US2726910A

US2726910A - Single pivot x-ray table

Info

Publication number: US2726910A
Application number: US470774A
Authority: US
Inventors: Eugene P Thomas; Robert J Wagner
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1954-11-23
Filing date: 1954-11-23
Publication date: 1955-12-13
Anticipated expiration: 1972-12-13

Description

Dec. 13, 1955 p, THOMAS r 2,726,910

SINGLE PIVOT X-RAY TABLE Filed Nov. 25, 1954 2 Sheets-Sheet 1 Fig.2.

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Q) 3 O 200 LL 0 45 90 Table Angle WITNESSES: |NVENTORS 4f Eugene P.Thomos 47! and Robert J.Wogner.

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' ATTORNEY Dec. 13, 1955 E. P. THOMAS ET AL SINGLE PIVOT X-RAY TABLE 2 Sheets-Sheet 2 Filed NOV. 25, 1954 Fig.3.

United States Patent SINGLE PIVOT X-RAY TABLE Eugene P. Thomas and Robert J. Wagner, Baltimore, Md., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application November 23, 1954, Serial No. 476,774

Claims. (Cl. 311-6) The present invention relates to X-ray apparatus and relates, in particular, to an X-ray table which is movable about a single support pivot.

It is an object of the present invention to provide an improved X-ray table which is tiltable about a single support pivot.

It is an additional object of the present invention to provide an improved cantilever supported single pivot X-ray table having more simple and less expensive control and drive apparatus for tilting or angulating the table relative to the table base or support floor.

It is a further object of the invention to provide a more reliable and improved control apparatus for the tilting movement of an X-ray table and for improving the table load characteristics.

It is another object of the present invention to provide an improved control for a single pivot X-ray table which provides a compensation for the variation in table load characteristics as the table is tilted between the opposite extremes of its allowable angular movement.

Other objects of this invention will be apparent upon reading the following description taken in connection with the drawings, in which:

Figure l is a perspective view of the X-ray table apparatus in accordance with the present invention;

Fig. 2 is a curve showing the compensating torque force applied by the spring control member to affect the tilt movement of the X-ray table;

Fig. 3 is a top plan view of the apparatus shown in Fig. 1, and

Fig. 4 is an end view of the apparatus shown in Fig. 1.

In general, we have provided a single pivot cantilever supported X-ray table which is controlled by a drive motor that applies its control force through a band brake controlled flywheel and drive sprocket to a control chain member which is operative with the contour surface of a cam or control member fastened to the X-ray table. To further support the X-ray table in its cantilever position about the single support pivot, a reaction roller or like device is provided to apply a compensating force to the X-ray table to counteract the gravitational weight of the cantilever supported X-ray table. In addition, a spring control member is provided to compensate for the shifting effect of the X-ray table load due to the center of gravity of the X-ray table passing from one side to the other of the support pivot. The spring control member is operative to apply a compensating torque force such that the load characteristic of the X-ray table never reverses, and the movement of the X-ray table is, therefore, substantially smooth and continuous.

Referring to Fig. l and Figs. 3 and 4 of the drawings in detail, an X-ray table is cantilever supported about a pivot connection 12. A control member 14 is rigidly fastened to the X-ray table 10 and is provided with a contour surface having a predetermined shape about which n a control chain member 16 is positioned and is operative.

F ice nection 20. A support base 22 is provided for the X-ray table 10 such that the pivot connection 12 is fixedly supported by the support base 22, and the X-ray table 10 is movable or tiltable about the pivot connection 12 relative to the support base 22. A drive motor 24 is provided for effecting the tilt motion of the X-ray table 10 through the control chain 16. The drive motor 24 is connected through a flywheel 26 about which is operative a suitable hand brake 28. The drive motor 24 is also connected to the drive sprocket 30 which is provided with suitable teeth such that it is operative to exert a force on the chain member 16 when raising the table to pull on the connection 18 between the chain 16 and the control member 14. When the motor 24 is reversed, the table 10 is lowered by means of the sprocket 30 rotating to feed out the chain 16. A stripper gear or like device 32 is provided to prevent fouling of the chain 16 even if the unloaded end of the chain becomes slack and has substantially no tension in it. The contour of the cam or control member 14 is predetermined as shown in Fig. l to provide a maximum torque with minimum tilt speed of the X-ray table when the load is high, such as when the table is in a substantially horizontal position or when the X-ray table 10 is substantially parallel relative to the plane surface or bottom 25 of the support base 22, and further, to provide a minimum torque with a maximum X-ray table tilt speed when the table load is small, such as when the X-ray table 10 is in an angular position of approximately 60 degrees or more relative to the bottom or plane surface 25 of the support base 22. The contour surface of the cam or control member 14 is operative such that it is effective to take up the chain 16 from the sprocket 30 at approximately the same rate as the chain 16 is pulled into the sprocket 30 when the motor 24 is rotating in either direction. The illustrated contour surface of the cam or control member 14 is superior to a circular arc shape in that a circular arc shape does not permit the desired adjustment of the table tilt speed or tilting torque to meet the table load characteristics.

The band brake 28 is operative with the flywheel 26 to provide a smoother stopping and starting of the table tilt movement. In starting to tilt the X-ray table 10, the flywheel 26 resists momentarily the applied torque from the motor 24, and in stopping the tilt movement of the X-ray table 10 by means of the band brake 28, the flywheel is efiective to temporarily resist the action of the braking force. The band brake 28 is operative for either rotational direction of the motor.

A spring control member 34 is provided to apply a compensating torque to more desirably adjust the load characteristic of the X-ray table 10. The spring control member 34 is fastened at one end 36 to the support base 22, and the other end 38 is connected to a terminating plug or piston 40 of a rope or cable 42. The cable 42 passes coaxially through the spring control member 34 and around a plurality of

pulleys

44, 46, 48 and 50 and is fastened to the cam or control member 14 by means of a pin or fastening member 52. The spring control member 34 is thereby held in compression by means of the cable 42 connected between the plug 40 and the fastener 52 such that the spring control member 34 applies a force to the cam or control member 14 to efiect the pivotal movement of the X-ray table 10 about the pivot connection 12, in accordance with the curve shown in Fig. 2. The center of gravity of an actual X-ray table 10 in accordance with the present invention is so located such that at approximately 70 degrees angulation of the X-ray table 10 relative to the bottom 25 of the support base 22, the load characteristic of the X-ray table shifts. In other Words, when the X-ray table 10 is at approximately an angle of 70 degrees relative to the bottom Plate25. of the supnn bas t X- av a e t nds torque to the X-ray table through the fastener 52, which compensating torque starts to increase from a table position of approximately 45 degrees relative to the bottom plate. 24 and increases as the table tilts to the vertical or approximately 90 degree angular position relative to the bottom plate 25. Therefore, due to the force applied by the spring control member 34, the X-ray table load effectively never reverses in that the force of the control 7 spring 34 overcomes the falling or gravitational effect of the X-ray table between the 70 degree angular position and the 90 degree angular position. This results in the tilting movement of the X-ray table being made'very smooth and very *readily controllable by the motor 24 driving through the drive sprocket and the chain control member 16. At a table tilt position of approximately degrees relative to the bottom plate 25, the compression of the spring control member 34 is at a minimum. For table tilt positions from approximately 45 degrees to approximately 90 degrees, the spring control member 34 is compressed in accordance with the portion of the curve to the right of the 45 table angle, as shown in Fig. 2. For a table tilt position from approximately 45 degrees down to zero and beyond in the Trendelenburg position up to 10 degrees, the spring control member 34 is used to store energy which is effective to raise the X-ray table lli back to approximately the 45 degree angular position.

A reaction roller member 54 is provided and is rigidly fastened to the support base 22 and applies a counteracting force to the back ,or reverse side 'of the cam or control member 14 as shown inFig. l. The reaction roller 54 is adjustable and is operative to ofliset the torque resulting from the weight of the cantilever supported X-ray table 10. The reaction roller 54 is very desirable v in that without it the bearings at the pivot connection 12 must be strong enough to by themselves completely resist the cantilever suspension torque.

The apparatus as shown in Fig. '1' and Figs. 3 and 4 provides greaterrigidity and static stability in all positions. Bolts may be provided to fasten the bottom plate 25 to a support floor or the like. However, this is not necessary in that the X-ray table apparatus will not tip over in any desired tilt position of the X-ray table 10. Further, the reaction roller 54 not only reduces the torque load on the bearings at the pivot connection 12, but in addition, absorbs a large portion of the X-ray table moment which would otherwise cause undesired deflection and twisting'ofthe X-ray table. 7

In accordance with the operation of the apparatus shown in Fig. 1 and Figs. 3 and 4, the drive motor 24 descent of the table is governed by controlling the feed out or slackening of the chain 16 relative to the connection 18. With a clockwise rotational direction of the "motor 24, theX-ray table can be tilted up to substantially a 90 degree position relative to the bottom plate 25.

With a counterclockwise rotation ofthe drive motor 24,

' the X-ray table can be tilted to the Trendelenburg position which corresponds to a position of the X-ray table which is 10 degrees below the horizontal position or parallel position relative to the bottom plate 25.

Although a specif c embodiment of the present invention'has been shown and described, it is to be underst od that st ll ur her modifisations ther o mayb made without departing from the spirit and scope of the invention.

We claim as our invention:

1. In X-ray apparatus including a table tiltable about a pivot and having'asupport base, the combination of a control cam member fastened to said table and including a predetermined contour surface having a pair of end portions, control chain means fastened between said end portions and operative with said contour surface, and motor means fastened to said support base and opera tive with said control chain means to tilt said table. about said pivot.

2. in X-ray apparatus including a table movable about a pivot and having a support base with said support base having a plane surface, the combination of a control member fastened to said table and having a predetermined contour surface, control means operative with said surface, motor meansoperative with said control means to control the movement of said table about said pivot with said contour surface being shaped to provide a maximum torque for tilting the table when said'table is positioned substantially parallel to said base and to .face, control chain means fastened to said control cam member and operative with said contour surface, and motor means fastened to said support base and operative with said control chain means to tilt said table about said pivot, and a spring control member fastened to said table and operative to apply a force to tilt said table about said pivot such that the table load characterist c does not reverse as the table is tilted from said first posit on to said second position.

4. ln X-ray apparatus including a table movable about a pivot, said table being cantilever supported about said pivot, the combination of first control means fastened to said table and including a cam member having a predetermined contour surface, second control means including a continuous flexible member operative with said surface to control the movement of said table about said pivot and third control means operative with the cam member of said first control means to compensate for the torque resulting from the cantilever support of said table.

5. in X-ray apparatus including a table tiltable about a pivot and having a support base, the combination of a control cam member fastened to said table and including a predetermined contour surface having a pair of end portions, control chain means fastened between said end portions and operative with said contour surface, and motor means including a flywheel and drive sprocket, said motor means being fastened to said support base and said drive sprocket being operative with said control chain means to tilt said table about said pivot, with said motor means further including a band brake which is operative with said flywheel to control the movement of said table.

Refereneest'lited the file of this patent UNITED STATES PATENTS i,820,436 Carlson Aug. 25, 3931 2,172,94l Manning et al Sept. 12, 1939 2,534,623 Pitts Dec. 19,1950 2,679,442 Koerner et al May 25, 1954 2,680,046 Stava June 1, r 2,692,173 'Lowitzsch Oct. 19, 1954 2,699,367 1955 Lipphaus et a1. Jan. 11,