US2208098A - Rotation mechanism for rock drills - Google Patents

Description

N A M F F U H C. M.

ROTATION MECHANISM FOR ROCK DRILLS Filed Aug. 17, 1939 \Q\\ III \H Q N D Ii Q m. @am v Y N\ L -Y Q .NM NN m. ,g rf. E

INWNTOR. 19K/T75 A TTORNE'Y Patented July 16, 1940 PATENT OFFICE RorA'rioN MEcHANrsM Fon ROCK DRILLs Mervin C. Human, Denver, Colo., assignor to Gardner-Denver Company, Quincy, Ill., a cor'- poration of Delaware Application August 17,

6 Claims.

My invention relates to improvements in rock drills and is more particularly directed to means for rotating the drill steel.

The principal object of the invention is to provide a rotation means for the drill steel which is operated upon the reciprocation of the piston hammer in one direction of its travel.

Another object of the invention is to provide a rotation mechanism whereby rotation of the steel ceases when the force necessary to rotate the steel exceeds a certain limit.

Still another object of the invention is to provide a rotation mechanism which will become inactive if the resistance to the rotation of the piston becomes abnormal.

Further objects of the invention will herein* after appear, and to all of these ends the invention consists of the features of construction, arrangement of parts, and combination of elements, substantially as hereinafter fully described and claimed in the specification and shown in the accompanying drawing, in which:

Figure 1 is a longitudinal sectional view showing what is known as a drifter drill with the improved rotation mechanism associated therewith. Y

Figure 211s an enlarged sectional view of the ring and ratchet head on the line 2-2 of Figure 1, and

Figure 3 is an enlarged in detail the ratchet ring. 1

Briefly the invention about to be described relates to a rotation mechanism for rock drills and is more particularly adapted to such a means used in connection with a drifting drill.

Ordinarily when operating a drifting drill, the operation of the drill is determined by the amount of penetration of the steel. In other words, there is a possibility during the penetration of the steel for the steel to stick, causing the hammering action of the drill to stop. This result is objectionable in that it requires the 4closing of the operating fluid valve, the movement of the drill backwardly and a resumption of the drilling operation. With the present improvement the reciprocating hammer serving to impart blows to the drill steel continues in its' operation even though rotation is not imparted to the drill steel. With such a mechanism it has been found that continued operation of the piston hammer serves in some instances to free the steel, permitting its ultimate rotation through the mechanism of the hammer. Broadly the invention relates to what is known as a slip rotation means for rock drills and is of such a sectional view showing character that when the load on the steel exceeds a certain limit, rotation of the steel is inactive.

Referring to the drawing in detail the numeral I indicates a drilling motor of the drifter type, having suitable means for mounting it upon a conventional guide shell indicated at 2. 'I'he motor I is composed ofa cylinder 3 within which is a reciprocating hammer 4. As is customary in a structure of this type, the piston 4 strikes the end of a drill steel 5 during its reciprocation, the steel being supported in a chuck end carried by a drilling motor.

The rear end of the cylinder 3 is provided with a valve chest Ii having therein a sleeve valve 1 supported by a valve plug 8 through which passes the conventional rifle bar 9 having at its rear end a ratchet head IIl provided with spring pressed pawls II which are engageable with a ratchet ring I2. The rear end of the cylinder 3 is closed by a backhead I3 provided with suitable connections for both water and air and a throttle valve for controlling the flow of air t0 the sleeve valve 1. The backhead, cylinder and chuck end are maintained in alignment by suitable side rods, not shown, which carry the usual cushioning springs, permitting a slight movement of the parts mentioned above with relation to each other. l

l As disclosed in Figure 1, the ratchetring Vis composed of two sections, the adjacent faces of which are provided with a number of sockets I 4 which receive therein the ends of expansion springs I5. The purpose of the springs being to hold the sections of the ring apart.

With the structure shown in Figure l, it will be observed that the chamber for the ratchet ring is formed by the outer face of the valve plug and the inner face of the backhead and the sections of the ring are forced outwardly against these faces when the ring occupies the space shown.

The inner surface of each section of the ring is provided with ratchet teeth I6 as shown in Figure 2 and engageable with these teeth are the pawls II carried by the ratchet head I0. I

During the operation of the drill, it will be obvious that when fluid is admitted to the sleeve valve 1, movement of the valve controls reciprocation of the hammer 4 and with the type of rotation disclosed as the hammer moves downwardly over the rifle bar 9 and by reason of the spring pressed pawls engaging the sections of the ring I2, the rie bar is free to rotate, permitting a direct outward movement of the hammer to contact the steel. When the valve 'l is shifted to cause the return of the piston 4, the pawls Il engage the ratchet ring, holding the rifle bar 9 stationary, rotating the piston 4 during its backward movement thus imparting rotation to the drill steel through the conventional chuck engageable by both the hammer and steel.

It frequently happens in operation of a drill of this type, that the strain imparted to the steel is greater than that of the rotation mechanism, the result being that the drill stops in operation. To prevent this and at the same time permit the continued engagement of thereciprocating hammer Withthe steel, the ratchet ring is formed of two sections held apart by springs, permitting slippage of the ratchet ring within its chamber, thus rendering inactive the rotation of the piston hammer and ultimately the steel.

With the invention just described, it is obvious that Ithe ratchet ring is frictionally held in place and this friction may be regulated by the tension of the expansion springs l5 together with tension exerted upon the side rods.

From the foregoing, it is thought that the construction, operation and many advantages of the herein described invention will be apparent to those skilled in the art without further description, and it will be understood -that various changes in the size, shape, proportion and minor details of construction may be resorted to without departing from the spirit or sacri'cing any of the advantages of the invention.

What I claim is:

1. In a uid operated tool, the combination of a cylinder member and a closure at its rear end forming a chamber therebetween, of a reciprocatory piston in the chamber, a riie bar engageable with the piston and having a head in the chamber, a ratchet ring in 'the chamber snrrounding the rifle bar head and having a ratcheting connection therewith, and resilient means carried by the ring for frictionally holding the same against movement during normal operation of the drill.

2. In a iiuid operated tool, the combination of a cylinder member and a closure at its rear end forming a chamber therebetween, of a reciprocatory piston in Ithe chamber, a rifle bar engageable with the piston and having a head'in the chamber, a ratchet ring in the chamber surrounding the rifle bar head and having a ratcheting connection therewith permitting rotation of the hammer during one of its movements, said ratchet ring carrying resilient means for holding it against movement during normal operation of the drill, and said resilient means permitting rotation of the ratchet ring during abnormal operations of the drill.

3. In a fluid operated tool, the combination of a cylinder member and a steel retaining chuck connected theretopa closure for the rear end of the cylinder forming a chamber between the two, a reciprocatory piston in the chamber, ratchet means actuated by the pistonfor imparting rotation to the chuck, said ratchet means including a ring frictionally held during the normal operation of the drill, said ring being formed of two like parts separated by resilient means, and said resilient means permitting the movement of the ring. as a whole during the abnormal operation ofv the drill.

4. In a fluid operated tool, the combination of a cylinder and a steel retaining chuck carried thereby, a backhead closing the rear end of the cylinder and forming the chamber therebetween, a reciprocatory piston in the cylinder serving to impart rotation -to the chuck, a ratchet means in the chamber `engageable with the piston for rctating the same during certain of its movements, said rotating means including a two .part ring positioned within the chamber, and means serving to separate the two parts of vthe ring holding the same against movement during normal operation of the drill and permitting movement of the ring during abnormal periods of operation.

5. A rock drill 'comprising a cylinderr having a piston chamber, a piston reciprocable in said chamber, rotation mechanism for rotating the piston including a riiie bar having a head, a ratchet ring surrounding the rifle bar head and rotatable within a chamber formed within the drill, said ratchet ring being composed of two parts, and means positioned between the parts normal operation of the `drill and permitting their movement toward each other during abnormal operation of the drill.

MERVIN C. HUFFMAN.

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