The balance should preferably be of the type shown in Fig. 162, having an
indicator projecting at right angles to the scale through a slot, as this
can be very easily fitted with a sliding index, I, in the form of a
1/4-inch strip of tin bent over at the ends to embrace the edges of the
balance.
CONSTRUCTION.
[Illustration: FIG. 162.--Plan of strength tester.]
[Illustration: FIG. 163.--Grips of strength tester.]
As the pressures on the machine are high, the construction must be solid
throughout. The lever frame, A, and pivot piece, C, should be of one-inch
oak, and the two last be screwed very securely to the baseboard. The shape
of A is shown in Fig. 163. The inside is cut out with a pad saw, a square
notch being formed at the back for the lever to move in. The handles of an
old rubber chest expander come in useful for the grips. One grip, D, is
used entire for attachment to the lever; while of the other only the wooden
part is required, to be mounted on a 1/4-inch steel bar running through the
arms of A near the ends of the horns. If a handle of this kind is not
available for D, one may substitute for it a piece of metal tubing of not
less than 1/2-inch diameter, or a 3/4-inch wooden rod, attached to an eye
on the lever by a wire passing through its centre.
Pages:
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284