A TUBULAR OR TELESCOPIC
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by the said John Gorham at the Office of
the Commissioners of Patents on the 26th July 1880.
JOHN GORHAM, of Bordyke Lodge, Tonbridge.
BALANCE."
"
A TUBULAR OR TELESCOPIC
My Invention consists of two tubes sliding one within the other, the outer tube
being by preference thinner and lighter than the inner one. Near one end of the
outer tube a scale pan is suspended by suitable means, in which is placed the
substance to be weighed. The inner tube, which may be either cylindrical or of
any convenient shape, or in the case of a heavy balance may be a solid rod and
made of any metal, accurately fits and slides within the outer tube, so that when
pressed in or pulled out it retains its position. A point is found upon the outer
tube, from which if suspended the tube or tubes and rod will exactly balance the
scale pan, and at this point a knife edge is inserted upon which the balance turns.
The balance is now at rest, but if the inner tube or rod be drawn out its equilibrium
is disturbed. A known weight being placed in the pan the inner rod or tube is
lengthened or shortened until equilibrium is restored. By dividing the space upon
the inner tube or rod between the zero point and that point at which the weight
referred to is balanced into as many equal intervals as there are grains in the weight
a graduated scale is obtained, in which the intervals are all equal and correspond to
equal multiples of weight in the pan. Thus, if a weight of one pound in the pan
is balanced by withdrawing one inch in length of the tube or rod a second weight
of one pound in the pan will require the rod or tube to be withdrawn two inches
in length, and these intervals may be subdivided as required to indicate ounces,
drams, grains.
A pointer or finger is placed between and either above or below the knife edges.
by which the tubular beam is supported, so that its coincidence with a line or mark
upon the pillar which carries the beam or an independent index or zero point may
shew when the balance is in equilibrium. To enable the inner tube or rod to be
withdrawn with great precision I cause a spiral or screw thread to be cut upon the
inner tube or rod, the corresponding thread being cut either in the outer tube or in
a nut with suitably milled head; this however is only needed in cases where great
accuracy is required.
I also use several lengths or draws of tube sliding one within the other where a
compact instrument is needed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Gorham in the Great Seal Patent Office on the 25th January
1881.
JOHN GORHAM, of Bordyke Lodge, Tonbridge, Kent. “A TUBULAR OR TELESCOPIC
BALANCE."
My Invention consists of two tubes sliding one within the other, the outer tube
being by preference thinner and lighter than the inner one. Near one end of the
outer tube a scale pan is suspended by suitable means in which is placed the
substance to be weighed. The inner tube, which may be either round or of any
convenient shape, or in the case of a balance intended for weighing heavy
substances may be made solid throughout its length, or part of its length, must
accurately fit and slide within the outer tube, so that when pushed in or drawn out
it retains its position. A point is found upon the outer tube from which if
suspended the tubes will exactly balance the scale pan, and at this point "knife
edges" or pins are inserted upon which the balance turns. The balance is now at
rest, but if the inner tube or rod replacing the tube in a balance intended for
weighing heavy materials be drawn out its equilibrium. is disturbed. A known
weight being placed in the scale pan the inner tube or rod is withdrawn until
equilibrium is restored, and a mark made upon the inner tube or rod at this point.
By dividing the space between the zero or that point upon the inner tube or rod at
which the empty scale pan is exactly balanced and the point or mark made upon
the inner tube or rod at which the known weight referred to is balanced, any degree
of accuracy may be obtained, equal intervals of length upon the tube or rod
being equivalent to equal multiples of weight in the pan. Or, in other words, if
one pound weight in the pan requires the inner tube or rod to be withdrawn one
inch in length, two pounds weight in the pan will cause the rod or tube to be
withdrawn two inches in length, and these intervals may be subdivided to indicate
ounces, drachms, grains, or according to the metric system. A. pointer or finger is
placed between and either above or below the knife edges by which the tubular
beam is supported, so that its coincidence with a line or mark upon the pillar which
carries the beam, or an independent index or zero point, may shew when the balance
is in equilibrium.
In order that my explanation may be made clearer a reference to the Drawing is
necessary.
Fig. 1 and Fig. 2 represent side and end views of a balance suitable for dispensing
or other light purposes; A, Fig. 1, is the outer tube; B, the inner tube or rod;
C, the knife edges or points of suspension; D, the pointer; E, the index; F, the
scale pan; G, the pillar supporting the beam; H, the stand; I, a small semicircular
crutch to steady the beam when set to weigh a number of articles of equal
weight.
Figs. 3 and 4 shew in section and end view a collar A, through which the beam
or outer tube slides, and also the inner tube B, made piston shape, the rod or tube
passing through a collar C, which it accurately fits; the outer tube is clamped into
exact position by the set screw E; this modification enables the outer tube to be
easily set with great accuracy, and the piston shape of the inner or sliding tube
enables this form of balance to be used for very delicate determinations of
weight.
Fig. 5 shews a screw adjustment, a screw of coarse pitch or thread being cut
upon inner tube or rod, and the weight being read off upon the divided and milled
headed screw by which the tube is drawn in or out.
Fig. 6 shews an arrangement of similar character. The square rod has a screw
or thread cut on it, and is forced in or out by turning the milled head through
which it passes, the weight being read off the rod.

page_text: Fig. 7 shews my balance suspended after the method in general use, the whole
folding up into small space.
Fig. 8 shews an oval-shaped tube suspended by a filament of silk, wire, or string;
this balance is specially suited for the pocket.
I also use several lengths or draws of tube when a compact instrument is
required.
Almost any material of a light nature may be used in making my balance, such
as paper, papier maché, ebonite, ivory, bone, box and other hard woods, glass, and
metal tube.
Having now described my Invention, and the best means with which I am
acquainted for carrying the same into effect, I would have it understood that I do
not confine myself to the precise details shewn and described, as they may be
varied without departing from the character of the Invention; but I clain as
under,-
1. A sliding tube or rod so graduated that equal intervals of length upon the tube
or rod shall indicate equal multiples of weight in the pan.
2. A collar provided with set screw or clamp so arranged that while the outer
tube accurately fits and slides within it the tube may be held fast at any desired
point by the set screw or clamp.
3. The piston or plunger form of the inner or sliding tube or rod.
In witness whereof, I, the said John Gorham, have hereunto set my hand
and seal, this Eleventh day of January, in the year of our Lord One
thousand eight hundred and eighty one.
25 Witness,
FRANCIS M. ROGERS,
Engineer,
29, Moorgate Station Bdgs.,
London, E.C.
JOHN GORHAM. (L.S.)