IMPROVEMENTS IN THE CONSTRUCTION OF TURNTABLES
Year: 1861

page_text: PROVISIONAL SPECIFICATION left by Charles Denton Abel at the Office
of the Commissioners of Patents, with his Petition, on the 18th April
1861. A communication from abroad by Jean Joseph Adolphe Poulet,
residing at Paris, in France.
I, CHARLES DENTON ABEL, Patent Agent, of 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, do hereby declare the nature of
the said Invention. for "IMPROVEMENTS IN THE CONSTRUCTION OF TURNTABLES,"
to be as follows:-
These improved turntables consist of two pair of parallel bearers of suitable
sectional form, one pair being at right angles to the other pair, so as to
intersect each other, and the distances between the respective bearers of each
pair corresponding with the. gauge of the railway, which four bearers are all
cast in one piece of cast steel, together with a portion of a ring corresponding
with the diameter of the turntable, and connecting the ends of the two bearers
of each respective pair. The turntable has also a further portion cast in one
with it situated in the central square space formed by the crossing of the four
bearers, and containing the socket by which the turntable is made to rest
upon the fixed upright central bearing fixed to the foundation plate. The
rails upon which the carriages pass on and off the turntable are either cast in
one piece with the before-mentioned bearers, or they may be separate and
bolted on, or the greater portion of them may be cast in one piece with the
bearers, and the parts forming the crossings may be formed separate so as to

page_text: be able to be renewed. At the crossings inclined planes are formed, upon
which the flanges of the carriage wheels rest while passing over the part of
the rail which is cut through, thus obviating concussion at those points.
Portions of a ring corresponding with the diameter of the turntable, are bolted
to the ends of the bearers in such a manner as to connect the ends of one pair
of bearers with the ends of the other pair, and thus in conjunction with the
portions of a ring cast in one with ends of each pair of bearers forming a
complete ring, which may serve as a bearing ring resting upon a loose set of
rollers underneath the turntable, or where the size of the turntable is not too
large, the whole ring is cast in one piece with the bearers. It is preferred to
have rollers fixed under the ends of each the bearers and running upon the
foundation plate; and the axle-boxes for such rollers may either be cast in one
with the bearers, or they may be formed separate and bolted to them. The
foundation plate may be of cast iron or of cast steel, and is provided with a
central upright post, forming the bearing upon which the turntable rests. At
the points of the roller path on the foundation plate, where the rollers of the
turntable rests upon it when the turntable is in the position for the carriages to
move on or off the same, the foundation plate is provided either with inclined
planes rising up to a small height above the ordinary level of the path of the
rollers, or else with a set of rollers placed in boxes, fixed to the under-
side of the foundation plate, which rollers project through openings to a certain
extent above the level of the roller path. By this arrangement the rollers of
the turntable only take a perfect bearing when at rest, whilst when in motion
'the turntable is carried either completely or nearly so by the central bearing,
thus greatly facilitating its motion.
The rollers both in the turntable and in the foundation plate may be of cast
steel or of cast.iron.