JP2007082805A - Lifting support mechanism of rear-part caster in care wheelchair - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide rear-part caster lifting support mechanism capable of lightly lifting/lowering rear-part casters by a pedal treading operation by a caregiver and preventing from being unexpectedly detached in the use. <P>SOLUTION: This lifting support mechanism of the rear-part casters is provided with the rear-part casters 14 at the tips of leg rods 12 pivoted to the rear part of a frame 1, a first link 18 is pivoted to a rod part 15, the upper end of a second link 20 is pivoted to the first link 18, the second link 20 is pivoted to an approximate intermediate portion of the leg rod 12 so as to frontward incline the first link 18, a crank 24 is provided in the lower end of the second link, and a downward energizing member 30 is provided in the log rod 12. This mechanism is provided with a floating support means 33 retaining the rear-part caster in a state slightly floated from the floor face in a normal state, the leg rod 12 is lowered by the second link by treading a pedal to lower the rear-part caster 14 and simultaneously therewith, rotates the first link 18 rearward, and a stopper 27 braking the rotation of the first link in a slightly rear part of the pivot part 23 is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an elevating support mechanism for a rear caster in a nursing wheelchair that is improved in safety, traveling performance, and usability by providing a caster behind a main wheel so that the caster can be moved up and down.

In order to prevent the wheelchair from tipping backward, and at the same time allowing a smooth movement even in a narrow place, a pair of casters are provided on the rear of the main wheels so as to be able to move up and down, and the main wheels are lowered by lowering the casters. Conventionally, wheelchairs that are kept floating from the ground contact surface are known.
In addition, the wheelchair shown in the following Patent Document 1 relating to the invention of the present inventors is such that a person riding on the wheelchair can manually and lightly lower the rear caster without being equipped with a hydraulic mechanism or an electric mechanism. It is a thing.
In addition, the wheelchair fall prevention mechanism described in Patent Document 2 below is such that a caregiver steps a pedal provided at the rear of the wheelchair as shown in FIGS. Thus, the rear caster can be lowered.
JP 2004-290275 A JP-A-2005-34626

  By the way, the raising / lowering support mechanism of the rear caster disclosed in Patent Document 2 has a parallelogram-shaped link formed at the rear part of the wheelchair, a rear caster is provided at the lower rear part of the parallelogram link, and the caregiver presses the pedal. By stepping, as shown in FIG. 11 of the same patent document, the parallelogram link is deformed to be slightly inclined forward, and the rear caster is held in the lowered state. . For this reason, if a backward force is applied to the rear caster during use, the holding state may be unexpectedly released. In addition, for example, even if the rear part of the wheelchair is lifted by a caregiver to change the direction or the floor surface is uneven and the rear caster hangs down in the concave part, the rear caster is used as an opportunity. May move backward and the lowered holding state may not be maintained. In addition, when the lower caster is released from the lowered state, it is necessary for the caregiver to lift the pedal with the instep. However, since the weight of the wheelchair and the occupant is applied, the pedal becomes heavy. There was a problem that could not be operated. If a large forward inclination angle of the parallelogram link in the lowered state of the rear caster is taken in order to prevent the rear caster from being unintentionally detached during use, the caregiver will step on the pedal because the pedal becomes heavier. It is in the situation that it becomes more difficult to lift it with the back. The present invention intends to solve such a problem in a care wheelchair.

Therefore, the invention described in claim 1 is a nursing wheelchair in which main wheels are rotatably provided on both sides of a frame that supports a seat, and a pair of front casters are provided on the front of the frame. A pair of leg rods extending rearward at the rear is pivotally attached so as to be rotatable in a vertical plane, a rear caster is provided at the tip of the leg rod, and the lower side of the leg rod is provided at the rear lower portion of the frame An extension hook part extending to the upper end of the leg link is pivotally attached to the extension hook part so as to be rotatable in the same plane as the leg hook. An upper end of the second link is pivotally attached to a portion extending to the upper part, and the second link is inclined forward in a state where the second link is positioned rearward of the first link. The substantially middle part of the link is pivotally attached to the substantially middle part of the toe, and the second rib The lower end of the hook is provided with a crank that bends and extends rearward in a substantially L shape, a pedal is provided at the tip of the crank, and a downward biasing member such as a spring or a gas spring for biasing the leg rod downward is provided. And supporting the leg rod with a spring stronger than the downward biasing member so that the rear caster is normally kept slightly lifted from the floor surface against the elasticity of the downward biasing member. The levitation support means is provided on the extension collar, and when the pedal is depressed, the leg heel is pushed down against the elasticity of the levitation support means by the second link, and the rear caster is lowered with respect to the frame. Two links rotate the first link backward, and the first link and the second link hit the first link when the first link is slightly behind the pivotal joint between the second link and the footrest. Standing almost vertically Thus, a stopper for stopping the rearward rotation of the first link is provided, and the rear caster is attached to the frame by the first link and the second link being held in the substantially vertical standing state by the elasticity of the floating support means. On the other hand, it is held in a lowered state.
According to a second aspect of the present invention, in the lifting support mechanism of the rear caster, the lifting support mechanisms on both sides operate integrally by connecting the first links of the lifting support mechanisms on both sides with horizontal connecting shafts. It is characterized by doing so.

  There is no risk that the rear caster held in the lowered state will accidentally come off during use. Moreover, the rear caster can be lifted and lowered easily by the caregiver stepping on the pedal. For this reason, usability improves and it can be used safely.

  FIG. 1 shows an embodiment of the present invention. FIG. 1 is an overall perspective view of a nursing wheelchair, FIG. 2 is a side view thereof, and FIG. In the figure, 1 is a frame formed by a light metal pipe so as to be foldable, 2 is a seat provided on the frame, and 3 is a pair of shafts 4 provided on both sides of the frame. The main wheels 5 are a pair of front casters (wheels whose turning direction can be freely changed in a horizontal plane) provided on both side edges of the front portion of the frame. The frame 1 is driven by the main wheels 3 and the front casters 5. Supported as possible. 6 is a footrest provided on the front part of the frame 1, 7 is an armrest part provided on both sides of the seat 2, and 8 is a handle established on the rear side of the frame 1 so that a caregiver can operate it. Part.

  Next, the raising / lowering support mechanism of the rear caster described in claim 1 will be described according to the enlarged view of the main part of FIGS. As shown in the figure, reference numeral 14 denotes a rear caster, which is provided with bearing pieces 10 projecting rearward from the shaft support portion 4 on both side edges of the rear portion of the frame 1 and extending rearward by a pair of pivots 11 inserted through the bearing pieces. The leg rods 12 are pivotally attached so as to be rotatable in a vertical plane, and the rear casters 14 are provided through the branch pipes 13 at the tip portions of the leg rods. Further, an extension hook portion 15 extending below the leg rod 12 is provided at the lower rear portion of the frame 1, and a pivot 17 is attached to a bearing portion 16 that is fixed to the lower side of the extension rod portion by welding. The first link 18 is pivoted by the pivot so as to be rotatable in the same plane as the leg rod 12. The first link 18 is composed of a pair of flat bars 18a and 18b, and the flat bars are arranged on both sides of the extension rod 15 and the leg rod 12 so as to extend upward with a gap therebetween, and the upper end thereof is It extends above the leg pad 12. Then, the pivot 19 is inserted into a portion of the first link 18 that extends to the upper part of the leg rod 12, and the upper end of the second link 20 is pivotally attached to the first link 18 via the pivot 19. Similarly to the first link, the second link 20 is also provided so that two flat bars 20a and 20b are located on both sides of the leg rod 12. Reference numerals 21a and 21b denote washers sandwiched between the flat bar 18a and the flat bar 20a and between the flat bar 18b and the flat bar 20b and having the pivot shaft 19 inserted therethrough. Then, the bearing cylinder 22 is fixed to the upper surface of the substantially middle portion of the leg rod 12 by welding, the pivot 23 is inserted into the bearing cylinder, and both projecting ends of the pivot are inserted into the flat bars 20a and 20b. In a state where the second link 20 is positioned behind the first link 18, the substantially intermediate portion of the second link 20 is set to the approximately intermediate portion of the leg rod 12 so that the first link 18 is inclined forward. Pivot. (See FIG. 5). A crank 24 is provided at the lower end portion of the second link 20 so as to be bent rearward in a substantially L shape, and a foot pedal 25 is provided at the tip of the crank. The crank 24 has a pair of flat bars 24a and 24b welded to the flat bars 20a and 20b. As described above, the flat bar 24a and the flat bar 24b are welded to the flat bars 20a and 20b in parallel to each other and have an appropriate interval. Therefore, the branch pipe 13 is avoided during the interval, and the crank 24 does not collide with the branch pipe 13. I am doing so. And the pedal 25 is fixed by the screw | thread 26 so that it may cross over the front-end | tip part of flat bar 24a, 24b. Reference numeral 27 denotes a stopper composed of a pair of ear-shaped pieces 27a and 27b formed at the lower end portion of the second link 20 so as to protrude outside the flat bars 24a and 24b. The stoppers 27a and 27b are formed so as to be able to contact the side surfaces of the flat bars 18a and 18b when the first link 18 and the second link 20 are in a substantially vertical standing state. I will explain it.

  Reference numeral 30 denotes a downward biasing member made of a coil-like tension spring having one end fastened to the extension rod 15 by a screw 31 and the other end fastened to the leg rod 12 by a screw 32. As a result, the leg rod 12 is pulled downward. Reference numeral 33 denotes a levitation support means provided on the extension collar 15, and the levitation support means includes a coil-shaped compression spring 35 in a vertical cylinder 34 which is fixed vertically on the extension collar 15 by welding. A shaft-like support member 36 is provided so as to be loaded and retracted from the upper end opening of the vertical cylinder 34, and the support member 36 is urged upward by the elasticity of the spring 35 and positioned in the vertical cylinder 34. A flange portion 37 is formed at the lower end portion of the support member 36, and the flange portion 37 is engaged with a flange 38 formed inwardly at the upper end opening edge of the vertical cylinder 34, whereby the support member 36 is The tube 34 is prevented from slipping out. The leg rod 12 is supported on the support member 36. The elasticity of the spring 35 is stronger than the elasticity of the spring 30 and strongly urges the support member 36 upward, so that the spring 35 resists the elasticity of the spring 30 and pushes the leg rod 12. It can be supported. Therefore, in the normal state, the leg rod 12 abuts on the support member 36, and the rear caster 14 is supported in a state of being slightly lifted from the floor as shown in FIGS. This prevents the rear caster 14 from contacting the floor surface during normal travel and does not exert resistance during travel.

  For this reason, when the caregiver steps on the pedal 25, as shown in FIGS. 7 and 8, the leg rod 12 is pushed down by the second link 20, and the rear caster 14 is lowered with respect to the frame 1, and the second link 20 Rotates the first link 18 rearward, and when the first link 18 is slightly behind the pivot 23 which is the pivotal attachment portion of the second link 20 and the leg rod 12, the stoppers 27a and 27b are moved to the first link 18 respectively. It abuts against the link 18 (side surfaces of the flat bars 18a and 18b) and restricts the rearward rotation of the first link 18. Accordingly, the first link 18 and the second link 20 are held in a substantially vertical standing state while being in contact with the stoppers 27a and 27b, and the rear caster 14 is held in a lowered state with respect to the frame 1. For this reason, as shown in FIG. 9, the main wheel 3 can be kept in the state of floating from the floor surface. In this state, since the wheelchair is supported by the front caster 5 and the rear caster 14, the traveling direction can be freely changed, and the lateral movement (direction orthogonal to the main wheel 3) can be freely moved. In this state, the support member 36 of the levitation support means 33 is pushed down by the leg rod 12, and the spring 35 is in a contracted state as shown in FIG. 8 and strongly urges the leg rod 12 upward. For this reason, for example, even if the rear part of the wheelchair is lifted by a caregiver for a change of direction or the like, the rear caster 14 does not hang down even if the floor is uneven and the rear caster 14 is positioned in the concave part. The state in which the one link 18 is slightly behind the pivot 23 that is the pivotal attachment portion between the second link 20 and the leg rod 12 is maintained, and the rear caster 14 is reliably held in the lowered state. Further, since the rear caster 14 is pivotally attached to the rear portion of the frame 1 so as to be rotatable in a vertical plane and is provided at the tip end portion of the leg rod 12 extending rearward, there are obstacles, steps, etc. Even if a rearward force is applied to the hitting rear caster, only a tensile force is applied to the leg rod 12, so there is no possibility that the lowered holding state of the rear caster is unexpectedly removed.

  7 and 8, the caregiver raises the pedal 25 by placing the back of the foot on the lower side of the foot pedal 25 and pulling up the pedal 25 as shown in FIGS. 4 and 5. The caster 14 can be returned to a state where it is slightly lifted from the floor surface. In this case, if the caregiver holds the handle portion 8 and lifts the rear part of the wheelchair a little, the caregiver can easily return it lightly only by requiring a force against the elasticity of the spring 35 of the levitation support means 33. 4 and 5, with the rear caster 14 slightly lifted from the floor, the rear caster 14 prevents the wheelchair from falling backward and the caregiver is biased downward. By tilting the frame 1 backward against the elasticity of the member 30, the front casters 5 can be safely lifted from the floor as shown in FIG. It can be safely and easily overcome without fear of falling backwards.

  Thus, in this care wheelchair, the rear caster 14 provided on the leg pad 12 is urged downward by the downward urging member 30 and supported by the levitation support means 33. Thus, the rear caster 14 is normally kept in a slightly lifted state without rubbing the floor surface to prevent the wheelchair from falling backward, and when the rear caster 14 is lowered with respect to the frame, The lowered state is maintained by elasticity and can be used safely. In addition, the upper end of the second link 20 is pivotally attached to the portion of the first link 18 that extends to the upper part of the leg rod 12, and the first link is positioned rearward of the first link. Since the substantially middle part of the second link is pivotally attached to the substantially middle part of the toe so that it is inclined forward, the rear caster 14 is slightly lowered by the lever action when the pedal is stepped on. And the first link hits the first link when the first link is slightly behind the pivoting portion 23 between the second link and the leg pad, and the first link and the second link are brought into a substantially vertical standing state. Since the stopper 27 for stopping the rotation of the link rearward is provided, if the pedal is pulled up by the instep, the first link passes the pivot part 23 forward without requiring a strong force, and the rear caster 14 The descent state is released It is. For this reason, operability is greatly improved.

In this embodiment, a coil-shaped spring is used as the downward biasing member 30, but the leg rod 12 can be biased downward using a gas spring instead of the spring. When a gas spring is used in this way, the frame 1 always tilts gently rearward, so that safety is further increased.
Further, in this embodiment, the stopper 27 is formed at the lower end of the second link 20, but this is to prevent the first link and the second link from standing upright and to prevent the first link from rotating backward. Therefore, it may be formed on another portion, for example, the extended flange 15.

  Next, an embodiment of the invention described in claim 2 will be described with reference to FIG. In this embodiment, the first links 18 of the lifting support mechanisms on both sides are connected to each other by a horizontal connecting shaft 40 so that the rear casters 14 on both sides can be simultaneously lifted and operated. This eliminates the need to operate the pedals 25 on both sides one by one, so that the operability is further improved. Reference numeral 41 denotes a gas spring used in place of the spring as a downward urging member for urging the leg rod 12 downward. The gas spring has a proximal end fixed to the frame 1 and its operating shaft. The front end of 42 is connected to one side of the second link 20 via a connecting fitting 43, and the leg link 12 is urged downward by pulling the second link forward by the elasticity of the gas spring. ing. In addition, in the reference numerals shown in FIG. 11, the same reference numerals as those in the above embodiment indicate the same parts as those in the above embodiments, and the description thereof will be omitted. The first link 18 and the second link 20 also have a function of stopping the first link from rotating backward when the first link 18 and the second link 20 are in a substantially vertical standing state.

The perspective view of the wheelchair for care which shows the embodiment of the present invention. The side view of the wheelchair for care which shows the embodiment of the present invention. The reverse view of the principal part of the wheelchair for care which shows embodiment of this invention. The perspective view of the rear caster raising / lowering support mechanism which shows embodiment of this invention. The partial cross section side view of the rear caster raising / lowering support mechanism which shows embodiment of this invention. The top view of the rear caster raising / lowering support mechanism which shows embodiment of this invention. The operation | movement state figure of the rear caster raising / lowering support mechanism shown in FIG. The operation | movement state figure of the rear caster raising / lowering support mechanism shown in FIG. The operation state figure of the care wheelchair shown in FIG. The operation state figure of the care wheelchair shown in FIG. The perspective view of the rear part of the wheelchair for care which shows other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Frame 3 Main wheel 5 Front caster 10 Bearing piece 11 Pivot 12 Leg rod 14 Rear caster 15 Extension hook 16 Bearing portion 17 Pivot 18 First link 19 Pivot 20 Second link 22 Bearing cylinder 23 Pivot (pivot part)
24 Crank 25 Pedal 27 Stopper 30 Downward biasing member 33 Levitation support means 40 Connecting shaft 41 Gas spring

Claims (2)

  In a care wheelchair in which main wheels are rotatably provided on both sides of a frame that supports a seat portion and a pair of front casters are provided at the front portion of the frame, a pair of leg rods extending rearward is provided at the rear portion of the frame. Each is pivotally attached so as to be rotatable in a vertical plane, a rear caster is provided at the front end of the leg bar, an extension bar part extending below the leg bar is provided at the lower rear side of the frame, and the extension bar A first link extending to an upper portion of the leg rod is pivotally attached to the portion so as to be rotatable in the same plane as the leg rod, and a portion of the second link is extended to a portion extending to the upper portion of the leg rod. An upper end portion is pivotally attached, and the second link is positioned rearward of the first link so that the first link is inclined forward so that the substantially intermediate portion of the second link is the abbreviation of the leg rod. It pivots to the middle part and bends in a substantially L shape rearward at the lower end of the second link A crank that extends, a pedal at the tip of the crank, a downward urging member such as a spring or a gas spring that urges the leg rod downward, and against the elasticity of the downward urging member In the normal state, levitation support means for supporting the leg heel with a spring stronger than the downward biasing member is provided on the extension heel so that the rear caster is kept slightly lifted from the floor surface, and the pedal is By stepping on, the leg link is pushed down against the elasticity of the levitation support means by the second link to lower the rear caster with respect to the frame, and at the same time, the second link rotates the first link backward, and the first link When the link is slightly behind the pivoting portion of the second link and the leg, the first link and the second link are brought into a substantially vertical standing state and the first link is rotated backward. System A stopper is provided, and the rear caster is held in a lowered state with respect to the frame by holding the first link and the second link in the substantially vertical standing state by the elasticity of the floating support means. The raising / lowering support mechanism of the rear caster in the nursing care wheelchair.   The raising / lowering support mechanism of the rear caster in the nursing wheelchair according to claim 1, wherein the first raising / lowering support mechanisms on both sides are connected by a horizontal connecting shaft so that the raising / lowering support mechanisms on both sides operate integrally. .

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