Improvements in or relating to Power and Weight Measuring Apparatus.
Year: 1894

page_text: Date of Application, 16th May, 1894-Accepted, 29th Sept., 1894
COMPLETE SPECIFICATION.
Improvements in or relating to Power and Weight Measuring
Apparatus.
We, EDWARD STEINFELDT, and FRIEDRICH WILHELM BLASBERG, both of
Dömbergstrasse Hanover in the Empire of Germany, Engineers 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 :-
In the accompanying drawings Figure 1 is a front elevation and Figure 2 a cross
section of a spring balance, constructed according to our invention, and Figures 3
and 4 are respectively similar views of portion of a modification thereof.
This balance is distinguished from the ordinary kinds of spring balance in use by
the double springs F and F which are arranged on each side, these being connected
by the slotted links L, and attached at their upper ends to pins or eye-bolts S fixed
to the case or box of the apparatus and at their lower ends to the arms Bo of the
yoke or frame B.
This latter is arranged in a well-known manner, being connected with the radius
rods H and H which are at right angles to the plane of the frame and secured to
its rods and U respectively, and one or more similar radius rods H² in planes
parallel with that of the frame B. The rack T is pivotted to the bar B¹ of the
frame B and is kept by a spring Q constantly in gear with the pinion Z secured on
the index spindle. The arms or studs P which are fixed to the body or case of the
balance project into the slotted links L.
When the dish or scale-pan (not shown in the drawings) secured to the upper
arm O of the frame B is weighted, the frame B is depressed, drawing down the
lower springs F, and, by means of them and of the slotted links L, straining the
upper springs F in proportion to the weight put in the dish; and, when a certain
weight has been attained, the further extension of the upper springs is prevented by
the tops of the slots of links L bearing upon the studs P, and, thereafter, the
increase of weight is borne by the stronger and lower springs F¹.
It is evident that these latter springs F undergo the same tension or strain as
the former F, so long as they support the weight in common, distributed through
the frame B, and at the moment when the links L are arrested by the studs P, that
strain, as indicated by the index-hand, is exactly that due to the weight then borne.
But as the weight increases beyond that point, the index-hand shows only the
strain on the lower springs, and this is exactly the continuation of that to which
the two sets of springs, upper and lower, were subjected in common.
The above-named circumstance is an important feature of this balance, as the
scale divisions for the lower springs F are the exact continuation of the scale for
all upper springs combined. Consequently if the index-hand and dial divisions
respectively are so arranged that the index-hand completes say one revolution, when
the slotted links L are arrested by the studs P, at which juncture the upper
springs F become inoperative as regards further increase in weight the same dial
scale may be employed to indicate any weighing in excess as shown by the lower
springs, then alone operative; only, in point of interpretation, in this case, the
weights corresponding to each separate division and numbers expressing their value
are materially larger, than those of the first revolution of the index hand. The
balance can therefore be very easily arranged so that, for instance, throughout the
first complete revolution all small weights from say 0 to 1 kilogramme shall be
indicated whilst greater weights say 1-10 kilogrammes shall be indicated by the
same divisions during the next following revolution. If then, for example, an outer
row of black divisions and figures on the dial is assigned to represent weights below

page_text: 1 kilogramme, while a second, inner row of red divisions and figures above 1 kilo-
gramme, there could be no possibility of error.
If such a row of numbers for weights over 1 kilogramme or, in general, of the
weights as determined (beyond that weight) by the lower, stronger springs F only,
appears on the dial of such a balance, the constant simultaneous strain of the
weaker, upper springs F to their maximum point of extension would prevent their
co-operative working beyond it, and make them practically fixed parts of the frame.
Thus, the exclusion of the upper springs F from co-operation in weighing the
beavier loads would be a great advantage, in respect of repair and maintenance..
The before-described arrangement, as shown in Figures 3 and 4 may be reversed
the stronger springs F being uppermost, and the weaker springs F lowerinost; in
this case, the frame B is provided with a driver B2 engaging in the slotted links L,
instead of the studs P as in the previous example, and abutting against the lower
end of the slots of L, so soon as the weaker springs F have attained the corre-
sponding maximum degree of tension, after which the springs F move down without
further elongation and the springs F1 become elongated.
This arrangement of parts coming one after another into operation, with automatic
cessation, can equally well be applied to traction-apparatus, used as dynamometers,
⚫of all kinds.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is;-
1. In connection with the measurement of power the combination of springs of
different strength one after the other in such manner that when traction is brought
to bear upon them each of them co-operates with the stronger springs placed behind
it but only up to a certain point when its further co-operation is automatically
arrested and thereafter the next following stronger spring lying behind the
preceding one is utilized with the same strain of traction which is continued up to
the predetermined limit of its capacity.
2. The combination described in Claim 1 of two unequal springs F and F¹ of
which the weaker F is arrested by means of an intermediate piece or link such
as L which just before the limits of elasticity of such weaker spring are attained
comes to rest against a fixed stop thus arresting the elastic or spring action of
the said spring.
3. The combination described in Claim 1 of two unequal springs such as F F¹
whereof the stronger F is operated by means of an intermediate piece or link with
which just before the limits of elasticity of the weaker spring are attained engages
a driver secured to the frame.
Dated this 16th day of May 1801
W. P. THOMPSON & BOULT,
Agents for the Applicants.