JPH0243936B2 - - 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 peripheral surface of the hole formed in the drive piece bites into the outer peripheral surface of the actuating shaft and connects the driving piece and the actuating shaft, not only is it easy to damage the outer peripheral surface of the actuating shaft, but also There is also the possibility 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 7. 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. Furthermore, when the operating shaft 14 moves in the direction opposite to the direction of the arrow a, the raised support body 9 is lowered. 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 7. 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 tapered body 30 that is slidably fitted onto the operating shaft 14 . This first tapered body 30 has an outer peripheral surface that is similar to the first tapered hole 21.
A plurality of slits 32 are formed in the peripheral wall along the axial direction, so that the peripheral wall can be elastically deformed in the diametrical direction. A first spring 33 is provided in a compressed state between one end surface of the first tapered body 30 and the first locking plate 27. 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 peripheral wall of the first tapered body 30 to contract. The tapered wall 31 on the outer circumferential surface is elastically deformed in the radial direction, and the tapered wall 31 on the outer circumferential surface is pressed against the inner circumferential surface of the first tapered hole 21, and the inner circumferential surface is in pressure contact with the inner circumferential surface of the first tapered hole 21.
is in pressure contact with the outer peripheral surface of. Therefore, the above first
The engaging body 22 and the operating shaft 14 are integrally coupled by the tapered body 30 , and 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 drive body 24 accommodates a cylindrical second tapered body 34 that is slidably fitted onto the operating shaft 14 . This second tapered body 34 has an outer peripheral surface formed as a tapered wall 35 having an angle corresponding to the second tapered hole 23, and a plurality of slits 36 along the axial direction are formed in the peripheral wall to reduce the diameter. It can be elastically deformed in this direction. A first receiving body 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 tapered body 34 on 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 disposed on the operating shaft 14.
It is slidably fitted on the outside while being joined to the locking plate 28 of. 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. In between, there is also an outer spring 4 which is stronger than the inner spring 39 and serves as a second spring.
0 is compressed and provided. These springs 3
The driving body 24 is urged toward the small diameter portion of the second tapered hole 23 by the restoring force of the second tapered hole 23, and the end surface of the small diameter portion and the end surface of the second holding body 34 are aligned with each other. It is in pressure contact with the plate surface of the locking plate 28. In this state, the second tapered body 34 is in a state where its peripheral wall is not elastically deformed in the diametrical direction, that is, the driving body 24
and the operating shaft 14 are not integrally connected. Therefore, the operating shaft 14 is
It can freely slide relative to the driving body 24 without being restrained by the tapered body 34 of. Also,
If the driving body 24 is slid against the biasing force of the outer spring 40, the second holding body 34 is not displaced by the biasing force of the inner spring 39, and the driving body 24
Since only the second tapered body 34 is displaced, the peripheral wall of the second tapered body 34 is elastically deformed in the diametrical direction, thereby integrally coupling the actuating shaft 14 and the driving body 24. That is, only when the driving body 24 slides toward the rear end of the operating shaft 14, the driving body 24 moves toward the operating shaft 1 via the second tapered body 34.
It is integrally combined with 4.

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. 47a 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. In addition, the rotating member 48
A petal 52 projecting outward from the end of the base body 2 is fixed to the upper end, and one end of a release rod 53 is pivotally connected to the lower end by a support shaft 54. 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. A stopper 56 such as a nut is attached to the end of the release rod 53 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 connected to the horizontal rod 2a of the base body 2.
The support shaft 58 is pivotally connected to a bracket 57 provided at the 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 so as to be 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 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 peripheral wall of the second tapered body 34 has a tapered wall 31 on the outer surface of the second tapered hole 2.
3 and elastically deforms in the diametrical direction, the inner circumferential surface presses against the outer circumferential surface of the actuating shaft 14 and connects the driving body 24 and the actuating shaft 14. Therefore, the movement of the drive body 24 in the Y direction causes the actuation shaft 14 to
are linked. When the actuation shaft 14 moves in the Y direction, the first
Since the tapered body 30 does not connect the engaging body 22 and the operating shaft 14, the operating shaft 14 is driven by the driver 24 in the Y direction. That is, by depressing the pedal 52, the operating shaft 14 is driven by the distance that the driving body 24 moves in the Y direction.

Next, when you release the pedal 52,
The driving body 24 and the second tapered body 34 accommodated 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 driving body 24 slides faster than the second holding body 34. Therefore,
At this time, since the peripheral wall of the second tapered body 34 does not come into pressure contact with the inner peripheral surface of the second tapered hole 23 and is elastically deformed in the diametrical direction, the driving body 24 is smoothly restored. Furthermore, the first tapered body 30 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 that the operating shaft 14 cannot return. do not have.

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 tapered body 30 accommodated in the first tapered hole 21 of the engagement body 22 is pressed by the release body 54 via the spacer 60, so that the first tapered body 30 It is slid toward the large diameter portion of the first tapered hole 21 against the restoring force of the spring 33. By sliding the first tapered body 30, the coupling state between the engaging body 22 and the operating shaft 14 by the inner and outer circumferential surfaces is released.
4 slides in the opposite direction to the Y direction due to the load applied thereto. In other words, the floorboard 8 descends horizontally.

FIG. 8 shows another embodiment of the present invention, in which a plurality of floor plates 8 are placed on the base 2, and one of them is rotatably attached to the base 2. The rotatable floor plate 8 is rotated and raised by an operating shaft 14 driven by a drive device 15. 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. A second
One end of the second link 67 (only one of which is shown) is fixed, and 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.

Further, in the present invention, a slit is formed in the peripheral wall of the first and second tapered bodies to enable the peripheral walls to be deformed in the diametrical direction, but instead of the slit, the tapered body may be divided into two semi-cylindrical shapes. Alternatively, it may be divided into three or four parts and may be deformable in the direction of diameter reduction.

As described above, according to the present invention, there is provided an engaging body in which a first tapered hole is formed and a first tapered body that is freely deformable in the diametrical direction is accommodated therein, and a second tapered hole is formed in which the first tapered body is accommodated. The second part is deformable in the direction of diameter reduction.
A drive body in which a tapered body is housed is fitted onto the actuation shaft, and the drive body and the actuation shaft are integrally connected by the second tapered body, so that the actuation shaft is intermittently moved in one direction. While driving, the second tapered body prevents the operating shaft from sliding in the other direction, and this blocking 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 coupling between the actuating shaft and the driving body deforms the second tapered body in the diametrical direction,
Since the inner and outer circumferential surfaces are pressed against the outer circumferential surface of the actuating shaft and the inner circumferential surface of the second tapered hole, there is a risk of damaging the outer circumferential surface of the actuating shaft or making the connection state uncertain. There is no such thing. 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, by simply changing the operating direction of one rotating member, two
Since it is possible to perform two operations, it is possible to not only simplify the configuration but also improve operability.

[Brief explanation of the drawing]

1 to 7 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 -
7 is an enlarged sectional view of the first and second tapered bodies, and FIG. 8 is a side view of a bed showing another embodiment of the present invention. 2... Base body (attachment part), 14... Operating shaft, 21... First tapered hole, 22... Engaging body, 23... Second tapered hole, 24... Drive body, 30... First tapered body, 3
3...First spring, 34...Second tapered body, 39...
Inner spring (second spring), 40... outer spring (second
spring), 54...release 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 drive body externally fitted on the actuating shaft so that the inclination direction of the taper hole is the same as the inclination direction of the first taper hole; the first tapered body presses against the outer circumferential surface of the operating shaft and the inner circumferential surface of the first tapered hole, and the operating shaft moves in the direction of the smaller diameter of the first tapered hole. a first spring that urges the first tapered body to a state where it prevents the above-mentioned, a second tapered body that is accommodated in the second tapered hole and is deformable in a diameter-reducing direction, and the drive body. Only when the second tapered body is driven in the direction of the larger diameter of the second tapered hole, the second tapered body is urged to a state in which the actuation shaft and the driving body are coupled and the actuation shaft is interlocked with the movement of the driving body. The second spring and the first tapered body are moved in the direction of the larger diameter of the first tapered hole against the biasing force of the first spring to connect the operating shaft and the engaging body. a release body that releases the actuating shaft so as to freely move the operating shaft in the direction of the small diameter of the first tapered hole; a drive rod that has one end connected to the drive body; and a release rod that has one end connected to the release body; a rotating member having a middle portion rotatably attached to the mounting portion, one end connected to the other end of the drive rod, and the other end connected to the other end of the release rod; The release rod is linked only to the rotation of the rotation member in one direction, and the release rod releases the release body from the coupling state between the operating shaft and the engagement body only when the rotation member is rotated in the opposite direction to the one direction. A driving device for an operating shaft, characterized in that it is configured to drive in a direction of release.