JP6963232B2 - Wheelchair caster device - Google Patents

Description

The present invention relates to a wheelchair used by an elderly person or a physically handicapped person, and relates to a caster device attached to the front side of the wheelchair.

Wheelchairs are indispensable for the physically handicapped, sick, and people who have difficulty walking, and the number of wheelchair users will increase in Japan, which is advancing into an aging society. There are various types of wheelchairs, but in recent years the demand has exceeded 400,000.
Due to the large population of wheelchairs, various improvements have been made to wheelchairs, while an environment has been created that makes it easier to use wheelchairs.

For example, sidewalks and parks have been developed to make it easier for wheelchairs to move, and the structure is such that wheelchairs can easily move inside stations and hotels. In addition, a vehicle model that allows a wheelchair to be mounted on a car is also commercially available, and the wheelchair itself can be folded compactly in order to make it easier to carry on the car and to put it away. There is.

FIG. 5 shows the appearance of a conventional general wheelchair. The wheelchair has a structure in which wheels are attached to the chair so that it can be moved while sitting on the chair. In the figure, (a) is the rear wheel, (b) is the caster, (c) is the chair, (d) is the steering wheel, (e) is the hand rim, (f) is the backrest, (g) is the arm support, and (chi). ) Indicates the side cover, (ri) indicates the brake handle, and (nu) indicates the foot support.

The wheelchair is supported by the above two rear wheels (a) and (a) and two casters (b) and (b) and has a movable structure, but the handle (c) is behind the chair (c). D), (d), and the lower end of the self-propelled hand rim (e), (e), and frame (le) that have the rear wheels (a) and (a) and are mounted concentrically with the rear wheels (a) and (a). Is equipped with foot support (nu) and (nu). A physically handicapped person can sit on the chair (c), and if there is a caregiver, the wheelchair can be operated by holding the handles (d) and (d), and if there is no caregiver, the physically handicapped person himself. Can be moved by turning the self-propelled hand rims (e) and (e).

When stopped at a predetermined place, operate the brake handle (li) to fix the rotation of the rear wheel (a). The casters (b) and (b), which are the front wheels, are pivotally supported so that their directions can be freely changed, and the direction of movement of the wheelchair can be changed.
Then, the physically handicapped person can sit on the chair (c) and put his / her feet on the foot supports (nu) and (nu), and the foot supports (nu) and (nu) are arranged horizontally to put the feet on. However, it is also possible to rotate and stand upright.

By the way, the road surface on which a wheelchair travels is generally paved, but even if it is a paved surface, it is not a completely flat surface and there are small steps in some places. In addition, a plate called a "block for guiding the visually impaired" is laid on the sidewalk surface as a mark for the visually impaired.
That is, a block (convex part) is provided on the surface so that the visually impaired person can recognize it by the tactile sensation of the sole of the foot, and a block laid on the road surface or the floor surface to safely guide the visually impaired person ( Plate).

Today, it is installed not only on sidewalks, but also in many places such as railway stations, public facilities, stores, and near the entrances and exits of shopping centers. In addition, a block is installed on the pedestrian crossing of the roadway, which has a different shape, called the "escort zone".
The convex portion provided on the block for guiding the visually impaired is relatively small, but when a wheelchair passes over this block, the caster as the front wheel may be an obstacle because its outer diameter is small.

That is, when the casters get over small protrusions and steps, the front side of the wheelchair must be pushed up, which increases the force to push forward, and a large force is required to turn the handle rim. Become. In particular, when the caster is positioned in front of the convex portion or the step and the wheelchair starts to move from the stopped state, it becomes more difficult to move.
On the other hand, when the wheelchair passes over the "block for guiding the visually impaired", the vibration is transmitted to the chair and the riding comfort is hindered.

Various patent applications for wheelchairs have been filed in the past.
For example, the "wheelchair" according to Japanese Patent Application Laid-Open No. 2003-334216 is a wheelchair capable of easily overcoming an obstacle such as a step during a strike, and is provided with an obstacle overcoming device for that purpose.
That is, it has a support frame, an auxiliary wheel frame, an operation frame, a connecting frame arranged on a quadrilateral link connected pivotally, and an elastic body, and the elastic body is urged to pull up the auxiliary wheel frame upward. Then, the training wheels rotate to the front wheel side by moving downward or upward of the operating lever, and after landing behind it, further rotate to the front wheel side by further possible or upward movement of the operating lever. It is a wheelchair that raises the front wheels above the training wheels.
"Wheelchair" according to Japanese Patent Application Laid-Open No. 2003-334216

As described above, the conventional wheelchair has the above-mentioned problems. The problem to be solved by the present invention is this problem, and a wheelchair caster device capable of smoothly traveling the wheelchair even if there are small steps or irregularities on the sidewalk surface and in which vibration is not transmitted is provided. offer.

The wheelchair according to the present invention is configured so that the chair is provided with rear wheels and front wheels (casters) so that the chair can be moved. The structure is the same as a conventional wheelchair.
The fork to which the casters constituting the caster device of the present invention is attached is provided with a spring function so that the spring can be bent and deformed when riding on a step or a convex portion.

By the way, as the spring, a leaf spring is used instead of a coil spring, and the spring is configured so that it can smoothly pass through the uneven surface due to the bending deformation of the leaf spring.
The fork consists of two legs that sandwich the casters, a leaf spring portion that connects both legs, and an upper plate portion that extends from the leaf spring portion. It has a fork receiver to be combined with the fork, and the fork receiver is composed of an upper plate portion and both leg portions, and an arcuate elongated hole is provided at the tip portion of the leg portion.
The upper plate portion of the fork abuts on the lower surface of the upper plate portion of the fork receiver, is combined, and is screwed to the spindle.

The fork to which the casters according to the present invention are attached has a leaf spring portion, so that the wheelchair can pass through a step or a "block for guiding the visually impaired" relatively smoothly, and vibration during passing. Is suppressed.
That is, when the chair approaches the convex portion, the leaf spring portion of the fork bends and deforms without lifting the chair, so that the wheelchair can pass through, the vibration transmitted to the chair is suppressed, and the chair is not lifted, so that the wheelchair is large. You don't have to push with force.

A perspective view from the front side of the caster device according to the present invention. A perspective view from the side surface of the caster device according to the present invention. The development view of the caster apparatus which concerns on this invention. The development view of the caster apparatus which concerns on this invention. The appearance of a conventional general wheelchair.

1 and 2 are external views showing a wheelchair caster device according to the present invention, FIG. 1 is a perspective view from the front side, and FIG. 2 is a perspective view from the side surface side. In the figure, 1 is a caster, 2 is a caster shaft, 3 is a fork receiver, 4 is a spindle, and 5 is a fork.
The caster device is attached to the front side of the wheelchair and can swing around the main shaft 4 to change its direction, and the caster 1 rotates about the caster shaft 2.

The basic structure of the caster device is the same as that of the conventional device shown in FIG. 5, but the caster device of the present invention raises and lowers the caster 1 without vibrating the chair as it is even if the road surface has small irregularities. It can be absorbed by motion. The fork supporting the caster 1 is formed of a leaf spring, and the leaf spring portion constituting the fork can be appropriately bent and deformed.

FIG. 3 shows a development view of the caster device of the present invention. The caster shaft 2 is inserted into the shaft hole 6 penetrating the center of the caster 1, and is attached to the fork 5. The fork 5 has two leg portions 7 and 7 having shaft holes 12 and 12 at the tip thereof, both leg portions 7 and 7 are connected by a leaf spring portion 8, and the leaf spring portion 8 is connected to an upper plate portion 9 from the leaf spring portion 8. Is extended.

Further, the fork receiver 3 is provided with the upper plate portion 10 and the leg portions 11 and 11 extending downward on both sides thereof, and the arc-shaped elongated holes 13 and 13 penetrate through the tip portions of the leg portions 11 and 11. The fork 5 is assembled to the fork receiver 3, but the upper plate portion 9 abuts on the lower surface of the upper plate portion 10, and the projecting pieces 14, 14 formed on both sides of the base portion of the upper plate portion 9 are the leg portions 11, The upper plate portion 9 is positioned by engaging with the grooves 15 and 15 formed between the 11 and the upper plate portion 10. Therefore, the legs 7 and 7 of the fork 5 abut on the inside of the legs 11 and 11 of the fork receiver 3, and the caster 1 is fitted between the legs 7 and 7 and the caster shaft 2 is inserted and attached.

By the way, the main shaft 4 extends downward from the base 16, and a bearing 19 through which the main shaft 4 is inserted is interposed between the lower surface 17 of the base 16 and the fork receiver 3, and washer 18a is above and below the bearing 19. , 18b are provided.
Then, the spindle 4 through which the hole of the bearing 19 is inserted penetrates the hole 20 formed in the upper plate portion 10 of the fork receiver 3, and also penetrates the hole 21 of the upper plate portion 9 of the fork 5, and the lower end portion of the spindle 4 Inserts the center hole of the bearing 22 and the nut 23 is screwed.

Here, the bearing 22 fits into the hole 21 and is positioned. Further, in the tip of the caster shaft 2 through which the shaft hole 6 of the caster 1, the shaft holes 12 and 12 at the tip of the leg of the fork 5 and the arcuate elongated holes 11 and 11 of the legs 11 and 11 of the fork receiver 3 are inserted. The nut 24 is screwed and fixed.
FIG. 4 shows a development view of the caster device from another direction.

By the way, in the caster device of the present invention in which the fork 5 is attached to the spindle 4, when the caster 1 rides on the convex portion existing on the road surface, if the caster 1 rises, the leaf spring portion 8 of the fork 5 bends and deforms. Can be done.
Of course, if you ride on the convex part slowly, the leaf spring part 8 will not bend and deform and the chair will be lifted, but in response to a shocking load, the leaf spring part 8 will bend and deform and push up the chair. There is no. Therefore, even if it moves on the visually impaired person guiding block installed on the road surface, it hardly feels vibration.
Further, since the leaf spring portion 8 bends and deforms when the caster 1 rides on the convex portion, the force for pushing the wheelchair can be small.

Both leg portions 7 and 7 to which the caster 1 is attached rotate with the bending deformation of the leaf spring portion 8, but the caster shaft 2 is an arcuate elongated hole 13 formed in the leg portions 11 and 11 of the fork receiver 3. , 13 can be moved along.

1 Caster 2 Caster shaft 3 Fork receiver 4 Main shaft 5 Fork 6 Shaft hole 7 Leg 8 Leaf spring 9 Top plate
10 Top plate
11 legs
12 shaft holes
13 Arc-shaped slotted hole
14 shards
15 grooves
16 bases
17 Bottom surface
18 washer
19 bearings
20 holes
21 holes
22 bearings
23 nuts
24 nuts

Claims (2)

In the caster device attached to both front sides of the wheelchair, the casters are attached to the tip of the leg of the fork via the caster shaft, and the fork is attached to the main shaft extending downward from the base side while being attached to the fork receiver. The fork is screwed and has a leaf spring part connecting both legs and an upper plate part, and protrusion pieces are formed on both sides of the base part of the upper plate part penetrating the hole through which the main shaft is inserted, and the fork receiver is described above. Legs are provided on both sides of the upper plate portion that penetrates the hole through which the main shaft is inserted, and an arcuate elongated hole into which the caster shaft is loosely fitted is provided on the tip end side of the leg portion. The projecting pieces that come into contact with the lower surface of the upper plate portion and are formed on both sides of the base portion of the upper plate portion of the fork engage with the groove formed between the leg portion of the fork receiver and the upper plate portion. The upper plate portion of the fork is positioned, both legs of the fork abut on the inside of both legs of the fork receiver, casters are fitted between the legs, and the caster shaft is inserted and attached. Is a wheelchair caster device that bends and deforms when the casters ride on the convex parts of the road surface. The caster device for a wheelchair according to claim 1, wherein a bearing through which a spindle is inserted is interposed on the upper surface side of the upper plate portion of the fork receiver and the lower surface side of the upper plate portion of the fork.

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