IMPROVEMENTS IN MOVABLE BEARINGS FOR TRAVELLING CRANES AND OTHER PURPOSES
Year: 1877

page_text: LETTERS PATENT to William Holmes, of Sheffield, in the County of York,
Engineer, for the Invention of "IMPROVEMENTS IN MOVABLE BEARINGS FOR
TRAVELLING CRANES AND OTHER PURPOSES."
Sealed the 20th October 1877, and dated the 3rd May 1877.
PROVISIONAL SPECIFICATION left by the said William Holmes at the Office
of the Commissioners of Patents on the 3rd May 1877.
WILLIAM HOLMES, of Sheffield, in the County of York, Engineer. " IMPROVE-
MENTS IN MOVABLE BEARINGS FOR TRAVELLING CRANES AND OTHER PURPOSES."
The object of my Invention is to keep the movable bearing at all times parallel
to the shaft or screw to be supported. The bearings are supported by links and a
double elbow lever, which form parallel motions; consequently when one bearing is
displaced the other is supporting the shaft or screw.
When applied to a travelling crane, where the gearing is required to pass over
the bearing, the wheel or the guard attached to it lowers the front bearing, and
raises the back one, or vice versa, and when applied to a slide lathe the nut on the
carriage or worm carrier acts in the same manner. This improved movable bearing
dispenses with the tumbler weights and springs generally employed.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Holmes in the Great Seal Patent Office on the 20th October
1877.
WILLIAM HOLMES, of Sheffield, in the County of York, Engineer.
"IMPROVE-
MENTS IN MOVABLE BEARINGS FOR TRAVELLING CRANES AND OTHER PURPOSES."
The object of my Inventon is to keep the movable bearings at all times parallel
to the shaft or screw to be supported. The bearings are supported by links and a
double elbow lever, which form parallel motions; consequently when one bearing is
displaced the other is supporting the shaft or screw.

page_text: When applied to a travelling crane, where the gearing is required to pass over
the bearings, the wheel or the guard attached to it lowers the front bearing, and
raises the back one, or vice versa, and when applied to a slide lathe the nut on the
carriage or worm carrier acts in the same manner. This improved movable bearing
dispenses with the tumbler weights and springs generally employed.
And in order that my Invention may be fully understood, and readily carried
into operation, I will proceed to describe the accompanying Sheet of Drawings, in
which Fig. 1 is an elevation, and Fig. 2 an end view of part of an ordinary travelling
crane to which my improved bearings are applied.
a is the shaft of the travelling crane, which is supported at each end in bearings
fixed to the main carriage; b is a bearing fixed to the cross carriage; this bearing
supports the boss of the mitre wheel c, which is connected to the shaft a by keys
and grooves, and transmits the motion to the hoisting gear, as usual. To the under
side of the bearing bis fixed the double horn plate 61, 62, the object of which will
be explained hereafter; d is a plate fixed to the main carriage; to this plate are
cast or fixed projections or snugs for the fulcrum studs of the elbow lever e, and for
the double links f and g. The links f and one arm of the elbow lever e support the
cradle or bearing h, and the links and the other arm of the elbow lever e support
the cradle or bearing i, and as the arms of the elbow lever e are of the same length
as the links f and g, it is evident that they form parallel motions and keep the
cradles and i at all times in line with the shaft a.
To each cradle is cast a projection marked respectively h¹, i', and these projections
are acted upon by the horns 61, 68. The projections d' on the plate d are to support
the ends of the links ƒ and g when down.
The mode of operation is as follows, and the Drawing represents the parts in the
positions they occupy when the cross carriage is supposed to be travelling in the
direction of the arrow in Fig. 1 -The horn b' acting on the projection h¹ is now
depressing the cradle h, links f, and one arm of the elbow lever e, thereby raising
the other arm of the elbow lever, the links g, and the cradle i. As soon as the
horn b¹ has depressed the links funtil they are in a horizontal position, as shewn by
the dotted lines in Fig. 1, the links g will be vertical, and the cradle i will then be
brought into position for supporting the shaft a. The parts will remain in these
positions until the cross carriage in its return traverse brings the horn b² against
the projection i¹, when the cradle i will be lowered, and the cradle / raised to support
the shaft a at the other side of the wheel c.
When my Invention is applied to a slide lathe or to other machine in which a
long shaft or screw requires intermediate support the nut on the carriage or the
worm carrier of the lathe or other travelling portion of the machine lowers one
cradle or bearing, and raises the other.
These improved movable bearings dispense with the tumbler weights and springs
usually employed for displacing one bearing and bringing another into position.
Having thus stated the nature of my Invention, and described a convenient way
of constructing and applying the same, I wish it to be understood that I do not
intend to limit myself to the details given, as the same may be varied to suit the
particular purpose to which the Invention is applied, I claim the movable bearings
supported by levers and links forming parallel motions, as described.
In witness whereof, I, the said William Holmes, have hereunto set my hand
and seal, this Eighteenth day of October, One thousand eight hundred
and seventy-seven.'
WILLIAM HOLMES. (LS.)