JP2018072133A - caster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a caster with a built-in a load sensor, the caster being capable of protecting the load sensor when is moved.SOLUTION: The caster includes: a wheel; a wheel supporting body for rotatably supporting the wheel; and a load sensor supported in the inside of the wheel, the load sensor having a strain body and a strain gauge; and a stopper in the wheel supporting body, the stopper being freely separated from or brought into contact with the strain body of the load sensor, the stopper being brought into contact with the strain body when the load on the strain body causes the amount of deformation of the strain body to reach a predetermined level, thereby preventing the strain body from deforming beyond a predetermined amount.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a caster including a load sensor therein.

  The biological information of the subject is one of important information for knowing the physical condition of the patient and the cared person in the field of medical care and care. For example, it is possible to grasp the respiratory state of the subject, to grasp symptoms such as sleep apnea syndrome and snoring, and to improve these symptoms.

  Patent Document 1 proposes a bed with a load detection function that detects a change in load applied to a bed body by a load detector attached to the bed body and detects a user's state on the bed surface of the bed body. Yes. And the caster mechanism for facilitating the movement of a bed main body is provided in the leg part of the four corners of a bed main body, and the structure which interposes a load cell in the inside of a caster mechanism is suggested.

Table 2013/108503

  However, as suggested in Patent Document 1, when a caster mechanism is provided at the four corners of the bed body and the load cell is interposed inside the caster mechanism, the load cell has a problem due to vibration when moving the bed. It can happen.

  Therefore, an object of the present invention is to provide a caster that includes a load sensor therein and that can protect the load sensor during movement.

According to an aspect of the invention,
Wheels,
A wheel support for rotatably supporting the wheel;
A load sensor supported inside the wheel support and having a strain body and a strain gauge;
Provided inside the wheel support so as to be able to contact with and separate from the strain body of the load sensor, and when the deformation amount of the strain body reaches a predetermined value due to a load applied to the strain body, A caster is provided that includes a stopper that abuts on the strain body and prevents the strain body from being deformed beyond a predetermined amount.

  The caster according to an aspect of the present invention may further include a stopper moving mechanism that contacts and separates the stopper from the strain body.

  In the caster according to an aspect of the present invention, the wheel support may include a first member in which the load sensor is accommodated, and a second member that is provided with the stopper and supports the wheel, and the stopper movement. The mechanism may move the first member and the second member relatively to bring the stopper into contact with and away from the load sensor.

  In the caster according to the aspect of the present invention, the wheel support may be attached to a leg portion of the bed, and the load may be a load of the bed.

  In the caster of the present invention, a stopper capable of contacting and separating from a load sensor supported inside the wheel support is provided inside the wheel support. For this reason, when the caster of this invention moves the bed attached to the leg part, a load sensor can be protected by making a stopper contact a load sensor inside a wheel support body.

FIG. 1 is a side view showing a state in which a caster of the present invention is attached to a leg portion of a bed. FIG. 2 is an enlarged side view showing the caster of the present invention attached to the leg of the bed. FIG. 3 is a cross-sectional view showing the internal structure of the wheel support section. FIG. 4 is a view corresponding to FIG. 3 of a caster according to a first modification of the present invention. FIG. 5 is a view corresponding to FIG. 3 of a caster according to a second modification of the present invention.

  Hereinafter, the caster according to the embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the caster 10 according to the embodiment of the present invention is attached to the leg portion 110 of the bed 100 in order to facilitate the movement of the bed 100.

  As shown in FIG. 2, the caster 10 includes a wheel 20 and a wheel support 30 that rotatably supports the wheel 20. The wheel support 30 includes a wheel support member 50 that supports the wheel 20, a ring member 60 provided on the wheel support member 50, and a cylindrical member 40 provided thereon. The cylindrical member 40 corresponds to the “first member” of the present invention, and the wheel support member 50 corresponds to the “second member” of the present invention.

  The cylindrical member 40 is a member for connecting the leg portion 110 of the bed 100 to the caster 10, and the tip of the leg portion 110 of the bed 100 is inserted into the open end 40a on one side thereof. The cylindrical member 40 is fixed to the leg portion 110 of the bed 100 by a bolt or the like (not shown). The other open end 40 b of the cylindrical member 40 is connected to the ring member 60. The ring member 60 is a member for connecting the tubular member 40 and the wheel support member 50, and the connection mechanism thereof will be described later. The wheel support member 50 includes a fork-shaped arm member 51 that rotatably supports both ends of the rotating shaft 20 a of the wheel 20, and an arm support member 52 that supports the arm member 51. The end of the arm member 51 opposite to the wheel 20 has a cylindrical shape, and a coaxial rotation shaft 53 is provided there. On the other hand, the arm support member 52 is provided with a cylindrical bearing. The arm member 51 is supported rotatably about the rotation shaft 53 by inserting the rotation shaft 53 into the bearing of the arm support member 52. The arm member 51 may be rotatably supported by providing the arm support member 52 with the rotation shaft 53 and providing the arm member 51 with a bearing into which the rotation shaft 53 is inserted.

  As shown in FIG. 3, a load sensor 70 is accommodated in the cylindrical member 40. The load sensor 70 is a so-called strain gauge type load sensor including a strain body 71 and a plurality of strain gauges 72 attached to the strain body 71. The strain generating body 71 is composed of a cylindrical small diameter portion 71a and a cylindrical large diameter portion 71b having a diameter larger than that of the small diameter portion 71a and lower than the small diameter portion 71a. Affixed to the side. The strain body 71 is in contact with the upper surface 52a of the arm support member 52 at the bottom surface of the small diameter portion 71a, and is in contact with the tip of the leg portion 110 of the bed 100 at the upper surface of the large diameter portion 71b. That is, in the cylindrical member 40, the vertical position of the load sensor 70 is fixed by the tip of the leg portion 110 of the bed 100 and the upper surface 52 a of the arm support member 52. When the load from the bed 100 is applied to the large-diameter portion 71b of the strain-generating body 71, the small-diameter portion 71a of the strain-generating body 71 is deformed, and therefore the magnitude of the load is applied by the strain gauge 72 attached to the small-diameter portion 71a. Can be measured.

  A cylindrical stopper 80 is provided on the upper surface 52 a of the arm support member 52 so as to surround the small diameter portion 71 a of the strain body 71. A gap is provided between the lower surface of the large diameter portion 71b of the strain generating body 71 and the upper end 80a of the stopper 80 to allow the small diameter portion 71a to be deformed to some extent. When the small diameter portion 71a is deformed by a load applied to the large diameter portion 71b, the distance between the lower surface of the large diameter portion 71b and the upper end 80a of the stopper 80 is reduced. When the deformation amount of the small-diameter portion 71a reaches a predetermined value due to the load applied to the large-diameter portion 71b, the lower surface of the large-diameter portion 71b abuts against the upper end 80a of the stopper 80, so that the small-diameter portion 71a is further deformed. Can not be. That is, the stopper 80 is provided to prevent the small diameter portion 71a from being deformed beyond the allowable range when an excessive load is applied to the large diameter portion 71b.

  A screw thread 52b is formed on the side surface on the upper surface 52a side of the arm support member 52, and a groove 60a that is screwed with the screw thread 52b is formed on the arm support member 52 side of the inner peripheral surface of the ring member 60. . Further, a flange 40c is formed at the open end 40b on the other side of the cylindrical member 40, and an annular shape projecting inward from the inner peripheral surface on the cylindrical member 40 side of the inner peripheral surface of the ring member 60. The engaging portion 60b is formed. Then, the thread support 52b of the arm support member 52 and the groove 60a of the ring member 60 are engaged with each other, whereby the arm support member 52 and the ring member 60 are connected, and the flange 40c of the tubular member 40 is engaged with the ring member 60. The cylindrical member 40 and the ring member 60 are connected by engaging the part 60b. In addition, between the lower surface of the flange 40c of the cylindrical member 40 and the upper surface 52a of the arm support member 52, a small diameter is provided, as is the case between the lower surface of the large diameter portion 71b of the strain generating body 71 and the upper end 80a of the stopper 80. A gap for allowing deformation of the portion 71a is provided.

  When the ring member 60 is rotated in a predetermined direction, the thread 52b of the arm support member 52 and the groove 60a of the ring member 60 move relative to each other, and the upper surface 52a of the arm support member 52 and the lower surface of the flange 40c of the tubular member 40 are moved. And move relative to each other. At this time, the small-diameter portion 71a of the strain-generating body 71 is deformed by the pressing force from the top surface 52a of the arm support member 52, and the upper end 80a of the stopper 80 and the bottom surface of the large-diameter portion 71b of the strain-generating body 71 are also close to each other. Move relative. When the ring member 60 is further rotated in a predetermined direction, the upper end 80a of the stopper 80 and the lower surface of the large-diameter portion 71b are moved relative to each other so that the upper end 80a of the stopper 80 is moved to the lower surface of the large-diameter portion 71b. bump into. That is, the strain body 71 can be fixed by the stopper 80 in a state where the small diameter portion 71a is deformed to the maximum allowable range.

  On the other hand, when the ring member 60 is rotated in a direction opposite to a predetermined direction from the state in which the upper end 80a of the stopper 80 abuts against the lower surface of the large-diameter portion 71b, the upper surface 52a of the arm support member 52 and the cylindrical member 40 The lower surface of the flange 40c moves relatively away from each other, and the lower surface of the large diameter portion 71b and the upper end 80a of the stopper 80 also move relative to each other. Thereby, the small diameter part 71a can be recovered to a state where the deformation amount does not reach the maximum allowable range. The flange 40c of the cylindrical member 40, the thread 52b of the arm support member 52, the groove 60a and the engaging portion 60b of the ring member 60 correspond to the “stopper moving mechanism” of the present invention.

  The caster 10 according to the embodiment includes the load sensor 70 inside the wheel support 30. For this reason, it is not necessary to separately install a load sensor under the caster. Further, when the caster 10 according to the embodiment moves the bed 100 attached to the leg portion 110, the stopper 80 is moved to the load sensor 70 by rotating the ring member 60 provided on the caster 10 in a predetermined direction. The load sensor 70 can be protected in a state in which a gap provided in advance to allow deformation of the strain generating body 71 is filled.

  Next, a first modification of the embodiment of the present invention will be described. The description which overlaps with the said embodiment is abbreviate | omitted, and it demonstrates centering around difference.

  As shown in FIG. 4, in the wheel support 130 of the first modification, the tubular member 40 and the arm support member 152 are connected by a ring member 160. A recess is formed at the upper end of the arm support member 152, and the load sensor 70 is supported by the bottom surface 152a of the recess. Moreover, the stopper 80 similar to the said embodiment is formed in the bottom face 152a of a recessed part. Similar to the above embodiment, a gap is provided between the lower surface of the large-diameter portion 71b of the strain body 71 and the upper end 80a of the stopper 80 to allow a certain amount of deformation of the small-diameter portion 71a. Further, between the lower surface of the flange 40 c of the tubular member 40 and the bottom surface 152 a of the recess of the arm support member 152, similarly to the space between the lower surface of the large diameter portion 71 b of the strain body 71 and the upper end 80 a of the stopper 80. A gap for allowing deformation of the small diameter portion 71a is provided. Further, a groove 152 b is formed on the inner peripheral surface of the recess of the arm support member 152.

  A cylindrical ring member 160 is interposed between the inner peripheral surface of the recess of the arm support member 152 and the outer peripheral surface of the cylindrical member 40. The inner diameter of the ring member 160 is substantially the same as the outer diameter of the cylindrical member 40, and the ring member 160 is configured to be rotatable along the side surface of the cylindrical member 40. A flange 160 a is formed at the upper end of the ring member 160, and a thread 160 b that meshes with the groove 152 b of the arm support member 152 is formed on the outer peripheral surface of the ring member 160.

  When the user rotates the ring member 160 in a predetermined direction via the flange 160a, the thread 160b of the ring member 160 and the groove 152b of the arm support member 152 move relative to each other, and the ring member 160 moves to the arm support member 152. It moves toward the bottom surface 152a of the recess. When the ring member 160 is further rotated in a predetermined direction, the ring member 160 is further moved, and the leading end portion 160c of the ring member 160 abuts against the flange 40c of the tubular member 40.

  When the ring member 160 is rotated in a predetermined direction from the state in which the front end portion 160c of the ring member 160 is in contact with the flange 40c of the cylindrical member 40, the lower surface of the flange 40c of the cylindrical member 40 is the recess of the arm support member 152. Move so as to approach the bottom surface 152a. At this time, the small diameter portion 71a of the strain body 71 of the load sensor 70 is deformed by the pressing force from the leg portion 110 of the bed 100 fixed to the tubular member 40, and the upper end 80a of the stopper 80 and the strain body 71 are deformed. The lower surface of the large-diameter portion 71b also moves relatively so as to approach each other. When the ring member 160 is further rotated in a predetermined direction, the upper end 80a of the stopper 80 abuts against the lower surface of the large-diameter portion 71b.

  On the other hand, when the ring member 160 is rotated in a direction opposite to the predetermined direction from the state where the upper end 80a of the stopper 80 abuts against the lower surface of the large-diameter portion 71b, the lower surface of the flange 40c of the tubular member 40 is supported by the arm support. The member 152 moves away from the bottom surface 152 a of the concave portion, and the lower surface of the large diameter portion 71 b also moves away from the upper end 80 a of the stopper 80. Thereby, the small diameter part 71a can be recovered to a state where the deformation amount does not reach the maximum allowable range. In the first modification, the flange 40c of the tubular member 40, the groove 152b of the arm support member 152, the thread 160b and the tip 160c of the ring member 160 correspond to the “stopper moving mechanism” of the present invention. . Also in the caster 10 which concerns on a 1st modification, the effect similar to the said embodiment can be acquired.

  Next, a second modification of the embodiment of the present invention will be described. The description which overlaps with the said embodiment is abbreviate | omitted, and it demonstrates centering around difference.

  As shown in FIG. 5, in the wheel support 230 of the second modified example, the tubular member 240 and the arm support member 252 are connected by a tubular connecting member 260. In the second modification, no flange is formed at the lower end of the cylindrical member 240. The load sensor 70 is supported on the upper surface 252 a of the arm support member 252. Further, a screw thread 252b is formed on the upper end side of the side surface of the arm support member 252.

  A cylindrical connection member 260 is interposed between the side surface of the arm support member 252 and the inner peripheral surface of the cylindrical member 240. The connecting member 260 is continuous with the large diameter portion 260a having an outer diameter larger than the outer diameter of the arm support member 252, the upper end of the large diameter portion 260a, and the tapered portion 260b whose diameter decreases upward. The upper end of the taper part 260b and the small diameter part 260c which continues are comprised. The outer diameter of the small diameter portion 260 c is substantially the same as the inner diameter of the cylindrical member 240, and the connection member 260 is configured to be slidable along the inner peripheral surface of the cylindrical member 240. The inner diameters of the large diameter portion 260a, the tapered portion 260b, and the small diameter portion 260c are substantially the same as the outer diameter of the arm support member 252, and the inner diameter of the connection member 260 is formed from the lower end of the large diameter portion 252 to the small diameter portion. A groove 260d that meshes with the thread 252b of the arm support member 252 is formed near the center of 260c. A gap for allowing deformation of the strain generating body 71 is provided between the upper end of the small diameter section 260 c and the lower surface of the large diameter section 71 b of the strain generating body 71. Also, a gap having the same size as the gap between the upper end of the small diameter portion 260c and the lower surface of the large diameter portion 71b of the strain body 71 is provided between the lower end of the cylindrical member 240 and the upper end of the tapered portion 260b. It has been.

  When the user rotates the connection member 260 in a predetermined direction via the large diameter portion 260a, the thread 252b of the arm support member 252 and the groove 260d of the connection member 260 move relative to each other, and the connection member 260 is moved to the arm support member. It moves upward along the side surface of 252 and the inner peripheral surface of the cylindrical member 240. When the connecting member 260 is further rotated in a predetermined direction, the connecting member 260 further moves upward, and the upper end of the tapered portion 260b of the connecting member 260 abuts on the lower end of the tubular member 240. At this time, the upper end of the small diameter portion 260 c hits the lower surface of the large diameter portion 71 b of the strain body 71. In the second modified example, the small diameter portion 260c of the connection member 260 corresponds to the “stopper” of the present invention.

  On the other hand, when the connection member 260 is rotated in a direction opposite to a predetermined direction from the state in which the upper end of the small diameter portion 260c of the connection member 260 hits the lower surface of the large diameter portion 71b, the upper end of the taper portion 260b is cylindrical. While moving away from the lower end of the member 240, the upper end of the small diameter portion 260c of the connection member 260 is also moved away from the lower surface of the large diameter portion 71b. In the second modification, the thread 252b of the arm support member 252 and the groove 260d of the connection member 260 correspond to the “stopper moving mechanism” of the present invention. Also in the caster 10 which concerns on a 2nd modification, the effect similar to the said embodiment can be acquired.

  In the above embodiment, the first modification, and the second modification, the thread and the groove that mesh with each other are formed in separate members, but the thread is formed in the member in which the groove is formed, You may form a groove | channel in the member in which the screw thread was formed.

  In the embodiment, the first modification, and the second modification, the strain body 71 of the load sensor 70 has a T-shaped cross section that includes a small-diameter portion 71a and a large-diameter portion 71b. However, the shape of the strain body 71 is not limited to this. Any shape capable of detecting a load from the bed 100 and filling a gap provided in advance to allow deformation of the strain generating body 71 with a stopper when the bed 100 is moved. Any shape is acceptable.

  As long as the characteristics of the present invention are maintained, the present invention is not limited to the above-described embodiments and modifications thereof, and other forms conceivable within the scope of the technical idea of the present invention are also within the scope of the present invention. Contained within.

  By attaching the caster of the present invention to the leg portion of the bed, it can be used to obtain the biological information of the subject on the bed based on the load detected by the load sensor built in the caster.

10 casters, 20 wheels, 30 wheel supports, 40 cylindrical members, 50 wheel support members, 51 arm members, 52 arm support members, 60 ring members, 70 load sensors, 71 strain bodies, 72 strain gauges, 80 stoppers

Claims (4)

Wheels,
A wheel support for rotatably supporting the wheel;
A load sensor supported inside the wheel support and having a strain body and a strain gauge;
Provided inside the wheel support so as to be able to contact with and separate from the strain body of the load sensor, and when the deformation amount of the strain body reaches a predetermined value due to a load applied to the strain body, A caster comprising: a stopper that abuts on a strain generating body and suppresses deformation of the strain generating body beyond a predetermined amount.   Furthermore, the caster of Claim 1 provided with the stopper moving mechanism in which the said stopper is contacted / separated with respect to the said strain body. The wheel support includes a first member that houses the load sensor, and a second member that is provided with the stopper and supports the wheel,
The caster according to claim 2, wherein the stopper moving mechanism moves the first member and the second member relatively to bring the stopper into contact with and away from the load sensor. The caster according to any one of claims 1 to 3, wherein the wheel support is attached to a leg portion of a bed, and the load is a load of the bed.

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