the time and for a long term are indeed burdens to their families and the society. Since they have lost the ability to take care of themselves, they need other's help to do daily routine acts such as going to the toilet, going to bed or moving, therefore, they gradually lose their confidence in life and even their self-respect.

The inventor, having deep compassion on those peoples, has expended a great deal of time and thought in studying and inventing this multi-function wheelchair which can not only alleviate burdens for a family with such an unfortunate member, but also help the people live more independently, reinforce their self-sustaining ability and increase their self-respect.

The main purpose of this invention is to construct a multi-function wheelchair, especially one that can also serve as a toilet. The other purposes included are to make this multi-function wheelchair mobile either automatically by electricity or by hand, available for sitting or lying and to equip it with versatile safety devices for preventing it from possible accidents.

Thus, according to the invention there is provided a multi-function wheelchair comprising a flush toilet consisting of a water tank, a toilet bowl and an excrement tank; and having a motor which operates to drive a mixer for breaking excrement, after which it is allowed into the excrement tank and settles to the bottom thereof, from where it may be pumped out by a motor pump; wherein, in order to enable use of the wheelchair as a seat or a toilet, a hole is formed in the seat facing said toi let bowl and a sub-seat is set under said seat which covers the hole to form a complete seat; and including means for raising said seat to allow said sub-seat to be pulled back and then lowered to a position just above the toilet bowl, and after using the toilet, to perform the movements of the seat and the sub-seat in reverse in order to return them to their original positions.

Preferably the wheelchair further comprises a sitting or lying changing device comprising means for adjusting the angles of inclination of a foot rest and the back of the wheelchair to positions suitable for sitting or lying.

Preferably, the wheelchair further comprises an automatic moving and driving device having two independent front wheels turned by separate motors which may be rotated clockwise or anti-clockwise at the same speed or, in order to cause the wheelchair to turn to the left or the right, may be rotated at different speeds.

An embodiment of the invention will now be described by way of example only and with reference to Figures 2 to 14 of the accompanying drawings in which: Figure 2 is a perspective view of a multi-function wheelchair constructed in accordance with the invention.

Figure 3 is a side sectional view of a toilet system incorporated in the wheelchair of Figure 2.

Figure 4 is an exploded perspective view of the toilet seat and sub-seat showing the mechanism for moving them relative to one another.

Figure 5 is a side view in the direction X shown in Figure 4 of the mechanism for moving the toilet seat and sub-seat.

Figure 6 is a top plan view of the automatic moving and driving device of the wheelchair.

Figure 7 is an electrical circuit diagram of the device used for operating the sub-seat Figure 8 is a diagram of the electrical circuit used for controlling the operations of flushing the toilet and breaking down excrement.

Figure 9 is a side view of the sitting or lying changing device of the wheelchair.

Figure 10 shows the gears which are associated with each of the driving wheels.

Figure 11 is a diagram of the electrical circuit which controls the operation of the sitting or lying changing device.

Figure 12 is a diagram of the electrical circuit which controls the operation of the automatic moving and driving device.

Figure 13 shows the relative positions of the detector lamps at the base of the wheelchair.

Figure 14 shows the positions of the switches and buttons on the arm rests used for controlling the movement of the wheelchair.

First of all, as shown in Figure 2, this wheelchair comprises sitting or lying changing device 2, toilet 3, automatic moving and driving device 5, and two sets of safety devices consisting of detector lamps 51,52.

Figure 9 is the side view of said sitting or lying changing device 2 which is electrically controlled in this multi-function wheelchair, comprising mainly an adjuster for the angle of the foot rest, and an adjuster for the angle of the chair back. It is based on the theory of an arm swinging around a fixed point to change the position of the foot rest and chair back suitable for sitting or lying. The revolving power generated by motor M4 is to be transmitted to rotating rod 90 via a combined set of a large gear and a small gear and said rotating rod 90 is then able to move both the transmitting rods 70, 71 of said foot rest adjuster and the transmitting rods 80,81 of said chair back adjuster with a connecting point 810 as a pivot.Therefore, according to the clockwise or counterclockwise rotation of rotating rod 90 (i.e. the clock-wise or counterclockwise rotation of said transmit motor M4), said transmitting rods of both said adjusters can be pushed forward or pulled backward.

Furthermore, along said transmitting rod 70 are two fixed points A,B; a limit switch A.P.S. is set at the point A for sitting and a limit switch B.P.S. is set at the point B for lying. As said transmitting rod 70 is moved such that point A or B coincides with either of said limit switches A.P.S., B.P.S., the power of motor M4 is immediately cut off to stop the rotation of said rod 90. Therefore, as long as the user pushes down either of sitting or lying buttons, this wheelchair can be changed automatically to the position for sitting or lying as he chooses.

Apart from the above-mentioned, said changing device 2 possesses two characteristics in its operation which will now be described with reference to Figure 11 as follows.

Firstly, the operation of said changing device 2 is controlled by 2 pairs of buttons P3,P4., which each have one button for the sitting position and the other for the lying position.

When one of either pair of buttons P3 or P4 is pressed down, said changing device 2 begins to change gradually the angle of said chair back 21 and said foot rest 22 relative to the seat 23 and if said button is released, said changing device 2 immediately stops working. Therefore, a wide variety of angles of inclination can be selected freely. Additionally, while pressing down said button continuously, said changing device 2 continues to work till said point A or B is touched and a limit switch automatically cuts off the power when either of the points A or B is touched.

Secondly, in order to prevent the user from being pinched and hurt between chair back 21 and arm rests 24 while said chair back 21 is changed from "lying" position to "sitting" position and is moving close to said arm rests 24, a safety device consisting of detector lamps 52 is set at the ends of arm rests 24 facing the chair back 21.

Figure 3 is the cross-section view of said toilet 3, which possesses water tank 31 controlled by a motor pump to pump water in it through a connecting pipe 315 to flush toilet bowl 32, and while the water in water tank 31 is automatically flushed in and washing toilet bowl 32, water is also automatically beginning to flow through a water inlet pipe 314 into water tank 31.

On top of water tank 31, there is a cover 313 which can be opened to pour water into said tank 31 as well. In addition, a hole 231 in said seat 23 faces the opening of toilet bowl 32. Inside excrement tank 33 is set a U-shaped pipe 330, whose one end is tightly connected with the bottom exit of toilet bowl 32 and whose other end has around its wall several filtering holes 3301. Mixwer 331 is fitted in a hollow space near said filtering holes.

Small leaves 3310 fixed around the shaft of mixer 331 are formed not only for breaking excrement to small pieces but also for churning, and forcing what is churned to flow upward. The shaft of mixer 331 protrudes out of the pipe coupling with a ball bearing in fixing base 332 and is rotated by motor 333. Said fixing base 332 can keep said shaft in position and let it rotate smoothly and besides, it is tightly sealed so that the dirty water in excrement tank 33 may not seep out.

As solid excrement is flushed away from toilet bowl 32 by the water in water tank 31 into Ushaped pipe 330 of excrement tank 33, it mixes with the water and then the mixture is gradually churned and broken to pieces by mixer 331, driven up by the force generated by leaves 3310, forced to penetrate through filtering holes 3301 and finally flow down to the bottom of excrement tank 33.

Solid excrement not small enough to pass through filtering holes 3301 will be repeatedly churned and broken to pieces until it is able to pass through said holes 3301, and stored at the bottom of said tank 33. When it reaches a certain amount, motor pump 335 set under the bottom of said tank 33 pumps it out of said tank 33.

Seat 23 is designed for regular sitting and for relieving nature as well. As to the design and function of seat 23, please refer to Figure 4, the structural view of seat 23 and sub-seat 203. Seat 23 is set on adjusting rods 232, 233 which are respectively fixed with pairs of nuts A1,A2 and A3,A4 at each of their two ends, and nuts Al, A2, A3, A4 are to be screwed together with four threaded rods D1,D2, D3,D4 fixed on support frame 235 by means of four ball bearings B1 etc. Four gears G21,G22,G23,G24 are respectively fixed with threaded rods D1,D2,D3,D4 and chain C2 is put around four gears G21,G22,G23,G24 to form a transmitting circuit. The power for moving said transmitting circuit is supplied by a first motor M1 with the aid of a first chain C1 and gear G1. As soon as motor M1 starts to rotate clock-wise or counterclockwise, adjusting rods 232,233 begin to be moved up or down, and the height of rising is controlled by a top detector switch T.D.S. and the lowering by a bottom detector switch B.D.S. As mentioned above, seat 23 is set on adjusting rods 232,233 and is bored with hole 231 just facing toilet bowl 32 as shown in Figure 3. Furthermore, under seat 23, there is sub-seat 203 made of a thin board on which a board having the shape of the hole 231 in seat 23 is fixed. When this wheelchair serves as chair for sitting, not for relieving nature, protruding part of sub-seat 203 just fits in hole 231 of seat 23, that is, seat 23 and sub-seat 203 fit together to form a complete seat. At this stage, two sides of said sub-seat are always settled on guiding rods 204,205.Under the left side of sub-seat 203 is placed rack C30 which engages with gear G3 and is driven by a motor M3 by means of a chain C3 (see Figure 5). Along guiding rod 204 two points, front and rear, are selected, and at the front point is fixed a front limit switch F.L.S. and at the rear point a rear limit switch A.L.S. The limit switches serve for controlling the back movement and returning movement of sub-seat 203 as Figure 5 shows.

Figure 7 is the diagram of the electrical circuit used for changing operation of seat 23 and subseat 203, and their changing movement is to be explained with reference to Figures 3,4 and 5.

When the user wants to use the toilet he first pushes toilet switch S1 for starting motor M1 which immediately operates to move chain C2, four transmitting rods D1,D2,D3,D4, and adjusting rods 232,233 in order, meanwhile seat 23 is being raised up and separated from sub-seat 203. When adjusting rods 232,233 are raised up to touch top limit switch T.P.S. the power of motor M1 is at once shut off, but motor M3 is instantly started to move chain C3, gear G3, and rack C30, and as a result sub-seat 203 slides backward along guiding rods 204,205 until it touches limit switch A.L.S., which shuts off motor M3. Simultaneously, motor M1 is at once started again to rotate adjusting rods 232, 233 to lower down again seat 23 to its original position, just above the toilet bowl.

After the toilet has been used, if flushing button P1 is pressed, motor pump 311 starts to flush water into toilet bowl 32 and, meanwhile, motor 333 on excrement tank 33 also starts to drive mixer 331. An additional characteristic relative to the control for flushing and dispersing excrement is described as follows with reference to Figure 8. Not till flushing button P1 is pressed down, does the action of flushing start, and if said button P1 is released, flushing is ceased right away. Therefore, the user can properly and effectively control the water volume in accordance with the necessity.

Furthermore, motor 333 and motor pump 311 are to be started at the same time, but since motor pump 333 is attached with a delay circuit, it can still continue to drive mixer 331 for one or two minutes more, i.e. a pre-set delay time, after flush button P1 is released. So it gives more time for excrement to be diluted in water and to be churned and broken to small pieces.

Figure 6 is the top view of automatic moving and driving device 5. This wheelchair is moved by front wheels 53,54 which are driven by two independent disc-shaped motors 55,56. In order to prevent the wheelchair from running fast, two reduction gears 535,546 are connected with the axes of motors 55,56. (Two disc-shaped motors with 12V, 75W were used by the inventor in a prototype and they attained an average speed of 1 km/h through the use of reduction gears.) In addition, reduction gears 535,546 act as brakes when motors 55,56 do not supply driving power. Rear wheels 57,58 are rotary ones able to help in changing the direction of the wheelchair.

The driving process of automatic moving and driving device 5, will now be described with reference to Figures 6 and 12.

Said device 5 is controlled by driving rod H shown in Figure 14 which may operate in one of four modes, "forward", "backward" "left", and "right". If said rod H is set on "forward", motors 55,56 force front wheels 53,54 to run straight ahead with same speed via reduction gears 535,546. While it is set on "backward", motors 55,56 rotate reversely to force front wheels 53,54 to run backward with the same speed.

When it is set on "left", motor 56 is shut off but motor 55 keeps rotating to force front wheel 53 to move on, so the speed difference between front wheels 53,54 together with the help of rear wheels 57, 58 turns this wheelchair to the left. By the same theory, if motor 55 is shut off and motor 56 keeps going to force front wheel 54 to move on, the wheelchair is turned to the right with the help of rear wheels 57,58. In order to prevent accidents caused by the user's improper operation, as shown in Figure 13, three detector lamps 51 are separately set near the base of the chair at the front, to the left and to the right. While this wheelchair is moving, no matter what direction it may go, said detector lamps 51 can perceive possible obstacles in a safety distance and automatically cut off the power of motor 55, 56 to prevent a collision.Additionally, under the bottom of base 6, there are also detector lamps 51 set on its left and right which can operate to stop the wheelchair when the wheelchair is going to cross a ditch or hollow.

Next, what it to be described in the axle equipment of front wheels 53, 54 whose side view is shown in Figure 10. Inside hub 540 is fixed a driving gear 5401 through whose center is positioned a transmitting axle 541. One end of axle 541 is connected with motor 56 via reduction gear 546. Between driving gear 5401 and clutch gear 545 is put a spring 542 around axle 541 to press clutch gear 545. Nut 543 is used to control engaging or releasing between driving gear 5401 and clutch gear 545 by screwing in or out of the end of axis 541. When driving gear 5401 is engaged together with clutch gear 545, frong wheel 54 is turned by said transmitting axle, that is, as transmitting axle is forced to rotate it drives front wheel 54 to turn in the same RPM. On the contrary, when clutch gear 545 is released away from driving gear 5401, front wheel 54 cannot be driven to rotate because transmitting axle just rotates idly. In other words, as long as clutch gear 545 is released from driving gear 5401, front wheel 53, 54 can not be turned by the transmitting axle even if motors 55, 56 are in the state of action. That is, this wheelchair can be moved by hand, if necessary, (i.e. pushed) without the use of motors 55,56.

Figures 14 shown the positions of all the switches and buttons used in this wheelchair. They are all arranged and placed on either left arm rest 241 or right arm rest 242. Arm rests 24 are made long enough so that the user's hands can stay on them without disturbing said buttons or switches.

On the front of left arm rest 241, a key switch K1 is set and in combination with key K2 is used to control the power, divided into three stages - Ill off (2) moving, (3) applying. As key K2 is switched to stage "moving", the power is only supplied to motors 55, 56 and their relative circuits, but the power for sitting or lying changing device 2 and toilet 3 is cut off. Therefore, when this wheelchair is in the action of moving, it is impossible to use said changing device 2 or toilet 3. Conversely, while said changing device 2 or said toilet 3 is being used, the wheelchair is impossible to move around. This is a design to meet practical necessity and is able to prevent accidents which may be caused by absent-mindedness and meanwhile, to save power consumption, too.Furthermore, the design of key K2 is purported to prevent others, especially curious people, from misuse causing damage to the parts of this chair.

On the surface of said left arm rest 241, flush button P1 is set to control motor pump 311 in flushing water from water tank 31 into toilet bowl, and simultaneously, it starts motor 333 to rotate mixer 331.

That is, water flushing and excrement treatment are carried out at the same time. A pump-out button P2 is used to control motor pump 335 under the bottom of excrement tank 33, which can pump out the sunken small excrement mixture on the bottom of said tank 33 through a rubber hole to a proper place or a container.

Two buttons P3, P4 are respectively set on the front and the rear of left arm rest 241, and both have a button for "sitting" and a button for "lying" for a user to select the condition of this chair by pressing either P3 or P4, the one nearer to the user's hand.

On the front of right arm rest 242, there is power lamp L1. When K2 is switched from "off" to "moving" or "applying", said lamp L1 is to be lighted.

If it doesn't light up or is very dim, it indicates that power is out or weak so that it cannot keep the wheelchair operating normally. The power available for this chair includes D.C. batteries and A.C. supplies.

Driving rod H is marked with four signs, A, B, R, L; A represents moving forward, B represents backing up, R represents turning to the right and L represents turning to the right. The user can use this driving rod H to go where he wants to go.

Alarm button P5 may be pressed for asking for help. Toilet switch S1 is marked with two signs "service" and "return"; if the user wants to use the toilet, he switches toilet switch S1 to "service" and said seat will automatically change into the proper position; after finishing, toilet switch S1 can be switched to "return" to make the seat return to the original condition.

Claims (11)

1. A multi-function wheelchair comprising a flush toilet consisting of a water tank, a toilet bowl and an excrement tank and having a motor which operates to drive a mixer for breaking excrement, after which it is allowed into the excrement tank and settles to the bottom thereof from where it may be pumped out by a motor pump; wherein, in order to enable use of the wheelchair as a seat or a toilet, a hole is formed in the seat facing said toilet bowl and a sub-seat is set under said seat which covers the hole to form a complete seat; and including means for raising said seat to allow said sub-seat to be pulled back and then lowered to a position just above the toilet bowl, and after using the toilet, to perform the movements of the seat and the subseat in reverse in order to return them to their original positions.

2. A wheelchair as claimed in claim 1 further comprising a sitting or lying changing device comprising means for adjusting the angles of inclination of a foot rest and the back of the wheelchair to positions suitable for sitting or lying.

3. A wheelchair as claimed in claim 2 further comprising at least two limit switches which can stop the action of the sitting or lying changing device automatically at predetermined sitting and lying positions respectively.

4. A wheelchair as claimed in claim 2 or 3 wherein the transmitting action of said sitting or lying changing device is controlled by a sitting or lying control button.

5. A wheelchair as claimed in claim 1 or claim 2 further comprising an automatic moving and driving device having two independant front wheels turned by separate motors which may be rotated clockwise or anti-clockwise at the same speed or, in order to cause the wheelchair to turn to the left or the right, may be rotated at different speeds.

6. A wheelchair as claimed in claim 5 wherein on the front to the right and left at the base of the chair are attached a plurality of detector lamps, and further detector lamps are attached under the base, for the purpose of perceiving obstacles in the path of the wheelchair, or ditches or hollows, and shutting off the power for said automatic moving and driving device in response to this perception.

7. A wheelchair as claimed in any preceding claim wherein the operation of the water flushing and the mixer revolving are activated simultaneously by a washing button, which stops the action of flushing at once whenever it is released, but does not stop the action of said mixer for a certain period of time previously set by a delay circuit.

8. A wheelchair as claimed in any preceding claim further comprising arms rests, wherein a safety device comprising detector lamps is set on the end of each of the arm rests facing the chair back and can act to stop the operation of said sitting or lying changing device at a safe distance when an obstacle is present between the chair back and the arm rest in order to prevent the user's hand or body from being hurt while changing said chair back from lying position to sitting position.

9. A wheelchair as claimed in any preceding claim further comprising a driving mechanism for each of the front wheels which comprises a driving gear positioned between the hub and a transmitting axle, and a spring, a clutch gear and a nut associated with said transmitting axle; such that if said clutch gear is engaged with said driving gear by screwing the nut towards the wheel, the front wheel itself will rotate together with said transmitting axle as a unit; and if said clutch gear is disengaged from said driving gear by releasing the nut, then the front wheel cannot be rotated because said transmitting axis rotates idly.

10. A wheelchair as claimed in any preceding claim wherein the sub-seat has a raised surface which fits into the hole in the seat.

11. A wheelchair substantially as herein described with reference to any of figures 2 to 14 of the accompanying drawings.