A keyboard adjustment device for a fully reclining wheelchair

Abstract

A retractable keyboard adjustment device for a fully reclining wheelchair consists of a movable inner keyboard with grooves and a fixed inner keyboard with protrusions connected together. A spline shaft is fitted inside the keyboard, and the splines are manufactured according to national standard involute teeth, with the same module and number of keys. The end face of the keyboard has a movable outer cover with a central hole and a fixed outer cover with a central screw hole. An electromagnetic coil is located on the fixed outer cover. A large central hole is provided on the spline shaft, and a spring is installed inside the large hole. A clutch lever is provided on the end face of the shaft. A bolt passes through the movable outer cover, the spline shaft, the large hole, and the spring, and is tightened onto the screw hole of the fixed outer cover. A backrest or foot pedal is welded to the outer ring of the movable inner keyboard. The fixed spline keyboard is welded to the outside of the wheelchair frame. Turning on the electromagnetic switch or pulling the clutch lever causes the movable inner keyboard to rotate, moving the backrest or foot pedal to a 180-degree horizontal position. Turning off the electromagnetic switch and clutch lever allows the person to recline fully in the wheelchair. This technology features a small and strong structure, and its size is even smaller when integrated into a folding wheelchair.

Description

Technical Field

[0001] This technology belongs to the field of rehabilitation medicine and wheelchairs for the disabled. Background Technology

[0002] Wheelchairs are a means of transportation for many patients with leg disabilities or illnesses who are unable to walk. Now, there are many varieties to suit the needs of different patients. Electric wheelchairs, in particular, are becoming increasingly popular due to their convenience. To accommodate various groups, electric wheelchairs with different functions have been developed, including both regular and electric wheelchairs. Patients who have been sitting in electric or push wheelchairs for a long time often want to lean back, and some patients simply cannot sit still and need to recline for comfort. To meet these needs, many wheelchairs now offer backrests that can recline flat or have adjustable angles. All wheelchairs with reclining functions involve adding more components, some of which include electric and pneumatic components to achieve automatic backrest height adjustment. The more components added, the higher the cost, increasing the complexity and overall weight of the wheelchair. Even so, most reclining wheelchairs do not reach a 180-degree flat position. Wheelchairs that can achieve a 180-degree flat position have even greater added weight and cost to ensure safety. The increased weight further complicates the already inconvenient experience for wheelchair users. Currently, lightweight wheelchairs, including folding lightweight wheelchairs and electric lightweight folding wheelchairs, cannot achieve a 180-degree flat position. Summary of the Invention

[0003] This invention discloses a spline adjustment device for a fully reclining wheelchair. The spline structure consists of a movable inner spline and a fixed inner spline, connected by a stepped configuration. The movable spline has a 1.5mm groove on its outer circumference, and the fixed spline has a 1.5mm protrusion on its outer circumference. The protrusion and groove together achieve concentricity of the inner splines and allow the spline to rotate. The module of the inner splines of the two inner splines is between m0.8 and m3, and the number of keys is between z20 and z40. The outer diameter of the two splines is between 25mm and 70mm. The width of the fixed inner spline is twice the width of the movable inner spline plus 1.5mm. Spline shafts with the same module and number of keys are fitted inside the two splines and mesh together. The width of the spline shaft is shorter than the width of the fixed inner spline. The 1.2mm splined key has a large central hole with a diameter of 14mm to 22mm. At the other end of this large central hole is a smaller central hole with a 6.5mm to 10.5mm diameter and a 3mm thickness step. A spring is installed inside the large central hole. One end face of the splined key has a groove for the solenoid coil and two screw holes for the clutch lever. The movable inner splined key has a movable outer cover with a 0.25mm step. This step engages with the inner splined key's internal splined hole. Four countersunk screws secure the movable outer cover to the movable inner splined key's end face. The movable outer cover has a 6.5mm to 10.5mm diameter central hole. The fixed inner splined key has a fixed outer cover with a 0.25mm step. This step engages with the inner splined key. Three countersunk screws in the inner spline hole secure the outer cover to the end face of the inner spline keyboard. The center of the outer cover has a fine-pitch screw hole (M6×0.8~M10×1). The cover has two clutch lever holes. A 24V electromagnetic coil is fixed to the inner end face of the cover with screws. The two clutch levers pass through the holes in the outer cover, and their threads are fixed in the screw holes on the end face of the spline shaft. The two clutch levers outside the outer cover are connected by a steel rod. A fine-pitch bolt (M6×0.8 or M10×1) passes through a 6.5mm~10.5mm diameter hole in the movable outer cover, through the large hole of the spline shaft, through the spring, and through a 6.5mm~10.5mm diameter × 3mm thick stepped hole, and is then rotated and fixed to the outer cover. Inside the fine-thread screw hole, a fine-thread bolt connects two keypads together to form a keypad adjustment device. Backrest rods are welded to the outer circumference of the movable keypads of the two keypad adjustment devices. The outer circumferences of the two fixed inner keypads are welded to the two sides of the outer frame behind the flat wheelchair seat. The 24-volt electromagnetic coil connecting wire inside the inner keypad device is connected in series with a rear electromagnetic switch and then connected to the wheelchair battery. Foot pedals are welded to the two movable keypads of the two keypad adjustment devices. The outer circumferences of the two fixed inner keypads are welded to the two sides of the outer frame in front of the flat wheelchair seat. The 24-volt electromagnetic coil connecting wire inside the inner keypad device is connected in series with a front electromagnetic switch and then connected to the wheelchair battery. A keypad adjustment device for a fully reclining wheelchair is thus installed on the wheelchair.

[0004] With this setup, under the spring's thrust, the spline shaft is positioned on one side of the movable inner spline keyboard, fixing the two inner spline keyboards together. The movable inner spline keyboard is thus fixed and cannot rotate. The backrest and footrest, welded to the movable spline keyboard, are also fixed in place, allowing the person sitting in the wheelchair to lean against the backrest and use the footrests. When activated, the electromagnetic switch, or by manually pulling the clutch lever outward, causes the spline shaft to be electromagnetically attracted and moved to the fixed spline keyboard side. The two backrest and footrests can then rotate freely up and down. The two backrests, along with the backrest fabric, can rotate forward 100 degrees and backward 170 degrees. The footrests can rotate 360 ​​degrees. The wheelchair's advantage lies in the fact that the spline keyboard adjustment device is welded to the outside of the left and right frames, allowing the backrest and footrests to be adjusted to any degree, easily achieving a 180-degree reclining position. Furthermore, the backrests can be adjusted 270 degrees, and the footrests 360 degrees. When applied to lightweight folding wheelchairs, the wheelchair becomes even smaller when folded. Furthermore, because the inner ring of the keyboard is entirely composed of keys, with 20 to 40 keys designed, each key is manufactured according to the tolerance of the national standard common normal. The internal splines and spline shafts mesh and bear force, resulting in high cumulative strength. No additional auxiliary accessories are needed. The splines are manufactured according to national standards, and the spline height is set low, making the keyboard smaller. This makes the wheelchair manufacturing simpler and lighter, and can be expanded to other folding furniture, medical carts, beds, and folding tables and folding shelves in factories. Attached Figure Description

[0005] Figure 1 This is a structural diagram showing the connection position of the keyboard in the keyboard adjustment device of a fully reclining wheelchair.

[0006] Figure 2 This is a structural diagram of the keyboard separation position of a keyboard adjustment device for a fully reclining wheelchair.

[0007] Figure 3 It shows the location of the keyboard on the side of the wheelchair connecting the backrest and footrest, as well as the rotation positions of the backrest and footrest.

[0008] Figure 4 This is a diagram showing the location of the keyboard on the back of the wheelchair.

[0009] Appendix Figure 1 Appendix Figure 2In the diagram, 1 is the welding position of the wheelchair backrest or footrest, 2 is the countersunk screw of the cover plate, 3 is the movable outer cover, 4 is the spring, 5 is the center large hole of the spline shaft, 6 is the spline shaft connection position, 6.1 is the spline shaft separation position, 7 is the spline shaft, 8 is the movable inner spline keyboard, 9 is the welding position of the wheelchair frame, 10 is the fixed inner spline keyboard, 11 is the connecting convex and concave steps, 12 is the fixed outer cover, 13 is the spline, 14 is the electromagnetic coil, 15 is the fixing screw of the electromagnetic coil, 16 is the fine thread bolt, 17 is the fine thread screw hole, 18 is the manual clutch lever, 19 is the electromagnetic wire, and 20 is the spline shaft groove.

[0010] Figure 3 21 is the keypad adjustment device connecting to the backrest bar, 22 is the backrest bar in the flat position, 23 is the backrest bar in the normal use position, 24 is the armrest folded up position, 25 is the armrest in the normal use position, 26 is the footrest in the flat position, 27 is the keypad adjustment device connecting to the footrest, 28 is the footrest in the normal use position diagram, and 29 is the frame.

[0011] Figure 4 21 is the keyboard adjustment device connecting the backrest rod, 23 is the backrest rod, 25 is the movable armrest, and 29 is the frame. Detailed Implementation

[0012] The following detailed description, with reference to the accompanying drawings, introduces the structural principle and usage method of a spline adjustment device for a fully reclining wheelchair disclosed in this invention. The spline adjustment device consists of two inner spline keys 8 and 10, and a spline shaft 7. The splines 8 and 10 within the two spline keys and the spline shaft 7 are all made according to the national standard involute tooth profile 13, national standard code: GB34781-83. The inner and outer splines have good meshing and high strength, thus enabling miniaturization and making it more suitable for lightweight folding wheelchairs. The spline adjustment device comprises a movable inner spline key 8 and a fixed inner spline key 10, along with a spline shaft 7. The two inner spline keys 8 and 10 are connected together using a convex-concave step configuration 11. The outer circle of the movable inner spline key 8... The inner spline keypad 10 has a 1.5mm groove and a 1.5mm boss on its outer circumference. The boss and groove work together to ensure the two inner splines are perfectly concentric and the keypad can rotate. The module of the inner splines of the two inner splines 8 and 10 is between m0.8 and m3, and the number of keys is between z20 and z40. The outer diameter of the two inner splines 8 and 10 is between 25mm and 70mm. The module size and number of keys are selected based on the wheelchair's load capacity and strength. Larger wheelchairs require larger modules and more keys, while lighter wheelchairs require smaller modules and fewer keys, resulting in a smaller keypad design more suitable for portability. The width of the fixed inner spline keypad 10 is the width of the movable inner spline keypad. The keyboard 8 is twice the width plus 1.5mm. Inside the two inner keyboards 8 and 10, there are spline switches 7 with the same module and number of keys, meshing together. The width of the spline switch 7 is 1.2mm shorter than the width of the fixed inner keyboard 10. The width settings of these three parts ensure that when the spline switch 7 moves into the fixed inner keyboard 10, it completely disengages from the movable inner keyboard 8, allowing the movable inner keyboard disc 8 to rotate, achieving a clutch function. The spline switch 7 has a large central hole 5 with a diameter of 14mm to 22mm. At the other end of the large central hole 5 is a small central hole with a diameter of 6.5mm to 10.5mm and a thickness of 3mm. A spring 4 is placed inside the large central hole 5. Normally, the spring 4 pushes the spline switch 7 towards one side of the movable spline switch 8. The central hole blocks the spring 4, and the spline shaft 7 is half engaged with the movable spline keyboard 8 and half engaged with the fixed spline keyboard 10. The fixed spline keyboard 10 is fixed and the movable spline keyboard 8 is also fixed by the engagement of the spline shaft. The backrest rod 23 or footrest rod 28 is welded to the welding position 1 on the outer circle of the movable spline keyboard 8 and is also fixed. When a person sits in a wheelchair, they can lean against the backrest and the footrest. The other end face of the spline shaft 7 is provided with a groove 20 for inserting an electromagnetic coil and two screw holes for clutch levers. This is a design for separating and merging the movable spline keyboard 8 in two ways. Both methods are convenient for human operation. In actual manufacturing, one method can be made. The end face of the movable inner spline keyboard 8 is equipped with a movable outer cover 3. The end face of the movable outer cover 3 has 0.A 25mm step is provided, which fits into the inner keyhole of the inner keypad. Four screws fix the movable outer cover 3 to the end face of the movable inner keypad 8. The movable outer cover 3 has a center hole with a diameter of 6.5mm to 10.5mm. The movable outer cover 3 covers the movable inner keypad 8, protecting the inside of the keyboard and also blocking the spline switch 7. The end face of the fixed inner keypad 10 is equipped with a fixed outer cover 12. The end face of the fixed outer cover 12 has a 0.25mm step, which fits into the inner keyhole of the inner keypad. Three countersunk screws fix the fixed outer cover 12 to the end face of the fixed inner keypad 10. The use of three screws for fixation is to distinguish it from the movable outer cover. The 0.25mm step on the end face of the two covers serves to ensure concentricity. The center of the fixed outer cover 12 has a fine-threaded screw hole 17. Fine-threaded bolts 16 are used to connect the two inner keypads 8 and 10 together. When the fine-threaded bolt 16 rotates into the fine-threaded screw hole 17, the bolt 16 is fixed in place. The other end is a smooth rod. The movable outer cover 2 can rotate by fitting its light hole onto the smooth rod. A 24V electromagnetic coil 14 is fixed to the inner end face of the fixed outer cover 12 with screws 15. The position of the electromagnetic coil 14 is directly opposite the electromagnetic groove 20 on the end face of the spline shaft 7. After the electromagnetic coil 14 attracts the spline shaft 7, the electromagnetic coil 14 is in the electromagnetic groove 20. This setting reduces space and makes the parts smaller. There are two clutch lever light holes on the fixed cover 12. The two clutch levers 18 pass through the fixed outer cover. The two clutch levers 18 are threaded into the threaded holes on the end face of the external splined shaft 7 through the open hole 12. The two clutch levers 18 are connected as one piece by a steel rod outside the fixed outer cover 12. This design facilitates manual operation of the clutch levers 18. A fine-threaded bolt 16 of M6*0.8 or M10*1 passes through the open hole of the movable outer cover 3 with a diameter of 6.5mm to 10.5mm, through the large hole 5 of the splined shaft 7, through the spring 4, and through the hole with a diameter of 6.5mm to 10.5mm.A 5mm*3mm stepped hole is rotated and fixed in the fine-threaded screw hole 17 of the fixed outer cover 10. The fine-threaded bolt 16 connects the two keypads 8 and 10, the two cover plates 2 and 12, the spline shaft 7, and the spring 4 into a single unit to form a keypad adjustment device. The fine-threaded thread 16 is fixed on the fixed outer cover 12. The other end of the fine-threaded bolt 16 is a smooth rod. The smooth hole of the movable cover plate 3 can rotate on the smooth rod. The backrest rod 23 is welded to the welding point 1 on the outer circle of the movable keypad 8 of the two keypad adjustment devices 21. The frame welding point 9 on the outer circle of the two fixed inner keypads 10 is welded to the frame 29. The position is fixed on both sides of the frame 29 behind the flat wheelchair seat. The movable keypad 8 is also outside the frame 29. The movable keypad 8 can rotate with the wheelchair backrest rod 23. The 24-volt electromagnetic coil inside the inner keypad device A rear electromagnetic switch is connected in series with the connecting wire 14, and then connected to the wheelchair battery. The voltage is the same as the wheelchair's voltage. The foot pedals 28 are welded to the welding points 1 on the two movable spline keys 8 of the two spline key adjustment devices 27. The frame welding point 9 on the outer circle of the two fixed inner spline keys 10 is welded to the frame, positioned on both sides of the frame in front of the wheelchair seat. The two spline key adjustment devices are located outside the frame 29. The 24-volt electromagnetic coil 14 inside the spline key device is connected in series with a front electromagnetic switch and then connected to the wheelchair battery. When the solenoid valve is opened, the spline shaft 7 is attracted to one side of the fixed spline key, allowing the movable spline key 8, along with the welded foot pedals, to rotate 360 ​​degrees. Through this setup and operation, the spline key adjustment device, along with the backrest and foot pedals, can rotate at any angle, allowing the wheelchair to recline to 180 degrees.

[0013] With this setup, under the normal pushing force of spring 4, the spline shaft 7 is positioned on one side of the movable inner keypad 8, that is, between the two inner keypads 8 and 10. The spline shaft fixes the two inner keypads 8 and 10 into one unit, thus fixing the movable keypad 8 in place and preventing it from rotating. The backrest rod 23 or footrest rod 27 welded to the movable keypad 8 is also fixed in place, allowing the person in the wheelchair to lean against the backrest and use the footrest. When the front and rear electromagnetic switches are turned on, the spline shaft 7 is electromagnetically attracted and moved to the side of the fixed keypad 10. Alternatively, the clutch lever 18 can be manually pulled outwards, allowing the backrest rod 23 and footrest rod 27 welded to the movable inner keypad 8 to rotate up and down. Because the fixed inner keypad 10... Welded to the outside of the frame 29, the two backrest rods 23, along with the backrest fabric, can rotate forward 100 degrees and backward 170 degrees. The footrest rod 27 can rotate 360 ​​degrees. When the backrest rod 23 and the footrest rod 27 are aligned with the seat, the front electromagnetic switch is turned off, or the clutch lever 18 is released. Under the push of the spring, the spline shaft 7 moves to the side of the movable inner spline keypad 8, that is, between the two inner spline keypads 8 and 10. The movable inner spline keypad 8 is then fixed and cannot rotate. The backrest rod 23 and the footrest rod 27 are then fixed at the level of the seat, allowing the person in the wheelchair to lie back and stretch their legs.

[0014] The key technology of the keyboard adjustment device of the present invention lies in the cooperation between the inner keyboard and the spline switch. This time, two tables are installed to make a set.

[0015]

[0016] With this design, the advantages of using it on a wheelchair are that the keyboard adjustment device is welded to the outside of the left and right frames, extending only a few centimeters, not exceeding the width of the two rear wheels or the width of the control panel. Therefore, it is within a safe range and has no impact on the wheelchair's movement. The extension only exceeds the width of the armrests, allowing the backrest and footrest to be adjusted to any degree, easily achieving a 180-degree reclining position. Furthermore, the backrest can be adjusted to 270 degrees, and the footrest to 360 degrees. When applied to a lightweight folding wheelchair, the folded wheelchair becomes even smaller. Furthermore, since the inner ring of the internal spline keyboard is entirely composed of keys, designed with 20 to 40 keys, each key is manufactured according to the tolerance of the national standard common normal. Each key of the internal spline and spline shaft is meshed and subjected to force, resulting in high cumulative strength. The backrest and footrest are strong enough to be placed in any position without the need for additional auxiliary accessories. The spline is manufactured according to national standards, and there is no need for gear-like rotation. Therefore, the spline retains multiple splines at the root of the standard tooth to maintain the force torque at the root. The key height is low, the spline keyboard is made smaller, the wheelchair is manufactured more simply, and the weight is lighter.

[0017] This invention can be extended to various medical vehicles, medical beds, and medical rolling stretchers; to folding furniture such as folding chairs, folding tables, and folding sofas; and to folding workbenches, folding shelves, and other folding components in factories. The above description is merely a preferred embodiment of the invention and is illustrative rather than restrictive. Many dimensions and shapes can be appropriately modified to achieve the same effect. It is readily understood by those skilled in the art that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of this invention, and all of these will fall within the protection scope of this invention.

Claims

1. A spline plate adjustment device for a full reclining wheelchair, characterized by: The device consists of a movable inner spline keyboard and a fixed inner spline keyboard, connected by a stepped concave-convex configuration. The movable spline keyboard has a 1.5mm groove on its outer circumference, and the fixed spline keyboard has a 1.5mm protrusion on its outer circumference. The protrusion and groove together achieve concentricity of the inner splines and allow the spline keyboard to rotate. The module of the inner splines on both keyboards is between m0.8 and m3, and the number of keys is between z20 and z40. The outer diameter of both keyboards is between 25mm and 70mm. The width of the fixed inner spline keyboard is twice the width of the movable inner spline keyboard plus 1.5mm. Both keyboards are equipped with spline shafts of the same module and number of keys that mesh together. The width of the spline shaft is 1.2mm shorter than the width of the fixed inner spline keyboard. The spline shaft has a diameter of 14mm to 2mm. A 2mm center hole is formed, with a smaller center hole at the other end, featuring a 6.5mm-10.5mm diameter step and a 3mm thickness. A spring is installed inside the center hole. One end face of the splined shaft has a groove for the solenoid coil and two screw holes for the clutch lever. A movable outer cover is fitted to the end face of the movable inner splined keyboard, with a 0.25mm step on its end face. This step is engaged with the inner splined hole of the inner splined keyboard. Four countersunk screws secure the movable outer cover to the end face of the movable inner splined keyboard. The movable outer cover has a 6.5mm-10.5mm diameter center hole. A fixed outer cover is fitted to the end face of the fixed inner splined keyboard, with a 0.25mm step on its end face. This step is engaged with the inner splined hole of the inner splined keyboard. Three countersunk screws secure the fixed outer cover to the end face of the fixed inner splined keyboard. The outer cover is fixed to the end face of the inner spline keyboard. The center of the outer cover has a fine-threaded hole (M6*0.8~M10*1). The cover has two clutch lever holes. A 24V electromagnetic coil is fixed to the inner end face of the cover with screws. The two clutch levers pass through the holes in the outer cover, and their threads are fixed in the screw holes on the end face of the spline shaft. The two clutch levers outside the outer cover are connected by a steel rod. A fine-threaded bolt (M6*0.8 or M10*1) passes through a 6.5mm~10.5mm diameter hole in the movable outer cover, through the large hole of the spline shaft, through the spring, and through a 6.5mm~10.5mm diameter * 3mm thick stepped hole, and is then rotated and fixed to the fine-threaded screw hole in the outer cover. Inside, fine-threaded bolts connect two keypads together to form a keypad adjustment device. Backrest rods are welded to the outer circumference of the movable keypads of the two keypad adjustment devices. The outer circumferences of the two fixed inner keypads are welded to the two sides of the outer frame behind the flat wheelchair seat. The 24-volt electromagnetic coil connecting wire inside the inner keypad device is connected in series with a rear electromagnetic switch and then connected to the wheelchair battery. Foot pedals are welded to the two movable keypads of the two keypad adjustment devices. The outer circumferences of the two fixed inner keypads are welded to the two sides of the outer frame in front of the flat wheelchair seat. The 24-volt electromagnetic coil connecting wire inside the inner keypad device is connected in series with a front electromagnetic switch and then connected to the wheelchair battery, thus forming a keypad adjustment device for a fully reclining wheelchair.

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