US1740685A - Expansible chamber motor - Google Patents

Description

Dec. 24; 1929. E. G. GARTIN EXPANSIBLE CHAMBER MOTOR Filed June 29, 1921 y $7 i Qii N fii Patented Dec. 24, 1929 arr STATES ELMER G. GARTEN, OF CLAREMOIE T, NEW HAMPSHIRE, ASSIGN'OR T SULLIVAN IIIA- CI-IENERY COMIPANY, A CORPORATION OF MASSACHUSETTS EXPANSIBLE CHAIYIBER MOTOR Appzication filed. June 29,

My invention relates to eXpansible chamber motors, and more particularly to eX- pansible chamber motors of the valveless type.

An object of my invention is to provide an improved expansible chamber motor. Another object of my invention is to provide an improved expansible chamber motor of the valveless type, especially adapted for use in rock drilling and for similar purposes. A further object of m invention is to provide an improved valveiess motor in which the length of the piston may be a minimum and the over-all length of the tool, together with its weight, materially reduced. A further object of my invention is to provide an improved valveless percussive motor having a very short piston and yet preventing material loss of pressure fluid by reason of its passage to the exhaust in an unexpanded condition. Other objects of my invention will be apparent from the following specification and appended claims.

In the accompanying drawings I have shown for purposes of illustration, one embodiment which my invention may assume in practice.

In these drawings,

Fig. 1 is a view partially in elevation and partially in central longitudinal section through a percussive tool constructed according to the illustrative form of my invention. V

Fig. 2' is a transverse section on the line 2-2 of Fig. 1.

Fig. 3 is a vertical transverse sectional view taken substantially on line 33 of Fig. 1.

Fig. 4 is a detail transverse section taken on line 44 of Fig. 1.

For purposes of illustration I have shown my invention embodied in a percussive tool comprising a cylinder 1 having a bore 2 of uniform diameter which cylinder is provided at opposite ends with head members 3 and 4. In front of the head member 3 is arranged a chuck housing 5 within which is disposed a chuck of usual form comprising a bushing 6 having the usual straight lugs 6 thereon cooperating, as later described. with straight grooves formed in the piston in transmitting rotation to the drill steel 8 dis- 1921. Serial No. 481,425.

posed in the chuck. To the rear of the head 4 is mounted a combined handle and head member 9 and between this member and the head member 4 is a member 10 whose function will later be explained.

\Vithin the cylinder bore 2, piston 11 is reciprocable, this piston being provided with a reduced striking bar 12 which is cut away at opposite sides as indicated at 13 to cooperate with the exhaust groove 14 and passage 15 formed in the head member 3. The piston 11 is provided in its main portion with a plurality of parallel, longitudinal, peripheral grooves 16, these grooves being spaced apart by longitudinally extending relatively narrow ribs 17. Admission to the cylinder bore 2 is by way of a port 18 disposed approximately mid-way of the length of the cylinder and to this port fluid under pressure is supplied by way of a fluid supply passage 19. In the top of the cylinder bore there are formed a pair of by-pass passages and 21 respectively, which are in alinement with each other and with the port 18. It will be noted that as the piston reciprocates, the pas sages 16 serve to connect the inlet port 18 by way of the by-passes 20 and 21 alternately with the opposite ends of the cylinder. It will be noted that an exhaust port 22 is provided in such position as to be opened by the rear end of the piston 11 when the latter is at the forward end of its stroke. The center of this exhaust port is spaced approximately 90 from the center of the inlet port, and a second exhaust port may be provided, as indicated at 22, at a diametrically opposite point in the cylinder. The piston is hollow as indicated at 24 and provided with a bushing 25 having spiral lands formed thereon and cooperating with spiral grooves 26 formed on the rifle bar 27 which projects through the head 4 into the cylinder. The rifle bar 27 is provided with a pawl carrier member 28 which carries pawls 29 cooperating with the teeth 30 formed on the interior periphery of the intermediate head member 10. The front end of the striking bar 12 is provided with straight grooves 31 cooperating with the straight lugs 6 on the bushing 6. It will be obvious that as the piston recipro cates, the ratchet 28 will cooperate with the ratchet teeth 30 and so that the piston will be caused to partake of a unidirectional but intermittent rotation. For the purpose of providing cleansing fluid for the drill steel 8, which is hollow as indicated at 32, I provide a pair of concentric air and water tubes secured in the rear head member 9 of the cylinder. The water is supplied to the inner or water tube 33 from a water connection 34 in a well-known manner. Surrounding the water tube is an air tube 35 to which air is supplied through a passage 36 which communicates at its forward end with the bore of the cylinder in the same transverse plane as the middle of the inlet port 18 by way of a port 37. Referring to Fig. 2, it will be noted that the port 37 is so disposed that the various pockets 16 cannot communicate with it at the same time that they communicate either with the inlet port 18 or with the exhaust port 22 and 22'.

The mode of operation of this device is as follows: Assuming the parts in the position shown in Figs. 1 and 2, it will be obvious that fluid pressure is being conducted from the inlet port 18 through the uppermost groove 16 to the by-pass 21 and so to the rear end of the cylinder. As the piston 11 moves forward, cut-off will occur at the moment when the rear end of the groove 16 passes the front end of the port 21.; Admission to the front end of the cylinder will begin at the moment when the front end of the groove 16 begins to communicate with the by-pass 20. During the forward stroke of the piston, exhaust takes place through the cut-away portions of the striking bar 13 and passages 14!: and 15, until the front end of the solid portion of the striking bar 12 reaches the head 3, which occurs before admission to the front end begins. Thereafter cushioning in the front end of the cylinder takes place. At the end of its forward stroke, exhaust takes place from the rear end of the cylinder by way of the exhaust port 22 and 22. It will be noted that, the piston reciprocates axially, it is also undergoing a step by step rotation, but it will be readily apparent that the fluid entrapped in the various grooves 16 will not be conducted to the exhaust ports 22, 22 unexpected, for each of the grooves 16 passes over the port 37 and so supplies a jetof cleansing fluid to the air tube before it g is into communication with the exhaust, and thereafter the fluid discharged to exhaust is not very much above atmospheric pressure.

From the foregoin description, it will be clear that I have provided a. valveless rock drill having a piston of much less length than is usual with valveless rock drills having the same piston stroke and in which all leakage or loss of fluid to the exhaust is avoided.

While 1 have in this application specifically described one form 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 invention may be embodied in various other forms without departing from its spiritor the scope of the appended claims.

W hat I claim as new and desire to secure by Letters Patent is:

1. In a rock drill, a cylinder, a piston reciprocable therein on admission of motive fluid thereto, means for imparting angular movement to said piston during reciprocation thereof, fluid supply and distribution means for said cylinder including fluid conducting passages formed in said piston, exhaust means for said cylinder with which said fluid conducting passages are communicable during movements of said piston, and passage forming means traversed by said fluid conducting passages upon angular movement of said piston for conducting live fluid to a drilled hole.

2; In a rock drill, a cylinder, a piston movable reciprecable therein on admission of motive fluid thereto, means for imparting angular movement to said piston during reciprocation thereof, fluid supply and distribution means for said cylinder including fluid conducting passages formed in said piston, exhaust means for said cylinder with which said fluid conducting passages are communicable during movements of said piston, and passage forming means traversed by said fluid conducting passages prior to the communication of the latter with said exhaust means and upon angular movement of said piston for conducting live fluid to a drilled hole.

3. In a rock drill, a cylinder, a piston reciprocable therein on admission of motive.

fluid thereto, means for imparting angular movement to said piston duing reciprocation thereof, fluid supply and distribution means for said cylinder including fluid conducting grooves formed on the periphery of said piston, exhaust means for said cylinoer traversed by said grooves during movements of said piston, and passage forming means communicable with said grooves during angular movement of said piston for conducting live fluid to a drilled hole.

4. In a rock drill, a cylinder, a piston reciprocable therein on admission of motive fluid thereto, means for imparting angular movement to said. piston during reciprocation thereof, fluid supply and distribution means for said cylinder including fluid conducting grooves formed on the periphery of said piston, exhaust means for said cylinder traversed by said grooves during movements of said piston, and passage forming means communicable with said grooves prior to the communication of the latter with said exhaust means and upon angular movement of said piston for conducting live fluid to a drilled hole.

5. In a rock drill, a cylinder, a piston reciprocable therein on admission of motive fluid thereto, rotation means for said piston, fluid supply and distribution means for said cylinder including circumferentially spaced fluid conducting grooves formed on the periphery of said piston, exhaust means for said cylinder controlled by said piston and with which said grooves are communicable, and passage forming means with which said grooves are sequentially communicable during rotation of said piston for conducting live fluid to a drilled hole.

6. In a rock drill, a cylinder, a piston reciprocable therein on admission of motive fluid thereto, means for imparting angular movement to said piston during reciprocation thereof, fluid supply and distribution means for said cylinder comprising a fluid inlet port and by-pass passages leading to the ends of the cylinder arranged in alinement longitudinally thereof, said piston having a series of longitudinally extending peripheral fluid conducting grooves adapted successively to connect said inlet port and bypass passages, exhaust means spaced circumferentially from said inlet port and controlled by said piston, said grooves communicating successively with said exhaust means during angular movement of said piston, and a port in said cylinder wall intermediate said inlet port and said exhaust means for conducting fluid from said grooves to the hollow drill steel.

7 In a rock drill, a cylinder, a piston reciprocable therein on admission of motive fluid thereto and having a striking bar thereon, means for imparting angular movement to said piston during reciprocation thereof, fluid distribution means comprising an inlet port, and bypass passages leading to the ends of the cylinder arranged in alinement longitudinally of said cylinder, a piston having a series of longitudinally extending peripheral fluid conducting grooves adapted to succesd sively connect said inlet port and by-pass passages, exhaust means comprising a port controlled by one end of said piston and spaced circumferentially from said inlet port and exhaust means controlled by said striking bar, said grooves communicating successively with said exhaust port during angular movement of said piston, and a port in said cylinder wall intermediate said inlet port and said exhaust port for conducting fluid from said grooves to the hollow drill steel.

8. In a rock drill, a cylinder, a piston reciprocable therein on admission of motive fluid thereto and having a striking bar thereon, means for imparting angular movement E to said piston during reciprocation thereof,

means cooperating with said piston to eflect intermittent but unidirectional rotation thereof, fluid distribution means comprising an inlet port and by-pass passages leading to the ends of the cylinder arranged in alinement longitudinally of said cylinder, a piston having a series of longitudinally extending peripheral fluid conducting grooves adapted to successively connect said inlet port and bypass passages, exhaust means comprising a port controlled by one end of said piston and spaced circui'nferentially from said inlet port, and exhaust means controlled by said striking bar, said grooves communicating successively with said exhaust port during angular movement of said piston, and a port in said cylinder wall intermediate said inlet port and said exhaust port for conducting fluid from said grooves to the hollow drill steel.

9. In a rock drill, a cylinder, a piston reciprocable therein, means for rotating said piston during reciprocation thereof, fluid distribution means comprising an inlet port and fluid conducting means on the periphery of said piston, exhaust means comprising a port in the cylinder wall, said port being disposed at a less distance longitudinally from said inlet port than the length of said fluid conducting means, and means for supplying cleansing fluid to the drilled hole including a port communicating with said cylinder bore intermediate said inlet port and said exhaust port.

10. In a rock drill, a cylinder having a pressure fluid supply passage communicating therewith and an exhaust passage, a piston reciprocable in said cylinder adapted to actuate a hollow drill steel having a circumferentially spaced longitudinally extending fluid conducting grooves formed therein, means for imparting angular movement to said piston during reciprocation thereof, a cleansing fluid supply passage communicating with said hollow drill steel, and means to successively connect one of said grooves with said supply passage, said cleansing fluid supply passage, and said exhaust passage during movements of said piston.

11. In a rock drill, a cylinder having a pressure fluid supply passage communicating therewith and exhaust means, a piston reciprocable therein adapted to actuate a hollow drill steel, spaced fluid conducting grooves formed in said piston, a passage adapted to supply pressure fluid to the hollow drill steel, and means to rotate said piston to cause one of said grooves to successively communicate with said pressure fluid supply passage, said passage adapted to supply pressure fluid to the hollow drill steel and said exhaust means during movements of said piston.

12. In a rock drill, a cylinder having a pressure fluid supply passage communicating therewith and an exhaust, a piston reciprocable therein adapted to actuate a hollow drill steel, circumferentially spaced fluid conducting grooves formed in said piston, a passage adapted to supply pressure fluid to the hollow drill steel disposed in the same plane as said pressure fluid supply passage, and means to rotate said piston to cause one of said grooves to successively communicate with said pressure fluid supply passage and said passage adapted to supply pressure fluid to the hollow drill steel and said exhaust.

13. In a rock drill, a cylinder having a pressure fluid supply port communicating therewith and an exhaust, a piston reciprocable in said cylinder adapted to actuate a hollow drill steel, circumferentially spaced longitudinally extending fluid conducting grooves formed in said piston, a cleansing fluid supply passage communicating with said cylinder and extending to said hollow drill steel and means to intermittently rotate said piston to successively connect said grooves with said supply port, said cleansing fluid supply passage and said exhaust.

14. In a rock drill, a cylinder, a piston reciprocable therein on admission of motive fluid thereto, means for imparting angular movement to said piston during reciprocation thereof, fluid supply and distribution means for said cylinder includin a plurality of fluid receiving pockets formed in said piston, exhaust means for said cylinder with which said pockets are communicable, and passage forming means traversed by said pockets during angular movements of said piston for conducting intermittent blasts of live fluid to a drilled hole.

15. In a rock drill, a cylinder, a piston-reciprocable therein on admission of motive fluid thereto, means for'imparting angular movement to said piston during reciprocation thereof, fluid supply and distribution means for said cylinder including a plurality of fluid receiving pockets formed in said piston, 4

exhaust means for said cylinder with which said pockets are communicable, and passage forming means traversed by said pockets prior to the communication of the latter with said exhaust means and during angular movement of said piston for conducting intermittent blasts of live fluid to a drilled hole.

16. In a rock drill, a cylinder, a piston reciprocable therein on admission of motive fluid thereto, means for imparting angular movement to said piston during reciprocation thereof, fluid supply and distribution means for said cylinder including fluid conducting passages formed in said piston, exhaust means for said cylinder with which said fluid conducting passages are communicable during movements of said piston, and passage forming means with which said fluid conducting passages are sequentially communicable during angular movement of said piston for conducting intermittent blasts of live fluid to a drilled hole.

17. In a r ck drill, a cylinder, a piston reciprocable therein on admission of motive fluid tiereto, means for imparting angular movement to said piston during reciproca tion thereof, fluid supply and distribution means for said cylinder including circumferentially spaced longitudinally extending fluid conducting grooves formed on the periphery of said piston, exhaust means for said cylinder with which said grooves are communicable during angular movements of said piston, and passage forming means with which said grooves are sequentially communicable during angular movement of said piston for conductingintermittent blasts of live fluid to a drilled hole.

In testimony whereof I aflix my signature.

ELMER G. GABTIN.

CERTIFICATE OF CORRECTION.

Patent No. 1,740,685. Granted December 24, 1929, to

ELMER G. GARTIN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 51, for the word "unexpected" read "unexpanded", and lines 88 and 89, claim 2, strike out the word movable"; page 3. line 98, claim 10, strike out the article "a" second occurrence; page 4, line 3, claim 12. strike out the word "and" and insert a comma; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 13th day of May, A. D. 1930.

M. J. Moore, (Seal) Acting Commissioner of Patents.

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