PORTABLE RAMP

Abstract

A ramp includes a plate member. The ramp is formed from a carbon fiber-reinforced resin having a longitudinal elastic modulus in the bridging direction of 50+ GPa, and a connecting section that connects the plate member which plate member can be divided into two in a plane perpendicular to the plate member and parallel to the bridging direction. A reinforcement part forms a plurality of hollow segments arranged single file along the bridging direction of the plate member. The cross section shape perpendicular to the direction of extension of the hollow segments is trapezoidal, the height of the trapezoid is 10 to 50 mm, the base angles are 45° to 90°, the width of the plane that contacts the trapezoidal plate member is 100 to 10 mm, and derailment preventing walls connect to portions of plate member side end faces and hollow segment side end faces.

Claims

1-5. (canceled)

6. A ramp to be placed over a step or a gap between objects for wheelchairs to travel, comprising: a plate member made of a carbon fiber-reinforced resin having a longitudinal elastic modulus in a bridging direction of 50 GPa or more; a connecting section splittable into two members by a plane which is orthogonal to the plate member and is in parallel with the bridging direction; a reinforcing section having a plurality of hollow segments disposed along the bridging direction; and a derailment preventing wall wherein the hollow segments have a trapezoid-shaped cross section orthogonal to the bridging direction, the trapezoid-shaped cross section having: a height of 10 to 50 mm; a base angle of a side contacting the plate member of 45° or more and less than 90°; and a width of the side of 100 to 10 mm, and wherein the derailment preventing wall is at least partially joined with a side end face of the plate member or a side end face of the hollow segments.

7. The ramp according to claim 6, wherein a reinforcing member is detachably inserted into at least one of the hollow segments made of a fiber-reinforced resin containing a woven fiber and comprises at least one surface, and at least one surface of the reinforcing member contacts an upper base of the trapezoid-shaped cross section of the hollow segment while at least one surface of the reinforcing member contacts a lower base of the trapezoid-shaped cross section of the hollow segment.

8. The ramp according to claim 7, wherein the reinforcing member is bonded to the upper or lower base.

9. The ramp according to claim 7, wherein the reinforcing member is fastened to the upper or lower base.

10. The ramp according to claim 7, wherein the reinforcing member is positioned by an external component part provided at a terminal of hollow segment.

Description

DESCRIPTION OF THE DRAWINGS

[0046] FIG. 1 is a perspective view of an example of a portable ramp viewed obliquely from above.

[0047] FIG. 2 is a perspective view of an example of a portable ramp viewed obliquely from below.

[0048] FIG. 3 is a bottom view of a portable ramp.

[0049] FIG. 4 is A-A cross section view of the ramp shown in FIG. 3.

[0050] FIG. 5 is a cross section view of hollow segment into which a reinforcing part having an I-shape is inserted.

[0051] FIG. 6 is a cross section view of hollow segment into which a reinforcing part having an X beam-shape is inserted.

EXPLANATION OF SYMBOLS

[0052] 1: ramp
2,2a,2b: plate member
3: upper end of ramp
4: lower end of ramp
5: derailment preventing wall
6,6a,6b,6c: hollow segment
7: hollow part of hollow segment
8: length of lower base of hollow part of hollow segment
9: height of hollow part of hollow segment
10,11,12: reinforcing member
θ,θ2: base angle

DETAILED DESCRIPTION

[0053] Hereinafter, our ramps will be explained sequentially. This disclosure is not limited to the following examples which are only representative.

[0054] Our ramps can be placed over a step or a gap between objects for wheelchairs or the like to travel, comprising: a plate member made of a carbon fiber-reinforced resin having a longitudinal elastic modulus in a bridging direction of 50 GPa or more; a connecting section splittable into two members by a plane which is orthogonal to the plate member and is in parallel with the bridging direction; a reinforcing section having a plurality of hollow segments disposed along the bridging direction; and a derailment preventing wall wherein the hollow segments have a trapezoid-shaped cross section orthogonal to the bridging direction, the trapezoid-shaped cross section having: a height of 10 to 50 mm; a base angle of a side contacting the plate member of 45° or more and less than 90°; and a width of the side of 100 to 10 mm, and wherein the derailment preventing wall is at least partially joined with a side end face of the plate member or a side end face of the hollow segments. It is preferable that the trapezoid-shaped cross section has the width of 90 to 70 mm and the height of 25 to 30 mm.

[0055] Our ramps improve specific rigidity used by a wheelchair user to get over steps in a building or steps between the ground and the doorway of vehicles such as automobile, train and bus against bending in the bridging direction by the hollow segment made of carbon fiber-reinforced resin having elastic modulus of 50 GPa or more in the bridging direction. Such an improved specific rigidity can achieve both weight saving up to 12 kg of ramp weight and long ramp length up to 3 m so that safety is ensured and burden is reduced for caregivers. For example, our lightweight ramp can be placed for wheelchairs to travel on by inclination angle of 14° (¼) or less over the height difference of 70 cm over which conventional short lightweight ramp cannot make wheelchairs get over because of steepness.

[0056] FIG. 1 shows a perspective view of an example of our ramps viewed obliquely from above. Symbol 1 indicates the ramp for wheelchairs to travel on while symbol 2 indicates plate member. Portable ramp 1 can be used as being placed over the gap between platform and train doorway. Upper end 3 of ramp 1 is placed on the train doorway while lower end 4 of ramp 1 is placed on the platform, for example. It is preferable that upper end 3 and lower end 4 of ramp 1 are tapered so that wheelchairs smoothly travel through the inclined ends. It is preferable that an antiskid rubber member is attached to a position to contact the doorway or the platform. It is preferable that upper end 3 and lower end 4 of ramp 1 are made of plastics because of light weight and cheap prices.

[0057] FIG. 2 shows a perspective view of an example of our ramps viewed obliquely from below while FIG. 3 shows a bottom view of our portable ramp. Symbol 5 indicates derailment preventing wall provided at both sides of ramp 1 while symbol 6 indicates hollow segment. Hollow segments 6 are provided as totally extending substantially along the longitudinal direction of plate member 1 in which moving bodies such as wheelchair travel. Such a long product structure extending between upper end 3 and lower end 4 can bear local load applied from tires of wheelchair or the like traveling on ramp 1.

[0058] FIG. 4 shows A-A cross section view of ramp 1 shown in FIG. 3. In FIG. 4, wheelchairs or the like travel on the top face of plate member 2. Symbols 6a,6b,6c indicate hollow segments, symbol 7 indicates hollow part of hollow segment and symbol 5 indicates derailment preventing wall.

[0059] When hollow segment 6 has a shape of trapezoid of which base angle is in a predetermined range, load bearing capacity against the load applied to plate member 2 on which a moving body travels can be improved. The base angle of less than 30° might have a shorter length of the hollow segment in the direction orthogonal to the plate member so that rigidity is insufficient. The base angle of more than 90° might have insufficient load bearing capacity. In FIG. 4, typical base angle θ of hollow segment 6b is shown.

[0060] The trapezoid is a kind of quadrangular in which at least one pair of sides opposite to each other are in parallel. It is preferable that the trapezoid is a regular trapezoid having a bottom side contacting plate member 2 longer than the top side. In FIG. 4, the top side is positioned under the bottom side contacting plate member 2. The load bearing capacity can be better with a structure where the bottom side is longer than the top side in the trapezoid having the top and bottom sides in parallel because such a shape of hollow segment can effectively suppress bending deformation of plate member when the load applied to the plate member is transmitted to the hollow segment.

[0061] In FIG. 4, hollow segment 6a has a shape of trapezoid having left base angle of 30° and right base angle of 60° while hollow segment 6c has a shape of trapezoid having left base angle of 30° and right base angle of 60°. Such symmetrical base angles of hollow segments 6a and 6c can achieve a uniform balance of receiving load.

[0062] It is preferable that one of the hollow segments is an isosceles trapezoid so that load is applied uniformly to the hollow segment from the moving body traveling on the top face of plate member 2 to achieve excellent load bearing capacity. Such an isosceles trapezoid can be realized by making the left and right base angles equal in hollow segment 6b shown in FIG. 4.

[0063] It is preferable that the hollow segments provided at an end of the plate member have a base angle of approximately 90° of which side face is provided in the same surface direction as the side end face of the plate member. It is preferable that at least one hollow segment is provided at an end of plate member 2. When one of the base angles of hollow segment is set to approximately 90°, strength of junction with derailment preventing wall 5 can be enhanced by increased number of junction sites.

[0064] In the cross section structural view shown in FIG. 4, hollow segments 6a are positioned at both ends of plate member 2. Hollow segments 6a have base angle θ2 of 90° at the outer side of end of plate member 2. Namely, hollow segments 6a having a side face orthogonal to plate member 2 are provided in the same surface direction as the side end face of plate member 2. Derailment preventing wall 5 is joined with both the side end face of plate member 2 and the side face of hollow segment 6a orthogonal to plate member 2.

[0065] It is preferable that ramp 1 is provided with derailment preventing wall 5 joined at least partially together with the side end face of plate member and the end face of hollow segment. It is more preferable that the derailment preventing wall is joined together with a whole surface of the side face of reinforcing part.

[0066] Such derailment preventing wall 5 provided at both right and left side faces of ramp 1 can prevent vehicles from falling off. Further, derailment preventing wall 5 can be carried easily and is hard to be broken even when a wheel runs thereon. When hollow segments 6a joined with derailment preventing wall 5 have a base angle of approximately 90° of which side face is provided in the same surface direction as the side end face of the plate member, the derailment preventing wall can be joined together with the side end face of the plate member in the plane orthogonal to the reinforcing part. When derailment preventing wall 5 is joined with both plate member 2 and hollow segment 6a by being joined together with the side end face of plate member 2 and the end face of hollow segment 6a, derailment preventing wall 5 can be improved in impact resistance against deformation and rupture.

[0067] It is preferable that derailment preventing wall 5 has a height of 15 to 30 mm projecting from the top face of plate member 2. It is not necessary that derailment preventing wall 5 extends over a total length of ramp 1. It is possible that derailment preventing wall 5 is not provided at upper end 3 or lower end 4. The “approximately 90°” allows flexibility of ±5° for convenience of design and production.

[0068] It is preferable that the hollow segment has a tangential direction angle of 30 to 90° at least at one tangential contact point to the plate member. It is more preferable that the tangential direction angle is 35 to 80°, preferably 45 to 60°.

[0069] From a viewpoint of weight saving, it is preferable that the ramp is made of a carbon fiber-reinforced plastic excellent in specific strength and specific rigidity. The reinforcing fiber may be a carbon fiber of polyacrylonitrile (PAN)-based, rayon-based, lignin-based or pitch-based, with or without surface treatment. The surface treatment may be performed with coupling agent, sizing agent, binding agent or additives. The above-described reinforcing fibers can be used solely or mixed by two or more kinds.

[0070] The fiber-reinforced plastic comprises reinforcing fiber and matrix resin, wherein the matrix resin may be a thermosetting resin such as epoxy resin, unsaturated polyester resin, vinylester resin, phenol (resol type) resin and polyimide resin, a polyester resin such as polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, poly trimethylene terephthalate (PTT) resin, polyethylene naphthalate (PEN resin) and liquid crystalline polyester resin, a polyolefin resin such as polyethylene (PE resin), polypropylene (PP resin) and polybutylene resin, a polyoxymethylene (POM) resin, a polyamide (PA) resin, a polyarylene sulfide resin such as polyphenylene sulfide (PPS) resin, a polyketone (PK) resin, a polyether ketone (PEK) resin, a polyetheretherketone (PEEK) resin, a polyether ketone (PEKK) resin, a polyether nitrile (PEN) resin, a fluorinated resin such as polytetrafluoroethylene resin, a crystalline resin such as liquid crystal polymer (LCP), a styrenic resin, an amorphous resin such as polycarbonate (PC) resin, polymethylmethacrylate (PMMA) resin, polyvinyl chloride (PVC) resin, polyphenylene ether (PPE) resin, polyimide (PI) resin, polyamide-imide (PAI) resin, polyetherimide (PEI) resin, polysulfone (PSU) resin, polyethersulfone resin and polyarylate (PAR) resin, a thermoplastic elastomer of phenol-based, phenoxy-based, polystyrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, polyisoprene-based or acrylonitrile-based, or a copolymer or modification thereof. Above all, it is preferably the epoxy resin or the vinylester resin from viewpoints of adhesion to carbon fibers, mechanical properties of shaped product and formability.

[0071] It is preferable that the fiber-reinforced resin of carbon fiber has a weight fiber content of 15 to 80 wt %. The content of less than 15 wt % might have insufficient load bearing capacity and rigidity so that a predetermined target function is not achieved. The weight content of more than 80 wt % might have voids to make a forming process have problems.

[0072] It is preferable that the fiber-reinforced plastic constituting the plate member or the hollow segments comprises continuous carbon fibers. The reinforcing fibers may be disposed in parallel with the longitudinal direction of the bridging direction of the ramp or disposed substantially orthogonal to the longitudinal direction. These disposition patterns can be combined to improve bending strength and surface pressure resistance as a whole ramp.

[0073] FIG. 5 shows a cross section view in which reinforcing member 10 detachably inserted into hollow part 7 of hollow segment 6 of ramp 1 comprises at least one surface of fiber-reinforced resin containing woven fiber. At least one surface of reinforcing member 10 contacts the upper base of trapezoid-shaped cross section of the hollow segment while at least one surface of reinforcing member 10 contacts the lower base of trapezoid-shaped cross section of the hollow segment. Reinforcing member 10 has such an H-shaped reinforcing structure shown in FIG. 5.

[0074] When ramp 1 is made longer deformation such as buckling and torsion might be caused other than a bending deformation. We improve resistance against the buckling or torsion caused in plate materials constituting the plate member of the ramp and hollow segment 6 so that excessive deformation mode is suppressed while the ramp length can be increased to 3 m or more. Then our ramp can be used for a step having a height difference of 70 cm or more which cannot be got over by wheelchairs with a conventional short lightweight ramp because of steep inclination. Because even local deformation can be suppressed usability and comfort are improved.

[0075] It is preferable that the reinforcing member is made of a material structurally having a shear resistance so that buckling deformation and shear deformation of the ramp body are suppressed. From a viewpoint of weight saving, it is preferable that the reinforcing member is made of carbon fiber-reinforced plastic excellent in specific strength and specific rigidity. The reinforcing fiber may be a carbon fiber of polyacrylonitrile (PAN)-based, rayon-based, lignin-based or pitch-based, with or without surface treatment thereon. The surface treatment may be performed with coupling agent, sizing agent, binding agent or additives. The above-described reinforcing fibers can be used solely or mixed by two or more kinds. It is preferable that the reinforcing fiber is reinforced and oriented in two or more directions. It is preferable that the reinforcing member has an in-plane shear elastic modulus of 3,000 MPa or more.

[0076] It is preferable that the reinforcing member has a shape capable of suppressing deformation of trapezoid-shaped cross section orthogonal to the extending direction of hollow segment. It is preferable that the shape capable of suppressing shear deformation is X-beam shape connecting the four vertexes of trapezoid-shaped cross section of reinforcing member 11 shown in FIG. 6 or I-beam shape connecting the two vertexes of trapezoid-shaped cross section of reinforcing member 12 shown in FIG. 6. For suppressing the in-plane buckling of hollow segment, it is preferable that the shape is H-shape connecting the top side and the bottom side of trapezoid of reinforcing member 10 shown in FIG. 5.

[0077] It is preferable that the reinforcing member inserted into the hollow segment is integrated by bonding so that reinforcement is improved.

[0078] It is preferable that the reinforcing member inserted into the hollow segment is integrated by mechanically fastening so that reinforcement is improved.

[0079] It is possible that the reinforcing member inserted into the hollow segment is positioned by an external component part provided at the terminal of hollow segment so that vibration is absorbed by friction loss on the contact surface between the hollow segment and the reinforcing member to improve stability in traveling on the ramp.

INDUSTRIAL APPLICATION

[0080] Our ramps are industrially available as ramps to be placed over a step between objects for wheelchairs to travel thereon.