Improvements in Speed Indicators.
Year: 1896

page_text: Improvements in Speed Indicators.
HENRY WRAY METCALFE of 36 Balls Road Claughton Birkenhead in the County
of Cheshire Engineer Royal Navy and WILLIAM OLIVER SMITH of 101 St. Martin's
Lane in the County of London Electrical Engineer do hereby declare the nature of
this invention to be as follows:-
This invention relates to improvements on a Patent granted to Henry Wray
Metcalfe No. 9225 of 1st June 1891 for "Improvements in Speed Indicators for
Steam Engines and other moving bodies applicable as a Governor."
Instruments made according to the said invention were not altogether satisfactory
owing to the wear of the cones and metal dises and through friction of the various
parts; to overcome these difficulties we provide a disc of ebonite firmly fixed between
two steel washers, slightly smaller in diameter, so that only the ebonite disc works on
the cone and we make the cone of a special bronze which works with ebonite without
wear or corrosion.
Between the main driver of the clock and the disc spindle we introduce an idle
wheel to allow the friction of wheel on this cone to be taken up by the spring
movement and under this clock centre we introduce ball bearings to reduce the
frictional work of the disc. We also introduce a special form of cap at the top of
cone pivot for lubrication.
We further completely enclose the working parts of the instrument in a water and
dust proof casing attachable to and detachable from the framework carrying the spiral
groove, by a thumb screw or catch.
The base of this casing is toothed, and gears with a pinion actuated from outside,
whereby fine adjustments of the spiral casing regulating the position of the disc on
the cone may be made.
The top of this casing is of glass, carried in a bezel free to revolve on the casing,
thus allowing of setting a reference pointer attached to the bezel, for marking the
position of the hand of the clock at any time.
This removable casing allows of easy access to the working parts, the inner framework
being in skeleton.
We prefer to mount the instrument on a pillar with a special suitable clutch
operated from the outside of pillar, for putting the instrument in and out of gear.
To allow of new discs being inserted when required, we provide special means for
allowing the spindle carrying the disc to be easily removed from the instrument.
Dated this 16th day of September 1896.
HENRY WRAY METCALFE.
WILLIAM O. SMITH.

page_text: We HENRY WRAY METCALFE of 36 Balls Road Claughton Birkenhead in the County
of Cheshire, Engineer Royal Navy, and WILLIAM OLIVER SMITH of 101 St. Martin's
Lane in the County of London Electrical Engineer do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
This invention relates to improvements on a Patent granted to Henry Wray
Metcalfe No. 9225 of 1st June 1891 for "Improvements in Speed Indicators for
Steam Engines and other bodies applicable as a Governor." We make the cone of
the instrument of Manganese Bronze and the disc of ebonite which we have found
work together with friction but without wear or corrosion. We introduce an idle
wheel to allow friction of the cone to be taken up and ball bearings to reduce as
much as possible the frictional work to be done by the disc. We provide a cover
arranged so that it may be turned by means of a hand wheel and toothed gearing
and the disc thus set to any desired position of the groove. We further provide a
moveable index attached to the bezel of the dial for marking the position of the
clock hand and a provision is made for easily removing the spindle carrying disc
for renewing the disc if required. We also provide a pedestal support with special
clutch arrangement for easily throwing the Instrument in and out of gear.
In the accompanying drawings:-
Fig. 1 is a side elevation of the internal arrangement, and Fig. 2 a plan with Box B
removed. Fig. 3 is a part section of Ball bearing arrangement. Fig. 4 is a general
arrangement, side view and part section, and Fig. 5 is a plan of the dial face. Fig. 6
is a view of the instrument on its column with the column partly in section.
A cone A is supported on a frame Fin bearings. Cone A is geared through coupling C
(Fig. 4) to the shaft whose speed of rotation is to be measured. Bearing on the
Cone is a disc D free to slide along a slotted spindle E (Figs. 1 and 4) parallel to one
side of the Cone, but prevented from turning on it by a feather. The shaft E is
pivotted on centre screws in a frame G (Figs. 1 & 2) (which is also pivotted) and
pressed towards the cone by a spring S so that the Disc D bears against the Cone A
with a steady pressure and is driven by it. The disc D is moved along the shaft E
by a forked slider H which slides on two guide rods R & R, (Figs. 1 & 2). By sliding H
along the guide rods the disc D can be moved up or down the cone A.
When the cone A revolves at any given speed it causes the disc D to revolve at a
speed which depends upon the position of the disc up or down the cone. The disc D
causes the shaft E to revolve by means of the featherway. The shaft E has a pinion
of 10 teeth on its upper end which gears into a wheel I (Figs. 1 & 2) of 20 teeth.
On the same spindle as the wheel I is a pinion of 10 teeth which gears into a wheel J
(Figs. 1, 2 & 3) of 60 teeth which is fixed to the spindle of the rotating box B which
carries the clock or time piece T (Figs. 4 & 5). The spindle of the rotating box B
rests on a ball bearing K (Fig. 3) which takes the weight of the time piece and so
reduces the frictional work of the disc. In order to increase the driving friction
between the cone A and the disc D, the disc D is made of a washer of ebonite held
between two steel washers L & L (Fig. 1) slightly smaller in diameter than disc D, so
that only disc D works on the cone A. The slider H has a projecting block M (Figs. 1 & 2)
on it, which gears into a spiral groove N (Fig. 4) cut in a spiral casting V (Fig. 4).
The casting V embraces the internal mechanism and is capable of being rotated
round it. The frame holding the internal mechanism being fixed to the base X
(Fig. 4) of the instrument. The cylindrical case Q of the instrument is fixed to the
casting V by means of two screws O & O, and is capable of being rotated by means

page_text: of the hand wheel W. By turning the hand wheel W the casting V is rotated and
the slider H caused to slide up or down the guide rods by means of the block M
which gears into the spiral groove, thus causing the disc to take up any position on
the cone governed by the angular position of the casing Q. This position is shown
by an index pointer U (Figs. 4 & 5) attached to the casing showing against a graduated
dial face Y (Figs. 4 & 5) placed concentric with the time piece T but above it with
the centre cut out so that the time piece, may be seen. This dial is fixed to the
base X of the instrument so that it neither turns with the case Q or with the
time piece T.
To facilitate the setting of the engines another index pointer U, (Figs. 4 & 5) is
provided which is attached to a ring Q, which rotates on the case Q-this pointer can
be brought opposite the hand of the time piece after the pointer U is set, and will
show whether the speed of rotation of the shaft or engine geared to the cone A is
faster or slower than the speed indicated by the pointer U.
We prefer to mount the instrument on a column of cast iron or other metal as
shown in Fig. 6.
The base of instrument X (Figs. 4 & 6) is firmly fixed to the metal column 2 (Fig. 6)
which is shown broken off and may be of any convenient height. Up the inside of
the column 2 runs a spindle 3 supported by a bearing 4. This spindle is geared to
the engine or shaft whose speed is to be measured. At the top of this spindle is
part of a clutch 5 which gears into the clutch C (Fig. 4) when the lever 6 is depressed
from outside the column 2. If the outside end of the lever 6 is raised, the clutch
part 5 is pulled out of gear with the clutch part C (Fig. 4) so causing the instrument
to cease indicating. A clamp screw 7 is provided to clamp the lever in either the
raised or depressed position.
Having now particularly described and ascertained the nature of our inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In a speed Indicator of the form described the combination of a Manganese
bronze cone working with an ebonite disc for the purpose above set forth.
2. In a speed Indicator of the form described the introduction of an idle wheel and
ball bearing for the purposes above set forth.
3. In a speed Indicator the combination of a case with gearing operated by hand
for the purposes set forth.
4. In a speed Indicator the arrangement of dial and index pointers for the purposes
above set forth.
5. In a speed Indicator, the clutch arrangement for throwing the instrument in and
out of gear, substantially as described and illustrated.
6. The construction of the Speed Indicator substantially as described and illustrated
Dated this 15th day of June 1897.
WILLIAM O. SMITH.
HENRY WRAY METCALFE,
Per William O. Smith,
Attorney duly authorized on his behalf.