IMPROVEMENTS IN AUTOMATIC WEIGHING MACHINES
Year: 1884

page_text: COMPLETE SPECIFICATION.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention for IMPROVEMENTS
IN AUTOMATIC WEIGHING MACHINES 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 the class of automatic scales in which the material to
be weighed is fed through an oscillating box, and discharged therefrom into a
receptacle or shute. The improvement consists first, in an angular partition placed
into the weighing box, so as to divide the same into two compartments having equal
capacity, but unequal form, so that the contents of either compartment will lie in
line vertically with the knife edge pivots of the oscillating box and thus nearly.
balance the box. Second, in the employment of a link, which is pivoted on a fixed
support above the oscillating box at one side of the centre of the same and
connected by a slot and pin with said oscillating box, so as to prevent said box from
maintaining a central position, the link serving to hold the box slightly tilted in
case of accident, when the box fails to operate in a normal manner. Third, in a
detent for locking the oscillating box in either of the two positions in which it is to
be filled. Fourth, in making the grain spout laterally adjustable to ensure both
compartments of the oscillating box being filled alike.
It further consists in buffer springs for arresting the motion of the oscillating
box, and in other details of construction which contribute to the perfection of the
mechanism and the accuracy of its operation.
Figure 1 in the Drawing is a sectional side elevation of the scale. Figure 2 is a
vertical, transverse section of the same. Figure 3 is a detail view of the detent
mechanism. Figure 4 is a partial top view of the same. Figure 5 is a horizontal
section on the line c c, Figure 2. Figure 6 is a detail vertical section on the
line kk, Figure 1.
Similar letters of reference indicate the same parts in the two figures of the
Drawing.
A bifurcated scale-beam H, having an arm I extending therefrom and forming a
1

page_text: depending from the side bars of the top of the main supporting frame A. The
arm I is provided with knife edges i on which is suspended the weight K, and the
extremity of the said arm I rests normally on the lug / projecting inward from
the end piece a of the frame A.
Upon the shorter arms of the scale-beam H is supported a rectangular frame m
upon knife edges projecting inward from the said arms of the scale-beam.
Perpendicular bars n, secured to the ends of the frame m and hanging therefrom,
are provided with bearings about midway of their length to receive the pivots n¹
of the oscillating box L. The lower ends of the perpendicular bars n are forked,
as shown at o, and are connected by rods p, which engage the gates r, that are
pivoted to, and form a part of, the angular bottom of the oscillating box L. The
gates ride upon the rods p and are closed in alternation as the box L is oscillated.
The oscillating box L is partly closed at the top, but is provided with a central
opening M, into which the material to be weighed is delivered by the bifurcated
spout N.
A knife-edged bar O extends longitudinally through the centre of the oscillating
box near the top thereof, and a bar O¹ extends longitudinally through the box at
the bottom and forms a seat for the free edges of the gates T.
The oscillating box L is, by an angular partition p³, divided into two compart-
ments L, L of like capacity, but dissimilar in form and disposed so as to place
nearly the same amount of the material being weighed in vertical alignment with
the pivot n², so that the oscillating box will at all times be nearly balanced on its
pivots, only a slight preponderance of weight being thrown upon the side being
filled, so that it will be enabled to discharge itself by its own gravity. The object
of this distribution of the weight is to relieve side strain and to diminish, as much
as possible, the friction of the releasing mechanism and thereby contribute to the
accuracy of the operation of the machine.
To the upper part of the bar O is secured a segment C¹, (see Figure 3) having on
its upper edge notches for engaging a detent pin a¹, which projects through a cross-
bar 6 of the frame m, and also through a cross-bar c of the main frame A B. The
detent pin a¹ is provided on top with a head c¹, and a stud d¹ projects upward from
the cross-bar c at the side of the pin a¹ in position to be touched by the head c¹,
whenever the pin a¹ descends. The detent pin a¹ is provided with a stude¹ (see
Figure 1) which rests normally on the cross-bar 61, of the frame m, and sustains the
pin on said frame m. A link f¹, pivoted to the cross-bar c at one side of the centre
thereof, is provided with a slot in its lower end for receiving a pin g', which projects
from the side of the segment C. In case of stoppage, or accident, the pin gl
strikes at the upper end of the slot when the box L ascends and oscillates, and the
link rides lightly on the pin and prevents the box L from stopping on the centre.
The ends of the segment C¹ are prolonged, and to the inner sides of the frame m
are secured semi-circular buffer springs h¹ (see Figure 2) against which the ends of
the segment strike at the end of each excursion of the oscillating box L.
The bifurcated spout N is provided with flanges 8, which rest upon cross-bars d,
of the top frame A, and are secured by bolts i¹, which pass through slots in the
cross-bars, as in Figure 4, and admit of adjusting the spout N to one side or the
other of the central line of the machine, to equalize the amount of material
supplied to either of the compartments of the oscillating box L. A valve Q placed
in the spout N, on the spindle R, is capable of seating on the valve seat T, and is
operated by a rod U, connected with a crank S on the end of the spindle R. The
rod U takes its motion from the lever F, which is placed in the opening D of the
hopper C at the bottom of the machine.
The lever F is provided with a plate E inclined each way from the centre, which
is depressed by the material discharged from the oscillating box L, so that whenever
one of the compartments of the said oscillating box is emptied the lever F is
depressed, closing the valve Q until after the matter discharged from the oscillating
box no longer weighs down said lever. The lever F is returned to its normal
position by the counter-weight G.

page_text: A register V, of ordinary construction, is mounted on the frame A. Its actuating
spindle e is provided with a perforated arm d", which receives a finger c¹¹, carried
by the rod U (see Figures 1 and 6). Whenever the lever F is moved by the
discharge of weighed materials from the oscillating box the register is operated by
the rod U to make one tally.
The operation of this improved automatic scale is as follows:-The material to
be weighed flows through the spout N into one of the compartments of the
oscillating box L. When the box is filled so as to move the weight K, the shorter
arm of the scale-beam descends and the frame m moves down with it, carrying the
detent pin a with it, and holding all of the parts supported by the frame m
relatively in the same position as when the filling of the compartment began, until
the head c¹ of the detent pin strikes the stud projecting from the cross-bar c,
when the said pin is arrested and the segment C¹ disengages itself from the pin and
the oscillating box L tips, opening the gate r in the lower part of the filled
compartment thereof, which allows the contents of the filled compartment to
escape, at the same time closing the gate of the other compartment and
bringing the upper part of the said other compartment under the supply spout N.
In this new position the detent pin a¹ engages the opposite side of the segment C¹
and holds the oscillating box in position until the second compartment is filled,
when the operation above described is repeated.
Having now particularly described and ascertained the nature of the said
Invention, and in what manner the same is to be performed, I declare that what
I claim is :
1 In automatic scales, an oscillating weighing box, provided with oppositely
arranged compartments L, L", each extending from the outer portion of the box
inward beyond the centre of oscillation of the box, as herein described, whereby
the body of the material being weighed is aligned vertically with the pivots of the
oscillating box, substantially as herein shown and described.
2nd In automatic scales, the oscillating weighing box L, provided with the
angular partition p³ and bars 0 0', substantially as herein shown and described.
3rd The combination, with an oscillating weighing box, of the slotted link f¹,
pivoted to a fixed support, and a pin g¹, carried by the oscillating weighing box,
substantially as herein shown and described.
4th In automatic weighing scales, the combination with the oscillating weighing
box L of a notched segment C¹ and a sliding detent pin a¹ carried by the weighing
mechanism, and a fixed arm c, capable of engaging the head of the detent pin after
a partial descent of the weighing box, as herein described.
5th The combination with the oscillating weighing box L, of buffer springs h³,
for arresting the motion of the said weighing box as described.
6th The combination with the register V and valve operating rod U of an
automatic weighing scale, of the parts c d for imparting motion from the said
rod U to the actuating spindle of the register, as herein specified.
7th The spout N, having slotted flanges 8, in combination with the frame A,
having bars d, and with the oscillating weighing box L, above which the spout can
be laterally adjusted, as specified.