A NEW OR IMPROVED APPARATUS FOR INDICATING, OR INDICATING AND RECORDING, THE SPEED OF REVOLVING OR MOVING BODIES
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by John James Royle at the Office of the
Commissioners of Patents on the 16th June 1877.
JOHN JAMES ROYLE, of 71, Market Street, in the City of Manchester, Mechanical
Engineer. "A NEW OR IMPROVED APPARATUS FOR INDICATING, OR INDICATING
AND RECORDING, THE SPEED OF REVOLVING OR MOVING BODIES."
The object of this Invention is, ―
1
1st. The construction of a simple apparatus for indicating the speed during
given time of revolving or otherwise moving bodies, such as the revolutions or
strokes of engines, shafts or parts of machinery, speed of railway trains, tram cars,
and other vehicles.
2nd. The combination of the before-mentioned apparatus with mechanism for
keeping a permanent record of such indications..
First. As applied to the construction of a speed indicator, this Invention consists
primarily of a differential motion in combination with a body having a uniform or
known movement, one modification being constructed as follows:-I mount a
differential motion, one member of which is driven by the engine or other moving
body, the speed of which is to be indicated (herein-after called the engine), the
second member whereof is controlled by a pendulum, and the third member is
arranged to actuate the bob of the pendulum, so as to lengthen and shorten the
pendulum, and so adjust it to the speed of the engine, the length of the pendulum
being the measure of the speed of the engine, and which can be indicated by means
of a suitable dial and pointer.
In another modification I arrange a differential motion consisting of a worm and
worm wheel. The worm wheel is controlled by a pendulum or balance wheel
escapement, so as to always revolve at a constant rate. The worm is set upon a
spindle capable of sliding in its bearings as the worm gears with the worm wheel.
A circular plate or roller (herein-after called the roller) is fixed upon the worm
spindle, and a disc driven from the engine is fixed so as to drive the roller by
frictional contact therewith. The action of this modification is as follows:-The
disc, as it drives the roller by frictional contact, causes the worm to travel through
the worm wheel by the difference between the speed of the roller and the speed of
the worm wheel, controlled as herein-before described. As the speed of the worm
wheel is uniform, any variation of the engine causes the worm to travel through the

page_text: worm wheel more or less, and alter the position of the roller upon the disc to a
position where the surface velocity at the point of rolling contact bears the same
proportion to the speed of the worm wheel. The position of the roller, therefore,
varies according to the speed of the engine. A suitable dial and pointer are provided,
by means of which the position of the roller upon the disc may be more readily
seen and read off, such disc being graduated by experimental test. The dial may be
graduated in "revolutions per minute or "miles per hour," or otherwise, according
to the unit of time selected or purpose to which the apparatus is applied.
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Secondly. A permanent record of the indications of the pointer may be obtained
by applying a drum carrying a sheet of paper, such drum being either driven by
separate clock movement, or by the engine, or by the differential motion, according
to the use to which the indicator is applied. A pencil or pricker, actuated from the
arbor of the pointer, and which consequently varies in its position according to the
indicated speed, marks such speed upon the paper carried by the drum, and so a
permanent record of the speed is obtained; or instead of a drum carrying a sheet of
paper, I may employ a disc driven in like manner to the drum and carrying a sheet
of paper upon its surface for a like purpose.