IMPROVE- MENTS IN APPARATUS FOR TRANSMITTING AND CONTROLLING MOTION
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by Robert Anthony Hardcastle at
the Office of the Commissioners of Patents, with his Petition, on the
5th November 1866.
I, ROBERT ANTHONY HARDCASTLE, of the Town and County of Newcastle-
on-Tyne, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN APPARATUS FOR TRANSMITTING AND CONTROLLING MOTION," to be as
follows:-
This Invention relates to a peculiar construction and arrangement of
combined coupling and break, more particularly applicable to machinery or
apparatus for raising and lowering heavy bodies with a view to transmitting
motion thereto when hoisting, and to regulating, controlling, or arresting such
motion when lowering weights.
In carrying out this Invention it is proposed to employ, in conjunction with
other parts arranged as herein-after described, two discs, in the contiguous
faces of which are respectively formed a series of annular concentric wedge-
shaped projections and a corresponding series of similarly shaped grooves, with a
view to obtaining the required adhesion or friction between the two discs
when pressed together. When used as a windlass break one of these discs is
keyed or otherwise secured to the pinion and the other disc is free only to
move longitudinally on the spindle, but in cases where it is required to have
a divided spindle, then one of the friction discs is keyed or otherwise secured
on to that portion of the spindle to which motion is to be transmitted or

page_text: whose motion is to be regulated, controlled, or arrested, whilst the other disc
is fitted on to the feathered or grooved square end of the other portion of
the spindle, which should be in the same axial line with the first, such disc
being free only to move longitudinally along the spindle when subjected to end
pressure. Between the last-mentioned friction disc and a smooth disc or
plate on the same spindle there is compressed a helical or volute spring or
springs, or a spring of india-rubber or other elastic medium, the convolutions
of the spring when a helical or volute spring is used, being by preference
made to gradually diminish in diameter towards the outer end, such spring
being composed of a bar of a double convex section, so that when pressed
home the curved outer side of one convolution will enter and press against
the curved inner side of the adjoining larger convolution. The requisite
degree of compression of the spring or end pressure is maintained by tie or
coupling rods, which connect the two last-mentioned discs, but which are free
to play longitudinally through the smooth disc when end pressure is applied to
the outer or smooth disc; this end pressure is applied by means of a screwed
tubular collar turning freely on the spindle and rotated by a hand wheel, such
collar being screwed into the end of a clutch box or frame, which may be
attached to the pinion disc or may rotate with the spindle, or the tubular
collar may be screwed on to the spindle, or I may dispense with the collar
and screw the spindle into the clutch box. If the clutch box rotates with the
spindle its interior should be provided with projecting ribs or recesses fitting
corresponding recesses or projections on the last-mentioned one of the two-
grooved faced friction discs and also the smooth disc, but if it rotate with or
is fixed to the pinion then it may be made smooth inside. By exerting an end
pressure on the smooth disc the increased compression of the spring thereby
produced will force one of the friction discs against the other, when the parts
will be coupled and rotatory motion will be transmitted. If the spindle be
not divided, as in the case of a windlass, the spindle is held fast and the
spindle will rotate on it; or if the spindle or one part of the divided spindles
be held stationary, and moderate pressure be applied to the spring, the
friction produced will by acting as a break arrest or controll the motion of the
other part of the spindle or the pinion. By compressing the spring until the
smaller convolutions partially enter and bed themselves into the larger ones
as before described, the resistance will be greatly increased. When the
clutch box is attached to the pinion a disc may be fitted on to the spindle, so
as to press on the outer face of the pinion, so that when pressure is employed
the pinion will be nipped between the friction disc and the outside disc, which
latter may be grooved as herein-before described. Any of the discs may be

page_text: faced or backed with wood or other material; when cheapness is an object
the springs may be dispensed with. The pinion friction disc, when the clutch
box rotates with the spindle, may be grooved on both sides, and the end of
the clutch box made with corresponding wedge-shaped projections, or vice
versa.