US 2359971 A
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Description (OCR text may contain errors)
1944- J. c. CURTIS DRILLING APPARATUS Filed Dec. 16, 1941 Patented Oct. 10, 1944 DRILLING APPARATUS John C. Curtis, Claremont, N. H., assignor to Sullivan Machinery Company, a corporation of Massachusetts Application December 16, 1941, Serial No. 423,193
My invention relates to drilling apparatus and more particularly to improved means for laying the dust emerging from a drill hole during drilling operations.
There is produced in the drilling of material such as rock, especially where hammer type drills are employed, a fine dust which emerges from the drill hole and mixes with the air making the latter unfit for breathing by the operator of the drill. It is, therefore, desirable that some means be provided for laying the dust produced in the hole. If fine streams of liquid are directed into the drill hole around the drill rod so that practically a continuous sheet of liquid is formed across the space between the wall of the drill hole and the surface of the drill rod, as in my invention, there is produced a very effective screen which prevents the escape of dry dust from the hole. The spraying of liquid into the hole during drilling is very effective in laying the dust since the particles of material are confined in a comparatively small space and a contact of the liquid with most of the particles is assured.
An object of my invention is to provide improved means for laying dust produced during drilling operations. Another object is to provide improved means for spraying liquid into a drill hole during drilling operations and producing a screen for preventing the escape of dry dust particles from the hole. Still another object is to provide with a drill mechanism of the hammer type, improved means for spraying liquid into a drill hole around the drill rod in a manner to assure an engagement between the liquid spray and the particles of dust produced in the hole. Yet another object of my invention is to provide an improved tool holding and dust allaying arrangement for use with solid tools. Other objects and advantages will appear in the course of the following description.
In the accompanying drawing I have shown for purposes of illustration one embodiment which my invention may assume in practice.
In the drawing:
Fig. 1 is a central vertical section through a rock drilling motor having the preferred embodiment of my invention associated therewith, some parts of the motor being shown in elevation.
Fig. 2 is an enlarged cross sectional view taken on the line 2-2 of Fig. 1.
Fig. 3 is an enlarged cross sectional view taken on the line 33 of Fig. 1.
In this illustrative construction the improved liquid spraying means, generally designated I, is
shown associated with a pneumatically operated, hammer type drill motor, generally designated 2, but it will be appreciated that the spraying means may be used as well with drill motors of other types.
The drill motor 2 comprises a cylinder 4 having a bore 5 within which a hammer piston 6 is reciprocably mounted. Formed on the hammer piston and extending forwardly through a front cylinder head I is a striking bar 8 for delivering impact blows to the rear end of a member 9 which transmits the impact blows of the hammer piston to a suitable working implement such as a drill tool Ii]. This member 9, in this instance, acts as a chuck for supporting the drill tool In and also forms the body of the improved spraying means I. At the rear end. of the cylinder bore is a rear head plate ll having a central opening through which a rifle bar [2 extends from a pawl and ratchet mechanism, generally designated I4. The rifle bar operatively engages a rifle nut l6 fixed within the hammer piston 6 for effecting rotation of the latter, in a manner well known by those skilled in the art, during its rearward reciprocatory movements within the cylinder bore. A rear head block I8 is provided with a recess for receiving the pawl and ratchet mechanism 14 and the rear head plate II, and is clamped by any suitable means, not shown, in engagement with the rear end of the cylinder 4 for holding the parts' in position. Motive fluid is distributed to the hammer motor through means, not fully illustrated, as it is unnecessary to the disclosure of the invention, but including a distributing mechanism generally designated 20 and embodying a distributing valve means for controlling fluid flow to the motor cylinder through suitable passages, in a well known manner. Fixed to the front cylinder head 1 by suitable means, not shown, is a chuck housing 2| having a chuck sleeve 22 rotatably mounted therein. Threaded within the chuck sleeve is a chuck nut 23 having straight grooves 25 for receiving straight lands 26 formed along the striking bar 8 whereby rotary movements of the hammer piston are transmitted to the chuck sleeve.
The member 9 is provided with a reduced rear portion 28 extending into the chuck sleeve 22 for receiving the blows from the striking bar of the hammer piston. In order that the member 9 may be rotated with the chuck sleeve, there are provided flat surfaces 29 along the portion 28, as shown in Fig. 2, and these fiat surfaces engage fiat surfaces 33 on the chuck sleeve. Formed in the forward end of the member 9 is a recess 3!, shown herein as being conical in shape, for receiving the rear end of the drill tool In and supporting the latter in axial alinement with the drill motor. At the rear end of the recess 3| is a slot 33 extending transversely through the member 9 and providing a space for receiving a suitable member, such as a wedge, for engaging the rear end of the drill tool and forcing the latter out of the recess 3!. The member 9 has associated with it liquid spraying means which comprises a passage 35 extending axially through the portion 23 of the member 9 and opening at its rear end into the chuck sleeve 22. Formed in an enlarged forward portion of the member 9 are passages 35 opening into the passage 35 and extending forwardly and outwardly from the longitudinal axis of the member 9. At the forward end of the member 9 is a circular recess 3? surrounding the opening of the recess 3!, and opening into this recess are passages 38 extending rearwardly and outwardly through the member 9 into communication with the passages 35. The forward ends of the passages 36 are stopped by plugs 39 so that any liquid supplied to the passages 35 will be directed through the passages 3% to the forward end of the member 9. The angle at which the passages 33 are formed is such that water discharging from the passages into the annular space or circular recess 3'! surrounding the rear portion of the drill tool is directed in streams converging at the forward portion of the tool. Desirably the inclination of the holes 38 is such that their axes extended meet the surface of the tool it just to the rear of the enlarged cutting head of the tool, and thereby, since, the jets expand as they leave the holes 33, at least a portion of the liquid discharged will enter the hole formed regardless of its depth within usual drilling ranges. The passages $6 and 38 are spaced angularly about the axis of the member 9 so as to provide a uniform distribution of liquid about the drill tool in streams that are closely spaced.
Any suitable means may be employed to supply a dust allaying fluid to the passages in the memher 9. According to the present invention, a tube ii extends axially through the pawl and ratchet mechanism 14, the rifle bar I2 and the striking bar 8, as is customary with wet drills, for conducting a liquid, such as water, from a chamber 52 in the rear head block 8 to the passage 35 within which the forward end of the tube terminates. Suitable connections are provided for supplying Water to the chamber 42 under pressure, and a packing 43 surround the rear end of the tube for preventing the escape of water from the chamber along the outer periphery of the tube.
As pressure fluid is supplied to the motor cylinder bore under the control of the distributing mechanism 20 to effect reciprocation of the hammer piston, the pawl and ratchet mechanism causes a slight rotary movement of the hammer piston on each of its rearward strokes. The rate of reciprocation is such, however, as to cause the hammer piston to rotate as much as several hundred revolutions per minute. Since the chuck sleeve 22 is operatively connected to the striking bar 8 of the hammer piston for rotation with the latter, and since the member 9 is connected through its portion 28 to rotate with the chuck sleeve, it willbe seen that the liquid conducting passages 36 and 38 will be caused to rotate about the longitudinal axis of the drill motor at the same rate as that of the hammer piston. As the passages travel around the axis of the motor, the streams of water discharged from the passages produce practically a continuous conical sheet of Water surrounding the drill tool and moving into the drill hole across the space' between the wall of the hole and the surface of the tool for wetting the dust particles and preventing the escape of the latter in dry condition from the hole.
As a result of this invention there are provided improved means for preventing the escape of dust from a hole while the hole is being drilled. It will be noted that the improved dust laying means is very compact, is inexpensive, and is adapted for use with drill mechanisms of various types. When the hole is shallow the jets will discharge along the tool surface into the hole; as the hole deepens the jets will enter the hole mouth directly; and if the hole gets so deep that the jets no longer directly enter the hole a radial sheet of liquid will, due to the direction and rotation of the jets, screen the mouth of the hole.
While there is specifically described in this application one form which my invention may assume in practice, it will be understood that this form of the same has been shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.
What I claim as new and desire to secure by Letters Patent is:
1. In an apparatus of the character described, a mounting for a drilling implement including a shank slidably receivable in a socket and adapted to have blows imparted thereto, a body formed integral with said shank and providing a tool socket, and means including forwardly and inwardly inclined passages in said body for discharging a liquid externally of a tool received in said tool socket and forwardly and inwardly into a hole formed by the tool.
2. In an apparatus of the character described, a mounting for a drilling implement including a shank slidably receivable in a socket and adapted to have blows imparted thereto, an enlarged body formed integral with said shankand providing a tool socket, and means for discharging streams of liquid longitudinally along the outer surface of a tool arranged in the tool socket, said last mentioned means including a passage extending axially through the shank and a plurality of passages in said enlarged body opening through the latter at points surrounding the tool socket, said plurality of passages being inclined forwardly and inwardly to direct liquid toward the mouth of a hole formed by the tool.
JOHN C. CURTIS.