IMPROVEMENTS IN WEIGHING MACHINES
Year: 1876

page_text: LETTERS PATENT to James Mackenzie, of Edinburgh, in the County of Mid-
Lothian, North Britain, for the Invention of "IMPROVEMENTS IN WEIGHING
MACHINES."
Sealed the 23rd March 1877, and dated the 27th September 1876.
COMPLETE SPECIFICATION filed by the said James Mackenzie at the Office
of the Commissioners of Patents on the 27th September 1876.
JAMES MACKENZIE, of Edinburgh, in the County of Mid-Lothian, North Britain.
"IMPROVEMENTS IN WEIGHING MACHINES."
My said Invention has reference to a new or improved construction or arrange-
ment of apparatus or machinery connected with the main lever of weighing
machines for recording the weights of railway and other waggons, trucks, or other
vehicles or heavy articles, quickly and in succession in an automatic, or nearly
automatic, manner, the same being improvements upon the Invention for "Improve-
ments in Weighing Machines," for which Royal Letters Patent were granted to
me, bearing date the 23rd September, A.D. 1869, and numbered 2773. And the
nature and novelty of the Invention consist essentially in a now or improved mode
and means of connecting a self-adjusting or differential poise or weight to the
weighing lever instead of the sliding and other poises ordinarily used, and in
steadying arrangements for the said lever and poise.
And in order that the nature of the new or improved construction and arrange-
ment of the mechanism and the best modes and means I am at present aware of
for putting my said Invention into effect or practice may be fully understood, I
shall now proceed to describe the several Figures on the accompanying Sheet of
Drawings which I have hereunto appended for that purpose, the same letters of
reference indicating the same or like parts in all the Figures where shown.
Figure 1 is a front elevation of one modification of the said new or improved
mechanism and recording apparatus, in which the hand lever performs the actual
marking or recording action; Figure 2 is a side elevation thereof; Figure 3 is a
plan corresponding to Figure 1; while Figures 4 to 10 show views of other modi-
fications or adaptations of the mechanism.
Referring to Figures 1, 2, and 3, a chain or metallic or other strap A is attached
to the extremity or other part of the lever B of the weighing machine. The other
end of the chain or strap A is connected at e to the lever or segmental bell crank C,
[Price Udl

page_text: from which the poise D is suspended by the strap & bearing upon the curvilinear
arm E thereof. The lever C is fulcrumed by pinching screws at c to brackets
carried on a transverse rail c¹ at one side of the frame Z, Z1, carrying the whole
mechanism and shown as made of cast iron in an open rectangular form. To an
extended arm of the lever or bell crank C (or any other appropriate point) is sus-
pended at C¹ a light metallic or other rod F, which carries at its upper extremity
a sharp serrated marking style G set horizontally or at right angles to the rod; or,
instead of this, a pencil, steel point, or chemically acting marking instrument, or
other marking style acting upon ordinary or chemically prepared paper, or other
surface may be used if preferred; the rod F being steadied and brought back to its
normal position off the paper by a weight F at its lower end. This style G is at
the proper time thrust upon a revolving drum or cylinder H, or it may be against
a sliding board or other surface when that is used. Upon this drum H (or board)
is placed a sheet of paper or diagram, ruled or marked with horizontal lines indi-
cating the degrees of weight in tons and fractions of tons, or otherwise, as may be
thought proper. In this modification, shown in Figures 1 to 3, the weighing
machine lever Bis controlled by a cross hand lever I (or other equivalent) fulcrumed
at the lower part 1 of the framing Z and worked by the person in charge; the
lever I, in Figures 1 and 2, is shown as in the position of locking the lever B, and
dotted in in Figure 2 as drawn forward by the attendant, so as to allow the lever B
to rise when the waggon or other article is in the correct position over the weigh-
.bridge of the weighing machine for being weighed, and also cause the marker G to
mark the paper at the point to indicate the weight. By the same forward motion
of the cross hand lever I, or other equivalent contrivance, the drum H (or board)
with the graduated paper attached is caused by the projection K to advance, so as
to oppose to the style G (or other appliance before mentioned) a fresh portion of
the surface after the weighing of each article or waggon The same action of the
projection K draws back the inner end of the two-armed lever L, thus causing the
outer end of the same lever to act upon the sliding block or presser M which
thrusts the style G forward, so as to perforate or otherwise mark the diagram paper
as above stated. A pawl N, actuated by a spiral or other spring n, is drawn back
over one tooth of the ratchet wheel O attached to the base of the drum H by the
projection K at the last part of the backward movement of the controlling hand
lever I. Upon the lever I being thrust in the spring n causes the pawl N to
advance and turn the drum H one tooth's length by the action of the ratchet O in
the direction of the arrow, shown in Figure 3, the drum being held in position and
prevented from turning in the reverse direction by the retaining spring pawl N¹.
Any sudden jerking of the weighing beam B in rising or falling is counteracted
by a new or improved atmospheric steadying governor or brake P, consisting of a
cylinder open at the top and close below with an easy fitting piston P¹, shown
dotted in in Figure 2, attached to the lower end of the rod Q, the upper end of
which is attached to the sliding stop or brake bracket Q¹ with wood or other soft
buffer on its under side resting on the lever B, or instead of this cylinder and
piston P, P¹, concentric cylinders, or other equivalent appliances, with suitable valve
or valves for obtaining a partial vacuum may be used. The weight of the steadying
piston P¹, and these attachments Q, Q¹, is counterpoised by the weight q¹ of the
lever q, the front end of which is connected to the brake Q so as to raise it clear
of the weighing beam B during the operation of weighing, the lever q being ful-
crumed on a bracket q¹ projecting down from the table Z¹, and the brake Q¹ sliding
in the fixed bracket attached to the frame Z. The weight or poise D is made
in the form of a hollow cylinder, so that lead or other material may be poured into
it to adjust it to suit the particular weighing machine and lever B to which the
mechanism is to be applied, and it is hung by the flexible strap d, or other
equivalent, to the point e of the lever C, so as to be carried by the differential or
curved arm E when the levers C and B rise in weighing, and steadied by the
chain V in falling, this chain being suitably attached to the frame Z for that
purpose, as shown in Figure 1.

page_text: The operation of this modification, Figures 1 to 3, is as follows:-The person in
charge keeps the controlling handle I in, as shown in Figures 1 and 2, until he
sees that the waggon to be weighed is in correct position upon the weighbridge.
He then draws the handle I towards him and thereby releases the weighing lever
or beam B, as shown in Figure 3 and dotted in in Figure 2. The pricker or
pointer G then rises till it stands opposite to the weight of the waggon, as indicated
on the diagram. The last inch of the motion of the hand lever I backwards
towards the person then acts upon the the lever L, and the pricker or pointer G
perforates or marks the diagram at the line which indicates the weight of the
waggon, and upon the controlling handle I being thrust back the drum H is moved
a tooth's length forward by the spring pawl n, as before described. This operation
is repeated for the next waggon, and so on until the whole train of waggons have
been weighed. This portable arrangement of differential poise and lever and
recording mechanism, described in reference to and shown in Figures 1, 2, and 3,
may be made to automatically turn the cylinder H with the graduated paper on it,
and also actuate the presser M and marking style G to mark the weights of the
different waggons in succession by their own act of going on to the platform or
weighbridge of the weighing machine, all by certain simple modifications and
additions, shown particularly in front and side elevation in Figures 4 and 5,
attached to the under side of the table Z, carrying the recording cylinder H at the
top of the frame Z, the table Z¹ being shown in section in both views to show this
automatic mechanism more clearly. In this self-acting arrangement, Figures 4
and 5, the recording mechanism is worked by a treadle or lever acted upon by the
waggon wheels in coming into the proper position on the weighbridge, which
treadle or lever causes the rod and pawl R (Figures 4 and 5) to act upon and turn
the ratchet wheel S, fixed on the spindle 8, revolving in the bearing brackets 8¹,
secured to the under side of the tablo Z, this motion carries round with it the two
ratchet wheels T and U which have just half the number of teeth in the wheel S,
so that the ratchet wheels T and U are set to act alternately, the one (T) working
the presser M, and the other (U) the drum H, through the intermediate pawls and
levers t and u respectively connected to the presser M and pawl N turning the
cylinder H. The waggon wheels are thus caused to actuate the whole mechanism,
the person in charge having merely to draw back the lever I and release the
weighing beam B at the proper time and to shut down when the weighing is
completed.
The ruled paper marked with the weights at the edges is fixed on to the
cylinders by springs or otherwise just before commencing to record the weights of
a set of waggons or other loads, and the cylinder may be made of truly turned
wood or iron to suit the paper, which may be ruled vertically to suit the distances
the cylinder H is turned by its ratchet wheels and pawl N, and the cylinder may
be covered with a thickness of cloth or other soft and removable material to allow
the marker G to pierce the paper without blunting it.
Although this improved mechanism, Figures 1 to 5, has been described as
recording or marking the weights of the waggons respectively as they pass over, or
pause for a few seconds on the weighbridge or platform of the weighing machine,
it is to be understood that the weights could be marked off on one part of the
cylinder H or a board in front of the position of the style or index G, so that the
weights of the waggons could be read from sight for a person to write them down
when that was preferred.*
Instead of the hanging weight D, d, and differential curved arm E, a vibrating
weight might be used, similar to that of the "bent lever balance," or it might be a
weight floated in mercury or other fluid. And, although it has not been shown,
the actual weights could be printed off on to a card or ticket previously prepared
for that purpose, and be inserted to be struck against the type set or engraved on
the cylinder, or other bar or equivalent, and inked by an endless band or ribbon.
For weighing carts, road waggons, or other articles, the same mechanism is used,
except that instead of an upright pointer F, G, being suspended from the bell

page_text: crank C a small chain or band is taken from the bell crank C over the axis of a
revolving pointer or index hand capable of traversing or oscillating over a circular
dial (or it might be a revolving dial and fixed pointer) which would take the place
of the drum and paper diagram, herein-before described; the weight being read off
by the attendant from the lettered disc or ring, or the weight may be stamped on
a weigh ticket by having type also set in or on the ring, all as shown in elevation
and transverse and horizontal sections in Figures 6, 7, and 8, which illustrate this
modification. Referring to these Figures, instead of the rod and marker F, G, a
cord g is attached at C¹ to the differential weighted lever C, E, and carried up over
and on or turned round a small barrel h¹ on the spindle of the indicating annular
disc or ring h, all carried within the close box i secured to the top Z³ of the
frame Z, the free end of the cord 9 having a counterweight g¹ attached to it to
keep it tight round the barrel W.
When
The ring at the upper front part is divided off to the right, as shown in
Figure 6, into hundredweights and fractions thereof, and a recess is formed in the
centre and front of the case i with a fixed index pointer j standing in the centre,
as shown at zero on the weighing ring h, Figure 6, when the mechanism is in its
normal position, so that as the lovers B and C rise by the weight on the platform
or weighbridge of the weighing machine, the weight is read off by the person in
front from the number on the ring / brought opposite the index pointer j.
the weight has to be printed on a ticket the letters are engraved or attached to the
back of the ring hat z to the right hand side of the case i, where a slit is formed
for a bent hand lever fulcrumed behind both on a stud projecting from the
back of the case i, as shown particularly in Figures 6 and 8, so that when the
levers B and C are steady and the ticket z inserted the hand lever is pulled
forward to press the ticket on to the type and stamp the weight upon it, the typo
being inked by a roller or otherwise a carbonised tape might be used between the
type and ticket for the like purpose without requiring to ink the face of the type,
the zero on the type is at the side opposite the handle in the normal position of
the parts, as shown at Figure 6.
A modification of this mechanism may also be used for weighing letters and
small packets by the use of the bell-crank arrangement, having the arm C, E, for
carrying the poise D suspended from a standard similar to that required for an
ordinary "scale beam." The weight of the article would in this case be indicated
by a pointer attached to the bell crank C, traversing over a stationary graduated.
are indicating the weight, Figures 9 and 10 showing a front elevation and a side
elevation respectively of this modification of my Invention for weighing letters.
Referring to these Figures 9 and 10, Z is the standard carrying the arc h graduated
or divided off into ounces and fractions thereof, zero being at the left hand side of
the arc.
The centre of the are has a stud c fixed in it, carrying the boss of the bell
crank or differential lever C, E, oscillating on it with the weight d, D, to the one
side or arm of which the light wire scale or tray k for holding the letters is carried,
while a pointer j is attached to the boss of the lever C, E, on the other side, shown
at zero on the arch in Figure 9, and which when a letter is placed on the scale k,
the pointer j traverses over the arc to the division indicating the weight of the
letter, which can then be read off by sight.
Having now described the nature of my said Invention and the manner of
carrying the same into effect or practice, I would observe that I do not confine
myself to the precise details herein shown and described, but what I consider novel
and original, and therefore claim as the Invention secured to me by the herein-
before in part recited Letters Patent is,---
First. The new or improved construction or general arrangement of recording
or registering mechanism with lever C, E, and self-adjusting poises or differential
weight D, d, for being applied to platform or other weighing machines, to indicate
or record the weights in succession as brought on to their weighbridge or platform,
all substantially as herein described in reference to and shown in the accompanying
Drawings or any mere modification thereof.

page_text: Second. The application of an atmospheric governor or brake to automatically
control or steady the movement of the weighing beam B of weighing machines,
substantially as herein described in reference to and shown in the accompanying
Drawings or any mere modification thereof.
Third. The employment of a sliding block or presser M to cause the marking of
the paper diagram, substantially as herein-before described in reference to and
shown in the accompanying Drawings or any mere modification thereof.
Fourth. The arrangement of ratchet gearing actuated by the waggon wheels,
shown in Figures 4 and 5, to render the apparatus entirely self-acting when
required, as herein described in reference to and shown in the accompanying
Drawings or any mere modification thereof.
In witness whereof, I, the said James Mackenzie, have hereunto set my hand
and seal, this Twenty-sixth day of September, One thousand eight hundred
and seventy-six.
JAMES MACKENZIE. (L.S.)