US2528770A - Automatic scarfing machine - Google Patents

Description

Nov- 7, 1950 E. MEINCKE 2,528,770

AUTOMATIC SCARFING MACHINE Filed May 23, 1946 46 /6 1 60 AMP TIMER CONTIROL I /Z W @161 /W CW EDWAR B EA E I FJ cKE M 14 BY W ATTORNEY t e-tented Nov. 7, 1950 AUTOMATIC SCARFING MACHINE Edward Meincke, Summit, N. J., assignor to The Linde Air Products Company, a corporation of Ohio Application May 23, 1946, Serial No. 671,711

Claims.

This invention relates to automatic machines for working bodies constituting a source of radiant energy such as hot steel.

Thi application is a continuation-in-part of application, Serial No. 620,700, filed October 6,-

1945. by Homer W. Jones and Edward Meincke, for Fully Automatic Desurfacing Control System, now Patent No. 2,479,624, issued August 23, 1949.

The main object of this invention is to provide an automatic scarfingmachine in which all of the functions are automatically carried out completely independently of any manual control other than that necessary to start the machine. Another major object of the invention is to pro vide improved means for progressively controlling the operating cycle in accordance with the positions of each body from th time it enters until the time it leaves the machine.

According to the invention, a hot ferrous metal body to be scarfed passes on a conveyor such as a roll table through loaded side guides arranged so a to gauge the thickness and width thereof, nefcre it passes through driven straightening rolls and oxy-fuel gas scarfing blowpipe heads located at a desurfacing station. The loaded side guides have Selsyn transmitters connected to them. These transmitters are coupled to Selsyn receivers the straightening rolls, blowpipe heads, and the gas control valves. Thus, when the body passes between the loaded side guides, the straightening rolls, blowpipe heads, and an appropriate number of nozzles are sized automatically by the Selsyn system.

At least one detecting device which is responsive to radiant energy from the hot body is located in the machine so as to respond to the presence of such body and control subsequent movement of the body in conjunction with the entire thermochemical scarfing thereof.

Tests have indicated that a photocell will react to flying sparks produced by the thermochemical desurfacing action. This applies whether or not the photocell is operated by light radiated from the hot steel, or from a separate light source using the body to be scarfed fo interrupting the light beam. Such difliculty has been solved, according to the invention, by use of infra-red sensitive means such as a thermopile detecting device consisting, for example, of a group of series-connected thermocouples on which the radiated heat energy from the hot steel is focused by a suitable optical system. This type of device is known as a radiation pyrometer. The voltage produced by the device is fed into an electronic amplifier and therein the energy output is stepped-up to a value where relays or other devices of like type can be operated under the control of energy radiated from the hot steel passing through the machine.

In the accompanying drawing:

Fig. 1 is a view in side elevation of a fully automatic scarfing machin exemplifying the invention;

Fig. 2 is a circuit diagram illustrating how the detectors are connected; and

Fig. 3 is a circuit diagram of a modification involving the use of only one detector.

Referring to Fig. 1 of the drawing, the illustrated machine M, which is adapted to be used in a steel rolling mill, preferably comprises a suitable frame F containing front and rear sets of upper and lowe horizontal rolls [2 and I4, and corresponding pairs of vertical rolls 16, through which the work W, such as a bar of hot steel, moves in passing through the machine. The rolls convey and guide the work W through the machine. The horizontally disposed work supporting conveyor rolls I4 are driven by a roll driving motor l8 through suitable connections, including a shaft 20. The upper horizontal rolls l2 are mounted in pairs on vertical slides 22.

The slides 22 are urged downwardly by compression springs 24 which bear against vertically adjustable abutments 26 provided with position adjusting screws 28. The screws 28 are threaded in horizontal members 30 of the frame F, and are automatically adjusted by a Selsyn receiver motor 32 through suitable connections including a shaft 34. The Selsyn receiver motor 32 is electrically coupled to a Selsyn transmitter 36 which is mechanically connected to a loaded work engaging arm 38. Th arm 38 is adapted to be elevated by the work W as the latter moves through the machine.

Loaded side guides 40 also engage the work W laterally, the side guides 40 also having Selsyn transmitters 42 mechanically connected thereto. Such transmitters 42 are electrically coupled to Selsyn receiver motors, not shown, that turn adjusting screws 44 to adjust the separation of the vertical straightening rolls l6, as well as work desurfacing blowpipe heads S. Thus, when the work W engages the loaded side guides 40 and arm 38, the straightening rolls and the blowpipe heads are sized automatically in accordance with the transverse dimensions of the work. Suitable apparatus for this purpose is more fully described and claimed in Doyle et al. Patent No. 2,323,979 dated July 13, 1943.

As shown in Figs. 1 and 2, an infra-red or 3 radiantenergydetectingdeviceuisfocus'edata 'polntinthepathoftheworkwadlacentthe back of the leading horizontal work straightenlng rolls I2. This detecting device 48 initiates, through an appropriate relay system described below, a reduction in speed of the work W as it approaches the scarfing heads S. A second detecting device 48 responds to the presence of the work W a couple of inches in front of the nozzles of the heads S and causes the preheat gases, cutting oxygen, and adjuvant powder to be turned on.

The use of adjuvant powder for improving the oxygen scarfing of metal is more fully disclosed and claimed in copending application Serial No. 547,062, filed July 28, 1944, for Thermochemical Metal Removal now Patent No. 2,470,999, issued May 24, 1949.

A third detecting device 60 is responsive when the work W entersthe blowpipe heads S and causes the adjuvant powder to be turned off, and the blowpipe heads S to close in around the work W, thus causing the nozzle shoes of the heads to ride on the surface of the work during the scarfing thereof.

when the scarfing cycle is completed each of the three detecting devices is responsive to the absence of work W and the preheat gas and cutting oxygen are automtically turned oil and the blowpipe units retracted a short distance in order to provide clearance for the entrance of a succeeding piece of work.

If short lengths of work are processed, and they follow each other in rapid succession, the detecting devices indicate the approach of each new piece and cause the preceding succession of operations to be repeated. If desired the detecting device 50, in addition to causing closure of the blowpipe heads S around the work W, may also cause the roll table speed to be returned to its former normal value for the remaining portion oi the desurfacing cycle.

Referring to Fig. 2 of the drawing, the detector 46 is connected to an amplifier 52, the output circuit of which includes the control circuit 64 of a relay 56. The relay 56 is connected to a supply circuit 68 and includes a normally closed switch 60 in a series circuit comprising the armature 62 of motor I8 and normally closed switch 64 of relay 66. This series circuit is connected to a supply circuit 68 so that a resistor I is normally shunted, causing the armature 62 to operate at full speed, the motor I8 having a shunt field winding 12 connected to the supply circuit 68. Thus, when either one of the normally closed switches 60 or 64 is open, the resistor I0 is in series with the armature 62, causing the latter to drive the work W at a reduced speed.

The detector 48 is similarly connected toan amplifier 14 having an output circuit including the control circuit I6 of a relay I8 which is provided with a normally open switch 80. The switch 80 when closed is adapted to cause the supply circuit 68 to energize solenoids 82, 84 and 86 of 2-way fuel gas, preheat oxygen, and cutting oxygen valves 88, 90 and 82, respectively, which control the supply of such gases to the scarflng heads 3 The detector 50 is connected to an amplifier 94 having an output circuit constituting the input circuit 26 of relay 66. In addition to the normalhr closed switch 64, the relay 66 includes another normally closed switch '58 in a series circuitincluding the solenoid I00 of a two-way adjuvant powder valve I02, and normalLv open switch 80 assume 4 bynyof I64. Therelsyllalsoincludes a normally open switch in which is adapted when closed to connect solenoid ll! of a four-way blowpipe unit movement control valve III in circuit relation with the supply circuit 88. The relay 66 also includes a normally open switch II2 connected to the supply. circuit II.

In considering the operation of the system In detail, when the forward end of the work W enters the field of the detector 48, radiant energy from the hot.work energizes the detector 42, such energy being amplified by amplifier 62, so as to operate relay 66 opening the normally closed switch 60, and inserting resistor I0 in series with the supply circuit and the armature 62 or motor I8, causing a reduction in speed thereof, and a corresponding reduction in the speed at which the work W is driven toward the desurfacing heads 8.. The motor I8 drives the work W forward at this reduced speed until the work enters the field of the detector 48. This results in the operation of relay 18, causing the preheat acetylene valve 88, the oxygen preheat valve 90, the cutting oxygen valve 92, and the adjuvant powder valve I62 to open.

As the forward movement of the work W continues it enters the field of detector which results in the operation of the relay 66, opening switches 64, 98 and closing switches I06, I I2. The opening of switch 64 insures continuance of the reduced speed at which the work is driven by motor l8, even when the switch 60 closes as a result of the trailing end of the work W eventually leaving the field of the detector 48. The opening of switch 98 results in the closure of the adjuvant powder supply valve I02 by deenergizing its solenoid I00. The closure of switch I06 results in the operation of four-way valve I I0, causing the blowpipe heads S to close around the work W, so that the nozzle shoes ride on the corresponding surfaces of the work as the latter is driven through the machine. The closure of switch II2 insures the continuance of the opening of the gas supply valves 88, 90, 92, even when the trailing end of the work W leaves the field of .the detector 46,

causing the switch to open.

When the trailing end of the work W finally leaves the field of the detector 56, the relay 66 is deenergized, resulting in the opening of switches I06 and H2, so that the supply of gases to the blowpipe heads S is discontinued and the heads S are also automatically retracted.

The modification shown in Fig. 3 involves only one detecting device 4 which is focused at a point in the path of the work W downstream of the last of the leading straightening rolls I2. The device 4, when energized, causes a sequence timer I I6 to operate. The timer I I6 causes a control I20 to carry out the several operations enumerated above, in preselected order with a preselected time interval between each operation. Timer H6 is adJustable to provide suitable ad- Justments whenever conditions, such/as the scarfing speed, are changed.

The detector H4 is coupled to an amplifier Ill and the latter is coupled to the timer Ill having its output coupled to a suitable control I26. The control I20 is operatively associated with the desurfacing blowpipe heads S, and if desired, with the driving system of the work moving rolls I4. Thus, when the work W enters the field of the detector II4, radiant energy-emanating from the hot work W causes the detector II4 to be energized, and the detector 4 continues to be energized until the trailing end of the work W eventuall! leaves its field.

As pointed out above the radiant energy detectors are preferably special radiation pyrometers comprising a thermopile provided with a lens system which is sighted directly on the path of the hot work. The radiant energy emitted by the heated work is converted into electrical energy which is suitably amplified. The preferred thermopile is an assembly of small thermocouples connected in series or parallel, which generates a direct current electr'omotive force of small magnitude. Since this direct current cannot be readily amplified, it is converted into alternating current by a vibrator, which alternating current is then amplified by an electronic system comprising a space discharge device to a value sufficiently high to operate a power relay.

Changes may be made without departing from the scope of the invention. For example, photocells with suitable filters or light combinations may be substituted for the radiation pyrometers. Also, photocells can be used in places where sparks are not present in the field of the detector, such as the period prior to turning on the cutting oxygen.

What is claimed is:

i. A fully automatic scarfing machine for thermochemicaily desurfacing work consisting of a series of elongated ferrous metal bodies which are at a hot rolling temperature, comprising, in combination, a frame adapted to be disposed in a work-conveyor line, front and rear sets of rolls mounted in said frame, a roll driving motor connected to said rolls to drive them at a rapid rate, supply circuit means for energizing said motor including a motor-speed reducing resistor, work scarfing blowpipe heads mounted between the front and rear sets of rolls, heat-sensitive work detecting means comprising at least one hot-body detector provided with an optical system focused on the path of the work between the front set of rolls and the scarfing heads, means responsive to said work detecting means for inserting said resistor in circuit with the motor to reduce the speed thereof, means including a valve for supplying preheat gas to said heads, means including a valve for supplying cutting oxygen to said heads, means including a valve for supplying adjuvant powder to said heads, control means responsive to said work detecting means for automatically opening the preheat gas valve, cutting oxygen valve and adjuvant powder valve as the body approaches the heads, compressed fluid means including a valve for closing the heads around and in contact with the moving work when such valve is open, means responsive to said work detecting means for automatically closing said adjuvant powder valve and opening said fluid valve as the body enters said heads without stopping, whereby the heads are automatically moved into contact with the moving body which is thermochemicaily scarfed as it is moved at reduced speed longitudinally through said heads by said rolls until the trailing end of the body leaves the field of said heat-sensitive work detecting means, and means responsive to said work detecting means for automatically closing the preheat gas valve and the cutting oxygen valve and shorting out said motor-speed reducing resistor when such trailing end of the body finally leaves such field of said hot-body detector, thereby restoring said motor to its higher speed.

2. A fully automatic scarfing machine for ther- 7s sive detector focused on the path of the bodies dimochemically desurfacing work consisting of a series of elongated ferrous metal bodies which are at a hot rolling temperature, comprising, in combination, a. frame adapted to be disposed in a work-conveyor line, front and rear sets of body straightening rolls mounted in said frame for body-size adjustment transversely of the path of the work, a roll driving motor connected to said' rolls to drive them at a rapid rate, supply circuit means for energizing said motor including a motor-speed reducing resistor, work scarfing blowpipe heads mounted between the front and rear sets of rolls for adjustment transversely of the path of the work, work engaging members located above the conveyor in front of the machine for gauging the size of each body as it approaches the front set of rolls, meanscontrolled by said members for automatically sizing the rolls and heads in accordance with the cross-sectional dimensions of each body as it enters the front set of rolls, heat-sensitive work detecting means comprising at least one hot-body detector provided with an optical system focused on the path of the work between the front set of rolls and the scarfing heads, means responsive to said work detecting means for inserting said resistor in circuit with the motor to reduce the speed thereof, means including a valve for supplying preheat gas to said heads, means including a valve for supplying cutting oxygen to said heads, means including a valve for supplying adjuvant powder to said heads, control means responsive to said work detecting means for automatically opening the preheat gas valve, cutting oxygen valve and adjuvant powder valve as the body aproaches the heads, compressed fluid means including a valve for closing the heads around and in contact with the moving work when such valve is open, means responsive to said work detecting means for automatically closing said adjuvant powder valve and opening said fluid valve as the body enters said heads without stopping, whereby the heads are automatically moved into contact with the moving body which is thermochemicaily scarfed as it is moved at reduced speed longitudinally through said heads by said straightening rolls until the trailing end of the body leaves the field of said heat-sensitive work detecting means, and means responsive to said work detecting means for automatically closing the preheat gas valve and the cutting oxygen valve and shorting out said motor-speed reducing resistor when such trailing end of the body finally leaves such field, thereby restoring said motor to its higher speed.

3. A fully automatic scarfing machine for thermochemically desurfacing a series of ferrous metal bodies which are at a hot rolling temperature, comprising, in combination, a frame, front and rear sets of rolls mounted on said frame for conveying the bodies in succession longitudinally therethrough, a driving motor for said rolls, a blowpipe scarfing head mounted on said frame for adjustment toward and away from the path of such bodies, means including a valve for supplying preheat fuel gas to said head, means in-- cluding a valve for supplying preheat oxygen to said head, means including a valve for supplying cutting oxygen to said head, means including a valve for supplying adjuvant powder to said head, a first heat-sensitive detector focused on the path of the bodies in back of the front set of rolls, means responsive to said detector for automatically retarding the speed of said motor as each body approaches the head, a second heat responrectly in front of the head, means responsive to said second detector for opening the preheat fuel gas and oxygen valves and the cutting oxygen and adjuvant powder valves as such body nears the head without stopping, thereby automatically starting the scarfing operation on the moving body, compressed fluid means including a valve for moving the head into contact with the body when the valve is operated, a third heat sensitive detector focused on the path of the bodies in entrance of the head, means responsive to said third detector for automatically closing the adjuvant powder valve and operating the fluid valve,

thereby, causing the head to engage the body, which is thereupon thermochemically scarfed at reduced speed until the trailing end of the body leaves the fleld of said third detector, and means resposive to the absence of the body from the fields of all of said three detectors for automatfined by claim 3, which also includes means for automatically holding the preheat gas valves 1 open until the trailing end of the body leaves the 1 field of the third detector.

5. A fully automatic scarflng machine for thermochemically scarflng work consisting of a series of elongated ferrous metal bodies which are at a hot rolling temperature, comprising, in combination, a frame, front and rear sets of rolls mounted on said frame for conveying the bodies in succession longitudinally therethrough, a driving motor for said rolls, a blowpipe scarflng head mounted on said frame for adjustment toward and away from the path of the bodies, means for moving the head toward and away from such path, means including valves for supplying preheat gases, cutting oxygen and adjuvant powder to said head, a heat-sensitive detector focused on the path of the bodies in back of the front set of rolls, a sequence timer controlled by said detector, and a control connected to said timer for automatically retarding the speed of said motor when a body enters the field of said detector, opening the preheat gas cutting oxygen and adjuvant powder valves as the body approaches the head, closing the adjuvant powder valve and moving the head toward the body as it enters the head, so that the body is scarfed as it moves through the machine, and then closing the preheat gas and cutting oxygen valves, retracting the head and restoring the speed of the motor when the trailing end of the body finally leaves the field of said detector.

-, EDWARD MEINCKE.

REFERENCES cl'rEn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,853,392 Zesbaugh .Apr. 12, 1932 1,951,426 Littler Mar. 20, 1934 1,984,051 Biggert, Jr. Dec. 11, 1934 2,016,414 Cramer 0ctw8, 1935 2,032,107 Bayle Feb. 25, 1936 2,089,015 Bucknam et al Aug. 3, 1937 2,158,069 Grover May 16, 1939 2,171,362 Gulliksen Aug. 29, 1939 2,177,276 Bucknam Oct. 24, 1939 2,205,182 Whitten June 18, 1940 2,244,822 Bucknam June 10, 1941 2,329,188 Denneen Sept. 14, 1943 2,448,657 Bucknam Sept. 7, 1948 OTHER REFERENCES Photocells and Their Application, Zworykin and Wilson, Ind. ed., 1934, pages "134-136. (Copy in Scientific Library.)

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