SU27497A1 - Instrument for demonstrating the lengthening of the wire from heating - Google Patents

Description

By means of the proposed device, it is intended to give a quick and clear proof of the elongation from heating of metallic wires. Convenient to demonstrate this phenomenon in front of an audience.

In FIG. 1 is a side view of the instrument; FIG. 2 - view from above; FIG. 3 and 4 are two versions of the device.

On the wooden board 1 on the four small legs 2 there are three vertical double posts 3, 4. 5. On the rack 3 on the axis // the lever 6 is pumped, equipped with a small load 7. On the rack 5 on the axis 9 the lever 8 is pumped, ending with an arrow at one end, having at the other end a small weight JO. Both levers 6-8 are connected by hinges 13 and J4. Levers 6 to 8 pass between the pillars 4, and an arc / 5 with divisions, indicated by the arrow of the lever 8 when the device is operating, is reinforced to one of them. Between the uprights 3, in the upper part of them, the grooved pulley J6 rotates on axis 77. Through this pulley, a thin metal wire, J8, is attached to the lever 6 at point 20 and to the base of the device at point J9. The device’s operation is to

that the wire J8, heated at some place by a lit match or some other heat source, is lengthened, as a result of which the lever 6 is lowered and, through communication 72, lowers the lever 8, and the arrow slides along the dial and shows the effect of heat on the wire / 8 . All parts of the device can be made of wood (plywood) or, moreover, in the latter case it is necessary to place some non-conductive material in the fixing points of the J8 wire. The arms and P and their connection 72 should be light and immobile in the joints. The pulley J6, through which the wire 18 is slung, must be of non-conductive material and rotate easily on axis 17.

FIG. 3 and 4 depict two versions of the same device, in which one of them (Fig. 4) wire 8 is thrown over two blocks. The wire can also be transferred to heat by including its ends in an electric current circuit, taking measures to ensure that the wire anchorage points and the pulley through which it is thrown are insulated. The weights 7 to JO serve for some balancing of the levers and 8 relative to the axes of rotation with

subject to a small margin in the right direction. The subject matter of the invention.

Claims (2)

1. A device for demonstrating the extension of the wire from heating, characterized in that one end of the test wire 18 is attached to the fixed part in the case of a boron, and the other end, thrown over the block, is attached to the hinge lever 6 (Fig. 1), which is connected with the pointer. 2. An embodiment of the apparatus according to claim 1, wherein the test wire 18 is slung over two blocks (Fig. 4). 13 iO 8 4 48 fng 3 FIG 4 eight