Year: 1894

page_text: Date of Application, 13th Jan., 1894
Complete Specification Left, 11th Oct., 1894-Accepted, 29th Dec.,
1894
ALFRED BLECHYNDEN Cavendish Park Barrow in Furness Engineer, do
hereby declare the nature of this invention to be as follows:-
My invention relates to an improved apparatus for automatically indicating the
number of revolutions per minute or other unit of time at which the shaft of an
engine or other machine is rotating.
A hollow circular drum in the interior of which are vanes of a suitable form is
mounted on an axis and is driven through the medium of suitable gearing by the
machine of which the speed of rotation of some part is to be indicated. In the
interior of the said drum there is a second set of vanes mounted on a spindle
whose axis is in the same line as that of the rotating drum. This spindle passes
freely through a hole in one of the sides of the drum and is maintained in position
by suitable bearings. This spindle with the vanes to which it is attached is
capable of rotating through a limited angle only, which angle is governed by the
resistance of a spiral or other suitable spring attached directly to the spindle or
indirectly by means of an arm or arms.
This spindle has an indicating pointer attached to it or worked from it by means
of levers or toothed sectors. The pointer is in front of a suitable dial on which
are marked the numbers of revolutions between such limits as it is intended they.
should be indicated.
The hollow drum is filled or partly filled with mercury.
The apparatus is mounted on such a frame or fitted in such a case as may be
convenient or found necessary.
The mode of operation is as follows. When the drum revolves the mercury is
put in motion by the vanes attached to the drum and is driven against the second
set of vanes in the interior, so that the tendency is for the second set of vanes to
revolve along with it, but its spindle being attached to a spring, the tendency to
motion is resisted until the effect of the springs resistance is equalled by that of
the impact of the mercury as it is driven against the vanes.
The dial is so graduated that when the apparatus is in this condition the pointer
stands at the number corresponding with the number of revolutions which the part
whose speed is to be indicated is rotating in the unit of time chosen.
Dated this 12th day of January 1894.
COMPLETE SPECIFICATION.
An Improved Revolution Indicator.
ALFRED BLECHYNDEN, Cavendish Park Barrow in Furness, 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:-
My invention relates to an improved apparatus for automatically indicating the
number of revolutions per minute or other, unit of time at which the shaft of an
engine up other machine is rotating

page_text: A hollow circular drum in the interior of which are vanes of a suitable form is
mounted on an axis and is driven through the medium of suitable gearing by the
machine of which the speed of rotation of some part is to be indicated.
In the interior of the said drum there is a second set of vanes mounted on a
spindle whose axis is in the same line as that of the rotating drum. This spindle
passes freely through a hole in one of the sides of the drum and is maintained in
position by suitable bearings.
This spindle with the vanes to which it is attached is capable of rotating
through a limited angle only, which angle is governed by the resistance of a
spiral or other suitable spring attached directly to the spindle or indirectly by
means of an arm or arms.
This spindle has an indicating pointer attached to it or worked from it by means
of levers or toothed sectors. The pointer is in front of a suitable dial on which
are marked the numbers of revolutions between such limits as it is intended they
should be indicated.
The hollow drum is filled or partly filled with mercury.
The apparatus is mounted on such a frame or fitted in such a case as may be
convenient or found necessary.
The mode of operation is as follows:- -When the drum revolves the mercury is
put in motion by the vanes attached to the drum and is driven against the second
set of vanes in the interior so that the tendency is for the second set of vanes to
revolve along with it, but its spindle being attached to a spring, the tendency to
motion is resisted until the effect of the springs resistance is equalled by that of
the impact of the mercury as it is driven against the vanes.
The dial is so graduated that when the apparatus
in this condition the
pointer stands at the number corresponding with the number of revolutions which
the part whose speed is to be indicated is rotating in the unit of time chosen.
In order that the invention may be more clearly understood reference is had to
the accompanying drawings in which
Figure 1 is a front view and partial transverse section Figure 2 a longitudinal
section and Figure 3 a sectional plan of the apparatus respectively.
Figures 4 and 5 shew enlarged views of the drum and its accessories; Figure 4
being a transverse and Figure 5 a horizontal section.
Referring to Figure 5 "a" is the drum, having attached to its interior the arms
or vanes "p" which rotates along with the spindle "6" to which it is fixed, the
said spindle being caused to revolve in some fixed ratio to the engine shaft or part
of the engine or machine whose number of revolutions per unit of time the
apparatus is designed to indicate. In this case the drum is operated by means of
the mitre wheels " C " and "d" and the spindle "e" which may be connected by
belt, toothed or worm gearing to the part whose revolutions are to be indicated.
Inside of the drum " a "and free to revolve therein-excepting in so far as its
motion may be resisted by parts not attached directly to the drum "a"-is the vane
wheel "ffixed to the spindle "g" to which is attached the toothed sector "h"
gearing into the pinion ";" on the spindle "." The vacant space in the
drum "a" is filled or partially filled with mercury. The motion of the spindle ";"
is resisted by the spring "k" to which the spindle is attached. The spring is
secured in the spring box "" or in other suitable manner. The spindle ""has
a pointer or hand "m " which indicates on the dial "n the angle through which
the spindle "i" moves in either direction from its normal or vertical position.
"
The whole apparatus may be mounted in a case such as "o" shewn in the
Figures 1, 2, and 3.
Having described the construction of the apparatus I shall now proceed to
describe its mode of operation.
The drum "a" being caused to rotate by means of its connection with the
revolving part of the machine whose revolutions it is intended to indicate,
the mercury rotates along with it by reason of the friction of the sides of the
drum a and the impact of the vanes "p." The mercury impinges against
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page_text: "
the vanes "f" which thus tend to rotate in the same direction as the drum “
and to turn the spindle "g" around its axis until the resistance of the spring "k"
acting through the pinion "j" and the sector "h" balances the forces of the
impact of the mercury on the vanes "f." The dial "n" is so divided that when
the hand comes to rest it points to the number of revolutions per unit of time of
the engine shaft or the part of the machine whose speed is intended to be
indicated.
In the case of an indicator designed for use with a machine which moves in
either direction such as an engine capable of being reversed the dial is similarly
divided on each side of the zero position of the pointer; it then indicates both
the direction and number of revolutions.
I have described the apparatus as for a dial in a vertical plane, but it will be
evident that the spindle "g" might be attached directly to the spring "k" and
have the hand also fixed to it or the sector "h" and the pinion "j" might not be
bevelled but be arranged with the spindle "i" vertical.
Having now particularly described and ascertained the nature of my inven
tion and in what manner the same is to be performed I declare that what 1
claim is :-
The apparatus constructed and operating substantially as described and shewn.
Dated this 11th day of October 1894.
A. BLECHYNDEN.