JP2016059557A - Leg length adjustment mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a leg length adjustment mechanism which enables non-step adjustment of a leg part.SOLUTION: A leg length adjustment mechanism comprises: a fastening shaft 21 penetrating a first frame 12 and a second frame 13; an eccentric cam part 22, which is disposed on one end side of the fastening shaft 21 protruding from the first frame 12, for moving the fastening shaft 21 in an axial direction of the fastening shaft 21, and pressing and bonding the first frame 12 and the second frame 13; a spring support part 31 provided on the other end side of the fastening shaft 21 protruding from the second frame 13; and compression spring means 32 disposed between the spring support part 31 and the second frame 13.SELECTED DRAWING: Figure 3

Description

  The present invention particularly relates to a mechanism used for adjusting the length of a leg portion of a walking assist device.

  Conventionally, there is JP, 2011-143243, A as a technique of such a field. The link (leg) used in the walking assist device described in this publication is formed in a hollow shape, divided into an upper link piece and a lower link piece, and a core material is inserted into the upper and lower link pieces. ing. Two cylinders are fixed near the ends of the upper and lower link pieces. A pin can be pushed into the cylinder, and several holes are formed above and below the core material. As described above, the link length adjusting unit uses the core material, the pin, and the hole. First, the user moves the upper and lower link pieces up and down with respect to the core material according to his / her height, and then aligns the cylinder and hole at the nearest position with an appropriate tool (for example, driver), etc. The upper and lower link pieces are fixed to the core by pushing the pins into the corresponding holes and engaging the pins with the holes. In this way, the link length is adjusted.

JP 2011-143243 A

  However, when adjusting the length of the link (leg part) described above, the length is adjusted by the cooperation of the hole and the pin. There is a problem that the thickness cannot be adjusted.

  An object of the present invention is to provide a leg length adjusting mechanism that enables stepless adjustment of the leg.

The present invention is a mechanism for adjusting the length of a leg having a first frame and a second frame sliding in the longitudinal direction with respect to the first frame,
A fastening shaft penetrating the first frame and the second frame;
An eccentricity that is disposed on one end side of the fastening shaft protruding from the first frame and that presses the first frame and the second frame by moving the fastening shaft in the axial direction of the fastening shaft. A cam part;
A spring support provided on the other end side of the fastening shaft protruding from the second frame;
Compression spring means disposed between the spring support portion and the second frame.

  In the above-described leg length adjusting mechanism, the eccentric cam portion is rotated to contract the compression spring means, while the cam surface of the eccentric cam portion and the spring support portion are moved relative to the first frame. Since the second frame is strongly pressure-bonded, the second frame can be locked at an arbitrary position with respect to the first frame. Further, by rotating the eccentric cam portion in the opposite direction, the pressure-bonding force between the first frame and the second frame is weakened, and the second frame relative to the first frame is adjusted for length adjustment. Can be easily slid. Thus, the stepless adjustment of the leg portion is possible only by the rotation of the eccentric cam portion. Then, due to the action of the compression spring means, when the second frame is slid with respect to the first frame, the backlash of the second frame with respect to the first frame can be prevented.

  According to the present invention, stepless adjustment of the leg portion is possible.

It is the front view and side view which show one Embodiment of the leg part to which the length adjustment mechanism based on this invention was applied. It is a perspective view which shows a length adjustment mechanism. It is sectional drawing of a length adjustment mechanism. It is a principal part expanded sectional view which shows the other example of a length adjustment mechanism. It is a principal part expanded sectional view which shows the further another example of a length adjustment mechanism.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a leg length adjusting mechanism according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the lower knee portion 2 </ b> A that forms a part of the leg portion 2 of the walking assist device 1 can be adjusted in length corresponding to the length of the user's leg. In the lower knee 2A, a lower meniscus support 3a of a knee pad 3 used for holding the meniscus of the knee is fixed to the upper part, and a footrest part 4 for placing a foot on the lower part. Is attached.

  The meniscus lower support 3 a and the footrest 4 are connected by a pair of left and right leg frames 10 and 11. One leg frame 10 is located on the upper side, an outer frame (first frame) 12 whose upper end is connected to one end in the left-right direction of the meniscus lower support portion 3a, and a lower leg, And an inner frame (second frame) 13 connected to a footrest angle adjusting unit 14 for adjusting the angle of the mounting part 4.

  The inner frame 13 is assembled so as to be slidable in the longitudinal direction within the outer frame 12. The footrest angle adjustment unit 14 connects the upper end of the link portion 4 a of the footrest unit 4 and the lower end of the inner frame 13.

  The other leg frame 11 is located on the upper side, the outer frame 15 having the upper end connected to the other end in the left-right direction of the meniscus lower support portion 3 a, and the lower leg frame 11, located on the lower side and front and rear of the footrest portion 4 And an inner frame (second frame) 16 connected to a footrest position adjusting unit 17 for adjusting the vertical position.

  The inner frame 16 is assembled so as to be slidable in the longitudinal direction within the outer frame 15. The footrest position adjusting portion 17 connects the upper end of the link portion 4 b of the footrest portion 4 and the lower end of the inner frame 16.

  On one leg frame 10 side, a length adjusting mechanism 20 for adjusting the length of the inner frame 13 with respect to the outer frame 12 is provided. On the other hand, on the other leg frame 11 side, the inner frame 13 can freely slide with respect to the outer frame 12 following the length adjustment.

  As shown in FIGS. 2 and 3, the inner frame 13 having a substantially U-shaped cross section is disposed so as to abut on the inner wall surface 12 d of the outer frame 12 having a substantially U-shaped cross section. The outer frame 12 has a flat plate portion 12a extending in the longitudinal direction, and a skirt portion 12b hanging from both ends of the flat plate portion 12a. The inner frame 13 includes a flat plate portion 13a extending in the longitudinal direction, a protruding strip portion 13b that is provided on the flat plate portion 13a and extends in the longitudinal direction so as to be in sliding contact with the inner wall surface 12d of the outer frame 12. And a skirt portion 13c that hangs down at both ends of the flat plate portion 13a.

  The flat plate portion 13a is provided with elongated holes 13d at equal intervals in the longitudinal direction, and the flat plate portion 12a of the outer frame 12 is provided with a length adjusting hole 12c extending in the longitudinal direction. Then, the tightening shaft 21 is inserted through the long hole 13d and the length adjusting hole 12c so as to penetrate the outer frame 12 and the inner frame 13.

  An end portion 21 a of the fastening shaft 21 protruding from the flat plate portion 12 a of the outer frame 12 is inserted into a central hole 26 a of the rotation shaft portion 26 that enables the eccentric cam portion 22 to rotate. In this state, the rotation shaft portion 26 is sandwiched between the step portion 21b formed at the proximal end of the end portion 21a of the tightening shaft 21 and the washer 24 pressed by the head 23a of the bolt 23. To the fastening shaft 21. An operation lever 25 is integrally formed with the eccentric cam portion 22 that rotates about the rotation shaft portion 26, and the eccentric cam portion 22 can be manually rotated by the operation lever 25.

  The eccentric cam portion 22 forms a pair on the left and right so as to sandwich the tightening shaft 21 from both sides (see FIG. 2). The operation lever 25 spans the left and right eccentric cam portions 22. The cam surface 22a of the eccentric cam portion 22 is formed by connecting one end A far from the center R of the rotation shaft portion 26 and the other end B close to the center R with a curved surface. Yes. That is, the radius connecting the center R and the terminal end B is shorter than the radius connecting the center R and the terminal end A. Therefore, by rotating the operation lever 25 in the direction of arrow C, the other end B can be moved to the position where the one end A was present.

  A spacer 27 is disposed between the cam surface 22 a and the flat plate portion 12 a of the outer frame 12. The spacer 27 is provided with a curved sliding surface 27a that comes into sliding contact with the cam surface 22a. By employing the spacer 27, the cam surface 22a does not directly contact the flat plate portion 12a of the outer frame 12, and wear of the cam surface 22a can be reduced and the eccentric cam portion 22 can be smoothly rotated.

  In the inner frame 13, a compression spring means 30 in which a plurality of disc springs are stacked is arranged in a space having a U-shaped cross section surrounded by the flat plate portion 13a and the skirt portion 13c. One end of the compression spring means 30 is supported by a spring support portion 31 formed in a flange shape at the end of the fastening shaft 21 protruding from the inner frame 13, and the other end of the compression spring means 30 is a flat plate of the inner frame 13. It is supported by the inner wall surface of the part 12a.

  In the length adjusting mechanism configured as described above, when the eccentric cam portion 22 is rotated in the direction of arrow C (see FIG. 3) by the operation lever 25, the end B moves to the position where the end A exists. Therefore, the pressure-bonding force between the outer frame 12 and the inner frame 13 is weakened, and the inner frame 13 can be easily slid with respect to the outer frame 12 for length adjustment.

  In contrast, by rotating the eccentric cam portion 22 in the direction of arrow D (see FIG. 3), the end A returns to the position where the end B exists, Since the inner frame 13 is strongly pressed against the outer frame 12 between the cam surface 22a of the eccentric cam portion 22 and the spring support portion 31, the inner frame 13 can be locked at that position with respect to the outer frame 12. it can.

  In this manner, the knee lower portion 2A of the leg portion 2 can be adjusted steplessly only by the rotation of the eccentric cam portion 22. Further, the action of the compression spring means 30 can prevent the inner frame 13 from rattling with respect to the outer frame 12 when the inner frame 13 is slid with respect to the outer frame 12. Furthermore, the use of the compression spring means 30 can reduce the influence of component variations, and there is little fluctuation in the crimping force.

  As shown in FIG. 3, the inner frame 13 is attached to the outer frame 12 by strongly pressing the inner wall surface 12 f of the skirt portion 12 b of the outer frame 12 and the outer wall surface 13 f of the skirt portion 13 c of the inner frame 13. It can be locked firmly. In this case, the inner wall surface 12f of the skirt portion 12b extending in the longitudinal direction is formed as a tapered surface that spreads outward toward the free end of the skirt portion 12b. Similarly, the outer wall surface 13f of the skirt portion 13c extending in the longitudinal direction is formed as a tapered surface that spreads outward toward the free end of the skirt portion 13c. The tapered surface may be at least in the length adjustment range in the outer frame 12 and the inner frame 13.

  By adopting the inner wall surface 12f and the outer wall surface 13f that form a tapered surface, the outer frame 12 and the inner frame 13 can be easily and firmly crimped by the wedge effect, and at the same time, the outer frame 12 and the inner frame 13 Can be easily released.

  In the locked state by the eccentric cam portion 22, the tensile and compressive load is received by the friction holding force between the inner wall surface 12f and the outer wall surface 13f, the yaw moment is received by the surface contact between the inner wall surface 12f and the outer wall surface 13f, and the pitch moment and roll The moment is received by the surface contact between the inner wall surface 12f and the outer wall surface 13f and the cam surface 22a. Such a structure is particularly resistant to yaw moment.

  The present invention is not limited to the above-described embodiment, and various modifications as described below are possible without departing from the gist of the present invention.

  For example, as shown in FIG. 4, a wedge-shaped mounting part 40 for contacting the inner wall surface 12 f of the skirt portion 12 b of the outer frame 12 is fixed to the outer wall surface 13 f of the skirt portion 13 c of the inner frame 13. Yes. The mounting component 40 extends in the longitudinal direction, and the outer surface of the mounting component 40 is formed as a tapered surface that spreads outward on the outer wall surface 13f of the skirt portion 13c toward the free end.

  As shown in FIG. 5, a rolling element (for example, a sphere or a cylinder) 50 may be disposed between the skirt portion 13 c of the inner frame 13 and the skirt portion 12 b of the outer frame 12. In this case, the rolling elements 50 are arranged in a housing recess 51 formed in the skirt portion 13c of the inner frame 13, and a plurality of rolling elements 50 are juxtaposed in the longitudinal direction.

  If a disc spring is used as the compression spring means 30, a large force can be obtained with a relatively small amount of contraction, and the mechanical characteristics can be stabilized and the size and weight can be reduced. It may be.

  Further, a scale may be provided on the inner frame 13 so that the adjustment amount can be seen visually.

DESCRIPTION OF SYMBOLS 2 ... Leg part 12 ... Outer frame (1st frame) 13 ... Inner frame (2nd frame) 21 ... Fastening shaft 22 ... Eccentric cam part 31 ... Spring support part 32 ... Compression spring means

Claims (1)

A mechanism for adjusting the length of a leg having a first frame and a second frame sliding in a longitudinal direction relative to the first frame,
A fastening shaft penetrating the first frame and the second frame;
An eccentricity that is disposed on one end side of the fastening shaft protruding from the first frame and that presses the first frame and the second frame by moving the fastening shaft in the axial direction of the fastening shaft. A cam part;
A spring support provided on the other end side of the fastening shaft protruding from the second frame;
A leg length adjusting mechanism comprising compression spring means disposed between the spring support portion and the second frame.

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