IMPROVEMENTS IN THE CONSTRUCTION OF TURN-TABLES
Year: 1879

page_text: LETTERS PATENT to Henry Bridgewater, of Watford, in the County of Herts,
Civil Engineer, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION
OF TURN-TABLES."
Sealed the 3rd October 1879, and dated the 23rd April 1879.
PROVISIONAL SPECIFICATION left by the said Henry Bridgewater at the
Office of the Commissioners of Patents on the 23rd April 1879.
HENRY BRIDGEWATER, of Watford, in the County of Herts, Civil Engineer.
"IMPROVEMENTS IN THE CONSTRUCTION OF TURN-TABLES."
This Invention relates to a mode of constructing turntables whereby great
facilities are offered for putting the parts together and for renewing the rails when
worn, no skilled labour being required in carrying out these operations, and great
strength and durability of the structure being secured with a minimum of liability
to fracture and derangement. The top and bottom rings or annular recesses,
between which the antifriction rollers that carry the turntable run, I form of
segments of bridge or flange rail iron, the butt joints of which I connect together
by clipping plates which fit over a pair of under-cut strips rivetted to the abutting
ends of the segments, and slightly tapered to allow of the chipping plates drawing
the abutting ends together as they are driven home.
The segment pieces forming the upper race are each connected to their girders
and cross girders by plates, as will be presently explained, the girders and cross
girders being themselves coupled together by sliding the same endways into cross
V grooves formed in coupling plates to receive the bevilled edges of the bottom
Hanges of such girders and cross girders. These girders I form by preference by
placing side by side two sections of bar iron, the web of which is flanged at top
and bottom and at both sides, as at Fig. 1 in the accompanying Drawing, or with
one flange at top and two unequal ones at bottom, as at Fig. 2. These sections
when placed together will constitute a box girder, and will form a base for the
sections of rail constituting the roadway of the turntable, and they are connected
to the segment pieces by pairs of overlying plates and rivets, such plates being set
longitudinally of the girders and parallel to each other and at such distance apart
as to receive between them a section of bridge rail, their inner edges being undercut
to form V guides for the flanges of the rail, which flanges are correspondingly

page_text: chamfered to fit the guides. The cross girders are formed and fitted in place in a
similar manner to the longitudinal girders, and the connecting plates serve to
secure the cross rails in place without the use of any other fastening. When the
segments forming the top race are connected together as above explained, the
sections of rail which are to form the crossways of the turntable are slidden end-
wise into place; and to prevent the rails creeping a key or wedge can be used to
each of the outside lengths of rail, which with the other portions of the rails will
thus be securely locked in place.
The clip plates which serve to connect the segments of the top race together may
be used to carry the catches which lock the turntable in position. It will be
obvious that instead of a box girder and bridge rail, girder iron of a section such
as that shewn at Fig. 3 may be used.
As a modification of this construction of turntable I propose to make the girders
of a section somewhat like a deep bridge rail with a flattened head, as shewn at
Fig. 4, and to slide on the top thereof an interlocking top rail.
cross girders will in this case be connected as before.
The girders and

page_text: "
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Bridgewater in the Great Seal Patent Office on the 23rd
October 1879.
HENRY BRIDGEWATER, of Watford, in the County of Herts, Civil Engineer.
IMPROVEMENTS IN THE CONSTRUCTION OF TURN-TABLES."
This Invention relates to a mode of constructing turntables whereby great
facilities are offered for putting the parts together and for renewing the rails when
worn, no skilled labour being required in. carrying out these operations, and great
strength and durability of the structure being secured with a minimum of liability
to fracture and derangement.
In Sheet I. of the Drawings Fig. 1 shews in partial plan view a turntable, con-
structed according to this Invention; Fig. 2 is a cross section of the same taken
through the centre of the turntable; and Fig. 3 is a partial elevation of the turn-
table, the outer case being removed.
A is the top ring or race, and A¹ the bottom ring or race, between which the
antifriction rollers B that carry the turntable run.
These antifriction rollers are
mounted as usual in a ring which is connected by radial arms with a boss, which
fits over the central pin or pivot C of the turntable.
The top and bottom rings A and A¹ are formed of segments of bridge rail iron,
which I connect together by butt joints, as shewn in the detached view, Fig. 4.
For this purpose I use clipping plates D, D, which fit over a pair of under cut
strips a, a, rivetted to the abutting ends of the segments, and are slightly tapered
to allow of the clipping plates drawing the abutting ends together as they are.
driven home.
The central bearing of the turntable is carried by a cruciform frame E composed
of bar iron of a similar section to that used for the girders to which it is perma-
nently connected.
F, F, are a pair of girders, which extend across the turntable from side to side,
and F, F, are a pair of cross girders, each composed of three lengths to provide for
the girders F, F, passing transversely through them.
The girders F are permanently connected with the cruciform frame E by means
of plates and rivets, and the middle sections of the cross girders are similarly
connected with the cruciform frame, and also with the girders F by plates and
rivets f¹, f. To ensure good firm joints of these parts I cut off the top and bottom
flanges of the abutting ends of the girder sections and of the cruciform frame, so as
to allow of the webs of these abutting ends coming into contact with the webs that
run up at right angles thereto. G, G, are plates formed with longitudinal and trans-
verse dovetail guides to receive the ends of the cruciform frame and the flanges of
the girders F and F1 respectively, so as to secure the parts together at the underside
of the table.
The segment pieces forming the upper race are connected to the girders
and cross girders F, F¹, by plates f³, f, as will be presently explained, the
girders and cross girders being themselves coupled together by sliding the same
endwise into cross. V-grooves formed in coupling plates H to receive the bevilled
edges of the bottom flanges of such girders and cross girders. The girders F, F¹,
are shewn as formed by placing side by side two sections of bar iron, the web
of which is flanged at top and bottom and at both sides, as seen best in Fig. 2.
By placing these sections, as shewn, I form therewith box girders, which serve
as continuous supports for the rails I, I', constituting the road ways of the turn-
table. The girders F are connected to two of the segment pieces forming the
ring A by pairs of overlying plates f³, f, which are rivetted to the segments and
girders, as indicated in Fig. 1. These plates it will be seen are set longitudinally
of the girders and parallel to each other, and at such distance apart as to receive
between them a section of bridge rail I, their inner edges being undercut to form

page_text: 1
V guides for the flanges of the rails, which flanges are correspondingly chamfered
to fit the guides. The cross girders F1 are formed and fitted in place in a similar
manner to the longitudinal girders, and the plates f which connect them perma-
nently with segments of the ring A-serve to secure the cross rails I' in place. The
plates are similarly utilized to hold down with the assistance of undercut
plates (which are rivetted to the girders) the ends of the sections of the rails which
bed upon the longitudinal and transverse girders, and by means of other undercut
plates f*, f*, rivetted to the inner ends of the outer sections of the transverse
girders, the attachment of the rails to the girders is completed.
When the segments forming the top race are connected together, as above
explained, the sections of rail which are to form the cross ways of the turn table
are slidden endwise into place, and to prevent the rails creeping a key or wedge
can be used (as shewn at i (Fig. 1) to each of the outside lengths of rail, which with
the other portions of the rails will thus be securely locked in place.
The clip plates D which serve to connect the segments of the top race together
may be used to carry the catches which lock the turntable in position.
From the foregoing it will be understood that my improved turntable is con-
structed of three main detachable parts, which are held together when in place by
means of the clipping plates D, D. On the removal of these plates the central
portion of the table, viz., the girders F, F, with the cruciform frame E, E, and two
segments of the race A, A, may be detached from the two side portions which
consist respectively of the outer sections of the cross girders F¹, F, and the
remaining segments of the race A. The facility thus offered for detaching the parts
composing the table provides for close packing of the same for transport.
It will be obvious that instead of a box girder and bridge rail, girder and rail
iron of other sections may be used.
One example of this is shewn in Sheet II., the Figures representing a turntable
constructed with girder iron of an H section and fitted with Vignolle or flat
bottomed rails. Fig. 5 is a plan view partly in section, and Fig. 6 is a cross section
of the turntable. Sheet III. represents on an enlarged scale details of this turn-
table. The change of section requires slight modifications in the details described
with reference to Sheet I. These modifications will however require no verbal
explanation. The clipping plates D are shewn as fitted with catches d for locking
the turntable in the desired position.
Having now set forth the nature of my Invention of "Improvements in the
Construction of Turntables," and explained the manner of carrying the same into
effect, I wish it to be understood that under the above in part recited Letters Patent
I claim,-
First. Constructing turntables of detacliable parts, as above described, and con-
necting the same together by clipping plates.
Secondly. Fitting the rails of turntables to their seats, in the manner and for the
purpose above described.
In witness whereof, I, the said Henry Bridgewater, have hereunto set my
hand and seal, this Twenty second day of October, in the year of our
Lord One thousand eight hundred and seventy nine.