US1086797A - Electrically-driven drill. - Google Patents

Description

W. P. TROTTER.

ELEGTRIOALLY DRIVEN DRILL.

APPLICATION FILED DBO. 31, 1907, 1 086 797; Patented Feb. 10, 1914.

2' SHEETS-SHEET 1.

Wit" eases \3 j Am) Cumin;

P. TRO-TTER. ELEGTRIGALLY DRIVEN DRILL.

APPLICATION FILED DEC. 31, 1907.

Patented Feb. 10, 1914.

2 SHEETS-BEBE?! 2.

UNITED STATES PATENT OFFICE.

WALTER F. TROTTER, 0F CHARLESTON, WEST: VIBGINIA,,AS SIGNOB TO THE JEFFREY MANUFACTURING COMPANY, A CORPORATION OF OHIO.

ELECTRIOALLY-DBIVEN DRILL.

Specification of Letters Patent.

Patented Feb. 10, 1914.

Application filed December 31, 1907. Serial No. 408,756.

tain new and useful Improvements in Electrically Dr.iven. Drills, of'which. the follow ing is a specification, reference being had therein to. the accompanying drawing.

This invention relates to electrically driven mining. machines and-more .especiallyto drills such as are used in .coal mines. for boring holes toreceive explosive charges and for other-purposes.

.The ob eet of this invention-sis to. provide; a drillof the-class specifiedhaving improved means ;of power transmission, improved means .of feeding and. such:;other improvements as-are evident from the following specification.

-In some mines explosive gases. are met with and serious explosionsv result if there be any exposed flame orisparks in the regionwhere Such. gases-collect. Asis. well known, the direct current motors commonly used. in driving drills ,frequentlycause sparks and flames of such nature that:ex.-- 'plosive gases of the kind found in these mines will be.fired. .I, therefore, preferto inclose all of the electrical parts of my drill in such a way that any. sparks which may form cannot be communicated to the external atmosphere.

In the accompanying drawingsin which is illustrated a practical embodiment of my improvements, Figure 1; is a perspective view of the drill and. its support. Fig. 2 is a vertical I longitudinal section through the drill, with the feed screw omitted. Fig. 3 is a rear end elevation of the drilL. Figs-4 and 5 are side and end elevations ofthe feed nut detached and shown onan enlarged scale.

I have shown my improved drill supported upon an adjustable frame A adapted to engage the floor and roof of the mine and rovide a firm support. The -motor B has its field frame 1, provided on either side with trunnions 2 whiclnare pivotally. supported in the sliding blocks o r..clamps A, which engage the channel side .bars. A of ;the.supporting frame. with thlsieone stru'ction the motor may swing. about; a. horizontal axis, may be raised or lowered and the. firame as a whole is, capable of swing ng bodily upon a vertical axis, thus providing a universally adjustable support for; the drill.

The field frame, 1 .carriesdhe oles 3-4, with the usual windings .at 3 The armature 5 mounted upon-a hollow shaft 6 which has supporting bearings at 7-8,

mounted=in endplates=9 and .10, of the mo, tor frame. Theseend plates-areboltedto the sides oredges-of'the field framein a manner to tightly inclose the field and armature. The plate 10 is formed withan extension oro -set 1.0. toreceive the'commutator- 21 and brushes 22 which are mounted upon insulating-blocks23 on the inner wall of the extension 140. .Into thefront end of theshaftis is threaded the pinion 11. This piniommeshes with .upperja-nd lowerxspur gears, 12 which arefastonshafts 13. These shafts, 13.- -have bearing supports at .13 in theend, plate .9, -and\at 13F. unthe plate 14 which ,forms one side .of a. earcasing 14, this gear casing being, .pre erably cast in one with the plate 9, as shown. Each of the'shaftsl3 carries a pinion. l5 and these pinions meslrwith the sg r gear 16 rigidly mountedon the .sleevel This sleeve has a. :long bearingsupport. in the extension 18 of. the .plateleifi; The drill.,screw 20 .is mounted inthe-hollow shaft 6 and the sleeve 17 and is adapted to be rotated by the ribs Omsplines, 1750f thesleevel'Z 'which sliding'lgv engage the grooves 20 .of the screw. At its front. end. the screw carries a drillbit as.2t and at its rear end I provide a handle 68. 1

.Thefeeding device is designated as an entirety by. 25. This feeding device is of the type shown and described in m pending application for apatent, filed eptem ber 7., 1906, Ser. No. 333,697. As my. present invention relates in part to-improvementsin feeding devices of this character, I will, therefore, describe in detail the feeding mechanism.

26 is. a shell bolted upon the shouldered end 18 of the extension 18 and having mounted upon its forward reduced end thrust collars 27 and ball cage 28 of the thrust bearing.

29 is-a. casing mounted upon the front of the shell 26 and having a cover 30 screwed into its front end. '6 The cover has a l inclosed that any flame due to sparking or laterally extending boss 3O which is bored out to receive the pin 31.

The feednut proper, 32, comprising the two semi-cylindrical sectionsis arranged in front of the cover 30 and is held rigidly in position by the casing 33.

This casing is made up ofv an upper part 34 and a lower part 35 which are formed with hollow bosses 34-35 to receive bosses 32 which project from the respective sections of the nut 32. Screw bolts 36 and 37 are threaded into the bosses 32 and assist in securing the feed nut and casing rigidly together. The upper and lower sections 34-35 of the casing are provided on one side with hinge lugs 34 and 35 which are pivotally mounted on the pin 31 carried by the bearing casing cover 30. On their opposite sides the casing sections 3435 are provided with clamping lugs, those at 34 on the upper section carrying the eye-bolt 38 which has its nut 39 in engagement with the lower side of the lugs 35 on the lower section of the casing. Each of these sections is formed at its rear end with an out-turned flange, which flanges abut the casing cover 30 and which are provided at one side with the fingers or lugs 3435 which are designed to embrace the cylindrical boss 30 carried by the cover 30.

It will be seen that with the construction provided, the feed nut together with its casing 33 is, so far as rotational movement is concerned, rigid with the casing 29-30 of the thrust bearing. To prevent the rotation of these parts the casing member 29 is grooved at 29 to receive a friction band 40, which is provided with clamping lugs 40 which carry a clamping bolt 41. On the side opposite the clamping bolt, the friction band is provided with a laterally projecting lug 40 designed to engage an abutment 42 which is bolted to the shell 26. It is clear that the clamping action of the band 40 may be varied by adjusting the tension on the bolt 41, so that the feed nut may be locked rigidly against rotation or may be permitted to have a slow rotation corresponding to the slippage between the friction band 40 and the casing 29.

At the commutator end of the armature shaft, I provide a collar 45 which is provided with internal splines 45* to engage the grooves of the drill screw and which is centrall supported by the casing shell 46 secure to the casing part 10*. This collar helps to properly support the drill screw and to prevent its coming in contact with the rapidly rotatin armature shaft 6.

I have already pointed out that the end plates 9 and 10 in connection with the field rame form a casing which tightly incloses the field, armature, commutator and brushes. In this way these parts are rendered flame proof, that is'to say, they are so thoroughly arcing within the casing can not pass to the outside of the casing to ignite any explosive gases that might be present in the surrounding atmosphere.

'47 designates as an entirety the combined starting box and connection box. That which I prefer and have shown in the drawings is similar to that shown and described in the pending application of Frank L. Sessions, filed February 18th, 1908, Ser. No. 416,546. This starting and connection box is entirely inclosed by the flame proof casing 48 and is attached to the motor frame by means of the screws 49.

57 represents the operating lever, by means of which the motor is started. As shown in Fig. 3, this operating lever is at the On position and is held in place by the spring catch 58. When this catch 58 is released, the operating lever 57 will move automatically to the Off position.

47 are plug openings adapted to receive the supply circuit terminals and are so constructed that the terminals may be inserted or removed without any sparks being communicated to the external atmosphere.

In the operation of my improved drill, its supporting frame A is first clamped in a suitable position between the floor and roof of the mine and the motor is adjusted to the desired height. Then by grasping the handle 68 on the rear end of the drill screw, the latter may be swung to the desired angle. The terminal sockets of the supply conductors are now inserted to engage the motor terminals and the starting handle moved to the On position. The rotation of the armature is transmitted through the reducing gearing consisting of the pinion 11, spur gears 12, pinions 15 and spur gear 16 to the sleeve 17, which in turn rotates the feed screw. If now the friction band 40 is tight enough to prevent rotation of the feed nut, the drill Wlll be fed forward in its rotation at the maximum rate. But if there is slippage between the friction band and the feed nut, the rate of feed will be roportionally diminished. Furthermore, if t e drill strikes exceptionally hard material slippage may occur at the friction band and thus breakage of some of the parts which might otherwise occur is obviated.

If explosive gases are present in the mine in which the machine is being used there is little or no danger of exploslons occurring by reason of the flame proof construction which has been setforth.

What I claim is:

1. In an electric-coal and rock drill, the combination of the motor housing, the motor shaft, detachable end walls for the housing, one of the said end walls being formed inwardly at its center to provide a tubular support for the motor shaft bearing, the

outer edges of the said end wall flanged outwardly in the form of a casing, the cover for the casing separable on lines parallel to a the axis of the shaft, the tubular extension formed at the center of the said cover, the drill shaft journaled in'the said tubular extension, and the drill feeding devices secured on the outer end of the said tubular extension.

2. In an electric coal and rock drill, the combination of the motor housing, the motor shaft,detachable end walls for the housing, one of the said end walls bein formed inwardly at its center to provi e a tubular support for the motor shaft bearings, the outer edges of said end wall flanged outward to provide a gear casing, the drill shaft and ears intermediate the motor shaft and drill s iaft and contained entirely within the said casing.

3. In an electric coal or rock drill, the combination of the motor shaft, the motor housing, the detachable end walls of the said housing, one of the said end walls being formed inwardly at its center to provide a motor shaft bearing support, the outer edges of the said end wall flanged outwardly in the form of a casing, the cover for the casing separable on lines arallel to the axis of the shaft, the drill sha t journaled in the said casing cover, and the intermediate gearshaft, the, cover for the casing ing contained within the casing, the said gearing transmitting 1power from the motor shaft to the drill sha v 4. In an electric coal or rock drill, the combination of the motor shaft, the field frame, the end walls detachably secured to the field frame and inclosing the motor, one of the said end walls formed inwardly at its center to provide a support for the motor shaft bearing, the outer edges of the said end wall formed outwardly away from the.

the said intermediate gearin shafts.

In testimon whereof I afiix my signature, in presence 0 two witnesses.

WALTER F. TROTTER.

Witnesses:

J N0. 0. Ecxnnr, J. J. SULLIVAN.

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