Year: 1887

page_text: Date of Application, 25th Nov.. 1887
Complete Specification Left. 10th Aug., 1888
Complete Specification Accepted, 14th Sept., 1888
1, WILLIAM CUNNINGHAM, of Gray House, near Dundee, in the County of Forfar,
North Britain, Engineer, do hereby declare the nature of this Invention to be as
follows, that is to say :-
My said Invention has for its object to construct in an improved manner a weighing
machine capable of weighing successive quantities in a rapid manner, and which whilst
indicating weights on a comparatively large and easily read dial, is not liable to rapid
wear or derangement.
In carrying out my Invention .I employ any convenient arrangement of metallic
spring or springs with a rack and pinion for turning an index over a graduated dial.
In spring weighing machines hitherto in use it has been considered necessary to make
the dial and the indicating mechanism inconveniently small in order to diminish the
injurious action on such mechanism of the jerks and vibrations of the scale caused by
suddenly putting in and removing the materials or articles that are being weighed.
By my Invention I prevent such jerks and vibrations from taking place and am
consequently enabled to use a large index and corresponding dial upon which small
differences of weight can be easily distinguished.
I provide mechanism for holding the scale firmly whilst the materials to be weighed
are being put into or removed from it. The scale may be thus held either with the
spring or springs unstrained, or with the spring or springs at maximum tension. In
the latter arrangement which I prefer, a vertically moving bar is made to depress the
scale into contact with a seat or stop, and this depressing bar is acted on by an
eccentric or cam on a horizontal shaft having also fixed on it a pair of disks which are
arranged for being frictionally driven by a pulley or ball between them. The driving
pulley or ball is on one end of a horizontal shaft which whilst the machine is being
used is kept continually rotating by means of a pulley on its other end and a driving
belt from a convenient power shaft. The shaft is held near its frictional driving
pulley or ball by a short arm of a three-armed lever centered on the framing, one of
the other arms of the lever being weighted, and the third arm being connected by a

page_text: cord or otherwise to a suitably placed handle. The weighted arm of the lever presses
the frictional driving pulley or ball against one of the disks and, turning it, causes the
cam or eccentric to push down the bar and depress the scale. An arm on the disk
shaft encounters a stop and prevents the shaft from being turned too far, whilst a
hollowed part of the disk stops the frictional contact of the pulley and disk. The
article or quantity of materials to be weighed is then put into the scale; and the
attendant draws down the handle thereby making the three-armed lever move the
frictional pulley or ball into contact with the other disk so as to cause the disks to
rotate in the opposite direction. The consequent rotation of the cam or eccentric
allows the scale to rise steadily by the action of the spring or springs until
the weight balances the spring or springs. The weight indicated on the dial is then
noted and the attendant lets go the handle whereupon the weighted lever arm causes
the reversal of the disk shaft and the consequent depression of the scale to its lowest
position. The rate of motion of the disks may be adjusted to be as rapid as possible
short of what would allow the scale to vibrate.
Dated this Twenty-fourth day of November 1887.
EDMUND HUNT,
Applicant's Agent.

page_text: I, WILLIAM CUNNINGHAM of Gray House near Dundee, in the County of Forfar,
North Britain, 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, that is to say
My said Invention has for its object to construct, in an improved manner, a weighing
machine capable of weighing successive quantities in a rapid manner, and which
whilst indicating weights on a comparatively large and easily read dial, is not liable
to rapid wear or derangement.
In carrying out my Invention I employ any convenient arrangement of metallic
spring or springs with a rack and pinion for turning an index over a graduated dial.
In spring weighing machines hitherto in use it has been considered necessary to make
the dial and the indicating mechanism inconveniently small in order to diminish the
injurious action on such mechanism of the jerks and vibrations of the scale caused by
suddenly putting in and removing the materials or articles that are being weighed.
By my Invention I prevent such jerks and vibrations from taking place and am
consequently enabled to use a large index and corresponding dial upon which small
differences of weight can be easily distinguished.
I provide mechanism for holding the scale firmly whilst the materials to be weighed
are being put into and removed from it. The scale may be thus held either with the
spring or springs unstrained, or with the spring or springs at maximum tension. In
the latter arrangement a vertically moving bar is made to depress the scale into
contact with a seat or stop and this depressing har is acted on by an eccentric or
cam actuated through engaging and disengaging gear from a continuously rotating
shaft, the action being controlled by the attendant worker by means of a handle.
And in order that my said Invention and the manner of performing the same may
be properly understood I hereunto append two sheets of explanatory drawings to
be hereinafter referred to and representing weighing apparatus as made with my.
improvements.
Figure, 1, on sheet, 1, of the drawings is a side elevation of the apparatus and figure, 2,
is a front elevation. Figures, 3, to 6, are enlarged views of details and are herein-
after particularised. In these drawings the same reference numerals are used to
mark the same or like parts wherever they are repeated.
The parts of the apparatus are carried by a frame standard, 7, formed with two
pairs of brackets, 8, 9, at its upper end. On one pair of brackets, 8, there is carried a
short horizontal shaft, 10, having fixed on it two disks, 11, 12, which are arranged for
being frictionally driven by a pulley or ball, 13, between them. This driving pulley, 13,
is on one end of a horizontal shaft, 14, which whilst the machine is being used is
kept continually rotating by means of a pulley, 15, on its other end and a driving
belt from a convenient power shaft. The shaft, 14, is held near its frictional driving
pulley, 13, by a short arm, 16, of a three-armed lever centered on a bracket, 17, one, 18,

page_text: The
of the other arms of the lever being weighted, and the third arm, 19, being
connected by a cord, 20, (or otherwise) to a suitably placed handle, 21.
shaft, 14, is at the belt pulley, 15, supported by a bearing, 22, which whilst
stationary is such as to allow of the slight angular movement of the shaft, 14,
required for putting the small driving pulley or ball, 13, in contact with one or other
of the disks, 11, 12. The weighted arm, 18, of the lever, presses the frictional driving
pulley, 13, against one, 11, of the disks and turning it, causes a cam, 23. formed on
it to push down a bar, 24, which depresses the scale, 25. The cam, 23, on the disk, 11,
is in the form of a spiral or volute-shaped groove, and it acts on a small antifriction
roller, 26, fitted to the bar, 24; and this bar, 24, is in two parts connected by a right-
and-left-hand screw, 27, by means of which its effective length can be accurately
adjusted. The upper end of the bar, 24, is forked and is guided by the disk shaft, 10,
on opposite sides of which the prongs of the fork pass; and the lower part of the bar
is guided by passing through a slot in a bracket, 28. A case, 29, containing the
spring or springs from which the scale, 25, is suspended, is fixed to the bracket, 28,
and has the indicating dial, 30, upon the front of it. The scale, 25, may be of any
convenient construction, but is represented as consisting of an approximately semi-
cylindrical shell, 31, fixed to a frame, 32, of bent tubing; and it is connected by a
hook at the top of the frame to the suspension rod, 33, of the weighing spring or
springs, whilst it is at its bottom jointed to a pair of radius rods, 34,
centered on a rod, 35, fixed to the standard, 7, these rods, 34, preventing
swinging motion without interfering with the vertical motion. The depressing
bar, 24, acts on a cross piece, 36, fixed to the scale frame, 32, near its
upper end, and adjustable stops, 37, are provided below the scale these stops being
fitted to frame standards, 38, and being adjusted so as to arrest the descent of the
scale when depressed by the bar, 24. An arm, 39, formed or fixed on the disk shaft, 10,
encounters a stop, 40, fixed to one of the brackets, 8, and prevents the shaft from
being turned too far, whilst a hollowed part of the disk, 11, stops the frictional contact
of the pulley, 13. The disks, 11, 12, and some other parts are shown enlarged in
figure, 3, on sheet, 2, the disks being in horizontal section.
With the apparatus as shown in figures, 1, 2, and 3, and hereinbefore described,
the article or quantity of materials to be weighed are put into the scale, 25, when
this scale is in the depressed position in which it is shown. The attendant then draws
down the handle, 21, thereby making the three-armed lever, 16, 18, 19, move the
frictional pulley, 13, into contact with the other disk, 12, so as to cause the disks to
rotate in the direction opposite to that for depressing the scale. The consequent
rotation of the cam, 23, allows the scale, 25, to rise steadily by the action of the
weighing spring or springs until the weight balances the spring or springs. The
weight indicated on the dial, 30, is then noted and the attendant lets go the handle, 21,
whereupon the weighted lever arm, 18, causes the reversal of the motion of the disk
shaft, 10, and the consequent depression of the scale to its lowest position.
The rate
of motion of the disks, 11, 12, may be adjusted to be as rapid as possible short of what
would allow the scale to vibrate.
Instead of the disks, 11, 12, and the driving pulley, 13, being made with plain
frictional surfaces they may be made with fine teeth as shown in figures, 4, 5, and 6,
on sheet, 2, of the drawings, figure, 4, being a horizontal section, figure, 5, a sectional
end elevation and figure 6, a sectional side elevation. At certain parts of the
disks, 11, 12, the teeth are absent, so that the driving pulley or bevil pinion, 13, is in
gear with either disks its driving action stops whenever the part of the disk without
teeth comes round to the place of the pinion.
As hereinbefore stated the apparatus may be arranged so that the action of the
bar, 24, is reversed and holds the scale in its highest position for receiving the article
or quantity of materials to be weighed. When, with this alternative arrangement, the
article or materials have been put into the scale, and the disks, 11, 12, are set rotating
the scale is lowered gradually and steadily until the tension of the weighing spring or
springs is such as to balance the weight of the article or materials, the rate of descent
being such as to avoid jerks and vibration.

page_text: Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1-The combination of parts constituting my improved weighing machine or
apparatus substantially as herein before described.
2-In a weighing machine acting with a spring or springs and index moving over
a dial, arranging a cam or eccentric in connection with which engaging and reversing
driving mechanism is provided, in a manner to cause the spring or springs to
gradually act on or be acted on by the article or materials being weighed substantially
as and for the purposes hereinbefore described.
Dated this Twenty-fifth day of July 1888.
EDMUND HUNT,
Applicant's Agent.