US3033551A - Tapping hole drill rig and drives - Google Patents

Description

May 8, 1962 A. BOWLAND 3,033,551

TAPPING HOLE DRILL RIG AND DRIVES Filed Feb. 4, 1960 4 Sheets-Sheet 1 IN VEN TOR.

May 8, 1962 A. BOWLAND TAPPING HOLE DRILL RIG AND DRIVES 4 Sheets-Sheet 2 Filed Feb. 4, 1960 INVENTOR.

BY 7 A L May 8, 1962 A. BOWLAND TAPPING HOLE DRILL RIG AND DRIVES 4 Sheets-Sheet 3 Filed Feb. 4, 1960 IN V EN TOR.

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May 8, 1962 Filed Feb. 4, 1960 A. BOWLAND TAPPING HOLE DRILL RIG AND DRIVES 4 Sheets-Sheet 4 INVEN TOR.

United States Patent 3,033,551 TAPPING HOLE DRILL RIG AND DRIVES Andrew Bowland, Pittsburgh, Pa., assignor to William M. Bailey Company, Pittsburgh, Pa., a corporation of Pennsylvania 7 Filed Feb 4, 1960, Ser. No. 6,731

11 Claims. (Cl. 266-42) This invention relates to new and useful improvements in apparatus for drilling tapping holes of metallurgical furnaces such as blast furnaces in steel plants.

The iron notch of a blast furnace must be opened by drilling a hole through the clay refractory material in the iron notch until the drill strikes the skull formed by the molten metal when further tapping is conducted by an oxygen lance to release-the molten metal which runs through the tap hole into the iron trough. The regular clay mixtures of about clay and /a coke breeze and crushed firebrick produces skulls Where the iron Washes the clay and when the hole is tapped, the iron flow will wash away the clay and enlarge the hole, which is subsequently plugged by means of a stream of clay under very high pressures.

In recent practice, the formation of a skull is eliminated by using a composition of 60% iron notch clay, 25% coke breeze and pitch or tar. The burning of the pitch or tar produces an exothermic reaction resulting in the formation of a porous refractory structure that will not wash away when contacted by the molten iron. It requires a somewhat larger drill to drill a hole in this material to tap the furnace because the hole does not en large with the flow ,of the molten iron therethrough.

Since there is no skull formed within the furnace, there is no need for the use of an oxygen lance and the hole may be tapped by drilling only.

The present invention deals with the mechanical drilling of tap holes by fully automatic means to eliminate the hazard of exposing workmen to the molten iron escaping from the iron notch and also to regulate the pressure on the drill tip during the drilling operation. Furthermore, by

.means of mechanical automatic equipment, the drill may be retrieved from the iron notch in time to save it from damage that would otherwise result from its contact with the molten iron emerging from the notch.

It is among the objects of this invention to provide apparatus for drilling tapping holes which utilizes a twostage feed mechanism, both stages of which may be operatedby pneumatic or hydraulic means or in which one stage may be operated by fluid pressure and the other by electric motor operated gear drives.

It is a further object of the invention to provide drilling apparatus for drilling tapping holes in which the forward feed of the drill may be actuated by one motor and the reverse movement 'by a second motor that are coordinated through an electrical control in a manner to automatically connect the reversing or retrieving motor when the feed motor is de-energized.

It is still a further object of the invention to provide a drill feed apparatus in which the movement of the drill is conducted in two stages, one of which includes a fluid pressure means which has the initial function of advancing the drill a predetermined distance and then maintain a predetermined drilling pressure on the drillbit while a a second stage of feeding is effected by a different actuating mechanism which advances the drill bit support on which said first stage feed mechanism is mounted.

It is still another object of the invention to provide a mount for the drilling apparatus for positioning the drill -in alignment with the iron notch of the furnace for the drilling operation and subsequently swing the drilling apparatus out of the region of intense heat in front of the iron notch when the iron is flowing therefrom.

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It is still another object of the invention to provide apparatus for drilling tapping holes in which the drill is driven by a motor mounted on a carriage that is slidably mounted on a traveling beam and is actuated by fluid pressure means, the traveling beam being suspended from a swinging boom and driven by an independent prime mover.

These and other objects of the invention will become more apparent from a consideration of the accompanying drawings constituting a part hereof in which like reference characters designate like parts and in which:

FIGURE 1 is a side elevational view of a tap hole drilling apparatus embodying the principles of this invention;

FIGURE 2 is a top plan view taken along the line 2-2, FIGURE 1;

FIGURE 3 is a rear elevation, partially in section, taken along the line 3-3, FIGURE 1;

FIGURE 4, a rear elevation, partially in cross section, taken along the line 4-4, FIGURE 5;

FIGURE 6 is a side elevation, partially in section, taken along the line 6-6, FIGURE 5;

FIGURE 7 is a diagrammatic illustration of the drill feed cylinder and air motor and the controls therefor;

FIGURE 8 is a diagrammatic illustration of the electrical and fluid pressure controls; and,

FIGURE 9 is a side elevational view corresponding to the view of FIGURE 1 of a modified form of traveling beam drive.

With reference to FIGURES 5 and 6 of the drawings, numeral 1 designates the wall of a cylindrical type of metallurgical furnace such asa blast furnace having an iron notch 2, a hearth 3, an iron runner 4 lined with refractory material 5, a slag runner 6 and a skimmer 7. The furnace is provided with a series of tuyeres 8 connected to the usual bustle pipe 9 and a furnace water trough 10 extends around the furnace wall. A splasher plate 10a extends above the iron runner 4 at the iron-notch to prevent the molten metal splashing around the equipment at the front of the furnace. In accordance with the present invention, drilling apparatus consisting of a drill 11 driven by a motor 12 mounted on a carriage 13, which in turn is mounted on a traveling beam 14, is mounted on a post 15 by means of a casting 16. Carriage 13 is operated by a piston cylinder 17. The frame 16 is mounted pling 20 to the motor 12 that is mounted on the carriage 13. The motor 12 is an air motor and is connected to a source'of fluid pressure by conduits 21 and 22. Conduit 21 is connected by a duct 23 and valve 24 to the air motor shaft 25 by a coupling 26, the motor shaft 25 being hollow conducts the air to the drill stem 11, which is also hollow, so that the air can be blown through the drill at all times to clear the cuttings at the drill bit and keep the drill cool. The carriage 13 is mounted on the traveling beam 14 in the manner shown in FIGURE 3, in which the traveling beam is an I-shaped member, the upper flanges of which are disposed in bearing strips or guides 27 and the lower flanges are disposed between the bearing strips or guides 28, the latter being securedto the carriage 13 that carries the drill motor 12 and the drill 11. The beam guides or strips 27 are disposed in an extension 29 of a bracket 30 having a flanged end 31 that is vertically movable in guides 32 and 33 of the boom 18, FIG- URE 2. The traveling beam 14 is provided with a sprocket 34, FIGURE 3, mounted on a-pad 35, the sprocket being engaged by a sprocket wheel 36 driven by shaft 37 journaled in anti-friction bearings 38 of a sleeve 39 that is mounted on the drive bracket 30. Shaft 37 is driven by gears 40 and 41, the latter being mounted on shaft 42 driven by a worm wheel 43 engaged by the Worm 44. The worm 44 is mounted on a shaft 45 of a gear reduction mechanism generally designated by the numeral 46, FIG- URE 2. which in turn is driven by a motor 47.

Shaft 45 is provided with a hand wheel 48 for manual operation when it is desired to move the traveling beam 14 a short distance for adjusting purposes.

The worm gear 43 is disposed in housing 49 and the shaft 45 extends through this housing to one side of a clutch 50. The other side of the clutch is connected to a drive motor 51 and the clutch collar 52 is actuated by lever 53 to engage and disengage the clutch with motor drives 46 and 51 in accordance with the direction of movement of the traveling beam 14. The clutch lever 53 is operated by an electrical solenoid 54 that controls the action of a pair of counterweights 55 and 56, shown in dotted lines in FIGURE 2.

Again referring to FIGURE 1 of the drawing, the motor drive support 30 may be raised or lowered by means of a hand wheel 60. ,This adjusts the vertical position of the drill 11 in relation to the iron notch shown in FIG- URE 6. A casting 61 is secured to the drive support 30', as shown by the pin and wedge 62 in FIGURE 2 of the drawing. A limit switch 63, FIGURE 1, having a switch arm 64, is engaged by a pair of lugs 65 and 66 that are adjustably mounted on a bar 67 that is carried by the traveling beam 14. The limit switch 63 controls the drive motor and reversing motor in accordance with the advanced position of the tap hole drill 11.

Carriage 13 slidingly mounted on the traveling beam 14, as shown in FIGURE 3, is provided with a bracket 68 connected to the end 69 of piston rod 70 that is disposed in a cylinder 71. The cylinder is fastened to the traveling beam 14 and is connected by conduits 72 and 73 to a source of fiuid pressure such as compressed air.

The cylinder 71 may move the carriage 13, to which the drill 11 is connected, towards the iron notch the distance of travel of the piston rod 70 and the traveling beam 14 may then be moved in the same direction by means of the drive motor 47 until the drill has bored out the iron notch and released the molten metal that has accumulated on the hearth 3 of the furnace, FIGURE 6.

The total movement of the piston rod 70 and the traveling beam 14 determines the distance of travel of the drill from its retracted position shown in FIGURE 5, to its fully advanced position shown in FIGURE 6. In operation, the cylinder 71 is first operated to advance the drill carriage 13 the distance of travel of the piston rod 70. A predetermined pressure is maintained in cylinder '71 to assert a predetermined pressure on the drill bit. Subsequent feeding of the drill by movement of the traveling beam 14 will not alfect the pressure on the drill bit because if the feeding pressure of the traveling beam is greater than the pressure in cylinder 71, the drill will simply not advance into the tapping hole. It will not retract but it will stand still because carriage 13 will be standing still while the traveling beam 14 continues forward movement in the dircetion of the iron notch. This is an important feature of the invention, because the combination of the air pressure feed and the motor drive feed provides even feeding of the drill and will not plunge the drill into the furnace when it breaks through the refractory in the iron notch. When the drill breaks through the refractory in the iron notch, limit switch 63 will trip and energize the reversing motor 51 and the solenoid 54 for effecting engagement of the clutch operator 52 with clutch 5h. The reversing motor operates at about twenty times the speed motor 47, so that the drill will be retrieved rapidly to avoid damage by burning or otherwise.

In the modification shown in FIGURE 9, the drill carriage and air motor and the carriage operating cylinder function in the manner described in connection with apparatus in FIGURE 1. However, instead of the traveling beam 14 being driven by the sprocket wheel, it is operated by an air cylinder 75 so that the total length of travel of the drill bit will be the length of the piston and cylinder 71 and piston and cylinder 75. The numeral 76 designates the piston rod in its extended position, the rod being connected at 78 to a bracket 79 attached to the traveling beam 14.

Like in the motor driven travel beam construction of FIGURE 1, the air feed cylinder 71 initially feeds the carriage 13 to advance the drill 11 into the iron notch. Pressure is then maintained in cylinder 71 while cylinder 75 is subjected to fluid pressure to advance the travel beam 14. If any abnormal resistance is encountered by the drill bit, continued forward feeding of the traveling beam 14 will not increase the pressure on the drill bit that is set by the pressure in cylinder 71.

The drill feed and pressure maintaining character-' istics of the air cylinder 71 will be more clearly understood from a consideration of FIGURES-7 and 8 of the drawing in which the conduits 72 and 73 are provided with regulating valves 80 and 81 that control the speed of piston travel that feeds the drill '11 into the refractory material of the iron notch. The numeral 82 designates a regulating valve which determines the pressure maintained in the cylinder 71 when the piston that feeds the drill has been extended. The numeral 83 designates hose connections, since the conduits 72 and 73 are flexible members. I The air motor 12, which is properly called the drill motor, is shown with the by-pass 23 and regulating valve 24 of FIGURE 1 by which air is conducted from the air conduit 21 to the hollow drill motor shaft 25 and thence through the hollow drill to the end of the drill bit to keep it cool and blow out the cuttings.

Numerals 84 and 85 designate operating valves and the numerals 86 and 87 designate pressure indicators.

In FIGURE 8 is shown a control panel with the two pneumatic controls 84 and 85 and some electrical controls 88, 89 and for the feed drive motors and the motor 19 for swinging the boom 18 that brings the drilling apparatus into alignment with the iron notch. I

As shown in FIGURE 5, the boom 18 is secured by a latch generally designated by the numeral 18a that extends from the wall of the blast furnace. The above-described apparatus operates briefly as follows:

Assuming the blast furnace is ready to be tapped to release the molten iron that has accumulated on the hearth 3 into the iron trough 4, motor 19.is energized by the control 90 and the boom 18 is swung from the dotted line position of FIGURE 5 to the full line position of FIGURE 5, which brings the drill 11 in alignment with the iron notch 2, FIGURE 6. In this position the drill 11 is in the center of the iron trough 4, as shown in FIGURE 5. The drill bit is centered vertically by adjusting the hand. wheel 66, FIGURE 1, and control $4 is operated to supply air through conduit 73 to the air cylinder 71. This moves the carriage 13 in a forward direction. Drill 11 is rotated by control 85, which directs compressed air to the air motor 12 to revolve the same and simultaneously valve 24 is opened to allow air to pass through the drill body and out at the end of the drill bit. The air motor 12 is energized before the air cylinder 71 is connected to the air supply so that the drill will be rotating at the time it is advanced in the direction of the iron notch. After the drill has been fed forward into the refractory material in the iron notch the distance of the piston travel in cylinder 71, the operator will turn valve 82 to maintain a predetermined pressure, as shown by indicator 86, FIGURE 7, on the drill bit. This pressure varies with the characteristics of the refractory material in the tapping hole and is set to maintain a uniform constant feed. The drive motor 51 is then energized by the controls 88 and 89 and the sprocket wheel 36 is rotated to move the traveling beam 14 in the direction of the iron notch and thus take over the feeding of the drill until it has penetrated into the furnace proper. If for any reason the drill meets with an obstruction such as a skull of the metal, the feeding of the traveling beam 14 does not impose any greater pressure on the drill bit because the pressure has already been determined by the pressure maintained in cylinder 71 and as the traveling beam 14 advances, the drill will simply remain stationary because the piston will be displaced by carriage 13 back into the cylinder 71.

This preset pressure on the air cylinder 71 not only provides uniform feeding, but also prevents the drill from plunging into the furnace when it breaks through the refractory material. However, the instant the drill does break through the refractory material in the iron notch, limit switch which has been set for the depth of drilling by means of the lug 65 and 66 will trip and de-energize motor 55 while at the same time energizing the reversing motor 47. This automatically energizes solenoid 54 which trips the clutch lever 53 and causes a reversal of the direction of rotation of the sprocket wheel 36 to retract the traveling beam and the drill. At the same time, the piston and cylinder 17 will be retracted and the drill is withdrawn from the iron notch before it can be damaged by the molten iron that flows out of the furnace into the trough 4. The operator then energizes motor 19 and swings the boom to the position shown in dotted lines in FIGURE 5 after releasing the latch 13a and the drill is out of the way of the hot molten metal that runs through the iron trough 4.

The operation of the modified form of the device shown in FIGURE 9, in which both the carriage 13 and the traveling beam 14 are moved by air pressure, is similar to that of the apparatus in FIGURE 1, except that the traveling beam is moved forward and reversed by operation of the air cylinder instead of the two electric motors; By means of the above-described drilling apparatus, tapping holes of blast furnaces and the like may be drilled by means of mechanical and fully automatic operation to avoid exposing workmen to the hazards incident to tapping iron notches, since there is no workman near enough the iron notch to be subject to danger when the flowing metal erupts from the iron notch. By means of this type of drilling equipment plugging compositions employing pitch or tar may be employed which is not washed away tion of rotation and a second prime mover for driving said wheel at high speed in the reverse direction of rotation.

3. Apparatus as set forth in claim 1 in which the carriage moving means consists of a fluid pressure cylinder having a piston connected to said carriage and control means for regulating the fluid pressure in said cylinder to thereby regulate the feeding pressure on the drill independently of the rate of movement of the beam in the by the molten iron and which prevents the formation of a skull at the end of the tapping hole.

The forward and reverse movements of the drill may be manually controlled instead of the automatic control by limit switch 63.

Although several embodiments of the invention have been herein illustrated and described, it will be evident to those skilled in the art that various modifications may be made in the details of construction without departing from the principles herein set forth.

I claim:

1. Apparatus for drilling tapping holes in iron notches consisting of a supporting frame, a traveling beam slidably mounted on said frame, drive mechanism for subjecting said beam to axial movement in opposite directions, a carriage mounted to be movable in an axial direction on said beam, means for subjecting said carriage to movement in opposite directions, a drill motor on said carriage, a drill connected to be actuated by said motor and means for maintaining a predetermined feeding pressure on said drill during the travel of said beam and carriage in the direction of the tapping hole. I

2. Apparatus as set forth in claim 1 in which the drive mechanism for subjecting the beam to sliding movement consists of a rack and gearwheel, a prime mover for driving said wheel at relatively slow speed in one direcdirection of the tapping hole.

4. Apparatus as set forth in claim 1 in which the carriage moving means consists of a fluid pressure cylinder having a piston connected to said carriage for extending the drill the length of piston travel, and control means for energizing the beam sliding drive to feed the drill into the iron notch while maintaining a predetermined pressure on said carriage piston.

5. Apparatus as set forth in claim 1 in which the carriage moving means consists of a fluid pressure cylinder having apiston connected to said carriage for extending the drill the length of piston travel and maintaining a predetermined pressure on said piston during and after movement of said carriage and during the drill feeding movement of said beam.

6. Apparatus as set forth in claim 1 in which the drill motor has a hollow shaft and the drill a hollow shank and a source of air pressure connected to said shaft to cool the drill shank and supply a blast of air to the drill bit.

7. Apparatus as set forth in claim 1 in which the carriage is actuated by an air cylinder and movement of the carriage on the beam is reversed when the cutting resistance to the drill exceeds the feeding pressure on the carriage.

8. Apparatus as set forth in claim 1 in which thebeam supporting frame is mounted on a slide for vertical adjustment and the slide is mounted on a swivel arm with means for latching the arm in drilling position.

9. Apparatus as set forth in claim 1 in which the carriage travel is substantially one-half the distance of feed travel of the drill and the movable beam the other half of the drill travel, and the carriage and beam are simultaneously retractable for fast removal of the drill from the tapped hole.

10. Apparatus as set forth in claim 2 in which the prime movers are electrical motors connected by a clutch to the'bearn drive, said clutch being actuated by a solenoid that is energized to move the clutch to connect the high speed motor to the beam drive when the low speed motor is de-energized.

'11. Apparatus for drilling tapping holes of metallurgical furnaces comprising a traveling beam mounted on a drive support for sliding movement thereon, a carriage mounted on said beam having a drill motor and drill supported thereon, an air cylinder and piston for actuating said carriage and actuating means for subjecting said traveling beam to sliding movement, means for supplying fluid pressure to said air cylinder to advance the drill carriage in the direction of the tapping hole and for maintaining a predetermined pressure on the drill bit and means for energizing said traveling beam actuating means to advance the beam in the same direction as the carriage.

References Cited in the file of this patent UNITED STATES PATENTS 1,911,138 Clute et al. May 23, 1933 1,916,261 Giese July 4-, 1933 2,418,021 Fleischer Mar. 25, 1947 2,626,667 Spiller Jan. 27, 1953 2,640,376 Johnson June 2, 1953 2,768,539 Wollenhaupt et al. Oct. 30, 1956

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