US3266104A

US3266104A - Continuous casting apparatus having a quickly disconnectable starter bar

Info

Publication number: US3266104A
Application number: US333383A
Authority: US
Inventors: Justin E Foldessy; Gallucci Francis
Original assignee: United States Steel Corp
Current assignee: United States Steel Corp
Priority date: 1963-12-26
Filing date: 1963-12-26
Publication date: 1966-08-16
Anticipated expiration: 1983-08-16
Also published as: GB1088598A; NL6415098A; ES307444A1; BE657214A

Description

Aug. 16, 1966 o ss ET AL 3,266,104

CONTINUOUS CASTING APPARATUS HAVING A QUICKLY DISCONNECTABLE STARTER BAR Filed Dec. 26, 1963 4 Sheets-Sheet l an 2 w I 2 '6\'\ 46 lg 8 5652 Q N INVENTORS J US TIN E. FOLDESSY FRANCIS GALLUCCI MXQM ATTORN E Y Aug. 16, 1966 J. E. FOLDESSY ET AL 3,266,104 CONTINUOUS CASTING APPARATUS HAVING A QUICKLY DISCONNECTABLE STARTER BAR Filed Dec. 26, 1965 4 Sheets-Sheet 2 Fig.5u

INVENTORS JUSTIN E. FOLDESSY FRANCIS GALLUCCI ATTOR NE YS Aug. 16, 1966 FQLDESSY ET AL 3,266,104

CONTINUOUS CASTING APPARATUS HAVING A V QUICKLY DISCONNECTABLE STARTER BAR Filed Dec. 26, 1963 ml c S m w w TwL N L R E A O V G T N. afl m C Wu TA R N... Y B

W07, NEW

Aug. 16, 1966 FQLDESSY ET AL 3,266,104

CONTINUOUS CASTING APPARATUS HAVING A QUICKLY DISCONNEGTABLE STARTER BAR Filed Dec. 26, 1963 4 Sheets-Sheet 4 IO G30 /|38 INVENTORS J U STIN E. F OLDESSY F RAN CIS G ALLUCCI wanda/,8, 5

ATTORNEY United States Patent 3,266,104 CUNTINUOUS CASTING APPARATUS HAVING A QUHCKLY DISCONNECTABLE STARTER BAR Justin E. Foldessy, Ogden Dunes, Ind, and Francis Gallucci, North Huntington Township, Westmoreland County, Pa, assignors to United States Steel Corporation, a corporation of Delaware Filed Dec. 26, 1963, Ser. No. 333,383 7 Claims. (Cl. 22--57.2)

This invention relates to apparatus for the continuous casting of metals and more particularly to starter bars used in continuous casting.

It is customary in the continuous casting of metals to provide an apparatus comprising a vertical tubular mold open at the upper end for receiving molten metal and open at the lower end for the discharge of a metal casting, cooling means comprising a plurality of water sprays located below the mold for directing cooling water against the casting, guide means comprising a plurality of guide rolls located between the water sprays for guiding the casting as it moves downwardly through the cooling zone, and motor driven pinch rolls located below the guide rolls and cooling means. The cooling means are mounted on a suitable immovable frame. The guide rolls and pinch rolls are mounted for rotation in suitable mountings, which are also mounted on an immovable frame.

It is necessary to close the lower discharge end of the mold initially when molten metal is being poured into the mold. This is usually done by the insertion of a starter bar into the bottom of the mold. The starter bar is an elongated metal bar, usually solid and rigid, which has a cross-sectional shape approximately the same as that of the mold with a slightly smaller cross-sectional area in order to permit ready insertion of the bar upwardly through the guide rolls and into the bottom of the mold. The starter bar, in addition to closing the discharge end of the mold while molten metal is being poured, also supports the metal column or casting as it descends through the guide rolls and pinch rolls.

After the starter bar has passed through the pinch rolls, it is severed from the casting. One or more cutting torches located a short distance below the pinch rolls are usually employed for the purpose. These torches cut the casting a short distance above the top of the starter bar. The starter bar, with a short length of casting attached to the top thereof, is lowered vertically, supported by a suitable platform, basket, or the like. At the bottom of its vertical travel, the starter bar is lowered to a horizontal position and transported horizontally away, by power driven rollers for example. The short length of casting attached to the starter bar must be removed before the starter bar can be used again.

Different ways have been suggested for handling the casting (excluding the short length which remains attached to the starter bar) after its severance from the starter bar. According to one way, the casting is cut into lengths by one or more cutting torches and lowered vertically and then transported horizontally in the same manner as the starter bar. According to another mode of operation, the casting after severance from the starter bar is deflected from its vertical path, by a horizontally reciprocable roll known as a pusher roll for example, and guided in a curved path from the vertical direction to the horizontal by means of rolls mounted in a guide frame. The casting is straightened when it reaches a generally horizontal position. If desired, the casting after straightening may be reheated if necessary and rolled.

Cutting the casting to separate the starter bar as above described has at least two disadvantages.

First, it is necessary to remove the short length of casting which remains attached to the starter bar after cutting. This must be done manually, often requiring considerable time and labor.

Second, the cutting torches now conventionally used require an unnecessarily long time to sever the casting.

It is an object of this invention to provide a starter bar which can be quickly and completely disconnected while said starter bar and casting travel downwardly.

It is a further object of this invention to provide a starter bar having secured to the top thereof a chill plate which is quickly releasable from the starter bar.

In the drawings:

FIG. 1 is an isometric view of the starter bar of this invention and chill plate secured thereto, with portions cut away and portions shown in section.

FIG. 2 is a sectional view, taken along the line 2-2 of FIG. 1.

FIG. 3 is a perspective view showing in detail a pin for engaging a casting with the chill plate.

FIG. 4 is a vertical sectional view of a starter bar according to a modified form of the invention.

FIG. 5 is a sectional view taken along the line 55 of FIG. 4.

FIG. 5a is an end elevation of the starter bar shown in FIG. 4.

FIG. 6 is an isometric view of a starter bar and casting attached thereto.

FIG. 7 is an isometric view of the starter bar after detachment from the casting.

FIG. 8 is a schematic drawing of an actuation system for automatically disconnecting the starter bar from the chill plate and casting.

Referring now to the drawings and especially to FIGS. 1 to 3 thereof, which illustrate one embodiment of the invention in detail, 10 indicates generally a starter bar which is adapted to be inserted into the lower portion of a tubular open-ended continuous casting mold 12 as indicated in FIG. 4. The mold may be of any cross-sectional shape desired, but in the usual practice a rectangular mold is used. Starter bar 10 generally is an elongated metal body, which may consist either of a single piece or of a plurality of sections which are detachable from each other and joined together by suitable means such as mortise and tenon joints. However, relatively short starter bars or plugs embodying the quick release mechanism to be described herein are also within the scope of this invention.

A metallic chill plate 14 rests on the upper end of starter bar 10 and is releasably secured thereto. This plate as illustrated herein is trough shaped, resting on the top surface of starter bar 10 which has the same trough shaped contour as plate 14. The chill plate serves four main purposes: to protect the starter bar from direct contact with the molten metal poured into the mold, to chill and solidify the molten metal along the entire surface of the chill plate, to grip the solidified casting firmly, and to provide means for quick disconnection to the starter bar from the casting with no part of the casting adhering to the starter bar.

Chill plate 14 has a plurality of cylindrical pins 16 extending therethrough and welded or otherwise fixedly secured to the chill plate. These pins are shown in detail in FIG. 3. Pins 16 have circular heads 20 at one end, the heads being of somewhat greater diameter than the pins themselves, and a necked portion formed by two opposed cut out portions which are defined by two parallel

vertical surfaces

24 and 26 which are parallel to the axis of the pins 16, and

horizontal shoulders

28, 30, 32 and 34 which intersect the

vertical surfaces

24 and 26. The cut out portions are in the lower portion of pins 16, near the end opposite from heads 20. Pin heads 20 are above chill plate 14 and provide for interlocking engagement between the chill plate and the casting when the portion thereof 3 abutting chill plate 14 has solidified. The cut out portions are located below chill plate 14 and provide for releasably securing chill plate 14 t starter bar so that the starter bar can be quickly disconnected from the chill plate and casting.

Chill plate 14 as seen from above is preferably of the same size and shape as the top section of starter bar 16. The .top section of the starter bar may have the same dimensions as the remainder of the bar, although frequently it is desirable for the top section to be slightly smaller than the remainder of the bar in both width and thickness to facilitate insertion into the mold. The contour of the top of starter bar 10 is the same as that of chill plate 14. Thus in the embodiment shown, chill plate 14 and the top surface of starter bar 10 are both trough shaped. However, chill plates of other con-tours, as for example flat chill plates, are also within the scope of the invention.

Chill plate 14 is preferably made of a metal, which must have a melting point not lower than that of the metal or alloy being cast. Advantageously the composition of the chill plate and the metal being cast are approximately the same. Thus, when a low carbon steel is being cast, the chill plate is advantageously made of low carbon steel. Metal is preferred to refractory as a chill plate material because of its higher heat transfer rate and faster solidification of the surface of the casting abutting the chill plate.

The chill plate must be thick enough to chill and freeze the molten metal of the casting along the entire surface of the chill plate and to prevent the melting of the plate from the heat of the molten metal; At the same time .it is highly desirable for the chill plate to be thin enough so that it will be heated throughout by the molten metal to a temperature high enough for rolling. This is advantageous because it is desirable to roll the metal casting without first removing the chill plate therefrom. Chill plates of about /2 inch thick have been found to be very well suited to the casting of ferrous metals and alloys. The chill plate should be at least about 4 inch thick so that it will freeze the entire surface of the metal abutting the chill plate and so that no holes extending through the entire thickness will be melted therein. The chill plate should not be substantially thicker than /2 inch, because excess thickness increases the possibility that the platewill become too cool for rolling before that stage of operation is reached. Plate 14 is thin enough not to interfere with the guide frame which directs the casting through a curved path from the vertical to a horizontal direction.

The starter bar 10 has a passage extending trans- .versely therethrough from one edge wall 42 of the starter bar to the-opposite edge wall 44. Passage 40 is T-shaped, being formed by the intersection of horizontal channel 46 of small depth and of a width slightly less than that of starter bar 10 and vertical channel 48 therebelow which is of substantial depth and considerably narrower than horizontal channel 46.

A slidable plate 51] (hereinafter called a slide plate) is provided in channel 40. Slide plate is a thin metallic plate which slides in the horizontal portion 46 of passage 40, and which is slightly shorter than passage 40 so that the edges of slide plate 59 will not extend beyond the

edges

42 and 44 of starter bar 10 in any position of the slide plate.

Slide plate 50 has a plurality of specially shaped slots 52, which receive pins 16 in interlocking engagement. Each of the slots 52 has a circular portion 54 and an oblong portion 56. The diameter of the pins 16 is slightly less than the diameter of the circular portions 54, but is greater than the width of the oblong portions 56 of slots 52. The distance between the

parallel walls

24 and 26 of the pins in FIG. 3 is slightly less than the width of the oblong portions 56 of slots 52. The distance between the

upper shoulders

28 and 32 and the

lower shoulders

30 and 34 in pins 16 is slightly greater than the thickness of slide plate 50. When slide plate 50 is in the position shown in FIG. 1, the pins 16 are out of alignment with the circular portions 54 of slots 52, and the

parallel walls

24 and 26 of pins 16 are in the oblong portions 56 of slots 52. In this position the oblong portions 56 of slots 52 engage slide plate 50 to secure plate 14 to the starter bar 10. When the slide plate 551 is moved to the left so that pins 16 are aligned with the circular portions 54 of slots 52, the starter bar 10 is then released from chill plate 14 and the attached casting. Pins 16 may have a cross-sectional shape other than circular. The portion 54 of slots 52 in that case is of the same shape as the cross-sectional shape of the pins but of slightly larger size, so that the pins can pass freely through these portions 54.

Movement of slide plate 50 is limited by flange 58, which is welded or otherwise attached to slide plate 50, and limit stop 60, which is fixedly secured to starter bar 10. Flange 58 depends from slide plate 50, and rides within the vertical channel 48. The width of flange 58 is less than that of channel 48, so that there is a clearance between the fiange and the channel walls. The length of flange 53 is immaterial provided it has sufficient cross section to withstand the shear stresses resulting from striking limit stop 69 and also provided it is no longer than slide plate 50. The height of flange 58 must be suflicient to permit a striker arm to strike this flange so as to move slide plate 50 to release position as will be hereinafter more fully described. The height of flange 58 thus depends on the casting speed and the length of time the striker arm remains in contact with flange 58. Flange 58 has portions 62 cut away to provide space for the lower ends of pins 16. Flange 58 also has a cut away portion 64 which provides space for limit stop 60. Cut away portion 64 defines a pair of vertical abutting

surfaces

66 and 68 which strike limit stop 60 and thereby limit the extent of sliding movement of slide plate 56. Limit stop 60 is located on the bottom wall of vertical channel 48, and is fixedly secured in channel 48 by pin 76.

Starter bar 10 has an indentation 72 .in edge wall 42 surrounding slide plate 50. This provides space for a striker arm 74, which strikes slide plate 50 and moves it to the left when the predetermined elevation for disconnection of the starter bar 10 from the chill plate 14 and casting has been reached, so that the striker arm will not interfere with the downward movement of the starter bar. The width of indentation 72 is the same as the width of slide plate 50 in the illustrated embodiment.

Starter bar 1% may also have a second indentation 76 of rounded configuration, located in edge 42 of starter bar 10 below indentation 72. Indentation 76 is adapted to receive a feeler arm 78, which is located at a fixed predetermined elevation. The entry of feeler arm 78 into indentation 76 automatically causes movement of striker arm 74 to strike slide plate 50 and cause disconnection of starter bar 10 from chill plate 14. A mechanism for accomplishing this result will be hereinafter described.

When the upper end of starter bar 10 with chill plate 14 attached thereto is inserted into the lower end of tubular continuous casting mold 12, a small gap extends around the entire perimeter of the chill plate 14 between the plate and the mold, due to the slight difference in cross-sectional area between the plate 14 and bar 10 on one hand and mold 12 on the other. Entry of molten metal into this gap can be prevented by means of a heat resistant seal such as an asbestos rope (not shown) extending around the perimeter of the starter bar in this gap.

A modified form of starter bar is shown in FIGS. 4, 5, and 5a. In these figures, 80 indicates generally a starter bar which is adapted to be inserted into the lower portion of a tubular open ended continuous casting mold 12 as indicated in FIG. 4. The starter bar of this embodiment is rectangular in cross section. Chill plate 81 rests on top of starter bar 80 and is releasa'bly secured thereto. The upper portion of starter bar 80 has

side Walls

32 and 83 and a top 84 which enclose a rectangular channel 85 which has a height substantially greater than the distance between the two side walls 82 and 83.

The top 84 of starter bar 80 in the illustrated embodiment is specially constructed to permit the starter bar to be used with castings of various widths. Top- 84 extends over the entire thickness of the starter bar, but the width of the top is less than that of the starter bar itself. A pair of L-shaped edge pieces 86 having horizontal portions 86a and upstanding vertical flanges 86b are bolted by bolts 87 to top 84. The horizontal portions 86a are of the same thickness as top 84. The inside edges of flanges 8612 are preferably beveled as shown at 86c. Spacers 88 may be inserted between edge pieces 86 and top 84 or omitted, depending on the width of the casting. The spacers are omitted if the width of the casting is the same as that of the starter bar, and are inserted if the casting width is greater than the width of the starter bar.

Chill plate 81 is a thin flat rectangular metallic plate having four sides 89 welded to the plate itself and extending upwardly at an angle. The angle of inclination of sides 89 and the angle of the bevel 86c are the same. A small clearance may be provided between beveled edge 86c and sides 89.

Chill plate 81 has a plurality (two as shown in the accompanying drawings) of pins 90 for anchoring the chill plate 81 to the lead end of the casting. Pins 90 are welded to chill plate 81 and extend both above and below the chill plate. In the illustrated embodiment pins 90 are square in cross section. Holes for pins 90 are provided in top 84. Pins 90 above the chill plate have heads 91 which are preferably rectangular or square and of a larger crosssectional area than pins 90. The lower portions of pins 90 below chill plate 811 have slots 92.

A slide plate 93 of generally rectangular shape is placed in channel 85 for sliding movement therein. The length of slide plate 93 is less than the width of starter bar 80, so that the slide plate does not overhang the edges of the starter bar in any position. A small clearance between slide plate 93 and the adjacent side walls 82 and 83 may be provided for free sliding movement.

Slide plate 93 has a plurality of upwardly extending L- shaped lugs 94, equal in number to the number of pins 90. When the slide plate is in the position shown in FIGS. 4 and 5, lugs 94 extend through the slots 92 in pins 90, so as to provide a locking engagement which secures chill plate 81 to starter bar 80. When slide plate 93 is slid to the left, to the dotted line position of FIG. 4, lugs 94 are moved away from pins 90, and the starter bar 80 is then released from chill plate 811 and the attached casting so that the starter bar can be lowered separately from the chill plate and attached casting.

Starter bar 80 is provided with a recess 95 contiguous with channel 85 and adjacent one edge of starter bar 80. A pair of

lugs

96 and 97 are welded to slide plate 93 and positioned respectively above and below the slide plate 93. The outer edges of slide plate 93 and lugs 96 and 97 line in a common plane.

Lugs

96 and 97 provide a striking surface for a striker arm 74, which moves slide plate 93 from its position as shown to a position wherein lugs 94 do not engage pins 90 so that starter bar 80' is released from chill plate 81. A limit stop 98 is provided to limit the movement of slide plate 93.

FIGS. 6 and 7 show schematically a continuous casting apparatus employing the novel starter bar and chill plate of this invention. This apparatus includes a conventional generally vertically extending mold 12 which is open at both ends, so as to provide an upper opening for the introduction of molten metal to form a casting 100 and a lower discharge passage through which said casting may descend continuously as it is formed, two sets of pinch rolls 101 located below the mold, means for bending a casting and deflecting it from its downward path to a laterally extending direction, indicated geenrally at 102 and herein illus trated as a fulcrum roll 103 and a pusher roll 104, and an automatic actuation system 105 responsive to the downward movement of starter bar for releasing the bar from chill plate 14 before the chill plate and casting reach the bending means. The automatic actuation system herein illustrated comprises a sensing mechanism 106 which includes an air cylinder 107 having piston 108 therein, a limit switch 109, and feeler arm 78, which is a piston rod in cylinder 107 and which terminates at one end in limit switch 109, thereby actuating the switch. Actuation system 105 also includes a second air cylinder 110, located above the first air cylinder 107 and having piston 111 therein. Striker arm 74 constitutes a piston rod in cylinder 110. A vertically traveling basket 112 receives starter bar 10 after it has been disconnected from chill plate 14 and casting 100, and further lowers the starter bar.

Cylinders

107 and 1 10, the mountings for the shafts of pinch rolls 10-1 and fulcrum roll 103, and the stationary supporting structure for pusher roll 104, are all fixedly mounted at predetermined elevations, preferably on a common supporting structure. Actuation system 105 is located a short distance above the lower pinch rolls 101, and bending means 102 is located a short distance below the lower pinch rolls 101.

Disconnection of starter bar 10 from chill plate 14 and casting is accomplished by striker arm 74 striking slide plate 50in starter bar 10 when the slide plate reaches the predetermined elevation at which striker arm 74 and cylinder 110 are located. Cylinder .110 is fixedly mounted a short distance above the lower pair of pinch rolls 101 and in a position laterally outward from that assumed by starter bar 10 and casting 100 during their descent. Striker arm 74 is normally retracted away from starter bar 10 as shown in FIG. 7. To release starter bar 10 from chill plate 14, striker arm 74 is extended to the position shown in FIG. 6, in which it strikes slide plate 50, moving it to the left and releasing bar 10 from plate 14. Striker arm 74 is then retracted. Striker arm 74 can be operated in any desired manner. In a preferred embodiment, arm 74 is operated automatically when starter bar 10 reaches a predetermined position.

FIG. 8 schematically illustrates the electromechanical automatic actuation system whose function is to release starter bar 10 from plate 14. The circuit in FIG. 8 is designed to provide the appropriate automatic control over air cylinders 107 and so that sensing arm 78 and striker arm 74 will be projected and retracted at the appropriate times. All components are shown in the deenergized position.

Air cylinders

107 and 110 are controlled by solenoid operated air valves 113 and 114 respectively. Solenoid valve 113 has a connection 115 for the supply of air under pressure, a pair of exhaust connections 116, and

connections

118 and 120 leading to either end of cylinder 107. Solenoid operated valve 114 is of identical construction having an air supply passage 122, a pair of air exhaust passages 124, and a pair of

connections

126 and 128 leading to the respective ends of cylinder 110.

Operation of solenoid operated valves 113 and 114 is controlled by the state of the contacts associated with control relays 130 and 132 and timing relay 134. Current for the electrical system is supplied from a power source (not shown) through

electrical lines

136 and 138. Switch 140 is located in line 136. When this switch 140 is closed, the actuation system 105 is supplied with power and is in condition to be operated.

Operation of system 105 is initiated by pushing one of the two

parallel push buttons

142 or 144, both of which are normally open, to closed position. When one of the push buttons is closed, relay 130 is energized, thereby closing the normally open contacts 130a and 13012. The closing of contact 13% energizes the solenoid controlled air valve 113 so as to supply air pressure from supply line 115 to cylinder 107 through line 120 so as to extend the sensing arm 78 forward sufiiciently to contact and ride on the edge 42 of the starter bar 10. It should be noted that when the sensing arm 78 is thus extended forward, the limit switch 109 is moved to the dotted line position 109a, in which position it is still open. Closing of switch 109 requires a further forward extension of the sensing arm 78.

Contact 130a closes to provide a holding action so that when the

push button

142 or 144 is released, the relay 130 will remain energized by current flowing between the

lines

136 and 138 through the normally closed contact 132a, the now closed holding contact 130a, and the relay coil 130. The two buttons 146 which are in this path of current flow are kept normally closed and are simply included for safety purposes to permit manually stopping the operation of this actuation system 105 at two different locations. Accordingly, the manual release of

buttons

142 or 144 will, because of the action of this holding contact 130a, leave the sensing arm 78 projected in a forward direction to ride on the starter bar 10.

As the starter bar descends, the sensing arm 78 will ride into the indentation 76, thereby causing the sensing arm 78 to project further forward (to the left in FIG. 8) so as to close the limit switch 109 (shown by the dotted line position 10%). As a consequence, relay 132 is energized through the now closed limit switch 109 and the normally closed contact 134a, which is controlled by timing relay 134 as will be hereinafter explained.

When relay 132 is energized, normally open contact 13212 is moved to the closed position, which in turn energizes solenoid operated air valve 114. This causes air under pressure from supply line 122 to be introduced into air cylinder 110 via connection 128, which moves the piston 111 in cylinder 110 and forces the striker arm 74 forward (to the left in FIG. 8) with sufficient force to cause the slide plate 50 to move to the left as seen in FIG. 1 sufiiciently to disengage the starter bar 10 from chill plate 14 and the lower end of the casting 100. The sensing arm 78 and striker arm 74 are spaced from one another the same distance apart as are the indentation 76 and the slide plate 50, so that the entrance of the sensing arm 78 into the indentation 76 results in the actuation of the striker arm 74 at just the appropriate time to cause the arm 74 to hit the slide plate 50.

The closing of the limit switch 109 also energizes the timing relay 134, the coil of which is arranged in parallel with the coil of the relay 132. Energizing of the timing relay 134 closes the normally open contact 134b, which contact 13411 then operates as a holding contact for both the relay 132 and the timing relay 134 so that when the sensing arm 78 is retracted automatically as explained later, the limit switch 109 may open without de-energizing the relay 132 and timing relay 134. The contact 134a is a normally closed contact which is associated with the timing relay 134 but whose state is not affected by the state of the timing relay 134.

When the timing relay 134 has been energized, it starts on a predetermined timing cycle, at the end of which the timing relay 134 mechanically opens the contacts 134a through mechanical linkage 1340, thereby de-energizing the relay 132 and the timing relay 134.

While the timing relay 134 is running through its preset time cycle, it as well as relay 132 remains energized. Normally open contacts 132!) are closed by the energizing of the relay 132 and remain closed during the timing cycle. Therefore solenoid operated air valve 114 remains energized and striker arm '74 remains in its forward posi tion (to the left in FIG. 8) while timing relay 134 is running through its preset timing cycle. The duration of this timing cycle is normally not over about two seconds.

Once the timing relay 134 has run its cycle, it mechanically opens contact 134a so as to de-energize both timing relay 134 and control relay 132. De-energizing of relay 132 causes contact 132b to revert to its normally open position and thus de-energize the solenoid actuated air valve 114. De-energizing of the solenoid actuated air valve 114 causes the air cylinder 110 to switch and retract the striker arm 74 to its normally retracted position free of the starter bar 10 or casting 100.

Energizing of relay 132 as a consequence of the sensing arm 78 entering the indentation 76 also acts to open the normally closed contacts 1320, thereby de-energizing the relay 130. This de-energizing of the relays 130 opens normally open contacts 1301) thereby de-energizing the solenoid actuated air valve 113 and causing the air cylinder 107 to retract the sensing arm 78. Thus the sensing arm 78 is,retracted and moved out of the way of the starter bar 10 and casting immediately after it has entered the indentation 76 and this retraction of the sensing arm 78 is achieved automatically.

After the timing relay 134 has gone through its timing cycle and caused the normally closed contact 134a to open, the timing relay 134 is de-energized and rests itself resulting in the normally open contact 1341: opening and the normally closed cont-act 134a reclosing. In this fashion actuation system returns to its initial state, that being the state illustrated in FIG. 8.- It should be noted that in this initial state all of the

relays

130, 132 and 134 are de-energized so that the contacts shown are in their normal position. It should also be noted that in this initial state the solenoid actuated air valves 113 and 114 are de-energized and place air pressure in the

cylinders

107 and 110 in such a fashion as to cause the sensing arm '78 and striker arm 74 to be in their retracted positions (to the right in FIG. 8).

It should be understood that FIG. 8 is a somewhat simplified schematic drawing of automatic actuation system 105. Additional safety buttons, fuses, meters and the like may be employed to provide informatiton and monitoring of the operation of this automatic actuation system.

Other automatic actuation systems besides the one illustrated can be used. If desired, sensing mechanism 106 can be omitted and the admission of fluid under pressure to cylinder 110 can be under the control of an operator.

Operation according to this invention will now be described with particular reference to FIGS. 6 and 7. Prior to the start of a casting, the upper end of starter bar 10 with chill plate 14 attached is inserted into the lower end of an open ended tubular continuous casting mold 12. Molten metal is then poured into the mold until it reaches a predetermined elevation near the top thereof. When this predetermined elevation is reached, the starter bar 10 and casting 100 are slowly brought downward at a uniform rate under the control of pinch rolls 101 (see FIG. 7). The outer surface of skin in casting 100, and the lower end of casting 100 which abuts chill plate 14, solidify while the casting is still in the mold and before movement of the starter bar downwardly is commenced. solidification of casting 100 around the heads of cylindrical pins 16 provides a tight interlock between the casting and plate 14.

After the height of metal in the mold has reached a predetermined level, starter bar 10 and casting 100 are brought slowly downward to the predetermined elevation at which the starter bar is to be disconnected from the casting. At that point it is desirable to detach the starter bar from the casting as quickly as possible. The starter bar, being of substantial length and inflexible, must be brought straight downwardly by suitable means such as a basket which is indicated diagrammatically at 112 in FIG. 6. The slide plate 50 in starter bar 10 can be quickly moved to the release position, whether manually or automatically, so as to permit starter bar .10 to be brought down independently of casting 100. Starter bar .10 is then rought rapidly downward, while casting 100 and chill plate 14 and pins 16 attached thereto continue to descend at a slow control rate still under the control of pinch rolls 101. This phase of operations is best illustrated in FIG. 7, which shows the starter bar after disconnecting from the casting. After the starter bar 10 has been taken out of the way and casting 100 continues to descend through lower pinch rolls 101, the casting may be further handled in any desired means. For example, the casting may be cut into sections by conventional cutting torches (not shown) located below pinch rolls 101; Al-

ternatively the casting may be deflected to a horizontal position (the casting still being quite hot and relatively plastic), after which it may be further handled in any desired manner.

The starter bar is completely separated from the casting in the present invention, with no part of the casting remaining attached to or adhering to the starter bar. This is in contrast to apparatus used heretofore, in which the casting is cut with cutting torches a short distance up from the end at which said casting is attached to the starter bar. Such procedure leaves a short length of casting attached to the bar.

One advantage of the novel apparatus herein is that less work is necessary to ready the starter bar for re-use than is the case in prior art apparatus where a small length of casting must be removed from the starter bar. Because no part of the casting is attached to the starter bar after disconnection, the time spent in removing the small length of casting attached to the bar after cutting according to the prior art is not required.

Another advantage is that the starter bar can be disconnected from the casting much more quickly than a casting can be cut with cutting torches as is necessary when previously known starter bars are used.

Various modifications can be made as will be recognized by those skilled in the art. While this invention has been described with respect to specific embodiments thereof, it is understood that it shall be limited only by the scope of the appended claims.

What is claimed is:

1. Apparatus for continuous casting comprising a starter bar having a transverse passage therein, a slidable plate movable between two positions in said passage, a chill plate on the upper end of said starter bar and quickly disconnectable therefrom, and means secured to said chill plate and adapted to be engaged by said slidable plate in one position thereof and to be disengaged in another position thereof.

2. Apparatus for continuous casting comprising an elongated starter bar having a transverse passage therein, a slidable plate movable between two positions in said transverse passage, a chill plate on the upper end of said starter bar, and means integral with said chill plate for securing it to said bar, said means being adapted to be engaged by said slidable plate in one position thereof and to be released when said slidable plate is moved to another position thereof.

3. Apparatus for continuous casting comprising an elongated metal starter bar having a transverse passage therein adjacent the upper end thereof, said transverse passage extending horizontally between two opposite edges in said starter bar, a slidable plate movable between two positions in said transverse passage, limit stop means preventing movement of said slidable plate beyond said two positions, a chill plate on the upper end of said starter bar and releasably secured thereto, a plurality of pins fixedly secured to said chill plate and extending through said chill plate and the upper end of said starter bar into said transverse passage, said pins having heads above the chill plate for providing an interlocking grip between the chill plate and a metal casting, said slidable plate having means for engaging said pins in an interlocking engagement when said slidable plate is in one position and for releasing said pins when said slidable plate is in another position.

4. Apparatus for continuous casting comprising an elongated metallic starter bar having a transverse passage adjacent the upper end thereof and extending horizontally between two opposite edges in said starter bar, a chill plate on the upper end of said starter bar and releasably secured thereto, a plurality of pins fixedly secured to said chill plate and extending through said chill plate and the upper end of aid starter bar into said transverse passage, said pins having heads above the chill plate for providing an interlocking grip between the chill plate and a metal casting, said pins also having a necked portion below said chill plate, a slidable plate movable between two positions insaid transverse passage, said slid.- able plate being shorter than said transverse passage, limit stops preventing movement of said slidable plate beyond said two positions, said slidable plate having slots therein, each slot consisting of one portion through which said pins can pass freely and an oblong portion narrower than said pins but wider than the necked portions thereof, whereby the oblong portions of said slots secure said pins in interlocking engagement in one position of the slidable plate and said slidable plate releases said pins when moved to another position.

5. The appaartus of claim 4 wherein said pins are cylindrical and said slots in said slidable plate consist of a circular portion larger than the diameter of the pins and an oblong portion extending in the direction of movement of said slidable plate.

6. Apparatus for a continuous casting comprising an elongated metallic starter bar having a transverse passage therein adjacent the upper end thereof and extending horizontally between two opposite edges in said starter bar, a slidable plate movable between two positions in said transverse passage, said slidable plate being shorter than said transverse passage, limit stops preventing movement of said slidable plate beyond said two positions, a chill plate resting on the upper end of said starter bar and releasably secured thereto, a plurality of pins fixedly secured to said chill plate and extending through said chill plate and the upper end of said starter bar into said passage, said pins having heads above the chill plate for providing an interlocking grip between the chill plate and an attached metal casting, said pins having slots below said chill plate, said slidable plate having upwardly and laterally projecting members extending through said slots when said slidable plate is in one position and retracted away from said slots when said slidable plate is in another position, thereby securing said chill plate to said starter bar when said slidable plate is in the first mentioned position and releasing the starter bar from the chill plate when the slidable plate is in the second mentioned position.

7. Apparatus for continuous casting comprising an elongated starter bar having a transverse horizontally extending passage therein, a slidable plate movable between two positions in said transverse passage, limit stop means for preventing movement of said slidable plate beyond said two positions, a chill plate on the upper end of said starter bar, and means integral with said chill plate for securing it to said bar, said means being adapted to be engaged by said slidable plate in one position thereof and to be released when said slidable plate is moved to another position thereof.

References Cited by the Examiner UNITED STATES PATENTS 333,718 1/1886 Babcock 238252 894,410 7/1908 Trotz 2257.2

944,370 12/ 1909 Monnot 2257.2 2,079,644 5/ 1937 Williams 22200.1 2,657,366 10/1953 Krtous 287-20 2,715,750 10/1955 Orr 287-20 2,973,233 2/1961 McPhee 287-20 FOREIGN PATENTS 725,323 3/1955 Great Britain. 729,359 5/ 1955 Great Britain.

J. SPENCER OVERHOLSER, Primary Examiner.

MARCUS U. LYONS, Examiner.

R. A. SANDLER, R. S. ANNEAR,

Assistant Examiners.

Claims

1. APPARATUS FOR CONTINUOUS CASTING COMPRISING A STARTER BAR HAVING A TRANSVERSE PASSAGE THEREIN, A SLIDABLE PLATE MOVABLE BETWEEN TWO POSITIONS IN SAID PASAGE, A CHILL PLATE ON THE UPPER END OF SAID STARTER BAR AND QUICKLY DISCONNECTABLE THEREFROM, AND MEANS SECURED TO SAID CHILL PLATE AND ADAPTED TO BE ENGAGED BY SAID SLIDABLE PLATE IN ONE POSITION THEREOF AND TO BE DISENGAGED IN ANOTHER POSITION THEREOF.