US42560A - Improvement in ratchet-drills - Google Patents

Description

MT1-3D STATES PATENT' Erice;

|MPaovEMENT IN aATcHET-DRILLS.

Specification forming part of LettersPatent No. l12,560, dated May 3, 1864.

To all whom it may concern:

Be it known that I, J oHN C. CHAPMAN, of Charlestown, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Ratchet- Drills, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, making part of this specification, in which- Figure 1 is a perspective View of my improved hand-drill. Fig. 2 is a vertical longitudinal section through the same.

In operating ratchet hand-drills as at present constructed a considerable loss of time and great inconvenience is occasioned in feeding, especially in confined or narrow places, as the workman is obliged at frequent intervals to insert the end of a small rod into one of the holes at the top of the feeding-shaft to turn it va little for each feed, it being impracticable to attach a wheel or other projecting device to this shaft on account of the confined positions in which these drills are generally employed, and these drills are also liable to become unsteady when the feedingshaft is nearly screwed out to its full extent.

My invention has for its; object to avoid these difficulties, and to produce a self-feeding drill that shall be more steady and durable than those now in use; and it consists in causing' the feeding-shaft (which is hollow and works on a screw projecting up from the drill-socket) to slide with a spline and feather in a hollow sleeve, to the lower end of whichV is attached a ratchet-wheel, operated by a pawl attached to the hand-lever which operates the drill, by which arrangement of parts, as the drill is operated, the hollow sleeve is rotated independently of the drill, carrying with it (by means of the spline and feather) the feedingshaft, which is thus raised on the screw-shaft to effect the feed as frequired. Theghollow sleeve, in combination with the screw-shaft, also serves as a support for the feeding-shaft, by which the drill is rendered more steady and durable than any now in use with which I am acquainted.

To enable others skilled in the art to understand and use my invention, I will proceed to describe the manner in which I have carried it out.

In the said drawings, A is the hand-lever,

which is enlarged at one end, so as to encircle the standing part or drill-socket, B, to which is attached a ratchet-wheel, C, with which engages a spring pawl, a, attached to the lever, bywhich means thedrill is rotated as the handle is vibrated, in a well-known manner.

D is a hollow sleeve, which iits over and incloses a screw-shaft, E, projecting up from the drill-socket B, the interior of the sleeve being of such a diameter at the bottom as to tit the lower end of the shaft E, where it is secured in place and prevented from being raised by a screw-nut, b, which works in the shaft E, and when in place rests on the shoulder c on the interior surface of the sleeve D, as seen in Fig. 2. A left-hand screw-thread is cut on the shaft E, on which works the hollow feeding-shaft G. This shaft is provided at its upper end with a steel point, 3, in the customary manner, and is made to exactly fit the interior diameter of the sleeve D, in which it slides with a spline and feather, e, on each side, as seen in Fig. 2, which prevents the feeding-shaft and holl w sleeve from being turned independently of each other, and the'v dust and chips are also eifectually excluded from the working parts.

To the lower end of the hollow sleeve D is attached a ratchet-wheel, H, the neck of which projects into the hollow sleeve D, where it -is secured by a pin or screw, 4, forming a shoulder, as before described, this wheel being operated by a spring-pawl,f, on the handle A. The wheel H is furnished with nearly twice the number of teeth that are on the wheel C, but the'number may be varied according to the amount of feed required. It will thus be seen that on the commencement of the vibration of the handle A in the direction of the arrow 5 the ratchet-wheel H, and with it the hollow sleeve D, will be carried forward by the pawl fa short distance before the pawl a commences to move the ratchet-wheel IC and and drill, thus revolving the feeding shaft G by means of .the spline and feather e, which causes it to rise on the screw shaft IIE, and effect the feed as required.

If a different feed is required, the ratchetwheel H may be taken off and replaced by one having a different number of teeth. In some cases, as when the hole is nearly bored through, the pawl fmay be disengaged from the wheel H and the sleeve D revolved by hand, or the feeding-shaft may be turned by a rod inserted into a hole in its upper end in the ordinary manner. r

It will be seen that the hollow sleeve D, in connection with the screw E, serves as a support for and steadies the feeding-shaft G when screwed nearly out, thus rendering the drill stift' and preventing it from shaking, which is a serious objection to those now in use, and also increasing its durability.

If desired, the ratchet-Wheel H may be dispensed with and the feeding effected by turning the sleeve D by hand, and the advantages of steadiness and durability above described still be retained, in which case it would be preferable to have a right-hand thread cut upon the shaft E, as it would be then4 more convenient-to turn the sleeve to the left.

A right-hand threadon the shaft Ev might also be employed with the ratchet-Wheel H but in that case the drill would be left-handed What I claim as my invention, and desire t secure by Letters Patent, is

1. A self-feeding ratchetdrill, in which th feedingashaft G is thrust out from an eXterio sleeve, D, by revolving the sleeve by a ratche and pawl operated by the hand-lever A, sub stantially as set forth.

2. The hollow sleeve D and feeding-shaf G, sliding therein with a spline and feathe in combination with the screw-shaft E, ope ating in the manner-'and for the purpose su stantially asdescribed. v J. C. CHAPMAN.' Witnesses:

P. E. TEsCHEMAoI-IER, N. W. STEARNS.

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