IMPROVEMENTS IN APPARATUS FOR INDICATING AND REGISTERING SPEEDS
Year: 1877

page_text: LETTERS PATENT to Thomas Walter Harding, of the Tower Works, Globe
Road, Leeds, in the County of York, and Robert Willis, of Tollington Park,
London, County of Middlesex, for the Invention of "IMPROVEMENTS IN
APPARATUS FOR INDICATING AND REGISTERING SPEEDS."
Scaled the 8th September 1877, and dated the 12th April 1877.
PROVISIONAL SPECIFICATION left by the said Thomas Walter Harding and
Robert Willis at the Office of the Commissioners of Patents on the 12th April
1877.
THOMAS WALTER HARDING, of the Tower Works, Globe Road, Leeds, in the
County of York, and ROBERT WILLIS, of Tollington Park, London, County of
Middlesex. "IMPROVEMENTS IN APPARATUS FOR INDICATING AND REGISTERING
SPEEDS."
Our Invention consists in improved apparatus for indicating and registering
speeds. It consists mainly in a case in which rotates a fan actuated from the motive
power or machine the speed of which it is intended to indicate. Within the said
case is also mounted a light spindle, which carries a pointer or index, and which is
also fitted with vanes placed near to but not in contact with the vanes of the fan.
By the rotation of the fan there is produced a tendency to rotate the vanes of the
pointer spindle, which is pulled back towards the zero point by the action of n
spring or weight.
According to the speed of the fan the pull of the spring or weight is more or less
overcome, and the position of the pointer indicates the speed on a dial. The pointer
spindle carries a fly wheel, with the object of steadying the movement of the pointer,
or the arms or vanes on the pointer spindle may be made of sufficient weight to
serve the purpose of the fly wheel.
The apparatus is made self-registering by transferring the movement of the pointer
shaft to a pencil or pricker acting on a traversing paper, which is connected with a
clockwork arrangement.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Walter Harding and Robert Willis in the Great Seal Patent
Office on the 11th October 1877.
THOMAS WALTER HARDING, of the Tower Works, Globe Road, Leeds, in the
County of York, and ROBERT WILLIS, of Tollington Park, London, County of
Middlesex. "IMPROVEMENTS IN APPARATUS FOR INDICATING AND REGISTERING
SPEEDS."
Our said Invention has reference to improved apparatus for indicating and regis-
tering speeds, and consists mainly of a case in which rotates a fan actuated by the
engine or machine the speed of which it is intended to indicate. Within the case is
a second and similar fan mounted upon and carried by a light spindle, which projects
through the front of the case, and there carries a pointer or index. By the rotation
of the first-named fan there is produced a current, which tends to rotate the second
fan attached to the pointer spindle, which is pulled back or retarded by the action
of a spring or weight.
According to the speed of the first or driving fan the pull of the spring or weight
is more or less overcome, so that the variations of speed are indicated by the position
of the index on a graduated dial.
. And in order that our said Invention, and the manner of carrying the same into
practical effect may be properly understood, we hereunto append a Sheet of expla-
natory Drawings to be herein-after referred to.
In this Sheet of Drawings the same reference numerals are used to mark the same
or like parts wherever they are repeated.
Fig. 1 of the accompanying Drawings is a vertical section of the apparatus, in
which the shaft 1 driven through the pulley 2 carries the first fan 3. By the side
of this, but not touching it, the second similar fan 4 is carried by a small steel
shaft 5, sensitively mounted, one end of which projects through the front of the
case, and there carries the needle or index 6, and as this index is kept back to the
zero point on the dial by the action of the spring 7 (best seen in the front view,
Fig. 2) the greater or less speed imparted to the first fan 3 overcomes more or less
the resistance of the spring 7 which retains the second fan 4, and the position of
the needle C on the dial 8 shews most correctly and sensitively all the variations of
the speed.
For the purpose of regulating the tension of the spring 7 the outer end of it is
attached by the split bolt 9 to the steel plate or bar 10. This bar, previous to
being hardened, is somewhat bent flatwise, so that by being pressed with its concave
side towards the front surface of the case by the steel screw 11 (which being hollow
also serves as a bearing for the spindle or shaft 5) causes the ends of said bar to
bind sufficiently against the case so as to prevent the bar from being moved by the
pull of the spring 7, but still so as to admit of the said bar being turned by hand
round the pivot screw 11 for the adjustment of the tension of the spring 7.
The wheel 4 (which together with its vanes forms the second fan) is made
sufficiently heavy to give steadiness to the movements of the pointer or index 6, but
the vanes themselves may be made heavy for same purpose when a light wheel is
used, or again a separate fly wheel may be mounted on the same spindle or
shaft 5.
Instead of the spring 7, as shewn, a weight and a cord passing over a scroll or
fusec on the spindle 5 may be used, or any other convenient means of producing the
necessary retard or pull on the spindle 5 in the contrary direction of the action of
the driving fan 3.
In some cases, where it is required to indicate forward and backward movement,
a second spring is mounted on the spindle 5 in a similar manner to the first spring 7;
such second spring acting in a contrary direction to the first spring, and the
equilibrium of the two springs when the fan 3 is at rest gives the zero point.
In order to obtain a record of the variations of the speeds indicated by the instru

page_text: ment it is necessary to connect the motion of the spindle 5 with a clockwork
registering apparatus, such as is already well known in connection with various
instruments, and particularly with registering barometers and gauges.
Fig. 3 is a partial front view, and Fig. 4 a partial side view of a convenient
arrangement for this purpose, 8 representing the dial of the instrument, and 5 the
index spindle, upon which is mounted the pulley 12, over which passes a cord 13, to
one end of which is attached a pencil 14, mounted in a carrier 15, while at the other
end of the cord there is a counterweight 16; the pencil carrier and counterweight
are guided by slots in the plate 17, which plate is mounted on pivots 18 and 19. At
certain intervals of time a clockwork arrangement swivels the plate 17 on its pivots,
and thus presses the pencil 14 against the graduated paper 20, which is also traversed
lengthwise by the clock.
Having now described our Invention, and the manner of carrying out the same,
we wish it to be understood that we do not confine ourselves to the exact details
indicated, but what we consider to be novel, and therefore claim is, the arrangement
substantially as described of fans and retaining springs or weights, for the purpose
of indicating and registering speeds.
In witness whereof, I, the said Thomas Walter Harding, have hereunto set my
hand and seal, this Tenth day of October, in the year of our Lord One
thousand eight hundred and seventy-seven.
THOMAS WALTER HARDING. (L.S.)