US123624A - Improvement in tape-measures - Google Patents

Description

lOH N A. EVARTS.

Improvement in Tape Measures.

No`.123,624. v Patemedreb.1a,1a72.

UNITEE STATES PATENT OFFICE.

JOHN A. EVARTS, OF WEST MERIDEN, CONNECTICUT, ASSIGNOR TO BRAD- LEY 8U HUBBARD, OF SAME PLACE IMPROVEMENT IN TAPE-MEASURES.

` Specification forming part of Letters Patent No. 123,624, dated February 13, 1872.

To all whom il 'may concern:

Be it known that I, JOHN A. EVARTS, of West Meriden, in the county of New Haven and State of Connecticut, have inventeda new Improvement in TapeMeasures 5 andIdo hereby declare the following, when taken in connection with the accompanying drawing and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawing constitutes part of this specification, and represents, in

Figure l, a side view; Fig. 2, an interior view, in position for arresting the return of the tape; and in Fig. 3, the reverse position.

This invention relates to an improvement in that class of tape-measures in which the tape is wound upon a barrel within the case by mea-ns of the reaction of a spring. An essential feature in this class of tape-measures consists in providing a device to arrest the return ofthe tape at any desired point after it has been withdrawn from the case. Various devices for this purpose have been resorted to; but in all cases some communication has been required from the outside of the case to the 'mechanism on the-inside, this-outside mechanism to be operated by the thumb and finger of the person holding the case. The object of this invention is to dispense with all projections upon the outside ofthe case, or communica-tion with the mechanism upon the inside;

and the invention consists in the arrangement of a pawl or its equivalent, in combination with the barrel, so that in one position the pawl will fall by its own gravity to engage the notches which prevent the returning of the barrel, and when this position is reversed the gravitation of the pawl will remove it from the notch and permit the barrel to return.

A is the case of a tape-measure, of any known form, within which the barrel B is arranged, with its spring, to revolve freely upon bearings in the center, and C, the tape running out through an opening, D, in the case, in the usual manner. P is a pawl, pivoted at a to one side of the case. In Figs. 2 and 3 this pawl is represented in its position when the case is closed, and it will be evident that it is to be pivoted to the side ofthe case, which is here removed for the purpose of illustration. This pawl is free upon its pivot, so that by its own weight it will swing freely; therefore in the position seen in Fig. 2, as the tape is drawn out, the pawl will engage with each successive notch on the barrel, and arrest the return of the tape whenever the strain upon the tape is relaxed, in substantially the same manner as in tape-measures of common construction. When desired that the tape should return, invert the case, as inl Fig. 3, or turn it so far that the weight of the pawl will tend to throw it from the notches. In such position, as seen in Fig. 3, the pawl falls away from the notches, leaving the barrel free to revolve. Thus, instead of requiring some sliding device,

4 pressure, or other mechanism, the pawl is actuated by its own gravity. No springs are required, the vexterior of the case is perfectly smooth or free from projecting mechanism, and it is practically impossible that this device should get out of order.

It will be observed that while the pawl is engaged with one of the notches, as seen in Fig. 2, the pressure of the barrel-spring is suficient to hold the pawl engaged 5 hence, while in that position it matters not how the case is held, the tape will not return until the tape is drawn slightly to disengage the pawl from the notch.

While I have described this pawl as being pivoted at one end and swinging free at the other, it will be evident that many other known arrangements may be employed which are substantially equivalent to this pawl; as, for instance, a slide moving freely, and others which it is needless here to mention. Y

V Claim. In a tape-measure in which the tape is drawn into the case by a spring within, I claim the e

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