DE34562C

DE34562C - Apparatus for illustrating the doctrine of the balance of forces

Info

Publication number: DE34562C
Application number: DENDAT34562D
Authority: DE
Original assignee: Firma LlSSER & BENECKE in Berlin S., Inselstrafse 6
Anticipated expiration: 1905-05-14

Description

KAISERLICHESIMPERIAL

PATENTAMT.PATENT OFFICE.

PATENTSCHRIFTPATENT LETTERING

KLASSE 42: Instrumente.CLASS 42: Instruments.

Patentirf im Deutschen Reiche vom 14. Mai 1885 ab.Patent granted in the German Empire on May 14, 1885.

Dem Physikunterricht fehlt es an einem handlichen Apparat zum Veranschaulichen der verschiedenen Fälle, die den Gesetzen vom Gleichgewicht der Kräfte unterworfen sind.Physics classes lack a handy device to illustrate the various cases subject to the laws of balance of forces.

Die zur Veranschaulichung einzelner Fälle bekannten Apparate basiren darauf, dafs Gewichte gegen Gewichte zur- Wirkung gebracht werden und dabei Zwischenmechanismen, namentlich feste Rollen nöthig sind, welche die Anschaulichkeit des Darzustellenden stören und auch direct durch Reibung, die nicht gehörig in Rechnung gezogen werden kann, das Ergebnifs des Versuches beeinträchtigen. Die Gegenlastgewichte müssen schon vor dem Versuch mit Hülfe der Gleichgewichtsgesetze berechnet werden, während doch letztere erst selbst Ergebnifs des Versuches sein sollen; man kann die stützenden Kräfte nicht bis zum Eintritt der gewünschten Erscheinung vor den Augen der Schüler deutlich wahrnehmbar allmälig steigen oder sinken lassen.The apparatuses known for the illustration of individual cases are based on the fact that weights be brought into effect against weights and thereby intermediate mechanisms, In particular, fixed roles are necessary, which disturb the clarity of what is to be represented and also directly through friction, which cannot be properly taken into account, affect the result of the experiment. The counter load weights have to be carried out before the Experiment can be calculated with the help of the equilibrium laws, while the latter only should themselves be the result of the experiment; one cannot use the supporting forces until entry the desired appearance before the eyes of the pupil clearly perceptible gradually rise or fall.

Bei dem vorliegenden Apparat dagegen sind statt der Gewichte Federspannungen benutzt, und zwar die Spannungen von langen· D-rahtschraubenfedern, deren Belastungen als ihren Längen proportional ohne Weiteres aus diesen Längen mit' den Augen und durch Messen wahrgenommen werden können, und bei denen Spannungsänderungen, durch Beobachten der Mafsänderungen festgestellt, und gesehen werden können.In the present apparatus, on the other hand, spring tensions are used instead of weights, namely the tensions of long D-wire coil springs, their loads as proportional to their lengths easily from these lengths with the eyes and by measuring can be perceived, and in which voltage changes, by observing the Changes in dimensions can be detected and seen.

Das Neue und Wesentliche des Apparates gegenüber der Anordnung an den bekannten Federwaagen besteht darin, dafs das Belastungsende der angewendeten Schraubenfeder festgestellt und das Au'fhängeende der Feder an einer Mefsschiene verrückbar gemacht Worden ist.The novelty and essential of the apparatus compared to the arrangement on the known Spring balance consists in the fact that the end of the load on the applied helical spring is determined and the suspension end of the spring on a Mefsschiene has been made displaceable.

Zum Apparat sind zwei oder mehrere mit Theilung versehene Lineale in zweierlei Weise verbunden. Entweder sind diese Lineale senkrecht parallel neben einander gestellt, Fig. i, oder sie sind wie die Schenkel eines Zirkels mit "je einem Ende auf einem horizontalen Zapfen drehbar oben an einer senkrecht stehenden Stativsäule befestigt, Fig. 2. Von jedem Lineal steht im Nullpunkt der Theilung ein fester Stift c ab, "der direct auf dem Lineal öder auf einem seitlich vom Lineal abstehenden Arm e befestigt sein kann, Fig. I bis 3. Prismatisch geführt, längs auf -jedem Lineal verschiebbar.und an allen Orten der Theilung feststellbar ist ein zweiter Arm h vorhanden, an dem das Mefsfeder-Aufhängeende befestigt wird. Als Mefsfeder dienen' lange, aus dünnem Draht eng- gewundene Schraubenfedern, die an dem unteren, dem Belastungsende,, je in einen Ring r verlaufen, durch welchen der feste Stift c im Nullpunkt der Linealtheilung hindurchgehen mufs. .Two or more graduated rulers are connected in two ways to the apparatus. Either these rulers are placed vertically parallel next to each other, Fig. I, or they are like the legs of a compass with "one end rotatably attached to a horizontal peg at the top of a vertical stand column, Fig. 2. Each ruler is at the zero point A fixed pin c abuts the division, "which can be attached directly to the ruler or on an arm e protruding laterally from the ruler, Fig. I to 3. Prismatically guided, displaceable lengthways on every ruler, and fixable at all locations of the division there is a second arm h to which the Mefsfeder suspension end is attached. Long helical springs, tightly wound from thin wire, serve as the Mefsfeder, each running into a ring r at the lower end of the load, through which the fixed pin c must pass at the zero point of the ruler division. .

Zum einfachen directen Abwägen einer Last wird zunächst vor Belastung der Feder der Aufhängearm k,. Fig. 2, auf .dem einen senkrecht hoch gestellten Lineal so hoch geschoben, dafs der Nullpunktstift c genau in den Mittelpunkt des Federendenringes r steht, der Ring also um diesen Stift schwebt. Man liest auf der Scala den Theilstrich ab, an dem der Aufhängearm steht, merkt sich' diesen Theilstrich und belastet nun die Feder durch Anhängen der Last an den Ring r. Letzterer wird dabei auf den Nullpunktstift sich auf-For the simple direct weighing of a load, the suspension arm k ,. Fig. 2, pushed so high on .dem a vertically raised ruler that the zero point pin c is exactly in the center of the spring end ring r, so the ring floats around this pin. One reads off the division on the scale on which the suspension arm stands, notes this division and now loads the spring by hanging the load on the ring r. The latter will focus on the zero point pin.

Claims

egen and transfer the load to this pin until the helical spring is tensed more and more by lifting the suspension arm h and finally its tension up to. has brought the size of the suspended load. One recognizes the equalization of the truck train downwards by the "upward pulling spring tension" by the fact that the ring r floats again around the pin c and this zero point pin is exactly in the middle of the ring The new position of the suspension arm, now to be read off, corresponds to the weight of the load to be measured.

This use of the spring balance with a floating but locally fixed load point can be used in many ways Use the equilibrium of forces theorems once you are in in the manner already mentioned, here indicated by the drawing, two or more the mentioned spring balances next to and with each other in use.

Fig. Ι illustrates this for the case in which a bar supports at its ends or, like here, is suspended and its load acts on moment arms of unequal length.

Before the beam was loaded, the end rings of both springs were brought into suspension in such a way that the zero point pins c and c ^{1 came} into the center points of the rings. As a result, the dead weight of the beam is expediently switched off for the following experiment; the same can no longer affect the result of the experiment. After loading the beam, the suspension arms h, and h 'are pulled up until the hovering of the rings r and r ¹ and the zero point pins play into the ring centers.' The different high positions of the suspension arms, which are entered, easily illustrate the effects of the differently large load moments; the spring tensions to be read correspond to im. In relation to each other the moment arm is in relation to the beam.

The apparatus with the compass-like arrangement of the spring balance rulers serves to illustrate the effect of forces in the force parallelogram. Fig. 4 makes this readily clear. On a partial circular disk I behind the rulers (Fig. 2 and 3) the angles set with the rulers can be read off, and these angles correspond to the spring tensions which can be read off after the ring has been correctly adjusted. Conversely, however, after previously determined spring tensions, the corresponding angles can be searched for by rotating the rulers around their fastening pins.

In the present case, the zero point for the scale is in the axis of rotation of the Rulers are laid and the feathers are drawn along the edges of the rulers that are inside the compass tense. These ruler edges run towards the pivot point as radii.

■ Fig. FIG. 2 also shows as an example how one can use a spring balance to illustrate the relationship between a fixed roller and the generation of force. A fixed roll b is placed on the joint pin of the rulers, which is extended outwards. The spring and the load direction -tangireh the role. In the one case these two directions coincide with one another, in the other case, shown in dotted lines, they form an angle with one another through the mediation of role b. In both cases, the spring tension can be recognized as exactly the same.

. If one spring is not sufficient for greater tension, two springs are used next to each other. Fig. 5, and if one wants their sensitivity to be the same as for the simple feather, if you keep two more feathers lengthways, Fig. 6.

PATENτ-Α ν saying:

An apparatus for making the theory of equilibrium clear, consisting of two or more rulers provided with graduation, on each of which a prismatically guided spring suspension arm can be shifted and clamped, which on the one hand carries a wire helical spring with an end ring, which surrounds a fixed pin c at the zero point of the graduation, whereby the rulers can either be a) parallel to each other or b) can be rotated like a compass at an angle to each other.

For this purpose ι sheet of drawings.