JPS6133948Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an operating device for vertically moving an operating table on which a patient to be operated is placed.

Generally, the operating table has a bed 1 as shown in Figure 1.
It consists of a support part 2 that supports the bed 1 so that it can be moved up and down, and a base 3 for installing the bed 1 and the support part 2 on the floor. Reference numeral 4 denotes a movable part that is connected to an operating device built in the support part 2 and moves up and down as will be described later, and the bed 1 is removably placed on this movable part 4. This support part 2
The structure of the operating device built into the machine for vertically moving the bed 1 is basically a screw feeding mechanism consisting of a threaded rod that is rotationally driven and a nut into which this threaded rod is screwed because it requires precise operation. Most of them are.

Most conventional operating devices for operating tables have the configuration shown in FIG. That is, the operating device built into the support portion 2 basically has a screw feeding mechanism consisting of a rotationally driven threaded rod 6 and a nut 8 into which the threaded rod is screwed. threaded rod 6
is fixed in the axial direction, but is rotationally driven by an electric motor 5 or the like, so that the nut 8 is moved up and down along the fixed guide 10. The screw feeding mechanism is not simply a type in which the threaded rod 6 is screwed directly into the screw rod 6, but a ball screw mechanism 7 is interposed between the screw rods 6 and the screw rod 6 to provide an extremely high precision screw feeding mechanism.

In order for the nut 8 to move up and down with such a screw feeding mechanism, a locking mechanism for the nut 8 is required. Natsuto 8
The key groove 8' formed in the key groove 8' is engaged and slid into contact with the key groove 8'. However, such traditional configurations
This has a fatal drawback to the functionality of the operating table. That is, the key 9 and the keyway 8', which serve as a rotation prevention mechanism for the nut 8, are installed at the sliding contact portion between the nut 8 and the fixed guide, and a gap (backlash) occurs in this rotation prevention mechanism of the nut. As for the combination of the key groove 8' and the key 9 that is slidably engaged with this groove 8', the key 9 and the key groove 8' are worn out due to repeated vertical movement of the bed 1, and a gap is created between the two. It is unavoidable to do so. Even if this gap is small, it will cause a large play (looseness) in the entire bed 1. That is,
As shown in FIG. 4, the distance (radius) r from the center of the nut 8, that is, the axis of the threaded rod 6, to the locking mechanism provided by the key 9 is small, and therefore the gap at the position of the key 9 is small. Even if there is, there will be a fairly large gap at the end of the bed 1 far away from the axis of the threaded rod 6. Note that 11 is an adjustment screw for the key 9.

Just as the operating table uses a ball screw mechanism as described above for the screw feeding mechanism of its operating device and requires high precision, very high precision is also required for its positioning. In particular, bed 1 is used in cases such as brain surgery.
A level of precision is required that does not allow even the slightest movement. Therefore, such a conventional operating table cannot withstand long-term use, and if used for a long time, it will become loose, resulting in a fatal defect in its performance as an operating table. The present invention provides an operating device for operating tables that completely solves these conventional problems, and the nut rotation prevention mechanism is located not at the sliding contact point between the nut and the fixed guide, but from the axis of the threaded rod. It is characterized in that it is installed at a far away position and is constructed by a groove formed in a fixed frame and a nut-side movable frame that engages with this groove via a rolling roller.

This invention will be explained below with reference to the illustrated embodiments.

In the operating device of the present invention, the nut 8 and the fixed guide 1
No nut rotation prevention mechanism is interposed in the sliding contact portion with 0, and this rotation prevention mechanism is installed on the outer part of the fixed frame 12 extending outward from the fixed guide 10. This position is a distance away from the axis of the threaded rod 6 by a distance (radius) R (R>r). At this position, a groove 12' is formed in the vertical direction parallel to the axial direction of the threaded rod 6, and the end 13' of the movable frame 13 on the nut side is engaged with this groove 12'. This constitutes the nut rotation prevention mechanism. In the illustrated example, the movable frame 13 is extended to the right from the movable part 4, but the movable frame 13 may be any frame as long as it can move up and down integrally with the nut 8.

The engagement of the movable frame 13, particularly its end 13' and the groove 12', is effected via rolling rollers 17, as shown in FIG. A roller support shaft 15 is held at the end portion 13' via an eccentric collar 14, and a rolling roller 17 is fitted to this roller support shaft 15 via a needle bearing 16, making it possible to achieve frictional resistance. It is made smaller. 18 is a tightening nut for fixing the roller support shaft 15 and the eccentric collar 14 to the member 13'.

The structure of the engagement mechanism of the movable frame 13 with the fixed frame 12 is clarified by FIG. 6, which shows an enlarged perspective view of the end thereof. In FIG. 6, each component, namely the rolling roller 17, the eccentric collar 14, the tightening nut 18, etc., is shown exploded to make it easier to understand their combination. In addition,
In FIG. 6, 19 and 20 are washers.

Since the movable frame 13 is engaged with the groove 12' in this way via the rolling roller 17, there is almost no wear between the two, and the rolling roller 17 is held via the bearing. Therefore, there is less wear and resistance with the movable frame 13. Therefore, even after long-term use, gaps do not occur in the nut rotation prevention mechanism, and even if gaps do occur, it will not occur when the bed 1
This should not cause major rattling.

The eccentric collar 14 is used to finely adjust the relationship between the roller support shaft 15 and the movable frame 13, and this fine adjustment is transmitted to the movable part 4, so that the bed 1 can be moved away from the transport vehicle (not shown). This is advantageous when aligning the coupling pin 1P protruding downward of the bed 1 and the coupling hole 4H of the movable part when transferring it to the support part 2.

It goes without saying that the present invention is not limited to the illustrated example. The vertical cross-sectional views shown in Figures 2 and 3 are schematic diagrams, and the details are complicated as they include an internal operation mechanism for tilting the bed, so the drawings are limited to these figures. Not done. Further, the ball screw mechanism 7 is not an essential requirement.

Further, the specific structure of the nut rotation prevention mechanism, which is the gist of the present invention, is not limited to the illustrated example. The installation position of the nut rotation prevention mechanism is advantageous if the distance R is large, and is not limited to the outer end position of the fixed frame 12 as shown in the illustrated example. The nut rotation prevention mechanism is also not limited to the illustrated example. As an operating table, it can be applied to either a fixed type or a movable type. A hydraulic rotary drive machine can also be used instead of the electric motor 5.

As described above, according to the present invention, in the operation mechanism for vertically moving the bed, especially in the screw feeding mechanism which is the main body, the nut rotation prevention mechanism is configured to have almost no gap. Even if gaps are formed due to long-term use, the bed does not become rattled, so it can withstand long-term use and maintain high performance for a long time. Furthermore, it has the advantage that there is little resistance in vertical movement operation, and it is easy to operate with little damage.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the external appearance of the operating table, Fig. 2 is a vertical cross-sectional view schematically showing the structure of a conventional support part, and Fig. 3 is a longitudinal cross-section schematically showing the structure of the support part according to the present invention. Figure 4 is a sectional view taken along line A-A' in Figure 2, Figure 5 is a sectional view taken along line B-B' in Figure 3, and Figure 6 is an exploded and enlarged perspective view of the main components of the present invention. FIG. 1...Bed, 2...Support part, 3...Foundation, 4
...Movable part, 5...Electric motor, 6...Threaded rod, 7...
...Ball screw mechanism, 8...Nut, 9...Key,
10...Fixed guide, 12...Fixed frame, 12'...
Groove, 13...Movable frame, 15...Roller spindle, 17
...Rolling roller, 18...Tightening nut.

Claims (1)

[Scope of utility model registration request] A threaded rod that is fixed in the axial direction and driven to rotate, a nut into which this threaded rod is screwed, and a nut that prevents the nut from rotating when the threaded rod rotates and the nut is displaced along a fixed guide. In the operating device, a threaded rod is rotationally driven and the nut moves up and down, thereby vertically operating a bed placed on the nut. The nut rotation prevention mechanism is arranged at a position outward from the sliding contact part and far away from the threaded rod axis, and the nut side engages with a groove formed in the fixed frame and this groove via a rolling roller. An operating device for an operating table, characterized by comprising a movable frame.