JP4449066B1 - Wheelchair footrest opening and closing mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a versatile remote control mechanism capable of opening and closing a wheelchair footrest even if the form and size are different, lightweight, easy to be retrofitted, and easy for a patient and a caregiver to operate a lever. Has a backup function that can be securely held in the “open” position.
[MEANS FOR SOLVING PROBLEMS] A main shaft (5b) is implanted in a base plate (5) integrally formed with a guide plate (5a) on both left and right sides of a wheelchair body, and a plurality of cable connecting holes (6d) or long holes (6d ') are provided on the main shaft (5d). An L-shaped operating lever 6 is pivotally attached to the main shaft 5b, a shaft 16 provided on a connecting jig 15 having an adjustable turning radius at the rear end of the footrest 4 and the cable connecting hole 6d or long hole 6d '; The rope 7 with the ridge 7b is connected between the two, and the L-shaped operating lever 6 is rotated to rotate the footrest 4 from the “closed” position I to the “open” position stop area III. Let
[Selection] Figure 1

Description

The present invention relates to an opening / closing mechanism for a footrest of a wheelchair used by a general disabled person.

  Conventionally, when getting in and out of a wheelchair, it has been necessary to bend forward and rotate the footrest between the “open” position where the footrest is substantially upright using hands or feet and the “closed” position where the foot is placed. This work is more laborious than it looks, and it is an unsanitary and really troublesome task.

In order to solve such a problem, a technique to be solved by a remote controller using a hand lever on both the left and right sides of the wheelchair body is introduced in the following document.

Each of the techniques introduced in Patent Documents 1 to 3 has a feature in the mechanism. However, the operation lever is only for a specific type, and unfortunately there is no technology with an adjustment function that can be retrofitted to fit various types of footrests of different types and sizes.
Whether or not the footrest can be opened and closed safely and reliably depends on whether or not the mechanism is correctly transmitted to the footrest by the rotation of the operation lever.

In Patent Document 3 described in each of the following documents, a lever that is integrally formed with a fixed rotation angle and radius is made to move in and out of the elastic tube in order to correspond to the rotation angle of the footrest depending on the type and size of the wheelchair. Although the length of the wire is adjusted, the distance between the footrest operating lever and the rear end of the footrest can be adjusted, but it is theoretically impossible to adjust to the pivot angle of the footrest.
In addition, there is a technology that determines the position (turning radius) of the wire set screw on the footrest side and makes it difficult to machine the pilot hole in the shape of the footrest. The turning radius cannot be adjusted, which makes retrofitting difficult. Therefore, in the “open” position where the footrest stands upright, it cannot be fully opened as in the case of using the limbs in the past, and a gap is formed between the foot support and the patient getting in and out is prevented.
Also, the ball plunger of the stop device in the “open” position is vulnerable to slight impacts, and since it does not have a backup function, it easily disengages and returns to the “closed” position, so it must be returned to the “open” position again. Otherwise, a patient who is not aware of this may cause an accident such as a footrest taking a footrest and trying to sit down.

  Any other document is a specified mechanism, which requires considerable modification means for retrofitting and lacks so-called versatility.

  JP 2006-305295 A   Memoir No.3132491   Japanese Patent No. 3910624

  Versatile for various types of footrests of different types and sizes, can be opened and closed as full as in the case of conventional manual operation, has a safe backup function, and can be easily retrofitted for both patients and caregivers. This is an issue that requires an ideal opening and closing mechanism that can be operated safely in the place where you are.

  Using the L-shaped operation lever that can independently adjust the turning radius of the connecting portion of the rear end of the rope footrest and the turning radius of the connecting portion of the switch on the switch side, the switch and the footrest By connecting a stretched elastic line to a part of the space, it is possible to cope with the opening and closing angles of various footrests of each company, and stably enable the maximum opening and closing rotation.

  Simple construction, low manufacturing cost, easy handling, no need to machine the wheelchair body or footrest of different types and sizes, easy retrofitting and when the control lever is “open” It has a backup function and is highly safe.

  The main part external view equipped with the opening / closing mechanism of the footrest of this invention wheelchair   B arrow view of FIG.   (A) A arrow view of FIG. (B) A-B-C cross-sectional view of FIG.   External view of switch 20 disassembled   4 is a development view of the guide plate 5a in FIG.   Illustration of the relationship between the switch and footrest during opening / closing operation   (A) Front view of another embodiment of an L-shaped operating lever. (B) DF cross-sectional view of FIG.   (A) External view of an example of wire use. (B) Detailed view of an example of a wire connecting part

The optimum embodiment of the present invention will be described specifically.
FIG. 1 is an external view of a main part of a wheelchair equipped with a switch 20, wherein 1 is an armrest part which is a part of the wheelchair body, and 2 is a foot support part. 2a has a footrest 4 loosely fitted to the footrest shaft 3 fixed to the right front (in technical terms, this is referred to as a skimmer and is free to rotate) and is adjusted to the height of the patient by a bolt 2b. The shaft is inserted into the foot support 2 so as to be height-adjustable, but the details thereof are known and will not be described.
The rope 7 is a rope 7 (particularly spring steel in this embodiment) formed in one of the plurality of holes 6d provided in the rope connecting portion 6b of the L-shaped operating lever 6 of the switch 20 and formed into a rib 7b. Since the wire is used, this is hereinafter referred to as a steel wire for short) and the hook 7a at the end is hooked, and the other end of the shaft is connected to the rear end 4a of the footrest 4 in FIG. 16 is connected.
Reference numeral 12 denotes a commercially available brake wire protective tube often used for bicycles and the like, which is inserted through the steel wire 7 and fixed to a single portion of the foot support 2 with a band 13.

  The right footrest 4 in FIG. 1 shows the state in the “closed” position during use, and the left footrest 4 ′ shows the state in the “open” position that is substantially upright. The right side toward the front of FIG. 1 is the front of the wheelchair, and the person sitting and operating with the right hand is the “right switch” 20. Since this structure is symmetrical, the description of the present invention about the left switch is given. The right switch 20 is also representative, and FIGS. 2 to 8 will be sequentially described.

FIG. 2 is a view taken in the direction of arrow B in FIG. Reference numeral 15 denotes a connecting jig for a cord having a U-shaped cross section for connecting the end of the steel wire 7 to the rear end portion 4 a of the footrest 4, and is a rotating jig centering on the footrest shaft 3 with the footrest 4 in between. The moving radius is adjustable and screwed from the back surface, and the steel wire 7 is inserted and fixed to a shaft 16 rotatably provided on the rear surface so that the footrest 4 can follow the rotation comfortably. Details of the connecting jig 15 are known from (Utility Model Registration No. 3144205).
A coil spring 14 provided between the footrest shaft 3 and the footrest 4 constantly urges the footrest 4 in the “closed” direction, and suppresses the rebound when it is rapidly returned from the “open” position to the “closed” position. In addition, the urging state at the “closed” position is maintained.

3A is a front view of the switch 20 as viewed in the direction of arrow A in FIG. 1, and FIG. 3B is a cross-sectional view taken along the line A-B-C in FIG.
FIG. 4 is an external view in which the switch 20 is disassembled. The base plate 5 is integrated with a guide plate 5a with an arc-shaped slot 5f through which the handle portion 6a of the L-shaped operation lever 6 is inserted, and a main shaft 5b is planted. The base plate 5 is provided with a band 8, a spring washer 8b, and a bolt 8a. It is firmly attached to the main body frame 1.

3 and 4, the operation lever 6 having a plate-shaped cross section, one side formed into a handle portion 6a and the other side formed into a steel wire connecting arm portion 6b and having an overall L-shape is formed in the main shaft 5b through a hole 6c. The steel that is pivotally attached and sandwiches the top of the handle portion 6a and screwes the two grips 6j into a T-shaped grip, and is directed downward by an angle θ1 from the horizontal line XX including the main shaft 5b parallel to the floor surface. The wire connecting arm portion 6b is provided with a plurality of steel wire connecting holes 6d at an appropriate interval from the center of the main shaft 5b.
The L-shaped operating lever 6 is fitted on a bush 5e inserted through the main shaft 5b, and pivotally mounted with a spacer 5d interposed between the base plate 5 and the bush 5e via a washer 5i. The L-shaped operating lever 6 is prevented from coming off by being sandwiched by 5h.
One of the plurality of holes 6d provided in the steel wire connecting arm portion 6b is formed by forming a part of the steel wire 7 into a close contact ridge 7b and hooking a hook 7a portion at the end thereof, and the other end is a footrest. 4 is connected to the shaft 16 of the connecting jig 15 attached to the rear end portion 4a of the connecting lever 15, and the footrest 4 follows the rotation of the L-shaped operating lever 6 without difficulty, and rotates (opens and closes) about the footrest shaft 3. To do.

3d ′ in FIG. 3 is the “open” position in which the footrest 4 is fully opened by rotating the L-shaped operating lever 6 from the “closed” position I to II, that is, when the footrest is in contact with the foot support 2. This is the position of the hole 6d.
Further, when the L-shaped operating lever 6 is rotated by β degrees to reach 5g1 or 5g2 of the stop area III, the ridge 7b extends by δ as shown by a temporary line 7b ″ and the footrest 4 is stably attached in an upright state. This will be explained in detail in the paragraphs (0020) to (0029).
3B is a cross-sectional view taken along the line A-B-C in FIG. 3A, and the L-shaped operating lever 6 is rotated by being inserted through a guide groove 5f (see FIG. 5) provided in the guide plate 5a. To do.

FIG. 5 is a development view of the grooved guide plate 5a as viewed from the direction indicated by the arrow A in FIG. 4, and is provided with a vertical groove 5f and a stop area III with a retaining member 5k, and a handle for the L-shaped lever 6. The portion 6a is inserted into the groove 5f and rotated along the groove 5f, and is inserted into the "open" position 5g1 or 5g2 of the stop area III as shown by a temporary line 6 'in FIG. Since the elongation of the streak is larger at the position of 5g2 than at the position of 5g1, the biasing force is naturally increased, and the stability of the footrest at the time of “opening” is increased.
The number of stop positions 5g stop area III is one place to provide multiple pieces plant as required.
While the footrest 4 is fully opened upright and a part of its surface continues to contact the foot support 2 (contact 4 ″ of the temporary line portion in the lower half of FIG. 6), the protrusion 7b extends and is attracted. Therefore, even if something collides with the footrest, the protrusion 7b is once extended by the amount of the deviation, but immediately returns to the original “open” position, that is, this is a backup function.

In FIG. 5, when the footrest 4 is returned to the “closed” position, the handle 6j of the lever 6 is once pulled to escape from the stop area 5g, and ends by contacting the lower stop frame 5m along the central long groove 5f in FIG. . This is the start position I of the handle 6a (see FIGS. 3 and 6) and the “closed” position of the footrest.
At position 1, the ridge 7b returns to the original contact state from the stretched state so far, and the coil spring 14 suppresses the bounce of the footrest 4 to the original "closed" state, so that the steel wire 7 is stretched substantially in a straight line. It looks like Figure 1.

FIG. 6 shows the operation of the opening / closing mechanism of the present invention.
The upper half is an operation schematic view of the switch 20 viewed from the same direction as FIG. 3A, and the lower half is an operation schematic view of the most common shape of the footrest 4 from the front. It replaces on the phase and is connected by a steel wire 7 part of which is formed into a strip 7b.
When this mechanism is attached to the wheelchair body, both the footrest 4 and the L-shaped lever 6 are in the “closed” position, and R1 <R2 is set, and the steel wire 7 is connected to the hole 6d of the steel wire connecting arm portion. What is necessary is just to connect with the axis | shaft 16 of the jig | tool 15 with which the footrest 4a was mounted | worn, and to test-rotate the said lever 6 from the position I to III, and to confirm that the footrest 4 opens and closes normally.

There are various types and sizes of the footrest 4 depending on the manufacturer, and the opening / closing angle varies slightly depending on the support structure of the footrest 4, but these are common within a range of approximately 90 degrees. In consideration, the shape of the front view of the footrest 4 in FIG. 6 which is the most commonly used general shape and can be used in various other types was selected.
R1 is the turning radius of the connecting jig 15 attached to the rear end of the footrest 4 (the distance from the center of the footrest shaft 3 to the connecting shaft 16), and α1 is approximately 90 degrees from “closed” to “opened”. It is a rotation angle.
The position 16 ′ is the position of the connecting shaft 16 when the footrest 4 stands upright (provisional line portion) and the tip portion 4 ″ abuts the foot support 2, and is the “open” position.

  When the contact position 16 'is rotated to the position II of the L-shaped operating lever 6, the steel wire connecting hole 6d is also rotated to the position 6d', and a part of the surface of the footrest 4 contacts the foot support 2. Further, the L-shaped operating lever 6 is further rotated by an angle β to be fitted into 5g1 or 5g2 of the stop area III, and the urging force corresponding to the elongation δ of the ridge 7 is maintained. Finish the operation as is.

Assuming that the straight line O2-S2 connecting the main shaft 5b on the L-shaped operating lever 6 side and the center line of the hole 6d at the position of "closed" I is a straight line O1- connecting the rotation center O1 of the footrest and the connecting shaft 16. When S1 is parallel and R2 = R1, the lever 6 and the footrest 4 start to rotate simultaneously in the same phase, the rotation angles α1 and α2 are equal, and the end points are 16 ′ and 6d ′, respectively. Rotate in parallel at the same time.
The aforementioned Japanese Patent No. 3910624 seems to have been developed based on such an idea.

  As shown in FIG. 3, the L-shaped operating lever 6 is directed to the O1-S1 axis of the footrest with the arm portion 6b facing downward by an angle θ1 with respect to the horizontal axis XX parallel to the floor surface including the main shaft 5b. Because the rotation angle α1 of the footrest can be connected in a wide range of (90 ° + θ1 °), it can keep the moment with respect to the foot support 2 when the footrest is “open”. The “open” effect of the footrest can be sustained. Further, since the handle portion 6a is formed upward by an angle θ2 from the XX axis regardless of the orientation θ1 of the arm portion 6b, the grip 6j can be brought closer to the patient and can be provided at a convenient position.

The L-shaped operating lever 6s shown in FIG. 7A has its head portion 6k expanded into a wooden shape in the direction of rotation, and a plurality of holes 61 are provided in the front-rear direction. This is another embodiment in which a grip 6j is provided so as to be easy. The grip 6j is hooked by the patient with two fingertips, and the two grips 6j are fixed with male screws 6i with the leading portion 6k sandwiched from the left and right.
FIG. 7B is a D-F cross-sectional view of FIG.

FIG. 6 of this embodiment is a case where R2> R1, and the lift L2 of the steel wire connecting portion 6d and the lift L1 of the shaft 16 of the footrest 4 are equal, and the rotation angle α2 of the L-shaped operation lever 6 is Since the rotation angle α1 of the footrest 4 can be smaller, the operation becomes very easy.
Relational expressions between the rotation angles αI, α2 and the rotation radii R1, R2 at this time
R1 × α1 = R2 × α2 (where α is radians)
If the respective connection positions are determined so that R2> R1, and α1 of the target footrest is measured, the rotation angle α2 of the target L-shaped operating lever 6 can be easily obtained from the above equation.

R1 may be approximately 25 to 35 mm, and R2 may be 30 to 55 mm.
For example, when R1 = 25 mm, αI = 90 degrees, and R2 = 35 mm, α2≈64 · 3 degrees is calculated from the above equation. That is, to turn the footrest 90 degrees by the L-shaped operating lever 6, it can be rotated by about 64 degrees, and can be reduced by about 30%. Further, when the L-shaped operation lever 6 is rotated from the “closed” position to the “open” position, the force required for the grip 6j is F, and it is required for pulling up on the shaft 16 provided on the footrest 4 (that is, the rotation radius R1). If the force is f, the turning radius of the grip 6j is R3
F = f × R1 / R3
Can be calculated. As an example, when R1 = 25 mm, R3 = 100 mm, and f = 1 kgf,
F = 1kgf × 25/100 = 0.25kgf
That is, the turning force of the grip 6j part can be opened and closed by 1/4 and the rotation angle is about 64 degrees as described above. By using the L-shaped operation lever according to the present invention, the position, the rotation angle, and the operation provided with the grip 6j. The burden on the patient is greatly reduced over all the forces.
The adjustment of R1 may be performed simply by appropriately shifting the position of the connecting jig 15 on the footrest 4 side, and R2 may be selected from among the plurality of striating connection holes 6d under the condition of R2> R1.

The plurality of steel wire connecting holes 6d are formed as one long hole 6d 'having a width h as shown in FIG. 7A, and the shaft 6g fitted therethrough is formed with a high thread as shown in FIG. 7B. The upper and lower sides are cut into parallel planes and the thickness is set as h 'to “turn-off” when nuts are tightened. The bush 6f is fixed to the appropriate R2 position with the nut 6h via the washer 5i, and the bush 6f is covered with steel wire. 7 hooks 7a may be hung.
In this way, the turning radius R2 can be adjusted steplessly within the range of the long hole 6d '. In addition to the shape of the L-shaped lever 6, the length and the rotation angle of the handle portion 6a can be freely selected with reference to this embodiment, and the most suitable one for a person with a hand or arm obstacle can be provided.

In the present embodiment, the arm portion 6b on the L-shaped operation lever 6 side is formed downward with respect to the turning radius R1 on the footrest 4 side, and further the turning radius R2 is made larger than R1. Therefore, the moment effect when the footrest 4 is “ opened ” can be kept large, and the stability is high accordingly.
As the ridge 7b, a durable one having sufficient strength and elongation to raise the footrest is used.
Also, if the L-shaped operating lever 6 is the sword shape 6s in FIG. 7 and a plurality of holes 6l are provided along the direction of rotation as shown in the figure, one or more grips 6j are selected at a position where the patient can easily operate. It is possible to install more than one according to.

    Although not shown, an elastic body that expands and contracts like rubber can be used instead of the stub 7b using a steel wire, and a wire can be used instead of the steel wire. FIG. 8A shows an example of the case where the wire 18 is used for the connecting portion. After winding I to 2 on the shaft 16 ′ fixed to the connecting jig 15 as shown by 18a in FIG. 8B, a commercially available aluminum circle is used. If the aluminum circular tube 19 is crushed so that the end portion 18b does not come out of the tube through the tube 19, it can be simply and safely and securely fixed.

[I] Armrest part of wheelchair body [2] Foot support part [3] Footrest shaft [4] Footrest [5] Base plate [5a] Guide plate [5b] Main shaft [5f] Groove hole [5g] Stop area [6] L-shaped operating lever [6b] Steel wire connecting arm [6d] Steel wire connecting hole [6s] Insulated wood operating lever [7] Steel wire [7b] Spring [14] Coil spring [15] Connecting jig [18] Wire [ 20] Switch

Claims (2)

A pair of left and right foot supports extending forward of the frame of the wheelchair body has a footrest loosely fitted to the footrest shaft, respectively, and connects between a switch provided on a side portion of the wheelchair body frame and a rear end portion of the footrest. An opening and closing mechanism for a footrest of a wheelchair that is configured to be openable and closable between a use position ("closed" position) and a substantially upright position ("open" position) by a rope having at least a part of an elastic body ,
The switch is integrated with a handle connecting portion and a rope connecting arm portion that can change the connecting position of the rope on a main shaft that is planted on a base plate with a guide plate for an L-shaped operation lever that is attached to the wheelchair body frame. The L-shaped operation lever is pivotally attached, and when both the L-shaped operation lever and the footrest are in the “closed” position, the center of the main shaft and the center of the connection hole of the cord connection arm portion are connected. The cord is connected so that the O1-S1 line connecting the O2-S2 line, the center of the pivot axis of the footrest and the connecting shaft of the footrest is substantially parallel, and the rope connecting portion of the L-shaped operating lever is rotated. The moving radius R2 is larger than the turning radius R1 of the footrest, and the handle portion of the L-shaped operating lever is shaped to be directed upward from a horizontal line passing through the center O2 of the main shaft regardless of the direction of the O2-S2 line. Specially Opening and closing mechanism of the wheelchair footrest. The opening / closing mechanism of the footrest of the wheelchair according to claim 1, wherein a top portion of the handle portion of the L-shaped operation lever is shaped like a tree, and a plurality of grip attachment holes are provided along a rotation direction thereof.

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