Patent Application
20140137328
The present invention relates to a lifting apparatus for converting a linear action by a linear actuator into a linear action in a different direction, and a bed provided with the same.
There is a lifting apparatus for linearly lifting and lowering a heavy item (for example, refer to Patent Literature 1 (JP 7-8481 A)). This lifting apparatus is formed by, for example, a linear actuator including an excellent thrust force and an X-shaped link structure.
As shown in
An object of the present invention is to provide a lifting apparatus in which a load applied to an actuator is as constant as possible without depending on a distance between an upper frame (top plate) and a base frame (foundation), and a bed provided with the same.
In accomplishing these and other aspects, according to one aspect of the present invention, there is provided a lifting apparatus comprising a link mechanism lifting and lowering an upper frame with respect to a base frame, wherein
These and other aspects and features of the present invention will become clear from the following description taken in conjunction with the embodiments thereof with reference to the accompanying drawings, in which:
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. It should be noted that the same constituent elements will be given the same reference numerals, and description thereof will be omitted in some cases. For easy understanding, the drawings are schematic focusing on the constituent elements.
As shown in
The link mechanism 80 includes a first arm 13, a second arm 14, a third arm 15, a fourth arm 16, and a fifth arm 17 as one example. The first arm 13 is one example of a driving side T-shaped arm, and the second arm 14 is one example of a driving side L-shaped arm. The third arm 15 is one example of a driven side T-shaped arm, the fourth arm 16 is one example of a driven side I-shaped arm, and the fifth arm 17 is one example of a rod shape conjunction arm.
The upper frame 11 includes a first protruding portion 22a fixed to a front end thereof, a second protruding portion 21a fixed in the vicinity of the first protruding portion 22a, a third protruding portion 27a fixed to a portion behind the second protruding portion 21a, and a fourth protruding portion 26a fixed in the vicinity of a portion behind the third protruding portion 27a and in a rear end of the upper frame. The second protruding portion 21a has a groove 21b extending in the longitudinal direction parallel to the upper frame 11. By disengageably engaging a first pivot point 20 to be described later into the groove 21b so that the first pivot point 20 can move slidably in the groove 21b, a slide guide 21 is formed. The first pivot point 20 is, for example, a driving side upper slide pivot point (support axis). The fourth protruding portion 26a has a groove 26b extending in the longitudinal direction parallel to the upper frame 11. By disengageably engaging a seventh pivot point 25 to be described later into the groove 26b so that the seventh pivot point 25 can move slidably in the groove 26b, a slide guide 26 is formed. The seventh pivot point 25 is, for example, a driven side upper slide pivot point (support axis).
The base frame 12 is arranged so as to face the upper frame 11. The base frame 12 includes a fifth protruding portion 19a fixed so as to face the first protruding portion 22a of the upper frame 11, and a sixth protruding portion 24a fixed so as to face the third protruding portion 27a of the upper frame 11. Therefore, a mounting surface 12x of the base frame 12 and a loading surface 11x of the upper frame 11 are arranged so as to be vertical to a straight line connecting a second pivot point 19 and a third pivot point 22 to be described later. The mounting surface 12x of the base frame 12 and the loading surface 11x of the upper frame 11 are arranged so as to be vertical to a straight line connecting an eighth pivot point 24 and a ninth pivot point 27 to be described later. The second pivot point 19 is, for example, a driving side lower fixed pivot point (support axis). The third pivot point 22 is, for example, a driving side upper fixed pivot point (support axis). The eighth pivot point 24 is, for example, a driven side lower fixed pivot point (support axis). The ninth pivot point 27 is, for example, a driven side upper fixed pivot point (support axis). The loading surface 11x is, for example, a lifting item contact surface for loading a lifting item.
As shown in
The link mechanism 80 is arranged between the upper frame 11 and the base frame 12. The link mechanism 80 is formed by various arms (the first arm 13, the second arm 14, the third arm 15, the fourth arm 16, and the fifth arm 17). This link mechanism 80 functions as one example of a link mechanism, and lifts and lowers the upper frame 11 with respect to the base frame 12.
The link mechanism 80 is formed by a first link mechanism 80a and a second link mechanism 80b. The first link mechanism 80a is, for example, a driving side link mechanism, and the second link mechanism 80b is, for example, a driven side link mechanism.
The first link mechanism 80a is formed by at least the first arm 13 and the second arm 14. The second link mechanism
Bob is formed by at least the third arm 15 and the fourth arm 16. The first arm 13 and the third arm 15 each are one example of a T-shaped arm. The second arm 14 is one example of an L-shaped arm. The fourth arm 16 is one example of an I-shaped arm.
The T-shaped arm is provided with connections at four points. The connections at four points of the T-shaped arm are connections at three points placed on a first straight line, and an offset connection at one point positioned on a second straight line which is inclined by a predetermined angle with respect to the first straight line from the center connection.
Connections at four points of the first arm 13 are a first connection 13a, a second connection 13b, a third connection 13c, and a fourth connection 13d. Specifically, these connections at four points are connections at three points placed on the first straight line SL1 between an upper end part and a lower end part of the first arm 13 (the first connection 13a, the second connection 13b, and the third connection 13c), and an offset connection (the fourth connection 13d) at one point positioned on a second straight line SL2 which is inclined by a predetermined angle θ1 with respect to the first straight line SL1 from the center second connection 13b. The first connection 13a is the second pivot point 19, the second connection 13b is a fourth pivot point 23, the third connection 13c is the first pivot point 20, and the fourth connection 13d is a fifth pivot point 29.
Connections at four points of the third arm 15 are an eighth connection 15a, a ninth connection 15b, a tenth connection 15c, and an eleventh connection 15d. Specifically, these connections at four points are connections at three points placed on a first straight line SL5 between an upper end part and a lower end part of the third arm 15 (the eighth connection 15a, the ninth connection 15b, and the tenth connection 15c), and an offset connection (the eleventh connection 15d) at one point positioned on a second straight line SL6 which is inclined by a predetermined angle θ2 with respect to the first straight line SL5 from the center ninth connection 15b. The eighth connection 15a is the eighth pivot point 24, the ninth connection 15b is a tenth pivot point 28, the tenth connection 15c is the seventh pivot point 25, and the eleventh connection 15d is an eleventh pivot point 30.
The L-shaped arm is provided with connections at three points. The connections at three points of the L-shaped arm are connections at two points, and an offset connection at one point positioned on a fourth straight line which is inclined by a predetermined angle with respect to a third straight line connecting the connections at two points.
Connections at three points of the second arm 14 are a fifth connection 14a, a sixth connection 14b, and a seventh connection 14c. Specifically, these connections at three points are connections (the fifth connection 14a and the sixth connection 14b) at two points placed on a third straight line SL3 between an upper end part and an intermediate part of the second arm 14, and an offset connection (the seventh connection 14c) at one point positioned on a fourth straight line SL4 which is inclined by a predetermined angle θ3 with respect to the third straight line SL3. The fifth connection 14a is the third pivot point 22, the sixth connection 14b is the fourth pivot point 23, and the seventh connection 14c is a sixth pivot point 32.
It should be noted that the L-shaped arm can function as a T-shaped arm by extending a part thereof. Therefore, the L-shaped arm in this embodiment includes the T-shaped arm. For example, although described in detail later, an eighth arm 211 of
The I-shaped arm is provided with connections at two points in both ends of the longitudinal direction.
The fourth arm 16 is provided with connections at two points in both ends in the longitudinal direction, that is, a twelfth connection 16a in an upper end part, and a thirteenth connection 16b in a lower end part. The twelfth connection 16a is the ninth pivot point 27, and the thirteenth connection 16b is the tenth pivot point 28.
The first connection 13a serving as the lower end part of the first arm 13 is rotatably connected to the fifth protruding portion 19a of the base frame 12 at the second pivot point 19. The third connection 13c serving as the upper end part of the first arm 13 is connected to the upper frame 11 slidably by the slide guide 21. Specifically, by disengageably engaging the first pivot point 20 into the groove 21b of the second protruding portion 21a of the upper frame 11, the third connection 13c of the first arm 13 is slidably connected to the upper frame 11.
The fifth connection 14a serving as the upper end part of the second arm 14 is rotatably connected to the first protruding portion 22a of the upper frame 11 at the third pivot point 22. The sixth connection 14b of the second arm 14 is rotatably connected to the second connection 13b of the first arm 13 at the fourth pivot point 23. The fourth pivot point 23 is, for example, a driving side arm connection pivot point (support axis).
The eighth connection 15a serving as the lower end part of the third arm 15 is rotatably connected to the sixth protruding portion 24a of the base frame 12 at the eighth pivot point 24. The tenth connection 15c serving as the upper end part of the third arm 15 is connected to the upper frame 11 slidably by the slide guide 26. Specifically, by disengageably engaging the seventh pivot point 25 into the groove 26b of the fourth protruding portion 26a of the upper frame 11, the tenth connection 15c serving as the upper end part of the third arm 15 is slidably connected to the upper frame 11.
The twelfth connection 16a serving as the upper end part of the fourth arm 16 is rotatably connected to the third protruding portion 27a of the upper frame 11 at the ninth pivot point 27. The thirteenth connection 16b serving as the lower end part of the fourth arm 16 is rotatably connected to the ninth connection 15b of the third arm 15 at the tenth pivot point 28. The tenth pivot point 28 is, for example, a driven side arm connection pivot point (support axis)
A driving side end part of the fifth arm 17 is rotatably connected to the fourth connection 13d of the first arm 13 at the fifth pivot point 29. The fifth pivot point 29 is, for example, a driving side lower coupling arm pivot point (support axis). A driven side end part of the fifth arm 17 is rotatably connected to the eleventh connection 15d of the third arm 15 at the eleventh pivot point 30. The eleventh pivot point 30 is, for example, a driven side lower coupling arm pivot point (support axis). An end part 18b of the linear actuator 18 is rotatably connected to an actuator fixing portion 31 of the fifth arm 17 in the vicinity of the driving side end part. The actuator fixing portion 31 is positioned between the fifth pivot point 29 and the eleventh pivot point 30.
One end part 18b of the linear actuator 18 is rotatably connected to the actuator fixing portion 31 on the fifth arm 17, and the other end part 18a is rotatably connected to the seventh connection 14c of the second arm 14 at the sixth pivot point 32. The sixth pivot point 32 is, for example, a driving side lower coupling arm pivot point (support axis). The linear actuator 18 is connected to any arms of the link mechanism 80 (the first arm 13, the second arm 14, the third arm 15, the fourth arm 16, and the fifth arm 17), so as to drive to lift and lower the upper frame 11 with respect to the base frame 12.
As shown on the left side of
Further, as shown on the right side of
When the inventors variously examined regarding the lifting apparatus 10 formed in such a way, it was found that by setting the configuration of the link mechanism 80 under a predetermined condition, a load applied to the linear actuator 18 by a heavy item loaded on the loading surface 11x of the upper frame 11 becomes substantially constant without depending on a position (height) of the upper frame 11. Specifically, it was found that with a triangular-shape formed by the fourth pivot point 23, the second pivot point 19, and the third pivot point 22, and a triangular-shape formed by the fourth pivot point 23, the fifth pivot point 29, and the sixth pivot point 32 as similar shapes in
Further, it was found that at this time, as the angle θ1 (=θ3) is more different from 90°, the load applied to the linear actuator 18 in accordance with the position of the upper frame 11 is changed more.
It should be noted that the load applied to the linear actuator 18 is obtained by multiplying the load by the heavy item loaded on the loading surface 11x of the upper frame 11 by a constant calculated by L1/L3.
In the embodiment, the triangular-shape formed by the fourth pivot point 23, the sixth pivot point 32, and the fifth pivot point 29, and the triangular-shape formed by the third pivot point 22, the fourth pivot point 23, and the second pivot point 19 are isosceles triangular-shapes having an apex angle of 2α (=θ11=θ12) which are similar shapes. The angle α is an angle made by the loading surface 11x of the upper frame 11 or the mounting surface 12x of the base frame 12 and L1 or L2 (the first straight line SL1).
The linear actuator 18 is arranged so as to connect the sixth pivot point 32 and the fifth pivot point 29. A change amount of a distance between the sixth pivot point 32 and the fifth pivot point 29 is a drive amount of the linear actuator 18. A distance between the third pivot point 22 and the second pivot point 19 is lifting height, and a change amount of the distance between the third pivot point 22 and the second pivot point 19 is a lifting amount. Therefore, a ratio between the drive amount of the linear actuator 18 and the lifting amount is L1/L3. As a result, the load applied to this lifting apparatus 10 becomes always constant without depending on the angle α.
It should be noted that in the embodiment, positional relationships between the pivot points of the third arm 15 are the same as the first arm 13 with L1=L4, L2=L5, L3=L6, and θ1=θ2. Regarding the second arm 14 and the fourth arm 16, L8=L9.
As shown in
The bed unit 50 includes the above lifting apparatus 10 inside thereof, and is formed in such a manner that a support member in an upper part of the bed unit 50 is lifted and lowered by the lifting apparatus 10 with respect to a base of the bed unit 50. The support member of the bed unit 50 is a member for supporting a mattress or the like on which a user lies. The wheelchair unit 60 is stored in a storage space 51 provided in a part on one side in the width direction in the bed unit 50 so as to form the bed state. In this bed state, the wheelchair unit 60 is lifted and lowered together with the upper frame 11 by the lifting apparatus 10. In the bed unit 50, the fifth arm 17 and the linear actuator 18 are arranged only on one side (on the far side in
The wheelchair unit 60 includes two armrests 61, an operation unit 62 provided in a front end of one of the armrests 61 (on the side opposite to the bed unit 50 at the time of combination), a seat unit 63 to be deformed from a chair form into a flat form by an input of the operation unit 62, and four wheels 64 for moving the wheelchair unit 60.
The separation type bed 40 of the embodiment can be deformed from a separated state in which the bed unit 50 and the wheelchair unit 60 are separated into the bed state in which the bed unit 50 and the wheelchair unit 60 are combined and the entire surfaces of the bed unit 50 and the wheelchair unit 60 are brought into a flat form, by moving the wheelchair unit 60 to the storage space 51 by the input of the operation unit 62 by an operator, and then bringing the seat unit 63 into a flat form. As shown in
Side rails 65 are installed on side surfaces of the separation type bed 40, and the user can be prevented from falling from the side surfaces of the separation type bed 40 by the side rails 65. As shown in
As shown in
The fifteenth connection 111b of the sixth arm 111 and the eighteenth connection 112b of the seventh arm 112 are rotatably connected at a fourteenth pivot point 114. In the lifting apparatus 100, a sixth pivot point 32 of the second arm 14 and a thirteenth pivot point 115 of the seventh arm 112 are connected by the fifth arm 17. An actuator fixing portion 31 on the fifth arm 17 and a fifth pivot point 29 of the first arm 13 are connected by the linear actuator 18.
In the lifting apparatus 100 of the first different configuration, lengths of the arms are the same i.e. the straight line SL8=the straight line SL5, the straight line SL9=the straight line SL7, and the straight line SL10=the straight line SL4. Therefore, a triangular-shape formed by a fourth pivot point 23, a second pivot point 19, and a third pivot point 22, and a triangular-shape formed by the fourteenth pivot point 114, a ninth pivot point 27, and an eighth pivot point 24 have the same shape. A triangular-shape formed by the fourth pivot point 23, the sixth pivot point 32, and the third pivot point 22, and a triangular-shape formed by the fourteenth pivot point 114, the ninth pivot point 27, and the thirteenth pivot point 115 have the same shape.
Regarding the fifth pivot point 29 or the sixth pivot point 32, the direction of the pivot point not connected to the linear actuator 18 with respect to the pivot point connected to the linear actuator 18 is defined as a determination direction 113. By arranging the actuator fixing portion 31 of the lifting apparatus 100 in the opposite direction to the determination direction 113 with respect to the pivot point connected to the linear actuator 18, the direction of a load applied to the linear actuator 18 in the lifting apparatus 100 is reversed from the load applied to the linear actuator 18 in the above lifting apparatus 10, so that a tensile load is added. As a result, the lifting apparatus 100 of the first different configuration is particularly effective in a case where the linear actuator 18 has a favorable characteristic with respect to tension.
As shown in
In the lifting apparatus 200, the eighth arm 211 is connected to other members at a third pivot point 22, a twelfth pivot point 212, a fourth pivot point 23, and a sixth pivot point 32. Specifically, the eighth arm 211 is rotatably coupled to the upper frame 11 at the third pivot point 22, slidably connected to a slide guide 213 provided in the base frame 12 at the twelfth pivot point 212, and rotatably coupled to the first arm 13 at the fourth pivot point 23. The slide guide 213 has a similar structure to the slide guide 21. That is, the base frame 12 has a fixed protruding portion 213a, the protruding portion 213a has a groove 213b extending in the longitudinal direction, and the twelfth pivot point 212 is disengageably engaged into the groove 213b so as to be slidably movable, thereby forming the slide guide 213. The twelfth pivot point 212 is, for example, a driving side lower slide pivot point (support axis). The fifth arm 17 is rotatably connected to a fifth pivot point 29 of the first arm 13.
In the lifting apparatus 200 of the second different configuration, a triangular-shape formed by the fourth pivot point 23, a second pivot point 19, and the third pivot point 22, and a triangular-shape formed by the fourth pivot point 23, a fifth pivot point 29, and the sixth pivot point 32 are similar shapes. In the second different configuration, when the sum of an angle (θ1) made by a segment (first straight line) connecting the second pivot point 19 and a first pivot point 20 and a segment (second straight line) connecting the fourth pivot point 23 and the fifth pivot point 29, and an angle (θ3) made by a segment (third straight line) connecting the third pivot point 22 and the twelfth pivot point 212 and a segment (fourth straight line) connecting the fourth pivot point 23 and the sixth pivot point 32 is 180°, a load applied to the linear actuator 18 by a heavy item loaded on a loading surface 11x of the upper frame 11 can be substantially constant without depending on a distance between the upper frame 11 and the base frame 12. That is, in the second different configuration, with θ1+θ3=180°, the load applied to the linear actuator 18 can be constant.
In the lifting apparatus 200, by connecting the linear actuator 18 to the sixth pivot point 32 of the eighth arm 211 and an actuator fixing portion 31 of the fifth arm 17, the load applied to the linear actuator 18 by the heavy item loaded on the loading surface 11x of the upper frame 11 can be substantially constant without depending on the distance between the upper frame 11 and the base frame 12.
According to the above embodiment, the lifting apparatus in which the load applied to the linear actuator 18 becomes constant without depending on the distance between the upper frame 11 and the base frame 12, and the bed provided with the same can be provided.
By appropriately combining arbitrary embodiments or modifications among the above various embodiments and modifications, effects provided in the embodiments or the modifications can be obtained.
It should be noted that although the example of the bed provided with the lifting apparatus is described in the embodiment, the lifting apparatus of the present invention can be utilized for various devices provided with a lifting device in addition to the bed.
The lifting apparatus according to the present invention and the bed provided with the same are particularly useful for a nursing care bed for lifting and lowering a care-receiver within a wide range, and useful in an ordinary house, a hospital facility, or a nursing care facility where the care-receiver in need of care resides.
Although the present invention has been fully described in connection with the embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-251750 | Nov 2012 | JP | national |
| 2013-216144 | Oct 2013 | JP | national |
