JPH0243935B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drive device for driving an operating shaft for vertically moving or rotating a bed floor plate.

For example, in hospital beds, it is known that the floorboards can be moved up and down or a part of the floorboards can be rotated. In such a bed, an operating shaft driving device is provided on the lower surface of the floor plate, and the operating shaft driven by this drive device drives the floor plate via a link.

Conventionally, as for the above-mentioned drive device, the actuation shaft is made hollow and has a female thread at one end, and a lead screw is screwed into this female thread and the lead screw is rotated to displace the actuating shaft. There are systems that displace the operating shaft using a hydraulic or hydraulic cylinder. However, the former method involves a large loss of labor due to the frictional force between the female thread and the lead screw, and the latter method not only requires an air compressor or hydraulic pump as a pressure source, but also
Various control valves are also required, which not only complicates the configuration and increases costs, but also poses a major problem in maintenance management.

In order to solve these problems, the special public
Drive devices disclosed in Japanese Patent Publication No. 45586 and Japanese Patent Publication No. 58-25463 have been proposed. In these prior arts, a drive locking part for the working shaft is provided on one side of a support tube in which the working shaft (rod) is telescopically built in, and a driving piece and a locking piece built in here are connected to the working shaft. The drive piece and the locking piece are loosely fitted into each other, and by the action of the so-called tilt lock between the driving piece and the locking piece, the actuating shaft can be intermittently sent in one direction while preventing return, or the action of the tilt lock can be released. It is now possible to turn it back in the other direction.

However, in a drive device that utilizes the effect of such a tilt lock, in order to drive the operating shaft, the drive piece is tilted and coupled to the operating shaft;
The drive piece must be displaced in this state. Therefore, since not only axial thrust but also rotational force is applied to the operating shaft from the inclined drive piece, this rotational force not only impairs the smoothness of the axial movement of the operating shaft, but also causes power loss. It turns out. In addition, since the edge of the inner circumferential surface of the hole formed in the drive piece bites into the outer circumferential surface of the actuating shaft and connects the drive piece and the actuating shaft, not only is it easy to damage the outer circumferential surface of the actuating shaft, but also There is also a risk that if the edge wears out, the connection with the actuating shaft may become uncertain.

This invention was made based on the above circumstances, and its purpose is to be able to drive the operating shaft intermittently in one direction by applying only thrust in the axial direction without applying rotational force to the operating shaft. With,
To provide a drive device for an operating shaft that can reliably drive the operating shaft without damaging the outer circumferential surface of the operating shaft.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6. Reference numeral 1 in FIG. 1 indicates a bed, and this bed 1 is provided with a base body 2 as a mounting portion. The base body 2 is formed from a rectangular frame body 3 and legs 5 which are vertically disposed at both ends of the frame body 3 in the longitudinal direction and have casters 4 at their lower ends. One end of a first link 6 is pivotally attached to the inner surfaces of both longitudinal ends of the frame 3, respectively. One end of a mounting piece 7 is pivotally attached to the other end of each of these four first links 6, and the other end of each of these mounting pieces 7 has a rectangular frame shape on which a floor plate 8 divided into a plurality of parts is placed. support 9
is connected to the four corners of the Both ends of a connecting shaft 10 are fixed to the middle part of each pair of first links 6 corresponding to each other in the width direction of the frame 3.
A second link 1 is provided at one axial end of each connecting shaft 10.
1 is fixed at one end, and both ends of an interlocking shaft 12 are pivotally connected to the other end of these second links 11. Further, one end of a third link 13 is fixed to an axially intermediate portion of one of the connecting shafts 10. The other end of this third link 13 is pivotally connected to the tip of an operating shaft 14 . This operating shaft 14 is a drive device 1 which will be described later.
5 intermittently in the direction of arrow a from the state shown in FIG. Actuation axis 14
is driven in the direction of arrow a, the third link 13
rotates in the direction of arrow b, and one of the connecting shafts 10
are linked. The rotation of one of the connecting shafts 10 causes a second
Since the other link shaft 10 is interlocked with the link 11 of the link 11 via the link shaft 12, the four first links 6 are rotated in the direction of arrow c by these pair of link shafts 10, and the floor plate 8 is rotated in the direction of arrow c. The support 9 on which is placed rises horizontally. Further, when the operating shaft 14 moves in the direction opposite to the direction of arrow a, the elevated support body 9 descends. Note that a mounting piece 16 is fixed to one end of the interlocking shaft 12, as shown in FIG. A buffer shaft 18 of a pair of buffer bodies 17, such as gas springs, is connected to the mounting piece 16, and is pivoted to one leg 5 of the base body 2. When the support body 9 is lowered, the buffer body 17 is activated so that the support body 9 can be lowered smoothly.

The drive device 15 is constructed as shown in FIGS. 3 to 6. That is, the engaging body 22 has the first tapered hole 21 formed in the operating shaft 14.
and a driving body 24 in which a second tapered hole 23 is formed.
are externally fitted into the tapered holes 21 and 23 with the same inclination direction. The engaging body 22 is the actuating shaft 1
The driving body 24 is located on the rear end side, and the large diameter side of each tapered hole 21, 23 is directed toward the rear end side of the actuating shaft 14. The above engaging body 2
On both sides of the base body 2, a pair of mounting plates 25 are vertically installed from a horizontal beam 2a constructed midway in the longitudinal direction of the base body 2.
The lower ends of are connected. Furthermore, one end of a connecting rod 26 is fixed to each of the four corners of one end surface of the engaging body 22. These connecting rods 26 extend toward the rear end side of the actuating shaft 14, and a first locking plate 27 is fixed to the middle part thereof, and a second locking plate 28 is fixed to the end thereof. In addition, these locking plates 2
A through hole 29 is formed in each of the holes 7 and 28 and is large enough to loosely fit the operating shaft 14 therein.

The first tapered hole 21 of the engaging body 22 accommodates a cylindrical first holder 30 that is slidably fitted onto the operating shaft 14 . This first holding body 30 has a plurality of through holes 31 arranged at predetermined intervals in the circumferential direction.
A first sphere 32 is rotatably held in each through hole 31 . The first holding body 30
A first locking plate 27 is provided between one end surface of the
A spring 33 is provided in a compressed state. The restoring force of the first spring 33 urges the first holding body 30 toward the small diameter portion of the first tapered hole 21, thereby causing the first spherical body 32 to move toward the small diameter portion of the first tapered hole 21. The inner circumferential surface of the hole 21 and the outer circumferential surface of the actuating shaft 14 are pressed against each other to integrally connect them. Therefore, movement of the operating shaft 14 toward the small diameter portion of the first tapered hole 21 is restricted.

Further, the second tapered hole 23 of the driving body 24 accommodates a cylindrical second holder 34 that is slidably fitted onto the operating shaft 14 . A plurality of through holes 35 are bored in the second holder 34 at predetermined intervals in the circumferential direction, and each through hole 35 has a second spherical body 3 .
6 is rotatably held. A first receiver 37 having an outer diameter smaller than the inner diameter of the large diameter portion of the second tapered hole 23 is slidably fitted onto one end surface of the second holder 34 onto the operating shaft 14. It is well established. Further, a second receiving body 38 having approximately the same outer diameter as the driving body 25 is slidably fitted onto the operating shaft 14 so as to be joined to the second locking plate 28 . An inner spring 39 as a second spring is compressed and provided between the first receiver 37 and the second receiver 38, and the inner spring 39 is provided between the end face of the drive body 25 and the second receiver 38. A compressed outer spring 40, which is stronger than the inner spring 39, is also provided as a second spring in between.
Due to the restoring force of these springs 39 and 40, the drive body 2
5 is biased toward the small diameter side of the second tapered hole 23,
This end surface on the small diameter portion side and the end surface of the second holder 34 are in pressure contact with the plate surface of the second locking plate 28 . In this state, the second sphere 36 held by the second holder 34 is in a rotatable state, that is, in a state in which it is not in pressure contact with the inner circumferential surface of the second tapered hole 23 and the outer circumferential surface of the actuating shaft 14. It's summery. Therefore, the operating shaft 14 is free to slide relative to the drive body 24 without being restrained by the second sphere 36. Further, the driving body 24 is connected to the outer spring 4.
If it is slid against the biasing force of 0, the second holding body 34 is not displaced by the biasing force of the inner spring 39, and only the driving body 24 is displaced, so that the second spherical body 36 is The inner circumferential surface of the taper hole 23 of No. 2 and the outer circumferential surface of the actuating shaft 14 are pressed against each other, and these two are integrally connected. In other words, the driving body 24 is integrally coupled to the operating shaft 14 via the second sphere 36 only when sliding toward the rear end of the operating shaft 14 .

A pair of protruding pieces 43 are provided on both sides of the driving body 24 to protrude outward in the radial direction, and one end of a band-shaped drive rod 44 is connected to each of these protruding pieces 43. At the other end of these drive rods 44, there is also a band-shaped connecting rod 4.
5 is fixed at both ends. A through hole 46 is bored in the middle of the connecting rod 45, one end of the connecting rod 47 is slidably inserted into the through hole 46, and the end protruding from the through hole 46 is fitted with a stopper such as a nut. 47 is attached to prevent the connecting rod 47 from being pulled out of the through hole 46. The other end of the connecting rod 47 is pivotally connected to the upper end of a rotating member 48 having a U-shaped cross section via a support shaft 49. A midway portion of the rotating member 48 is pivotally connected to the lower end portions of a pair of mounting members 50 that are vertically disposed from the widthwise central portion of the longitudinal end portion of the base body 2 by means of a support shaft 51. Further, a petal 52 protruding outward from the end of the base body 2 is fixed to the upper end of the rotating member 48, and one end of a release rod 53 is pivotally attached to the lower end by a support shaft 54. There is.
The other end of the release rod 53 extends toward the longitudinal center of the lower surface of the base 2, and is slidably inserted into a through hole 55 bored in the lower end of the release body 54, which has a U-shaped cross section. ing. This release rod 53
A stopper 56 such as a nut is attached to the end protruding from the through hole 55 to prevent the end of the release rod 53 from coming out of the through hole 55. The upper end of the release body 54 is pivotally connected to a bracket 57 provided on the horizontal rod 2a of the base body 2 by a support shaft 58. Further, a through hole 59 into which the operating shaft 14 is loosely fitted is bored in the middle of the release body 54. A spacer 60 having a smaller diameter than the small diameter portion of the first tapered hole 21 is provided between the release body 54 and the end surface of the engagement body 22 and is slidably fitted onto the operating shaft 14 .

When raising the floor plate 8 in the drive device 15 configured in this manner, the pedal 52 protruding from one longitudinal end of the base body 2 is stepped on. Then,
As shown by the chain line in FIG. 5, the petal 52 causes the rotating member 48 to rotate in the direction of the arrow X about the support shaft 51, so that the end portion is connected to the upper end of the rotating member 45. The connecting rod 47 is pulled in the direction of arrow Y, and the driving body 24 is interlocked with this through the driving rod 44. The driving body 24 is displaced in the direction of the arrow Y in FIG. It moves in conjunction with the driving body 24 while receiving a force in the direction opposite to the Y direction. Therefore, the second sphere 36 held by the second holder 34 comes into pressure contact with the inner circumferential surface of the second tapered hole 23 and the outer circumferential surface of the actuating shaft 14 to couple them together. , the actuation shaft 14 is interlocked with the movement of the drive body 24 in the Y direction. When the actuation shaft 14 moves in the Y direction, the first sphere 32 accommodated in the first tapered hole 21 of the engagement body 22 does not connect the engagement body 22 and the actuation shaft 14;
4 is driven in the Y direction by a driver 24. In other words, the operating shaft 14 is moved by the distance that the driving body 24 moves in the Y direction by depressing the pedal 52.
is driven.

Next, when you release the pedal 52,
The driving body 24 and the second holding body 34 housed in the second tapered hole 23 move in the Y direction until they hit the second locking plate 28 due to the restoring force of the outer spring 40 and the inner spring 39. Slide in the opposite direction. At this time,
Since the restoring force of the outer spring 40 is greater than the restoring force of the inner spring 39, the driver 24 slides faster than the second holder 34. Therefore, at this time, the second spherical body 36 does not come into pressure contact with the inner circumferential surface of the second tapered hole 23 and the outer circumferential surface of the actuating shaft 14, so that the driving body 24 is smoothly restored. Furthermore, the first sphere 32 accommodated in the first tapered hole 21 of the engaging body 22 prevents the operating shaft 14 from sliding in the direction opposite to the Y direction, so the operating shaft 14 does not return. .

Therefore, by repeatedly depressing the pedal 52, the actuating shaft 14 is intermittently driven in the Y direction by a predetermined amount. That is, since the operating shaft is driven in the direction of arrow a in FIG. 1, the floor plate 8 is raised horizontally.

When lowering the floor plate 8 that has been raised in this manner, the petal 52 is lifted in the direction of arrow Z in FIG. Since the release rod 53 is pulled in conjunction with the movement of the petal 52, the release body 54 is rotated by the release rod 53 in the direction of arrow W in FIG. 6 about the support shaft 58. Then, the first holding body 30 accommodated in the first tapered hole 21 of the engaging body 22 is pressed by the releasing body 54 via the spacer 60, so that the first holding body 30 is pressed by the releasing body 54.
The holding body 30 is slid toward the large diameter portion of the first tapered hole 21 against the restoring force of the first spring 33. By sliding the first holding body 30, the engaging body 22 and the operating shaft 1 are connected to each other by the first sphere 32.
4 is released, the actuating shaft 14 slides in the opposite direction to the Y direction due to the load applied thereto. In other words, the floorboard 8 descends horizontally.

FIG. 7 shows another embodiment of the present invention, in which a plurality of floor plates 8 are placed on the base body 2, and one of them is rotatably attached to the base body 2. The rotatable floor plate 8 is rotated and raised by an operating shaft 14 driven by a drive device 5. That is, one end of the first link 65 is pivotally attached to the tip of the operating shaft 14. The other end of the first link 65 is fixed to a midway portion of the connecting shaft 66. One end of a second link 67 (only one shown) is fixed to both ends of this connecting shaft 66,
The other end of the second link 67 is pivotally connected to a mounting piece 68 hanging vertically from the rotatable floor plate 8.

Therefore, when the actuation shaft 14 is driven in the direction of arrow a by the drive device 15, the first link 65
rotates in the direction of arrow b, and the second link 67 rotates in the direction of arrow c, so that the floorboard 8 can be rotated upward in the direction of arrow d.

As described above, according to the present invention, there is an engaging body in which a first tapered hole is formed and the first sphere is accommodated therein, and a second taper hole is formed in which the second sphere is accommodated.
A driving body containing a sphere is fitted onto the operating shaft, and the driving body and the operating shaft are integrally coupled by the second sphere to intermittently drive the operating shaft in one direction. In addition, the second spherical body prevents the operating shaft from sliding in the other direction, and this blocked state can be canceled by the release body. Therefore, when the actuating shaft is driven by the drive body, it only receives thrust in the axial direction from the drive body, and does not receive rotational force as would be the case when using the action of a conventional tilt lock. It is driven smoothly and without any loss of force. Furthermore, the connection between the actuating shaft and the driving body is
Since the second sphere is pressed against the inner circumferential surface of the second tapered hole formed in the drive body, there is a risk of damaging the outer circumferential surface of the actuating shaft or making the connection state uncertain. There is no.

In addition, a drive rod connected to a drive body and a release rod connected to a release body are connected to a rotating member, and depending on the rotating direction of the rotating member, the drive body drives the operating shaft or operates. It is now possible to release the connection between the shaft and the engaging body. In other words, two operations can be performed by simply changing the operating direction of one rotating member, which not only simplifies the configuration but also improves operability.

[Brief explanation of the drawing]

1 to 6 show one embodiment of the present invention, FIG. 1 is a side view of the bed, FIG. 2 is a plan view of the base, FIG. 3 is a sectional view of the main part of the drive device, and FIG.
The figure is also a plan view of the petal part, and Figure 5 is the 4th part.
Figure - Sectional view along the line, Figure 6 is Figure 3 -
FIG. 7 is a side view of a bed showing another embodiment of the invention. 2... Base body (attachment part), 14... Operating shaft, 21... First tapered hole, 22... Engaging body, 23... Second tapered hole, 24... Drive body, 32... First sphere, 33...
First spring, 36... Second sphere, 39... Inner spring (second spring), 40... Outer spring (second spring),
54...Released body.

Claims (1)

[Claims] 1 An operating shaft, an engaging body that is fitted onto the operating shaft and fixed to the mounting portion and has a first tapered hole formed therein, and a second tapered hole formed therein.
a driving body externally fitted on the operating shaft so that the inclination direction of the taper hole is the same as the inclination direction of the first taper hole; a first spherical body accommodated in the first taper hole; The first sphere is in pressure contact with the outer circumferential surface of the operating shaft and the inner circumferential surface of the first tapered hole to prevent the operating shaft from moving in the direction of the small diameter of the first tapered hole. The first spring biases the sphere, the second sphere accommodated in the second tapered hole, and the actuation occurs only when the driving body is driven in the direction of the larger diameter of the second tapered hole. A second spring biases the second sphere into a state in which the shaft and the driving body are coupled and the actuating shaft is interlocked with the movement of the driving body; The actuating shaft is moved in the direction of the larger diameter of the first tapered hole against the biasing force to release the coupling state between the actuating shaft and the engaging body, and the actuating shaft is made freely movable in the direction of the smaller diameter of the first tapered hole. a release body; a drive rod having one end connected to the drive body; a release rod having one end connected to the release body; a rotating member having one end connected to the other end and the other end of the release rod connected to the other end, the drive rod being interlocked only with the rotation of the rotating member in one direction, and the release rod being coupled with the rotation of the release rod in one direction. An actuating shaft drive device, characterized in that the releasing body is driven in a direction that releases the coupling state between the actuating shaft and the engagement body only when the member is rotated in the opposite direction to the one direction.