Patent GB-745087-A (GB)
Title: Improvements in and relating to tiltable table structures
Inventor: FLEURY GEORGE ROBERT
IPC: A61B6/04
Filed: 1953-07-17
Abstract: 745,087. X-ray apparatus. METROPOLITAN-VICKERS ELECTRICAL CO., Ltd., and INTEGRAL, Ltd. July 19, 1954 [July 17, 1953], No. 19931/53. Class 98 (1). A tiltable table structure comprises a table mounted on a support and tiltable thereon by means of a jack about one of two axes extending transversely of and spaced from each other longitudinally of the table, and includes at least one pair of first pins (at least one pin for each axis) carried by the table (or its support) and received in the normal, usually horizontal, position of the table in open bearings, and a selectively operable latching mechanism arranged when operated to retain one pin of each pair in its bearing while allowing the remaining pin of each pair to leave its bearing, whereby action of the jack at a position on the table between the axes and in a direction tending to move the pins out of their bearings will cause the table to tilt about the pins retained by the latching mechanism. As shown in Fig. 1, a table having a frame 2 composed of box-like members and a spaced top 3 is supported horizontally by two pairs of pivot pins 4 resting in open bearings 6 in a base 1. Control pedals 7 operate latches to retain one pair of pins 4 in their bearings so that the table is tilted about the selected axis on operation of a hydraulic jack 8. As shown in Fig. 3, each latch consists of a hooked member 13 pivoted to a mounting block 10. A lever 16, also pivoted to block 10, carries a roller 15 which normally engages the end of member 13 so that its hooked end keeps the pivot pin 4 in its bearing. Lever 16 is held in position by a toggle link 18. When a pedal 7 is operated, a flexible cable 17 connected thereto breaks the toggle so that lever 16 rocks to release member 13, which is rocked on its pivot by a spring 14 to release pin 4. When pin 4 moves out of its bearing, further movement of member 13 brings its end to a position wherein it engages roller 15 to prevent return of lever 16 until pin 4 re-enters its bearing. After one of the pedals 7 has released a latch, its further movement actuates a valve admitting pressure fluid to jack 8 to tilt the table. The fluid is thus under pressure all the time that the table is tilted, and this pressure operates two stops, one of which locks the unactuated pedal, and the other of which prevents return of the actuated 'pedal to latching position. Thus once a latch has been opened and the table tilted, it cannot be closed, nor can the other latch be opened, until the table has been returned to horizontal position. The levers 16 of the pair of latches on each side of the table may be linked together. In order that this mechanism may remain operative when the table is vertical, or nearly so, spring devices 9 are mounted near the table ends and have levers engaging the base 1 when the table approaches vertical position to maintain pressure in jack 8. The latches and upward tilt are controlled by the outer pedals 7; the middle pedal controls a valve which allows the table to return to horizontal position under its own weight. The valve may be associated with means which slow up the return of the table as it approaches horizontal position. The jack is preferably mounted at one side of the table. In this case to avoid bending moments it may be mounted in a gimbal attached to base 1, and its piston-rod may be connected to the table by a spherical bearing. The fluid is then supplied through the gimbal pivot.