JPH0446741Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a locking device for a simple rotary seat, and particularly relates to an improvement of the seating portion of an electric wheelchair.

[Prior Art] Recently, electric wheelchairs have been provided as vehicles to replace the legs of elderly people with weak legs or physically disabled people.
This electric wheelchair usually has a tricycle- or four-wheel vehicle-type vehicle body equipped with running and steering wheels, a driving device, a speed control device, and a braking device, as well as a seat for the user to sit on. The vehicle is

By the way, seats in this type of vehicle are different from seats installed in other vehicles such as automobiles, and may have elbow rests in addition to the seat plate and backrest plate, so the shaft is placed in the center of the seat plate. The seat plate is installed vertically so that it can be rotated horizontally at a predetermined angle, and the seat rotates so that the armrests do not become an obstacle when people with weak legs sit down or leave the seat. , to make it easier. Therefore, if the seat is configured to be rotatable, a device is required to lock the seat from rotating during travel.

The conventional simple rotary seat locking device fixes a disc directly below the seat plate to a shaft installed vertically on the seat plate, and drills a pair of through holes in the disc at a distance from each other. A single removable pin is biased from a part of the vehicle body so that it can move forward and backward, and
A lock lever for advancing and retracting the pin was extended to the side of the seat so that it could be operated. In other words, operate the lock lever to remove the pin from one hole, rotate the seat plate around the shaft, rotate the seat plate a predetermined angle, and when the pin engages with the other hole, the lock will be locked again. It was said that it would be done.

[Problems to be Solved by the Invention] However, according to the above-mentioned conventional locking device for a simple rotary seat, the seat plate on which the weight of the seated person is applied is simply fixed by the pin and the through hole in which the pin engages. When used for a long period of time, the diameter of the through hole increases as the pin wears away, causing so-called wobbling in the engagement between the pin and the through hole, resulting in an inconvenient seating sensation.

In view of the above-mentioned circumstances, this invention was made for the purpose of providing a simple rotating seat locking device that does not cause rattling even when the seat of an electric wheelchair is used for a long period of time.

[Means for Solving the Problems] In order to solve the above-mentioned problems, this invention provides stand tubes that are fixed upright, have tapered cut surfaces, and are biased so that the tapered cut surfaces are always in pressure contact with each other. A shaft consisting of an upper shaft and a lower shaft is inserted in the axial direction, a seat plate is fixed to the upper shaft, and an operating lever is rotatably penetrated in the diametrical direction, and a cam surface is formed on the operating lever, A simple rotating seat locking device is constructed by inserting into the shaft a pipe having one end that contacts the cam surface and the other end that contacts the lower shaft.

[Function] According to the above structure, when the operating lever is rotated around the shaft, the cam surface rotates and moves the pipe in the axial direction, thereby causing the upper shaft to move against the force of the coil spring. direction, the tapered cut surface separates, and the upper shaft can rotate around the axis. When the operating lever is returned to its original position, the cam surface rotates in the opposite direction and comes into contact with the pipe, causing the upper shaft and lower shaft to rotate. are brought into pressure contact again by the force of the coil spring, and this pressure causes the axes of the upper and lower shafts to shift relative to each other via the tapered cut surface, and a force in the direction of diameter expansion acts on the stand tube, causing the shaft to stand. Lock it into the tube and secure it.

[Example] Next, an example of the present invention will be described based on the drawings. FIG. 1 shows the skeleton of an electric wheelchair equipped with an accelerator device according to the present invention, in which 1 is the vehicle body, 2 is the rear wheel, 3 is the storage battery mounted on the vehicle body 1, 4 is the seating device, and 5 is a steering handle, 6 is a steering wheel which is a driving wheel, 7 is a chain belt or pulley belt that endlessly connects a sprocket 9 or a pulley fixed to the shaft 8 of the steering wheel 6 and the output shaft 11 of the electric motor 10; 12 is a pulley belt. 13 is a brake lever, and 14 is a switch box. The steering handle 5 has a main shaft 15 and a horizontal shaft 16 perpendicular to the main shaft 15. An accelerator device 17 is fixedly attached to the intersection of the main shaft 15, and the horizontal shaft 16 has both ends bent into a U-shape. Grips 18, 18 are attached.

The seating device 4 has a frame 1 having a bilaterally symmetrical configuration.
9 and 19 are a part 19a that fixes the seat plate 20, a part 19b that fixes the back plate 21, and an elbow rest part 19.
A seat mounting plate 22 is connected to the bottom surface of the portion 19a, and a shaft 23 is vertically provided on the seat mounting plate 22 by welding or the like. The shaft 23 is fitted into a stand tube 24 vertically erected on the vehicle body 1, and can be rotated and locked within a predetermined angle. As shown in FIG. 2, a bearing 25 is fixed to the upper end of the stand tube 24, and an annular seat 26 is placed on the bearing 25. The annular seat 26 is integrally connected to the shaft 23 via a pin 27 in the diametrical direction, and an operating lever 28 passes through the shaft 23 above the pin 27 and is fixed with washers 29, 29. . Shaft 23
consists of an upper shaft 23a and a lower shaft 23b which are bisected by cutting a cylindrical tube perpendicularly and diagonally to the axis to form tapered cut surfaces 23c and 23d, and the lower shaft 23b has a center hole 30. A bottom portion 31 is formed.
A pipe 32 and a rod 33 are coaxially inserted into the shaft 23. The pipe 32 has an upper lid 34 on its upper end that comes into contact with the operating lever 28, and the pin 27 and the elongated holes 35, 35.
The lower end portion is in contact with the bottom of the shaft 23. Rod 33
has an upper end extending downward from the center hole 30 of the shaft 23 through the pin 27, and a coil spring 38 is elastically mounted on the lower end thereof via a washer 37 fixed with a nut 36. As shown in FIG. 3, the operating lever 28 has a cam surface 39 formed by cutting out a part of its circular cross section into a flat shape, and the coil is arranged so that the cam surface 39 and the upper cover 34 are always in contact with each other. The spring 38 is attached to the lower shaft 23
b is pressed against the upper shaft 23a, and the upper shaft 23a is connected to the operating lever 2 through the long holes 35, 35.
It is pressed to 8.

Therefore, the operation of the above embodiment will be explained as follows.
In FIG. 3, when the operating lever 28 is rotated around its axis, the cam surface 39 comes off from the top cover 34 as shown in FIG. 4, and the circular circumferential surface of the operating lever 28 comes into contact with the top cover 34. Therefore, in FIG. 4, the pipe 32 moves downward through the elongated holes 35, 35 through which the pin 27 is inserted, and is pulled away from the upper shaft 23a against the force of the lower shaft 23b and the coil spring 38. Therefore, the pressure contact between the tapered cut surfaces 23d and 23c of the shaft 23 is released, so that the shaft 23, the pipe 32, the rod 33, and the annular seat 26 are supported by the bearing 25 and can rotate in the horizontal direction. Then, when the seat plate 20 is stopped at a desired position and the operating lever 28 is returned to its original position to bring the cam surface 39 into contact with the upper cover 34, the lower shaft 23b is moved from the upper shaft 2 by the force of the coil spring 38.
3a, the tapered cut surface 23c,
23d are pressed against each other. Tapered cut surface 23
When c and 23d are brought into pressure contact, the upper shaft 23a and the lower shaft 23b do not shift and move along their tapered cut surfaces due to the force of the coil spring 38.
Therefore, the upper and lower shafts 23a and 23b press the inner diameter surface of the stand tube 24 in opposite directions, creating frictional resistance between the inner circumferential surfaces of the stand tube 24, and this frictional resistance causes the shaft 2 to
3 is fixed non-rotatably around the axis. Furthermore, even if a rotational force acts on the seat plate 20 and the shaft 23 attempts to rotate, as long as it is within the resistance of the frictional resistance, the force pushing up the spring 38 will cause the upper and lower tapered cut surfaces 23c and 23d to rotate. Due to the misalignment, the shaft 23 may become attached to the stand tube 24.
The rotation can be stopped by the frictional resistance that comes into contact with the

Although this invention has been explained using an electric wheelchair as an example, it is not limited to electric wheelchairs, and it is clear that it can be used for a rotating chair, a rotating seating device, or other rotating lock devices.

[Effects of the invention] As explained above, according to this invention, an upper shaft and a lower shaft, which have tapered cut surfaces and are biased so that the tapered cut surfaces are pressed into contact with each other, are attached to a stand tube that is fixed upright. A shaft is inserted into the upper shaft in the axial direction, a seat plate is fixed to the upper shaft, and an operating lever is rotatably passed through the operating lever in the diametrical direction, a cam surface is formed on the operating lever, and one end is in contact with the cam surface. and a pipe having the other end that abuts the lower shaft is inserted into the shaft, so that the axes of the upper shaft and the lower shaft may be misaligned with each other via the tapered cut surface due to the biased force. As the shaft expands in the diameter direction inside the stand tube, the seat plate is prevented from rotating at any position, and the tapered cut surface is constantly prevented from sliding due to the biased force, so the shaft and stand Since the clearance between the tubes is constantly removed, no rattling occurs. Moreover, to release the pressure on the tapered cut surface, all you have to do is move the upper shaft slightly in the axial direction, so only a small amount of force is required to lock and unlock the seat, making it ideal for electric wheelchairs used by the elderly, etc. .

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an electric wheelchair embodying the present invention, FIG. 2 is a vertical cross-sectional front view of the main parts, FIG. 3 is a vertical cross-sectional side view of the main parts, and FIG. 4 is an explanatory view of the function. 4... Seating device, 19... Frame, 20...
Seat plate, 21... Back plate, 22... Seat mounting plate, 23... Shaft, 24... Stand tube, 25... Bearing, 26... Annular seat, 27
... Pin, 28 ... Operation lever, 30 ... Center hole, 31 ... Bottom, 32 ... Pipe, 33 ... Rod, 34 ... Top cover, 35 ... Long hole, 38 ... Coil spring, 39 ... ...cam face.

Claims (1)

[Scope of utility model registration request] A shaft consisting of an upper shaft and a lower shaft, which have tapered cut surfaces and are urged so that the tapered cut surfaces are always in pressure contact with each other, is inserted in the axial direction into a stand tube that is fixed upright, and a seat plate is attached to the upper shaft. A pipe is fixed to the shaft and is rotatably passed through the operating lever in the diametrical direction, a cam surface is formed on the operating lever, and the pipe has one end that contacts the cam surface and the other end that contacts the lower shaft. A simple rotary seat locking device characterized by being inserted into the locking device.