US1740689A - Drilling mechanism - Google Patents

Description

haven/Z071' E. G. vGARTIN DRILLING MECHANISM Filed Sept. 27, 1926 Dec. 24, l 92 9.

Patented Dec. 24, 1929 nire STATES EL'MER G. GARTIN, OF CLAREMONT, NEW HAMPSHIRE, ASSIGNOR TO SULLVAN MA- CHINERY COMPANY, A CORPORATION OF MASSACHUSETTS DRILLIN G MECHANISM Application filed September 27, 1926.

This invention relates to drilling mechanisms and more particularly but not exclusively to rock drills of the hammer type.

An object of this invention is to provide an improved controlling mechanism for hammer rock drills. Another object is to provide improved fiuid distributionv means for the motor of the rock drill. It is also an object to provide an improved automatic fluid distribution valve arranged within the throttle valve for controlling a hammer rock drill. A still further object of this invention is to provide improved hole cleansing means associated with the improved controlling mechanism. These and other objects of this invention will, however, hereinafter more fully appear.

ln the accompanying drawing I have shown for purposes of illustration one embodiment which this invention may assume in practice. ,t

1n this drawing,

Fig. 1 is a central longitudinally extending sectional view through a hammer rock drill in which my improved controlling mechanism is incorporated.

Fig. 2 is a fragmentary view simllar to Fig. 1 illustrating the hammer piston and distribution valve in a different position.

Fig. 3 is a transverse horizontal sectional view taken on line 3 3 of Fig. 1, the throttle valve being shown in open position.

Fig. 4 is a detail view illustrating the fluid y distribution valve.

Fig. 5 is a detail transverse horizontal sectional view taken on line 5 5 of Fig. 1 illustrating one of the valve throwing passages.

Fig. 6 is a detail Sectional view showing t-he throttle valve in closed position, the view being fragmentary and taken in the plane of section line 3 3.

Fig. 7 is a detail transverse horizontal sectional view taken on line 7 7 of Fig. 1 illustrating one of the motor supply passages, the

throttle valve being shown in open and closed positions.

Fig. 8 is a detail transverse horizontal sectional view taken on line 8 8 of Fig. 1 illustrating one of the motor exhaust passages,

Serial No. 138,088.

the throttle valve being shown in open and closed positions.

In the illustrative embodiment of the invention there is shown a rock drilling motor of the hammer type comprising a cylinder 1 having a bore 2 in which a hammer piston 3 is reciprocably mounted. As shown disposed at the forward end of the cylinder 1 is a buffer ring or cylinder head 4, the latter being clamped between the forward end of the cylinder and a chuck housing 5. The rear end of the bore 2 of the cylinder is closed by a suitable back head 6. As is usual in rock drills the back head 6, the cylinder 1, the front head 4, and the chuck housing 5 are maintained in assembled relation by means of side rods 7 (see Fig. 3). The piston 3 is provided with a forwardly projecting striking bar 8 having straight longitudinally extending flutes or grooves 9 formed on the periphery thereof and these flutes cooperate with straight longitudinally extending teeth 10 formed within a chuck nut 11, the latter being threadedly connected, as at 12, to a chuck sleeve 13 rotatably mounted within the chuck housing 5. Fixed within the forward end of the chuck sleeve 13 is a chuck bushing 11i having a polygonal socket 15 which receives the shank end of a usual hexagonal collared drill steel 16. The drill steel 16 is allowed to freely reciprocate within the chuck bushing 14. Furthermore, the drill steel 16 is maintained within the chuck housing by means ofa usual drill steel retainer 17.

To effect rotation of the chuck sleeve 13 and consequent-ly the drill steel 16 during reciprocation of the hammer piston there is provided a ratchet ring 18 threadedly connected, as at 19, within the back head 6 and this ratchet ring is provided with internal ratchet teeth 20. Arranged concentrically within the ratchet ring 18 is a usual rotatable pawl carrier 21 having usual spring pressed pawls, not shown, which cooperate with the ratchet` teeth20 in a well known manner. As shown, formed integral with the pawl carrier 21 and projecting forward within the cylinder 1 is'a rotation bar 22 having spiral liutes or grooves 23 which cooperate with spirally formed teeth 24 formed on a rifle nut 25 threadedly connected, as at 26, within the rear end of the hammer piston 3. Interposed between the ratchet ring 18 and the cylinder 2 is a collar 27 having a central aperture through which the rotation bar 22 extends. As is well known in the art, the pawls engaging the ratchet teeth 20 prevent rotation of the rotation bar 22 in one direction but permit rotation thereof in the opposite direction. When the piston moves forward within the cylinder 1 these pawls slip over the ratchet teeth and the piston moves freely in the cylinder to impart a blow to the shank of the drill steel. During rearward movement of the piston the pawls engage the ratchet teeth and due to the spiral flutes 23 in the rotation bar cooperating with the spiral teeth 24 formed within the rifle nut 25 Vangular movement is imparted to the piston 2. As the piston. moves angularly the straight grooves 9 Aformed on the striking bar 8 and cooperating with the straight teeth 1() on the chuck nut 11 cause rotation of the chuck sleeve 13 and consequently rotation of the drill steel 16. As shown, the drill steel 16 is made hollow7 and a cleansing liquid is adapted to be conducted thereto in a usual manner through a fluid conducting tube 28 fixed at its rear end, as at 29, within the back head 6 -and extending' coaxially through the rotation bar and hammer piston, the free forward end of the tube projecting within the bore in the drill steel. Pressure fluid is also adapted to be intermittently supplied from the front end of the cylinder bore to the bore in the drill steel as the piston reciprocates through the flutes 9 in the rifle bar 8in a well known manner.

In my improved construction it will be observed that Yformed integral with and disposed laterally of the cylinder 2 is a boss 30 having formed therein a longitudinally extending bore 31 arranged parallel with the axis of the motor cylinder. In accordance with this invention, rotatably mounted within the bore 31 is a cylindrical throttle valve 32 having a rearwardly projecting sleeve 33 extending through av bore 34E formed within the back head 6. A flanged bearing sleeve 35 is interposed between the rear end of the valve 32 and the back head 6 and this sleeve provides a bearing for the rear end of the valve. As clearly shown in Fig. 1, secured as by a transverse bolt 36 to the rear end of the sleeve 33 is a lever 37. The inner plane surface of this lever has formed therein notches 38 with which a spring pressed plunger 39 is adapted to cooperate, the plunger 39 being slidably mounted within a bore L10 formed in the back head and disposed parallel with the bore 34. The notches `for the automatic fluid distribution valve as hereinafter described.

The throttle valve 32 has formed therein a bore 44; within which a reci pr cable fi id distribution valve generally designated e5, herein of the four spool differential type, is slid ably mounted. The valve l5 comprises end spools e6 and i7 of diierent diameters and central spools A3 and 49 fitting the bore 44, the latter spool having formed thereon an enlarged flange of the same diameter' as he spool 47 for purposes to be later described. Connecting the spools 46, 47, 13, and t9 are reduced portions 51. As clearly shown in Fig. 1 the bore del has formed intermediate its ends an enlarged chamber 52 to which pressure fluid is adapted to be supplied through the supply passage 43 and the port 4:2 in the throttle valve Disposed at each side of the chamber 52 are grooves 53 and 5 which communicate respectively through passages 55 and 56 with longitudinally elongated arcuate recesses or slots 57 and 53 formed in the cylinder 2. A passage 59 connects the recess 57 with the rear end of the cylinder bore, while a passage 60 connects the recess 53 with the forward end of the cylinder bore. Disposed within the forward end of the throttle valve 32 and maintained in position thereagainst by the spring l1 is a buffer plug 61 with whichthe forward end of the distribution valve 45 is adapted to engage, while formed integral with the throttle valve 32 at the rear end of the bore dei is an annular projection 62 which forms a buffer for the rear end of the distribution valve. The motor exhaust comprises grooves 63 and 6e formed contiguous to the remote ends of the bore ist and these grooves communicate with the atmosphere through ports 65 and v66 and through lateral passages 651 and 66a respectively communicating 'ith the atmosphere as clearly shown in Fig. 3. Coinniunicating with the cylinder bore 2 and suitably spaced longitudinally thereof are usual valve throwing passages 67 and 63, the former connecting the cylinder bore with the eXtreme rear end of the bore Llei, while the latter connects the cylinder bore with the eX- treme forward end of the bore est for purposes to be hereinafter described. j

Associated with the improved controlling mechanism is improved means for effecting a hole cleansing operation, that is, to supply a supplemental amount of pressure fluid to the hollow drill steel to blow out the hole.

This improved holo cleansing means includes a stem 69 slidably mounted within a bore 70 formed within the throttle valve 32 and alined with the bore 44. The rear end of the stem 69 has preferably formed integral therewith a push button 7l and arranged between this push button'and the sleeve 33 and disposed in a 1oore 72 formed in the sleeve is a coiled spring 72a encircling the stem. This spring normally maintains the stem 69 in its extreme rearward or inoperative position. Movement of the stem 69 is limited by means of a slot 73 formed in the latter and a transverse pin 7 4 carried by the throttle valve 32. The space at the rear end of the valve 44 is vented to atmosphere by means of a longitudinally e5;- tending groove 75 formed in the stem 69, while the space the forward end of the distribution valve is vented to atmosphere Jthrough a. restricted port 76 formed in tl e buffer plug 6l, this port connecting the space lat the front end of the valve with the atmosphere through a port 77 formed in the lcoss at the forward end thereof.

The operation of the improved drilling mechanism is as follows. The hammer drill may be supported in any suitable manner with the cutting end of the drill steel i6 against the work. The operator then grasps the lever 37 and rotates the throttle valve 32 from the position shown in Fig. 6 to the position shown in Fig. 3, consequently bringing the lateral port 42 in the valve in communication with the supply passage 43. Pressure fluid flows from the passage 43 through port- 42 into the central chamber 52, the fluid flowing from this chamber through the grove 53, port 55, recess 57 and port 59 to the rear end of the cylinder bore to act on the rear surface of the piston, consequently effecting forward movement of the latter, it being assumed that the parts are in the position shown in Fig. l. At

I the same time the forward end of the cylinder bore 2 is opened to atmosphere through ports 60, recess 58, port 56, groove 54, groove 64, port 66, and the forward exhaust passage 66a, the latter communicating with the atmosphere. As the hammer piston moves forward A it overruns the throwing passage 67 and pressure fluid is consequently admitted from the rear end of the cylinder bore to the space at the rearward end of the distribution valve 45. Accordingly the distribution valve will be thrown sharply forward from the position shown in Fig. l to the position shown in Fig. 2. The piston continues to move forward by expansion of the fluid until it assumes approximately the position shown in Fig. 2. The piston thereafter moves rearwardly by rebound and the expansion of the fluid within the cushioning space at the forward end of the cylinder. As the piston moves rearwardly the port 60 is uncovered and motive fluid then flows from the central chamber 52 through annular groove 54, port 561 recess 58, and port 60 to the forward end of the cylinder bore` and consequently rearward movement of the piston is continued. During rearward movement of-the piston the rear end of the cylinder bore 2 is opened to atmosphere through port 59, recess 57, port 55, groove 53, groove 63, 65, and the rear exhaust passage 6 a communicating with the atmosphere. During rearward movement of the piston the throwing passage 68 is uncovered by the piston and consequently pressure fluid is admitted from the cylinder bore to the space at the forward end of the distribution valve and consequently tl e latter is sharply thrown upwardly from the position shown in Fig. 2 to the position shown in l. lvlfhen the distribution valve assumes the position shown in Fig. 2 the pressure fluid acting on the flange maintains the front end of the valve tightly against the buffer 6l and prevents fluttering of the valve while held in such position. rlhe pressure fluid acting on the forward surface of the enlarged spool maintains the rear end of the valve tightly against the buffer 62 when the valve assumes the position shown in Fig. l. Excessive pressures are prevented from building up in the spaces at the opposite ends of the valve 45 by means of the vent passages and 7 6 respectively.

lllhen it is desired to effect a hole cleansing operation the operator presses downwardly on the push button 7l, consequently moving the stem 69 into engagement with the rear end of the distribution valve 45 and moving the latter downwardly against the front buffer plug 61 to the position shown in Fig. 2. Fluid then continuously flows from the central chamber 52 through the groove 54, port 56, through the recess 58 and port 60 to the forward end of the cylinder bore consequently moving the hammer pist-on to its extreme rearward position. Fluid then flows continuously from the front cylinder bore through the flutes in the striking bar to the opening in the drill steel and hence to the bottom of the hole.

As a result of this invention an improved controlling valve mechanism is provided for the rock drilling motor which is of exceedingly simple and compactstructure, the fluid distribution valve being arranged coaXially within the throttle valve. It will further be noted that by arranging` the distribution valve coaxially within the throttle valve and by having improved hole cleansing means associated therewith it is possible for the operator to cleanse the drill hole without removing his hand from the throttle valve handle. These and other uses and advantages of my improved controlling mechanism will be clearly apparent to those skilled in this art.

wWhile l have in this application specifically described one embodiment which my invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the inventi-on may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What l claim as new and desire to secure by Letters Patent is:

l. A fluid actuated motor comprising a cylinder, a piston reciprocable therein, fluid distribution means including` a multiple spool valve having two central spools of equal diameter controlling supply and exhaust of motive fluid for said cylinder, an end spool of the same diameter adapted to be subjected to pressure for throwing and holding said valve in one position, and another end spool, one of said central spools having a larger area presented to pressure than theother in one position of the valve to hold the valve more positively in such position.

2. ln a fluid actuated motor, a cylinder, a piston reciprocable therein, fluid distribution means including a multiple spool fluid actuated valve having its central spools or" equal diameter controlling supply and exhaust ofl motive fluid for said cylinder, end spools adapted to be subjected to pressure for throwing and holding said valve in its different positions, and means of increased diameter provided by one of said central spools for increasing the unbalanced area subjected to live pressure after throwing of said valve in one direction to assist in holdingl said valve more positively in one position.

3. A fluid motor comprising a cylinder, a piston reciprocable therein, fluid distribution means including a four spool fluid actuated valve having two central spools of equal diameter controlling supply and exhaust of motive fluid, end spools adapted to be subjected to pressure for thro-wing and holding said valve in its different positions, one of said end spools being of larger diameter than the central spools, and means on said central spool adjacent said larger spool providing an unbalanced area adaptedto be subjected to live pressure for increasing the unbalanced pressure tending to hold the valve in one position.

4. A fluid actuated valve for rock drilling motors having two central spools for controlling fluid supply to opposite ends of a hammer motor, an end spool of the same diameter as said central spool for throwing said valve in one direction when subjected to pressure, another end spool of larger diameter than said other spool for throwing said valve in the other direction when subjected to pressure, and a flange on one of said vcentral spools adapted to be subjected to live pressure for holding said valve in one position.

5. In a rock drilling apparatus, a fluid actuated motor comprising a cylinder, a piston reciprocable therein, fluid distribution means for effecting reciprocation of said piston including a multiple-spool valve, said valve having one spool at each end thereof adapted to be subjected to pressure for throwing the valve in opposite directions, central spools for controlling fluid distribution for opposite ends of said cylinder respectively, and means on one of said central spools providing an unbalanced area subjected to live pressure in one position of the valve for holding the same more positively in position.

6. In a rock drilling apparatus, a fluid actuated drilling motor comprising a cylinder, a piston reciprocable therein, fluid distribution means including a four-spool valve having two central spools of equal diameter controlling supply and exhaust of motive fluid for said cylinder and end spools having areas adapted to be subjected to pressure for throwing said valve, piston controlled means for supplying said areas with cylinder pressure, and a flange of' increased diameter on one of said central spools adapted to be subjected to live pressure in one position of the valve for holding the valve in such position.

7. ln a roel; drilling apparatus, a fluid actuated motor comprising a cylinder, a piston reciprocable therein, fluid distribution means including a four-spool valve having two cenitral spools of equal diameter controlling supply and exhaust of motive fluid for said cylinder, 'rotation mechanism for causing said piston to rotate a drill steel on its rearward stro-lie, said valve also having end spools adapted to cause throwing of said valve when subjected to pressure, piston controlled means for supplying pressure to said end spools, and a flange of increased diameter on one of said central spools adapted to be subjected to live pressure when said valve is in position to cause admission of fluid to the forward end of the cylinder for holding said valve more firmly in such position.

In testimony whereof l aliiX my signature.

ELMER G. GARTIN.

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