US2143105A - Feeding mechanism for rock drills - Google Patents

Description

Jan. 10, 1939.

J. C. CURTIS FEEDING MECHANISM FOR ROCK DRILLS Filed April 2l, 1956 3 Sheets-Sheet 1 Jan. 10,1939, J. C. CURTIS 2,143,105

FEEDING MECHANISM FOR ROCK DRILLSv I l 3 Sheets-Sheet 2 Filed April 2l, 1936 ABY- I l ATroRNEY Jan. l0, 1939. .1. c. CURTIS FEEDING MECHANISM FOR ROCKl DRILLS 3 Sheets-shet' Filed April 2l, 1936 Jo/-fA/cz caff/5 INVENTOR ATTORNEY Patented Jan. 10, 1939 UiTE STATES PATENT OFFICE FEEDING MECHANSM FOR RQCK DRILLS Application April 21,

7 Claims.

This invention relates broadly to rock drills, but more particularly to a feeding mechanism for rock drills of the percussive type.

One object of this invention is to produce a feeding mechanism for rock drills susceptible of manual and automatic operation for imparting feeding motion to the drill.

Another object of this invention is to provide a feeding mechanism for rock drills with means in readily operable for selectively transforming the feeding mechanism in a manually or automatically operated mechanism.

Another object of this invention is to provide a normally automatically operated feeding device for rock drills with means shaped and disposed in the most common manner whereby manual feeding motion may be imparted to the drill irrespective of said mechanism.

Other objects and advantages more or less an- ;t cillary to the foregoing and the manner in which the various objects are attained, reside in the speciiic construction and aggroupment of the elements peculiar to this structure, as will become apparent from a more complete examination of this specification, in the claims of which there are assembled certain specific combinations of parts and specific constructions indicative of the scope and spirit of the invention.

In the drawings:

.do Fig. 1 is a longitudinal view partly in section illustrating a rock drill having the improved feeding mechanism applied thereto, the rock drill being shown positioned atone extreme end of its travel.

Fig. 2 is a view similar to Fig. l illustrating the rock drill in another position.

Fig. 3 is an enlarged longitudinal sectional View of the connection between the drill and the feeding mechanism.

Fig. 4 is an enlarged cross sectional View taken in a plane indicated by line d--fi in Fig. l.

Fig. 5 is an enlarged cross sectional view taken in a plane indicated by line 5 5 in Fig. 1.

Fig. 6 is a view similar to Fig. 5 illustrating some of the parts in dierent position.

Fig. 7 is an enlarged sectional View taken in a plane indicated by line 1 1 in Fig. 5.

Fig. 8 is a sectional View tak-en in a plane indicated by line 8 3 -in Fig. 5.

Fig. 9 is a side elevational view of the part shown in Fig. 8.

Figs. 10, 1l and l2 are cross sectional views taken in a plane indicated by line Iii-lil in Fig. 5 and looking in the direction of the arrows terminating the line. lFor purpose of illustration,

ne at) 1936, Serial No. 75,593

(Cl. Z55-45) the handle located at the extreme left end of Fig. 5 has been shown in dotted lines in these three gures.

Fig. 13 is a longitudinal sectional View taken in a plane indicated by line 1,3-13 in Fig. 5 illus- 5 trating the left end portion of the mechanism shown in Fig. 1.

Fig. 14 is an enlarged cross sectional view taken in a plane indicated by line it--M in Fig. 2.

Fig. 15 is an enlarged sectional View taken in a plane indicated by line Iii-i5 in Fig. 10.

Referring to the drawings in which like symbols designate corresponding parts throughout the several views, It represents a percussive rock drill or drilling motor having a piston (not shown) reciprocable therein for imparting blows to a drill steel l1 reciprocably mounted within the front housing of the rock drill. The motive fluid may be admitted into the motor ESS through a connection i8 forming a part of the back head 19.

The lower -wall of the motor i6 extends laterally to form two longitudinally disposed guides 2li, which are slidably guided within the corresponding guideways 2| formed with the upper portion of a tube or shell 22. This shell is located under the motor l5 to support the same, and has its lower portion also formed with guides 23 slidably guided within the guideways 24 of a stationary support 25. For mounting purpose, this support has a conical portion 25 depending therefrom. The length of the support 25 is substantially equal to one half the length of the shell 22, which is slidable relatively thereto with the motor IS slidable on the shell.

Located within the right end of the shell 22 in Fig. 1, hereinafter denoted as the front end of the mechanism, there is a sprocket wheel 21 rotatably 'mounted on a shaft or bolt 28 transversally disposed through the shell 22. The position of this shaft is such that the sprocket wheel 21 protrudes f below the shell through a short slot 29 provided in the bottom of the shell.

Mounted within the rear end of the shell 22, there is a housing 30 secured therein by bolts 3l extending through the housing and shell. Transversally disposed within the housing 33, there is a shaft 32 which is formed with an integral handle 33 extending outside of the housing for rotary movement within a vertical plane located on the left hand side of the assembly when viewed from the left end in Fig. l. Disposed through the shaft 32 adjacent the handle 33, there is a cross pin 34 of a length substantially equal to the bore 35 of a cover or cap 36 secured to the side of the housing 3l) by bolts 31. Clamped between the cap V36 and u the adjacent side wall of the housing 36, there is the partly annular shoulder 33 of a sleeve The side wall of the sleeve 39 is partly machined to form two diametrically opposed substantially V- shaped cams 48 with the bottom thereof arcuated as at 4I to accommodate the pin 34, while the top ends thereof are recessed as at 42 to form stops and locks for the pin 34.

Journaled on the shaft 32, there is a sleeve 43 which extends beyond the inner end of the shaft. This sleeve has its right end portion in Fig. 5 slotted to slidably receive the cross pin 44 of a short shaft 45, which is slidably mounted within the sleeve 43 in abutting engagement with the shaft 32. The cross pin 44 carries a clutch member 46 slidably mounted on the sleeve 43, and formed with splines 41. This clutch member is constantly urged toward the left in Fig. 5 by the effort of a compression spring 45, which is seated on a washer 49, the latter being secured to the sleeve 43 by a spring clip 50.

The splines 41 of the clutch member 46 are capable of operative engagement with the corresponding splines 5I of a worm gear 52, which is rotatably mounted within the housing Meshing with the teeth of the worm gear 52, there is a Worm 53 disposed longitudinally within the housing 38 and rotatable by a crank handle 54, which is secured thereto by a bolt 55.

Intermediate its ends, the sleeve 43 has secured thereon by a. key 55, a sprocket wheel 51, which is located between two spacers 58 and 59, the former having the worm wheel 52 rotatably mounted thereon. The housing 35 has an arcuated wall 60 extending behind the sprocket wheel 51 as shown in Fig. 13, while ahead of the sprocket wheel the housing is provided with two substantially rectangular openings GI and 82, the purpose of which will be explained later.

Adjacent the cap 36, there is secured on the sleeve 43 by a key 63 a disk E4, which has its peripheral wall formed with teeth 65. Pivotally mounted within the wall of the housing 3i) adjacent the peripheral wall of the disk 64, there are two sets of pawls 55 and 61. In the present construction, there are shown six pawls 53, which are located with respect to the teeth 55 for alternative operative engagement with one side thereof, and two pawls 81 capable of alternative engagement with the other side of the teeth 55. Each of these pawls has a torsion spring 68 associated therewith for constantly urging the pawls in engagement with the teeth 65 of the disk 54. The pawls 66 and 31 are somewhat longer than the Width of the disk 64, and extend beyond the latter over a cam plate 69, which is rotatably mounted between the disk 64 and the cover 36. The normal outside diameter of this plate is substantially equal to or somewhat greater than the outside diameter of the disk 64, and has a hub like portion rotatably mounted within the sleeve 33. This hub 10 is also slotted to receive the cross pin 34 by which the rotation of the shaft 32 is transmitted to the cam plate 68, while the sleeve 39 is locked against rotation to the cover 35 by a small lock pin 1I. The peripheral wall of the cam plate 69 is formed with two diametrically opposed cut away portions or notches 12 of a sufficient length for accommodating the pawls 66.

Depending from the drilling motor I5 into the shell 22, there is a longitudinally apertured lug 13 having a sleeve 14 extending therethrough and formed with a collar 15 engaging one side of the lug. The collar has a flat portion 16 engaging the lower wall of the motor I6 to lock the sleeve against rotation relative to the lug. The other end of the sleeve 14 is threaded to receive a nut 11 engaging the other side of the lug. Within the sleeve 14, there is a longitudinally disposed pin 18 having a nut 19 secured to the inner end thereof, and engaging a rubber buffer 8U located between the nuts 11 and 19. The pin 18 extends through the nut 11 where it is fastened thereto by a cross pin 8 I, to the end of a chain 82. From the apertured lug, the chain 82 extends rearwardly through the rectangular opening 8l formed Within the housing 30, where it passes over the sprocket wheel 51, and therefrom it extends forwardly toward the support 25, through the rectangular opening 62. The other end of the chain is finally secured to the rea-r end of the support 25 by a bolt 83, which is adjustable longitudinally by nuts 84 within an apertured lug 85 depending from the support 25.

Secured by a cross pin 86 to the sleeve 14 mounted within the apertured lug 13 of the motor I6, there is the end of another chain 81, which chain extends forwardly over the sprocket Wheel 21 mounted Within the front end of the shell 22. From the sprocket wheel 21, the chain 81 extends rearwardly toward the support 25, Where its other end is aflixed to the front end of the support by a cross pin 88.

From the foregoing, it will be noticed that the portion of the chains 82 and 81 extending from the drilling motor lug 13 to their respective sprocket Wheel, is located inside of the shell 22, while the portion thereof extending from the sprocket Wheels to the support 25, is located under the shell 22.

In the operation of the mechanism, let us assume that the handle or lever 33 of the shaft 32 is positioned as shown by dotted lines in Fig. 10. In this instance, the cross pin 34 of the shaft 32 is engaging the bottom 4I of the cam 48, thus permitting the short shaft 45 to assume the position shown in Fig. 5 and thereby causing the engagement of the clutch member 46 with the corresponding splines 5| of the worm gear 52. Due to the effort of the compression spring 48 on the clutch member 46, the short shaft 45 is constantly urged toward the left in Fig. 5, thus exerting pressure on the end of the shaft 32 for maintaining its cross pin 34 in forcible engagement with the cam 4I). When the parts are positioned as shown in Fig. 5, it will be understood that the sprocket wheel 51 is normally locked against rotation due to the interengagement of gear 52 and worm 53, preventing thereby the accidental slidable movement of the motor I6 relative to the shell 22 and support 25. It Will also be understood that manual rotation may be imparted to the worm gear 52 by the worm 53 and crank handle 54, which rotation is transmitted to the sleeve 43 by the cross pin 44. From the sleeve 43 the rotation is transmitted to the sprocket wheel 51 through the key 55, and to the disk 64 through the key 63. In this instance, the plate 69 which is connected to the momentarily stationary shaft 32 by the cross pin 34 is held in the position shown in Fig. 10. In this position the normal peripheral wall of the disk engages the end of the pawls 66 and 61 which protrudes from the disk 64, thus preventing the engagement of the pawls with the teeth 65 of the disk, and thereby permitting the free rotation of the sprocket wheel 51 which is manually imparted thereto by rotating the crank handle 54. Since the sprocket wheels 21 and 51 are carried by the shell 22, and that the chains passing over these sprocket wheels have one end ference.

axed to the support and the other end to the motor, it will be understood that the rotation of the sprocket wheel l will cause the longitudinal movement of the shell and motor relative to the support, the drilling motor moving in the same direction as the drill but at a double rate of speed, its possible range of travel being equal to the combined range of travel of the motor on the shell and of the shell on the. support.

When it is desired to change thefeeding mechanism from a manual to an automatic operation, it is only necessary to shift the lever or handle 33 in either the position shown in Fig. l1 or Fig, 12. During the rotation of the handle 33 from the position shown in Fig. l) to the one shown in Fig. 11 for instance, the cross pin 3 engaging the cam 40 will move from the bottom f3! into the recesses 42, thus causing the longitudinal movement of the shaft 32 and the consequential slidable movement toward the right in Fig. 5, of the short shaft 45. The cross pin 44, carried by the short shaft i5, will cause the clutch member d5 to move out ci engagement with the worm gear 52 as shown in Fig. 6. When the handle 33 is positioned as shown in dotted line in Fig. ll, the plate 69 being rotated by the cross pin 35 will alsobe positioned as shown in this last ligure, that is with the notches i2 in opposition to the pawls t6, thus permitting the operative engagement of the pawls with the teeth S5 of the disk 64.

During the operation of the drilling motor i6, the reversal of the piston strokes therein will impart jars or forward and rearward movement to the motor i 5, thus normally imparting oscillatory motion to the sprocket wheel 5l. When the plate 69 is positioned as shown in Fig. ll, the pawls @t engaging one side of the teeth 65, will prevent the rotation of the disk 54, sleeve 43 and sprocket wheel 5i in a clockwise direction in Fig. 11, thus preventing the rearward movement of the motor I 6. During the forward movement of the motor, the sprocket wheel 5i and disk 64 will rotate in a counterclockwise direction in Fig. 11, which rotation is not checked by the pawls E6 since the latter will simply ride the teeth 65 without inter- From the foregoing, it will be understood that when the handle 33 is positioned as shown in Fig. l1, the drilling motor i5, dueto the jars imparted thereto, is capable of step by step forward movement, while the rearward movement thereof is prevented by the engagement of the pawls 66 with the teeth of the disk E54.

When it is desired to feed the motor rearwardly, the handle 33 may be rotated in the position shown in dotted line in Fig. 12. In this instance, the cross pin 34 riding the cam 4S will again be positioned within two of the recesses 2, thus again causing the disengagement of the clutch member 46 with the worm gear 52 as shown in Fig. 6. The plate 69 being driven by the cross pin 34 will assume the position shown in Fig. l2 to permit the engagement of the pawls 6i with the teeth 65 oi the ring 6d and prevent the engagement of the pawls 65. In this instance, the rotation of the disk 64 and sprocket wheel 5i in a counterclockwise direction in Fig. l2 is prevented by the engagement of the pawls Si with the teeth S5, thus preventing the forward movement of the motor I6. During the rearward movement of the motor, the sprocket wheel 51 and disk 64 will rotate in a clockwise direction in Fig. l2, which rotation is not checked by the pawls El' since the latter will simply ride the teeth of the disk Si without inter-- ference, thus permitting a step by step rearward movement of the motor.

When it is desired to manually feed the motor I6 toward or away from the Work, the handle 33 may simply be positioned as shown in Fig. 10, thus causing the reengagement of the clutch member i6 with the worm gear 56 as shown in Fig. 5, and positioning the plate B9 as shown in Fig. 10 to maintain the pawls E35 and 61 out of engagement with the teeth 65 of the disk 69.

When the feeding mechanism is automatically operated, it will be understood that the shell 22 and motor i5 are fed toward or away from the work in the manner speciiied in connection with the manual operation of the mechanism, the motor moving in the same direction as the shell but at a double rate of speed.

During the operation cf the drilling motor I3, the jars of the latter transmitted to the chain 82 which passes over the sprocket wheel 5l, will be greatly cushioned by the rubber buffer 80 mounted within the apertured lug i3, thus protecting the chain against sudden jars which may cause the breakage thereof, as well as eliminating excessive vibrations in the mechanism associated with the sprocket wheel 5l.

Although the foregoing description is necessarily of a detailed character, in order to completely set forth the invention, it is to be understood that various rearrangements of parts and modification of structural detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

I claim:

1. In a drilling apparatus, the combination with a stationary support, of a shell slidable thereon, of a drilling motor slidable on said shell having jars imparted thereto, a` mechanism associated with said motor and shell for imparting slidable movement thereto, means manually oper- 'ated connectable with said mechanism for actuating the same, means automatically operated 'by the jars of said motor connectable with said mechanism for actuating the same, and means for selectively connecting said manually or automatically operated means with said mechanism.

2. In a drilling apparatus, th-e combination with a stationary support, of a shell slidable thereon, of a drilling motor slidable on said shell having jars imparted thereto, a mechanism associated with said motor and shell for imparting slidable movement thereto, said mechanism being normally automatically operated by the jars of said motor, manually operable means connectable with said mechanism for actuating the same independently of said jars, and means for connecting said manually operable means with said mechanism and simultaneously rendering the automatic operation thereof ineffective.

3. In a drilling apparatus, the combination with a stationary support, a shell slidable thereon, a drilling motor slidable on said shell having jars imparted thereto, a sprocket wheel carried by said shell meshing with a chain connected to said support and motor, a jar resisting mechanism and a manually operable rotation mechanism connectable with said sprocket wheel for either causing a step by step slidable movement of said motor and shell due to the jars of said motor or for imparting continuous slidable movement to said motor and shell, and means for selectively connecting either of said mechanisms to said sprocket wheel.

4. In a drilling apparatus, the combination with a stationary support, a shell slidable thereon, a drilling motor slidable on said shell having jars imparted thereto, a mechanism associated with said motor and shell including movement transmitting means for transmitting continuous slidable movement to said motor and shell and movement checking means for checking the jars of said motor in one direction and thereby causing astep by step slidable movement of said motor and shell in the other direction, and means for selectively and operatively connecting said movement transmitting or checking means with said mechanism.

5. In a drilling apparatus, the combination with a support, of a shell slidabie thereon, of a drilling motor slidable on said shell, of a feeding mechanism associated with said motor and shell for effecting the slidable movement of said motor at a faster rate of speed than that of said shell, manually operable means and means automatically operable by the jars of said motor connectable with said mechanism for actuating the same, and means for selectively connecting said manually operable or said automatically operable means with said mechanism.

6. In a drilling apparatus, the combination with a support, of a shell slidable thereon, of a drilling motor slidable on said shell, of a feeding mechanism associated with said motor and shell for effecting the slidable movement thereof at a greater rate of speed for said motor than for said shell, manually operated means and power operated means connectable with said feeding mechanism for actuating the same, and unitary means for selectively connecting either of said operated means with said mechanism.

7. In a drilling apparatus, the combination with a support, of a shell slidable on the support, of a motor slidable on the shell having a piston reciprocable therein imparting jars thereto tending to move the motor back and forth relative to the support, means utilizing the jars oi the motor for eiecting a step by step movement thereof in one direction including a sprocket Wheel rotatably mounted on the shell near each end thereof, a chain meshing with said Wheels and connected to the support and motor for movement with the latter normally resulting in the oscillatory movement o1' the wheels, and a mechanism carried by the shell including stop means associated with one of said wheels for selectively controlling the direction of rotation thereof to enable a step by step movement of said chain and consequently of said motor in one or the other direction.

JOHN C. CURTIS.

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