Patient's Table

The invention relates to a patient's table of the type having a vertically adjustable couch plate that is horizontally movable in two directions and rotatable about a vertical axis.

Patient's tables for X-ray examinations and radiotherapy of the above-mentioned type are known, which are rotatable about a vertical axis and can also be slid longitudinally and transversely to the couch surface. These tables are also adjustable vertically.

In these prior tables, the mechanisms for providing sliding mobility of the couch surface of the table were not vertically compact, particularly those which provided longitudinal sliding far beyond a column supporting the couch surface. Accordingly, these prior designs necessitated substantial thickness and/or height in the frames of the tables. Because of their extra thicknesses, these tables could be collapsed vertically only to a limited extent.

Another disadvantage of the known tables is that they provided insufficient stability when the couch surface was extended to its extreme positions, that is to say fully extended relative to the supporting column.

An object of the invention is the achievement of a patient's table in which the overall height of a couch surface with guideways for permitting transverse and longitudinal sliding movement can be reduced; and its stability, as regards the bracing of the moments with the couch plate extended, improved in spite of a reduced overall height.

The use of an intermediate support attached only at one side, permits the arrangement of all the guideways for longitudinal sliding of the table in a space with low overall height.

In a further embodiment of the invention, the intermediate support includes two steel rails each having two grooves, between which a continuous belt is inserted to revolve around two rollers, by which the couch plate can be driven. A long base for the moments generated by the couch plate and the patient is formed by the intermediate support in the extended position.

A reliable grounding of the couch plate can be ensured by an electrically conductive construction of the belt or a copper foil attached to the belt.

In a further embodiment of the invention, the grooves necessary as counterparts to the grooves in the intermediate support are attached to ribs on the guide pedestal and on a prolongation of the couch plate.

A play-free and therefore also vibration-free guide system is formed by cylindrical rollers with axes positioned mutually at 90.degree. alternately.

The couch plate is advantageously driven by a drive motor, the output pinion of which is in mesh with a tooth system on the intermediate support.

By virtue of the lateral arrangement of the intermediate support, the overall height of the couch surface can be minimized. Also a high bar can be provided beneath the couch plate, which has a favorable influence upon sagging.

The invention is described more fully with reference to the accompanying drawings, in which:

FIG. 1 is a partial cross-sectional view through a patient's table in accordance with a preferred embodiment of the present invention along the line I--I in FIG. 2;

FIG. 2 is a plan view of the patient's table;

FIG. 3 is a cross-sectional view through the couch surface along the line III--III in FIG. 2;

FIG. 4 is a sectional view along the line IV--IV in FIG. 3;

FIG. 5 is a cross-sectional view through the couch surface along the line III--III in FIG. 2, and

FIG. 6 is a sectional view along the line VI--VI in FIG. 5.

In FIG. 1, a patient's table 1 is mounted rotatably on an axis of rotation A. The rotary bearing 3, which is not a part of the invention and is only described briefly for better understanding, includes a ring gear 9 inserted firmly into a depression 5 in the floor 7, and a ring 11, on the inside of which a ball bearing or roller bearing 13 is placed and braced against the ring gear 9.

A motor gear unit 15, a conventional direct-current motor with a worm gear, for example, is attached to the ring 11 by a drive pinion 17 and is drivably connected to the ring gear 9.

The foot 21 of the column 23 of the table 1 is placed upon the ring 11, which is covered by a disc-shaped plate 19. A scissor-type lift 25, which is located in the column 23, can be transported by a hydraulically driven or electrically driven drive mechanism 27 from a folded position, in which the couch plate 29 of the table 1 occupies the lowered position, into an extended position (Table 1 raised). The column 23 is enclosed by a bellows 31 in order to protect the scissor-type lift 25 and its articulations and guide mechanisms, and also as a protection against accidents.

The couch plate 29 is mounted with longitudinal sliding mobility in a longitudinal guideway of a guide support 33. The guide support 33 is also slidable on the column 23 conjointly with the couch plate 29 tranversely to the longitudinal extent of the couch plate 29. The construction of the transverse guideway is not a part of the invention and is therefore not shown and described in more detail; it may be of similar or identical construction to the longitudinal guideway. A recess 35 may be provided on each side in the couch plate 29 for the attachment of so-called C-arms 36, which when placed outwardly (upwardly) permit an irradiation from underneath, or, when placed inwardly (downwardly), permit a lateral irradiation (FIG. 2).

The extreme positions of the couch plate 29 are visible in FIGS. 1 and 2; in solid lines on the one hand, the couch plate is extended to the greatest possible height and to the right; in chain-dotted lines the couch plate 29 is extended in the lowest position and fully to the left.

The guideways 37 and 39 for the longitudinal sliding of the couch plate 29 are visible in detail FIG. 3. The guideway 37 includes two spaced steel rails 41, 43 located mutually parallel and firmly mutually connected, forming an intermediate support 38, which has vee-shaped grooves 45, 47 on the mutually facing sides of the rails. As counterparts to the grooves 45 on the rail 43, grooves 51 are made in a recess 49 on the guide pedestal 33, extending along the recess 49 on a rib 50. Analogously, grooves 53, which are set into a bar 55 of the couch plate 29, which bar is provided with a rib 54 and is received in the recess 49, are located opposite the grooves 47. Cylindrical rollers 57, for example, RD type longitudinal guides of Messrs. Schneeberger, Roggwil, Switzerland, are inserted with alternate axial position into the grooves 45, 51 and 47, 53, so that low-friction and precise longitudinal guidance of the couch plate 29 on the guide pedestal 33 is ensured. Grooves of circular arcuate cross-section and balls may also be provided instead of vee-shaped grooves. The intermediate support 38 formed by the rails 41 and 43 includes return rollers 59 attached to the ends of the rails 41 and 43, which are mounted rotatably on vertically fitted axes 61 (see FIG. 4). A continuous belt 63, which is either coated with an electric conductor 65 or is itself of electrically conductive construction, travels over the return rollers 59 in order to establish an electrical connection between the couch plate 29 and the guide pedestal 33. The belt 63 is screwed on one side 67 to the bar 55 of the couch plate 29 and on the other side 69 to the guide pedestal 33, so that a mechanical connection is established between the couch plate 29 and the guide pedistal 33. The height of the intermediate support 38 is preferably equal to or slightly less than the height of the bar 55.

A guideway 39, arranged on the other flank of the bar 55, includes a plurality of rollers 71 arranged in a straight line on the side of the recess 49, which are received in a groove 73 made on the bar 55 of the couch plate 29 and can roll along its flanks 74. A drive motor 77 with a pinion 79 is inserted into a recess 75 on the side of the steel rail 43; this pinion 79 meshes with a tooth system 81 on the rail 41 and can slide the latter along the guide pedestal 33. A type No. 0130 820 072 flat motor with gear from Bosch, in Germany may be used as a drive motor for example.

In another embodiment of the invention and as shown in FIGS. 5 and 6 the rollers 71 are replaced by a roller guideway 83, a type JJ ball cage from Messrs. Schneeberger, Roggwil, Switzerland, for example, which is inserted between the rolling surface 85 of the couch plate 29 and the rolling surface 87 on the guide pedestal 33.

Due to the connection of the couch plate 29 to the guide pedestal 33 via the belt 63, the couch plate 29 slides twice as fast and twice as far as the guideway 37 when the latter is driven by the drive motor 77.

In order to slide the couch plate 29 into the extreme left-hand position, that is to say fully extended to the left (FIG. 1), the guideway 37 with the steel rails 41 and 43 is moved to the left by the drive motor 77. Because the motor 77 is connected firmly to the guide pedestal 33 and the guideway 37 is likewise in communication with the guide pedestal 33 through the first side 67 of the continuous belt 63, and the second side 69 is also screwed to the couch plate 29, the latter moves at double speed, and the couch plate 29 always travels twice the distance of the guideway 37. When the couch plate 29 is fully extended, the guideway 37, the length of which corresponds approximately to the length of the guide pedestal 33, is located half inside and half outside the guide pedestal 33. It therefore forms both a precise guideway for the couch plate 29, and also a long base to absorb the moment upon the points of support between the couch plate 29 and the guide pedestal 33 when the couch plate 29 is extended and loaded with a patient.

While this invention has been described in accordance with a preferred embodiment of the invention, it is recognized that variations and changes may be made therein without departing from the invention as set forth in the claims.