US1372914A - Automatic valve for independent-rotation drills - Google Patents

Description

W A. SMITH. AUTOMATIC VALVE FOR INDEPENDENT ROTATION DRILLS.

APPLICATION FILED MAY II, I918.

Patented, Mar. 29, 1921.

mm m Q Q g INVENTOR.

B I, /v

/ ATTORNEYS.

STATES earner "WILLIAIE A. SMITH, F EASTON, EENNSYLVANIA, ASSIGNOR TO INGERSOLL-EAND COIMPANY, OF JERSEY CITY, NEVT JERSEY, A CORPORATION OF NEW JERSEY.

AUTOMATIC VALVE FOB INDEPENDENT-ROTATION DRILLS.

Application filed May 11, 1918.

To all whom it may concern:

Be it known that 1, WILLIAM A. SMITH, a citizen of the United States, residing at Easton, in the county of Northampton and State of Pennsylvania, have invented a certain new and useful Improvement in Automatic Valves for independent-Rotation Drills, of which the following is a specification.

This invention relates to fluid operated percussive tools and in particular to a fluid operated percussive drill having a fluid operated motor for rotating the drill steel or bit.

The objects of the present invention are to provide a fluid operated tool of the above type with means to automatically control and regulate the amount of fluid supplied to the drill bit rotating motor which will permit a relatively small amount of fluid to pass from the main supply chest of the tool to the rotating motor when the drill is operating idly and will permit a greatly increased amount of fluid to pass to the motor when the drill is operating under working conditions, and permit a proportionate amount of fluid to pass when the motor is operating under various conditions of load and speed. Furthermore, the means employed serve to prevent a waste of fluid when the drill is operating idly as for instance when the drill is flrst started or while the drill is being advanced to the work or withdrawn therefrom, the means provided for automatically controlling the supply of fluid to the rotating motor being independent of the means for supplying motive fluid to the percussive element.

With these and other objects in view the present invention consists in the features of construction and operation set forth in the following specification and illustrated in the accompanying drawings forming a part hereof, in which:

Figure 1 shows a longitudinal view of a percussive tool containing the present invention;

Fig. 2, a sectional view of the controlling valve for the rotating motor.

Fig. 3, a longitudinal view of the forward portion of a percussive drill shown in section; and

Fig. 1, a sectional view taken on the line 4-4 of Fig. 3.

Referring more particularly to the draw- Specification of Letters Patent.

Patented Mar. ea, rear.

Serial No. 233,978.

ings, 1 refers to the cylinder of a percussive tool provided with the present invention. Within the cylinder 1 reciprocates the piston 2 which at the forward end of its stroke strikes the drill bit 3 retained in place within a chuck 4 in the forward end of the cylinder 1. A rotating motor 5 which comprises a pair of spur gears operates through gears 6 a gear .7 provided on the chuck 4 to rotate the chuck 4 simultaneously with the reciprocations of the piston 2.

Fluid for operating the piston and rotating motor is supplied from a suitable source (not shown) the conduit or passage for supplying the fluid to the rotating motor 5 being shown at 8. Within this conduit 8 is located the valve forming the subject matter of the present invention. This valve comprises a sleeve 9 secured transversely in the cylinder 1 by means .of a threaded portion 10 and within the sleeve 9 is a hole 11 extending substantially throughout its length in which fits a valve 12. In the position of the valve as shown in Fig. 2 fluid passing through conduit 8 is allowed to leak past the outer head 13 of the valve .12 into a branch conduit 1 1 to the conduit 15 leading directly to the rotating motor 5. For this purpose the valve sleeve 9 is provided with slotted or. cut out portions 16. to permit the fluid mitted to pass through the sleeve 9 and past the valve 12 at all times, in order to insure that the pressure ahead of the motor will build up and be available to open the valve wider if the motor is stalled or retarded. The valve 12 is held in the position shown by means of a light spring 17 contained within the sleeve 9 and pressing against the outer head 13 of the valve 12. An additional inner valve head 18 is provided which balances the valve against endwise movement due to fluid pressure and for convenience the valve has short projections 19 at either end one of which serves to prevent the valve 12 from completely closing OK the passage through the valve and the other serves to make the valve symmetrical and reversible.

The valve 12 when there is no pressure in p 15 to the motor 5.

creased flow of fluid through conduit 15to rotate motor 5, which amount is dependent upon the pressure against thedrill bit and the speed of rotation of the drill bit.

The branch conduit 14 is extended to intercept and join the lower end of the sleeve 9 and valve 12 so that the pressure on the farther side of the valve 12 from the fluid supply will be always acting on the'end of the valve to press it upwardly and enlarge the opening through the valve 12 from conduit 8 to 15. The spring 17 is, however, just sufliciently strong to hold the valve 12 in the position shown when the pressure in the conduit 14 is very low and when pressure in conduit 14 increases above a given pressure the fluid pressure acting against the piston head 18 or in other words the back pressure in conduit 15'unbalances the valve 12 and forces it to move upwardly and open more widely the passage from conduit 8 to 14'.

In operation, when the drill is operating idlyithe motor 5 takes but very little fluid to operate it and after the motor comes iup to its maximum speed the motor will operate on a pressure insufficient to open the valve; that is, the pressure within the conduit 14 will be insuflicient to counteract the pressure .of the spring 17 7 As soon, however,.as'resistance is encountered in rotating the :drill" bit 3, pressure increases in the conduits 14 7V and 15 and a back pressure is exerted against the valve dependent upon the speed-of motor 5 and pressure on the drill bit 3 so that the pressure on the lower end of the inner head 18 is increased suflicientlyto force the valve to partially open and allow additional pressure to reach and operate the motor 5. When the resistance to the rotation of the drill bit 3 is withdrawn as when the drill is I being removed from the hole the back pressure against the valve 12 within'conduits 14 and'15 drops to a point sufiicient-to permit 1 the spring 17 to expand and partially close the valve again so that the rotation is continued by a very small expenditure of fluid.

It is to be understood that the present showing and description disclose only one SPQClilC embodiment of the present invention,

and that other forms and modifications are included within the spirit and scope thereof,

' as expressed in the appended claim;

7 a stemand inner and outer heads, the outer head controlling the port in the sleeve leading to the motor, and the inner head closing said sleeve and having a projection adapted to bear 'on the valve chest and normally maintain the valve open so as to permit a small quantity of fluid to flow past-the outer head to the motor and keep the motor running under light load, and insure that the pressure ahead of the motor will build up and beavailable to open the valve wider if the motor is stalled or retarded.

In testimony whereof, I havehereunto-set my hand. r

, wiLLii M'A. sMrrH Witness WM. C. MORRIS.-

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