US142005A - Improvement in pendulum-levels - Google Patents

Description

A. C. L. DELSARTE. Pendlum Levels. N0. 142,005, V PatehtedAugustl9vJ873.

ADRIEN CHARLES LOUIS DELSABTE, OF PARIS, FRANCE.

IMPROVEM'ENT IN `PENDULUMLEVELS.

Specification forming part oi Letters Patent No. 142,005, dated August 19, 1873 vapplication,filed August 31, 1872.

To all whom it may concern:

Be it known that I, ADRIEN CHARLES Louis DELSARTE, of Paris, in the Republic ofFrance, have invented certain Improvements in Pendulum-Levels, of which the following is a speciiication: s

In the hitherto-known pendulum-levels the index or hand for indicating on a dial-plate or graduated limb the variations in level forms an immediate part of the pendulum -'rod, in consequence of which, if a short rod be made use of, the indications on the limb do not with a rod of comparatively very small length,

which, consequently, permits of reducing the levelto a very small compass. For this purpose I interpose between the pendulum-rod and theindex a pinion and wheel; or, if wished, two or more sets of such gearing, by which means the sensibility of the level may, consequently, be increased to any required extent, though the pendulum-rod be'of a comparatively very small length; and I further make use, in combination with the said gearing, of an arrangement for causing the indentations or teeth of4 the gearing to constantly fully engage into each other, and by thus exerting their full eifect insure the accuracy of the indications of the indexr v In the annexed drawing, Figure l shows a full size front elevation view of my improved pendulum-level; Whereas the Figs. 2 and 3 represent, on a scale double that of Fig. I, respectively, a side and a back elevation view of the mechanical parts of the level, the dialplate and the pinion being in Fig. 2 represented as partly cut away and some vother parts shown in vertical section, while lin Fig. 3 only part of the teeth of the wheel which drives the pinion are represented.

In these three figures the same letters refer to corresponding parts.

The dial-plate A, and mechanical parts connected thereto, are xcd in a frame, (l, the four sides c1 c2 o3 c4 of which require to be situated exactly at right angle to each other, and those, c1 and c3, at right angle with the zero of the dialplate. The spindle or axis m of the hand or index B carries a pinion, i, of such length as to allow the two toothed spur-wheels D and D of acting simultaneously on the indentations of the said pinion, these wheels D and D being situated parallel to each other on the same spindle a, and of exactly the same size and indentations,the number of teeth of these wheels and of the pinion depending on the speed to be given to the index B. The pivoted ends of the spindles m and n turn in the dial-plate A and in a potance or bridge, Gr. The wheel D is iixed, and the other, D', tted loose, on the spindle n, and this latter wheel, D, is provided with ay counterweight, d', by the effect of which the wheel D will constantly exert a kind of leverage on the pinion r, and cause the tooth of this latter, which, at the time being, is in gear with one of the teeth of the wheel D, to be acted upon to the full extent of its power by the said tooth of the wheel D, by which means Vthe accuracy of the indications of the index B will be insured. The pendulum-rod j' is very short, and provided at its lower end with a comparatively very heavy bob or weight, F, whereas at its upper end the said rod is fixed to a forked piece, H, which may swing freely on a pin, t',

inserted in the hub or socket J, by which the Y wheel D is fixed t0 the spindle a.

In small instruments in which gearing is made use of if the teeth are not mathematically true-t'. e., if their curved ends are not perfectly epicycloidal-which in practice, and

particularly in cheap-instruments, is seldom Y the case, there always exists a twofold action` the index carried by the pinion is comparatively long. In this invention the counterweighted loose Wheel D forces the tooth of the pinion, which for the time being is engaged with the wheel, to come and remain in contact with the corresponding tooth of the driving-Wheel, Whatever may be the shape of the curved part of the teeth.

The counterweighted loose Wheel is found preferable to a hair-spring, because a spring will make a series of extensions and contractions before actually coming to rest.

The manner of making use of my improved pendulum-level is exactly the same as for other instruments of the same class, any de- Witnesses:

ABRAHAM GERARD BRADE, JEAN BAPTISTE STIRNLING.

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