US1988445A - Rotation device for drilling mechanisms - Google Patents

Description

D. K. DOVELI,

ROTATION DEVICE FOR DRILLING MECHANISMS Filed J y 29,

flUDLEY m Dot/ELL BYM W,

HTT'

Patented Jan. 22, 1 935 nnvron- Fon DRILLING. V MECHANISMS Dudley K. DovellfEl fPjaso, Tex., .assignor to 8111- I livan Machinery Company, a corporation of.

Massachusetts f Application July 29.1930, Serial No. 471,581

- 3 Claims;

Thisinvention relates to drilling mechanisms and more particularly to improved .meansfor cona trolling drill steel rotation-of a fluid pressure actuated hammer type drill t In various types of drilling mechanism, especially of the pneumatic hammer type, the drill steel is intermittently rotated by the hammer'piston through a pawl and ratchet mechanism cooperating with a rifle bar and nut. In certain.

types of drilling mechanisms, such as stopers, it is particularly desirable to be able todisconnect the drill steel rotating mechanism while permitting continued reciprocation of the hammer piston. I '1 It is an object of my invention to provide improved means whereby the drill steel rotating mechanism may be variably controlled. while permitting continued reciprocation :of. the hammerpisto-n. A further and more specificobject is to provide improved meansfor releasing the ratchet of the pawland ratchet rotating mecha nism and in the specific aspect'of the invention to provide an arrangement whereby the ratchet. may be released by rotating a suitable member. to permit a pawl or other suitable stop element to be moved out of the path of the ratchet when it is desired to stop steel rotation.

Other objects and advantages will be mor'eap parent to those skilled in the art and. modificae tions of my invention will likewise be readily ap--' parent to such persons, from the following description of the accompanying drawing, in Which,-

Fig. 1 is a side elevation of a stoper type of drilling mechanism equipped with an illustrative form of the improved rotation control means;

Fig. 2 is an enlarged transverse section taken substantially on the line 2--2 of Fig. 1;

Fig. 3 is a fragmentary longitudinal section through the drill motor showing the ratchet mechanism and hammer piston; and

Figs. 4 and 5 are elevational views of the cam for controlling the operation of the ratchet mechanism.

While I have shown my improved rotation control in connection with a drilling mechanism of the stoper type generally indicated at 1, it will of course be understood that the same may be applied to various other types of drilling tools whether suitable for rock drilling or otherwise, although for various reasons the improved ratchet control is particularly applicable to a stoper type of hammer drill provided with a suitable feed, generally indicated at 3, and which 5 may be of the fluid actuated type or of any other type whereby a drill steel 4 carried in a usual chuck housing 5 may be fed with the drilling motor. The motor is of the conventional piston hammer type having a hammer piston 6' provided with' a fluted striking .bar '7, the flutes of which engage a suitable nut of the chuck whereby. rotation of the pistonwill effect'rotationof the chuck and in turnrot'ation of i drill steel 1in. any usual manner. To effect pistonr'otation an internal ratchet 8, journaled 10 inithe rear headof themotdrgcooperates with a series ofspring pressed pawls 9. .These pawls are pivotallysupported inasuitable' head 10 which hasa bar 11 from which a rifleLbar 12 extends foricooperation with a spiralnut 13 secured in a bore of the piston 6; Assuming the ratchet 8v to. be held stationary, .rearwardmovement of the pistonyficau'ses it to: be'partially rotated due to rifle bar 12 being held stationary by engagement of the pawls with thefixed ratchet. This partial rotation of the piston is transmitted to the drill ste'el from striking bar 7 but upon forward movement' of-.the piston the rifle bar 12 is partially rotate'dina counterclockwisedirection, as viewed in Fig. :2', during whichatime the pawls 9*s1ipover the internal .ratchet teeth... As isiusual, successive'reciprocating movements of the piston efiects a constant step by step rotation'of the drill steel. In the .type of motor herein disclosedja hollow distributing sleeve valve 14 is provided for effecting the'necessary fluid distribution to actuate the piston .6 and through. which bar, 11 extends- V 1' 7 To release the ratchet 8, thereby permitting the rifle bar 12 to oscillate during reciprocation of the piston 6 and hence not transmit any rotation thereto, the ratchet is provided with a peripheral groove 15 one end shoulder ofwhich is adapted to be engaged by a radially movable. stop pawl 16 suitably pivotally supported in a relatively wide recess 18 of the drill head, whereby when the stop pawl is moved to the other side of its wide recess, as shown in dotted lines in Fig. 2, the ratchet 8 may freely rotate 'as the rotation pawls are successively oscillated.

The means for holding the control or stop pawl 16 in operative position for effecting steel rotation comprises a pin 20 pressed into engagement with pawl 16, as by a cam 21 having a flat portion 22 which rides upon the inner end of pin 20. The cam 21 is actuated by any suitable means such as a handle 23 and in addition is provided with a recess 24 for engagement with the reduced end of a lock pin 25. This lock pin is held in position by a leaf spring 26 suitably secured at one end on the drill casing while the 55 whereby no rotation will be transmitted to the steel although the piston may continue'to reciprocate To prevent possible reverse rotation of the ratchet ring during steelrotation, a. pivoted spring-held stop pawl 30 engages a notch 31' in the ratchet periphery. This pawl isinclined so as to resist reverse rotation but pen-nit forward rotation when the other stop pawl 16 is-released, and yet will drop into notch 31 when pawl 16 is moved from its. inoperative to. operative. position. Groove 15, is of suificient length to. permit proper clearancefor the swinging ofipawl 16. 1

From the foregoingdescription it. willbe readily apparent that drill steel rotation may. be discontinued during continued reciprocation of the hammerpiston. merelyzbylifting lock pin 25 and rotating handle 23,.in a clockwise directionwhereupon-the cut away portion 33' of cam 21; permitsholding pin 20 12011110178 away. from pawl 16 to permit it to move to it's; inoperative position. "To reestablish steel rotationxthe handle 23;:ls :rotated. downwardly to the position shown. in Fig. 2 therebymoving pin 20 and pawl 16 into the position as shown, although it will. of course be :seen that.

if the peripheral .groove=15. doesnot happen. to: be in suchranangular position as to permit pawl: 16 to drop therein, due itothe ratchet 8, having. been rotated, the pawl 16 will simply ride upon the periphery. of the ratchet until groove l5yis finally rotated around to the necessary position-where pawl 16 will drop During such. :a condition the operator would merely maintain alight pressure upon the handle 23 until'the grooveisengaged', whereupon the lock pin 25 'wouldautomatically'fall into recess2i and positively hold the device in operative condition. vAt the-same time reverse pawl 30 will dropinto'notch :31.

While there is in this application'specifically described one form which this inventionmay assume inpractice, it-will be understoodthat this form ofthe same is shown for purposes of'illusholding members, one arranged to engage one of said shoulders and. the other to engage the other of said shoulders and each rotatable on an axis spaced from the axis of rotationof said pawl and ratchet elements into its shoulder engaging position, and means for causing said members concurrently to. have. engagement, with the shoulders with whichthey-respectively cooperate.

42,111 a hammer drilling mechanism, tool rotation mechanism including a ratchet, means for rotatably supporting said ratchet, means for preventing rotation of. said ratchet including relatively opposed shoulders adjacent the periphery oixsaid ratchet, pivoted pawlsrotatable on axes spaced. from..,the axis-of ratchet rotation and swingable' -on such axes, one into engagement with oneiof 'saidshoulders andthe other with the other of saidrshoulders, and also swingable out of engagement. with said shoulders, and means for at will holding one. of said elements against swing-ingoutof "engagement with its cooperating shoulder. I 1 e 3. .In ahammer drillingmechanism, tool rotationmechanism. including a ratchet, means for rotatablysupporting said ratchet, means for preventingv rotation of. said ratchet including relatively opposed shoulders adjacent the periphery ot .sai'dratchet.,.pivoted pawls rotatable on axes spaced: from the. axis of ratchet rotation and swingable. on. such axes,..one,into engagement with oneaoflsaid. shoulders and the other with theother: ofsaid shoulders, andalso swingable out of engagement with said shoulders, and a 'cam foripositively swinging one of said pawls into engagement with its cooperating shoulder and locking it there.

. DUDLEY K. .DOVELL.

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