US1570239A - Drilling machine - Google Patents

Description

Patented Jan. 19, 1926.

UNITED STATES PATENT OFFICE.

DRILLING MACHINE.

Application filed September 4, 1920. Serial No. 408,282.

To all whom it may concern.

Be it known that l, GEORGE H. GILMAN, a citizen of the United States, and a resident of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Drilling Machines, of which the following description in connection with the accompanying drawings is a specification, like characters on the drawings representing like parts.

My invention relates to drilling machines and particularly but not exclusively to a hammer rock drill.

My invention will be best understood from the following drawing and specification of one specific embodiment of my invention submitted for illustrative purposes, while its scope will be more particularly pointed out in the appended claims.

In the drawings:

Figure 1 shows a longitudinal sectional elevation of the submitted embodiment of my invention.

Fig. 2 shows a partial section on the line 22 of Fig. 1.

Figs. 3 and 4 respectively show sections on the lines 33 and 4-4 of Fig. 1; and

Fig. 5 shows a section on the line 5-5 of Fig. 2.

The submitted embodiment of my invention comprises a cylinder member 1 provided with a large bore 2 and a reduced forward bore 3. Mounted for reciprocation in the cylinder is a piston having a large portion 41 fitting the large bore 2 of the cylinder and an extension or hammer bar 5 adapted to enter and fit in a fluid tight manner the reduced bore 3 of the cylinder. At the front end of the cylinder is rovided a chuck bushing 6 which carries t e shank of the drill steel 7. The rearward end of the cylinder is closed by the head plate 8 provided with a reduced portion 46 which enters the bore 2 of the cylinder. The head plate forms one section of a valve cage, the other section of which is provided by the block *9, held in assembled relation, as tar as angular movement is concerned, with the plate 8 by member beiandg means of dowels 10.

Carried by the cylinder member is a head block 11 and slida-bly mounted on the exterior cylindrical portion thereof is a sleeve 12 of the handle member 13, the handle held in assembled relation with the'he block by means of the nipple 14, which is screw-threadedly secured to the head block and extends through a slot 15 in the sleeve. The nipple 14 serves as aconnection for the airhose for supplying motive fluid for operating the machine.

For controlling the supply of motive fluid I provide a throttle valve 16 which is adapted to be actuated by movement of the handle member relative to the head block. As the specific details of the throttle valve and its operating mechanism form no part of my present 1nvent1on, the same will not be further described except in so far as necessary to explain how they are coordinated with the other portions of my device. The head block is recessed to form a sleeve 17 secured by means of the screw threads 18 to the rearward portion of the cylinder. At one side of the sleeve l provide a boss 19, which is perforatedto receive a bolt 20, the head 21 of which is cut away at 22 to conform with the exterior surface of the cylinder. When the sleeve is screwed into position, the bolt 20 may be tightened by means of the nut 23 to bind the surface 22 of the bolt head against the surface of the cylinder and thereby prevent relative turning between the head block and cylinder.

At the bottom of the recess of the head block forming the sleeve is formed an annular passage 24 in communication with the passage 25 adaptedto be placed in .communication with the source of motive fluid by means of "the throttle valve 16 in the manner hereinbefore referred to. As is clearl shown by Fig. 1, the sleeve of the head lock receives the valve cage sections 8 and 9,'and when the sleeveis screwed into position it clamps the o posed faces of the valve cage sections toget er, clamps the opposite face of the section 8. to the rear face of the cylinder and clamps the opposite face of the section 9 to the face formed by the bottom of the recesses in the sleeve, in order to hold the parts firmly in assembled relation and to form fluid tight joints between the faces mentioned.

The opposed faces of the valve cage sections 8 and 9 are recessed to form similar U-shaped passages 26, the recesses in the section 9 are being connected to the annular groove 24 in the head block by means of passages'27 communicating with the legs 28 of the recesses. As illustrated in Figs. 1

lid

and 4-, the recesses are provided with upstanding annular portions providing the valve seats 29 30. Between the valve seats is adapted to vibrate a reed serving as controlling valve for supplying motive fluid for actuating the piston. lhis reed is in the form of a steel spring 31, one end of which is secured to the valve cage. For so securing the reed, l have shown one side thereof provided with a raised portion 32, received in a recess in the valve section 8, the end of the reed being adapted to be clamped between the opposed faces of the sections when the head block is screwed on the cylinder. The portions of the sections adjacent the reed may be cut away to allow the same to vibrate and for this purpose I have shown the valve cage section 8 cut away to form the slot 33, the opposed walls of which form a guide for the edges of the reed. For permitting the reed to seat I have shown the valve seat 29 bevelled to conform to the shape which the surface of the reed assumes when in contact with the valve seat.

Leading from the seat 29 is a passage 34 for conducting motive fluid to the rear end of the cylinder, and from the seat 30 leads a simlilatr passage 35 which connects by means. of the passage 36 at right angles thereto with a passage 37 extending through both valve cage sections and the wall of the cylinder to the front end of the latter and communicating therewith through a port 33. It will thus be noted that the sections of the valve cage are recessed to provide a motive fluid chambpr which is connected to the source of motive fluid and to opposite ends of the cylinder and that when the sections are clamped together, said chamber is rendered fluid tight, and further that l have provided means carried by said sections which clamp one end of the reed between the sections to provide means for securing the reed to one of them.

For exhausting the front end of the eviinder, the forward reduced bore is provided with an annular groove 39 which communicates by way of the passage 40 with the atmosphere. When the hammer bar 5 withdraws from the bore3 of the cyl nder, the front end of the cylinder is connected to the atmosphere and when the hammer bar euters the reduced bore such communication is interrupted. For exhausting the rear end of the cylinder it provide passages ll in communication with an intermediate portion of the cylinder by way of a slot 42. At their other ends these passages extend into the valve cage section 8 and open into a slot 4:3 in communication with the annular groove dd formed in the head block sleeve. The groove ll communicates with the atmosphere by means of a passage 45. When the rear end of the cylinder in its forward stroke uncovers the passage l2, the rear end to the U-shaped recess formed by the valvecage sections, passes across the valve seat 3 and into the passage 35 whence it finds its way to the front end of the cylinder through the passages 36, 37 and 38. At this time the rearward end of the cylinder is connected to the atmosphere through the groove 42, the

passages all, grooves a3 and dd passage to and under these conditions the reed is held firmly against the valve seat 29 and the piston moves rearwardly.

/V hen the piston moves rearwardly through part of its stroke it covers the eshaust exit 42 from the rear of the cylinder and hence traps and compresses motive iluid in the rear end of the cylinder, which tluid exerts sufficient pressure on the reed through the port 34 to cause the reedto move into contact with the opposite seat 30, this movement if the compression is not sufficient to effect it being aided by the reduction of pressure in the ll-shaped passage of the valve cage when the hammer bar with draws from the reduced cylinder portion 3, thereby opening the passage 37 to the atmosphere. When the valve moves to the position opposite to that shown by Fig. 1, the air is admitted to the rear end of the cylinder through the port 3% to drive the piston forwardly, the exhaust from the front-end escaping through the reduced cylinder portion 3 to the atmosphere ,by way of the grooves 39 and passage 40. W hen the hammer bar enters the reduced cylinder portion, the exhaust in the forward end is out ed and the motive fluid trapped in the cylinder is compressed. The pressure of the compressed fluid is transmitted to the valve through the port 38, passages 37, 36 and 35 and acts on the valve to exert a force tending to reverse it, which tendency will be increased if insufficient to shift when the piston uncovers the groove 4:2 and thereby reduces the pressure in the valve cage by permitting the live air then being admitted through the passa e 35 to the rear end of the cylinder to ex aust directly to the atmosphere. It will be ob= served that the motive fluid which is compressed in the front end of the cylinder acts on a much smaller area of the piston thanrthe motive fluid which is compressed in the rear end of the cylinder and further that there is a larger volume of motive fluid compressed on the rearward stroke than on the forward stroke. This permits the piston on its forward stroke to exert greater power than on its rearward stroke, which results in lessened rec roe

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and clamped vibration against the hand of the operator while delivering a powerful blow to the tool.

Although I have described one specific embodiment of my invention for illustrative purposes it is to be understood that I am not limited thereby to its specific mechanical details or to its proportion or arrangement of parts and that extensive deviations therefrom may be made without departing from the spirit of my invention.

Claims:

1. A percussive tool having in combination, a cylinder,a hammer piston for actuating a work performing tool carried at the forward end of said cylinder, a valve cage closing the rearward end of said cylinder, a handle' member having a socket receiving the end of said cylinder and clamping said valve cage to said cylinder, said valve cage having transverse sections with opposed peripheral annular faces in fluid tight contact, a chamber formed in said cage and surrounded by said annular faces, a passage leading from said handlev member to said chamber, a vibratory reed removably clamped between said sections and extending transversely into said chamber, said reed at one end thereof having a projection enterin a recess in one of said sections for positidning said reed and for preventing slipa e ai d cylinder and entering said chamber through ports at opposite sides of the free end of said reed whereby said reed may control said ports.

2. A percussive tool having in combination, a cylinder, a piston, a valve cage carried by said cylinder, said valvecage having sections, means for clamping said sections together, a reed clamped at one end between said sections, said end of said reed having a transverse projection, and a transverse recess in one of said sections receiving said projection.

3. In a percussive drill, a cylinder, a piston therein, a sectional valve cage, a vibratory reed positioned transversely of said cylinder, a head block adapted to receive said valve cage, means for securing said head block to said cylinder adapted to clamp said reed between said sections, and means for coordinately actuating said reed an said piston including ports and passages formed in said section and in said cylinder for conveying motive fluid controlled by said reed and by said piston.

l. In a percussive drill, a valve cage having opposed sections with annular faces in fluid tight contact, fluid passages formed in said sections, a vibratory reed for controlling said assages carried by said cage between said annular faces of said opposed sections, and means for positioning and holding said reed in alignment with said ports.

thereof, and passages leading" from 5. In a percussive drill, a cylinder, a piston therein, a valve cage having a plurality of sections, one of said sections having formed therein a recess, a passage leading from said recess to one end of said cylinder, another section having a passage leading to the cylinder end opposite to the first mentioned cylinder end and communicating with said recess, seats about the connections of said passages with said recess, a vibratory reed having a portion interposed between said seats and another portion between the opposed faces of said sections, said opposed faces having portions in fluid tight relation to prevent the passage of fluid from said recess to the exterior of said cage, and means for clamping said sections together.

6. In a percussive drill, a piston, members secured together and forming a fluid tight chamber therebetween, a vibratory reed extending through said chamber, said reed being detachably clamped at one end thereof between said sections adjacent one side of said sections, said reed and one of said sections having means for positioning said reed relatively to said sections and for preventing lateral movement of said reed, valve seats on opposite sides of said reed, a source of motive fluid, a connection from said source to said chamber, and passages for conducting said motive fluid from said seats to actuate said hammer.

7. In a percussive drill, a piston. members secured together and forming a fluid tight chamber therebetween, a vibratory reed clamped between said members and extending through said chamber, said reed having a projecting portion at one end received by a recess in one of said sections, valve seats on opposite sides of said reed, a source of motive fluid, a connection from said source to said chamber, and passages for conduct ing said motive fluid from said seats to actuate said hammer.

8. In a percussive drill, a cylinder, a piston, members secured together at one end of said cylinder and forming a fluid tight chamber therebetween, a vibratory reed, extending through said chamber transversely to said cylinder, said reed being at one end thereof clamped between said members, valve seats on opposite sides of said reed, a source of motive fluid, a connection from said source to said chamber, and passages for conducting said motive fluid from said seats to actuate said hammer.

9. In a percussive drill, a cylinder, a piston therein, a member having a passage connected to a source of motive fluid, a second and a third member aligned with each other and with the first member, one of said second and third members being recessed to provide a chamber, one of said second and third members having a passage for connecting said chamber with the passage of lid the first member, Vibratory reed in said chamber and having one end thereof damped between said second and said third members, means for detachably connecting said first mentioned member to said cylindeifor clamping said second and third members together, and valve seats and passages arranged with said reed for the admission of fluid alternately to the opposite ends of said cylinder.

10. in a neumatic hand hammer a cylinder, a free impact piston in said cylinder, a head block closing the rearward end of said cylinder, said head block having transverse sections, a handle member engaging said cylinder and holding the sections of said ease head block in assembled relation therewith, a removable vibratory reed carried by said head block transversely of said cylinder and being clamped at one end between said sections, a source of motive fluid, ports and passages controlled by said vibratory reed for alternately admitting fluid from said source to opposite ends of said cylinder, and exhaust means for said cylinder directly controlled by said piston and arranged to be closed before the piston reaches the end of its stroke in each direction.

In testimony whereof, I have signed my name to this specification.

enonen H. UKLMAN.

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