US3038222A - Mechanical ingot stripper - Google Patents

Description

June 12, 1962 sHlNTARo NAKAMURA 3,038,222

MECHANICAL INGoT STRIPPER 2 Sheets-Sheet 1 Filed April 19, 1960 June 12, 1962 sHlNTARo NAKAMURA 3,038,222

MECHANICAL INGQT STRIPPER Filed April 19, 1960 2 Sheecs--Sheei'I 2 3,033,222 Patented .lune 12, 1962 3,038,222 MECHANHCAL WGT STPER Shintaro Nakamura, Tokyo, .l'apan (26 of No. 403 Kanegasaku, Matsudo-shi, Chiba-lien, tapan) Filed Apr. 19, i960, Ser. No. 23,]l94 Claims priority, application Japan Nov. 13, i959 9 Claims. (Cl. 22-95) This invention relates to stripping mechanisms and particularly to a mechanical ingot stripper 1for separating molds, hot boxes or the like from ingots.

While not necessarily limited thereto, the present invention is particularly adapted for and may be advantageously used in the steel industry for the separation of molds from steel ingots. The formation of ingots from molten steel involves the pouring of molten metal from a pouring ladle into a bot-tomless and topless mold which rests on -a supporting surface and utilizes the supporting surface for a bottom. While the sides of molds are usually tapered upwardly and inwardly slightly to facilitate the separation of the mold from the ingot after the ingot has cooled, the ingot tends to stick to the mold and it is ordinarily necessary to utilize considerable :torce in separating the mold fromthe ingot. A variety of stripping devices have been heretofore utilized for this purpose, including special :stripping cranes which are particularly designed for the separation of molds from ingots. However, stripping cranes are quite complicated in nature, extremely large in size and may not be used for general purposes. Portable ingot strippers, which are hung by the hook of a common crane, hoist, or other lifting device, are generally more economical and flexible in use and the ingot stripper of the present invention is of this type.

Portable ingot strippers may be classified as being either purely mechanical in nature or power operated. Both types generally include a pair of gripping arms or hooks for clasping the mold and pulling upwardly thereon, and a stripping ram or plunger which presses downwardly on the ingot simultaneously with the lifting of the mold. In purely mechanical ingot strippers, the lifting force of the crane, tending to raise the ingot off of the ground, is transmitted through levers to push downwardly on the ingot, while in power driven ingot strippers an elecrtic motor or hydraulic fluid is used to force the stripping ram downwardly against the ingot. While hydraulically operated or motor driven ingot strippers have possessed certain automatic features, they nonetheless are of limited portability, due to the electric wires or hoses connected to the stripper which interfere with its free transfer. Moreover, ingots are handled at relatively high temperatures and special precautions must be taken to protect the motors or other heat-sensitive parts from excessive heat. While purely mechanical strippers may be transferred from place to place with greater ease and are less subject to damage or mechanical failure, they have heretofore been limited in the operations which they could automatically perform. Upon the application of the stripping device to a mold, it has been necessary for a workman to manually apply the gripping arms or hooks to the mold and manually remove the mold from the stripping mechanism upon the completion of the operation. Such manual steps Iare not only cumbersome, time consuming and costly, but due to the high temperatures at which the molds and ingots are handledJ such excessive handling of the stripper in potentially dangerous.

The inventor of the present invention, therefore, proposed some time ago a mechanical ingot stripper which is automatically operable upon the lowering and lifting of the device to grasp the mold between a pair of gripping arms, strip the mold from the ingot, release the mold in a desired location and maintain the gripping arms and ram in a position ready to grasp and strip another mold upon being lowered into engagement therewith.

Said ingot stripper has an outer frame composed of a pair of suspension links pivoted on a hook adapted to be lifted by a lifting chain or the like of a crane and a pair of links connected to said suspension links at their outer ends and joined together on a pin at their inner ends, an inner frame composed of a pair of suspension links pivoted on a tube fixed to the hook and a pair of gripping arms which are connected to the second suspension links at -their outer ends and joined together at their intermediate points by a pin, a lock key spindle slidably mounted in the tube xed to the hook and connected to the pin on which the intermediate points of gripping arms are joined, a locking chamber provided below the tube and adapted to lock and release the key spindle by rotating by means of cams to hold the gripping arms open or closed by xing the distance between the locking chamber and the pin joining the intermediate points of the gripping arms, and a ram connected to the pin o-n which the inner end of the links of the outer frame are pivoted and adapted to apply pressing force to an ingot in the mold when the hook is raised utilizing the links as levers having fulcrums at their intermediate points which are connected by connecting links to the pin joining the gripping arms which pin being connected to a stand placed on the mold. This ingot stripper has many advantages over the conventional ingot strippers but the construction is rather complicated due to the fact that the locking key spindle is always located in the locking chamber and the tube below the hook and the stand to be placed on the mold are always connected by the key spindle whether it is locked or released even if the distance between them is varied.

Furthermore, it is impossible to perform the stripping operation when the mold is a type which is tapered downwardly since a mold is always lifted while an ingot therein is pressed downwardly with the ram of the stripper.

The object of the present invention, therefore, is to eliminate such disadvantages of the lstripper of the former invention and to provide an ingot stripper of simple construction which has the key spindle separable from the locking chamber and can be used for stripping an ingot from a mold irrespective of whether a mold is tapered upwardly or downwardly or not tapered at all.

According to the present invention the powerless ingo't stripper for removing a mold from an ingot comprises a hook adapted to be attached to a hoisting device of a crane, a pair of tongs connected to the hook through a system of links including a lazy tong linkage and adapted to be closed -to grip a body located between the pair of tongs, a tongs key automatically operable to be locked and unlocked in a locking chamber provided in a block carrying the tongs by the up and down motion of the hook caused by the hoisting device of a crane and adapted to keep the tongs in opened condition when it is locked, and a device adapted to press down another body to be removed from the first body when the latter is being gripped and pulled up by the tongs, the tongs key being separable from and insertable into the locking chamber and the spindle of the key being rotatable by means of cams provided in the inside circumference of la tube in which the -top portion of the spindle is inserted to effect the locking and unlocking o-f the key in the locking chamber.

Other objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings wherein: Y

FIG. l is a general `front View of the ingo-t shipper according to one of the embodiments of the present invention;

FIG. 2 is a side view of the same;

FIGS. 3, 4 and 5 are views on an enlarged scale itllustrating the construction of a key which has been known prior to the present invention but not in a stripper of the type of the present invention, FIG. 3 being a view illustrating a tube in which a key spindle is rotatably mounted, FIG. 4 a front view of the key spindle and FIG. 5 a side view of the same respectively;

IG. 6 is a general view of the ingot stripper according to another embodiment of 4the present invention; and

FIG. 7 is a side view of the same.

The rst embodiment of the present invention illustrated in FIGS. 1 and 2 has arm levers 1, 1', the outer ends of which are hinged at 2, 2 to the outer ends of suspension levers 3, 3 respectively. The lower ends of the arm levers 1, 1 are pivoted together by a pin 4 while the suspension levers 3, 3 are connected to a hook 5 by a pin `6, the system of levers is designated as a lazy tong linkage which is adapted for being movable to extended and retracted positions. The dotted position of member 26 illustrates the lazy tong linkage in the retracted position, the solid portion of 26 illustrating the lazy tong linkage for assuming the extended position, the said hook being connected to the hoisting rope of a crane (not shown) which is transportable. The pin 4 is slidable along a slot 7 provided in a support member 8 upstanding from a base pressing plate 9 and the lower ends of the levers 1, 1 and a cam 10 are pivoted on the pin 4.

The levers 1, 1 are yalso connected to the top part of the support member `8 by a pin 11 through connecting links 12, 12 the lower ends of which are pivoted respectively to intermediate points 13, 13 of the levers 1, 1'. These intermediate points are selected much closer to the pin 4 than to the outer ends 2, 2' of the levers 1, 1 and act as fulcrums for the rotation of said levers. On the pin 4 is also mounted a ram rod 14 which is movable up and `down with the pin 4. Giipping arms namely tongs, 15, 15 are hung from pins 16, 16 on the top portion of the support member 8. The tongs 15, 15 are closed to grip a mold 17 by their weight but it is preferable to provide springs 18, 18 to pull them inwardly to secure the grip even if the apparatus is tilted by some chance during its operation. A tongs key 19 is xed to the upper ends of the levers 3, 3' and is adapted to enter into a key lock chamber 20 provided on the upper end of the support member 8 and to be automatically rotated by an angle of 90 to effect locking.

When the key is further rotated by an angle of 90, it is unlocked. Such a locking system has long been known in the ant and it will scarcely require any specic explanation. However, it will be brie-ily explained with reference to FIGS. 3, 4 and 5 for the sake of better understanding of the apparatus of the present invention.

The key 19 is composed of a tube 21 which has a wave shaped upper cam 22 and a wave shaped lower cam. 23 to form a groove 24 extending circumferentially. In this circumferential groove 24 is inserted a. transversal projection 25 of a cylindrical key spindle 26 as shown in FIGS. 4 and 5, extruding the lower end 20' from the bottom of the tube 21. When the hook 5 is lowered, the cylindrical key spindle 26 enters into the key lock chamber 20 and the end of the cylindrical key spindle 26 abuts against the base of the key lock chamber 20, which is integral with the support member `8. Accordingly when the hook is further lowered, the projection 25 of the key spindle 26 comes into contact with the upper cam 22 and is rotated by an angle of 45. Then when the hook 5 is lifted thereby raising the tube 21 having the cams 22, 23, the projection 25 of the cylindrical key spindle 26 comes into contact with the lower cam 23 and is rotated by a further angle of 45 to complete the rotation of 90 of the cylindrical key spindle 26. When the key spindle 26 is rotated by an angle of 90, the lower end 26 of said key spindle comes into engagement with the key lock chamber 20. It is apparent that when the key 19 is `lowered again and lifted, the cylindrical key spindle 26 is again rotated by an angle of 90 and the engagement between the lower end 26 of the cylindrical key spindle 26 and the key lock chamber 20 is released and the key 19 can be lifted upwardly being separated from the key lock chamber 20.

The suspension levers 3, 3' have also first restraint links 27, 27 each of which has one end pivoted at an intermediate point 2S or 28 of the levers 3, 3 and the other ends forming brake shoes 29, 29 respectively. These links 27, 27 are connected respectively to the top portion of the support member `8 through second restraint links 30, 30 connected to intermediate points 31, 31 of the links 27, 27 as shown in the drawing.

The operation of this apparatus is as follows: Assume that the hook 5 is lowered to place the support 3 of the apparatus on a mold 17 when the key 19 is locked in the key lock chamber 20. The end of the key spindle 26 abuts against the bottom of the key lock chamber 20 but the tube 21 of the key continues to descend and hence the upper cam 22 of the tube 21 cornes into contact with the projection 25 of the key spindle 26 to rotate it by 45 When the hook 5 is raised from this condition, the tube 21 of the key 19 is raised to bring the lower cam 23 into contact with the projection 25 of the key spindle 26 to rotate it by further 45. As the result, the key 19 is unlocked and can be raised being separated from the key lock chamber 20. The lifting of the hook 5 brings about the rise of the outer ends 2, 2' of the levers 1, 1 and tends to lower the pin 4 at the lower ends of said levers, rotating the levers 1, 1 around their fulcrums 13, 13.

When the pin 4 is thus lowered, the gripping arms 15, 15 are closed to grip the mold 17 since there is no interfering cam 10 between the arms 15, 15 any longer.

The pin 4 is connected to the ram 14 adapted to press downwardly an ingct 32 in the mold 17 and the `force pressing the ingot 32 will be greatly intensitied because of the ratio of the arm lengths from the fulcrum 13 to the outer end 2 and the inner end 4 of the levers 1 and 1. The gripping arms 15, 15 clamp the mold and tend to lift the mold 17 when the hook 5 continues -to be raised while the ram 14 tends to press down the ingot 32. Thus the stripping of the ingot 32 from the mold 17 can be effected.

If the hook 5 is lowered after effecting t'ne stripping to place Ithe support member 8 on the mold 17 and the lowering of the hook 5 is continued, the key 19 will enter the key lock chamber 20 on the top of the support member 8 and the key spindle 26 will be rotated by the upper cam 22 and then, when the hook is lifted, by the lower cam 23 of the tube 21 thereby locking the key 19 in the key lock chamber 20. When the key 19 is lowered suiiiciently to be locked in the key lock chamber 20, it is evident that levers 1, 1 are opened to bring the cam 10 in a raised position in the slot 7 to open the tongs 15, 15.

Under this condition where the tongs 15, 15' are locked in opened condition, the crane carrying this apparatus can be transported to any desired place to descend this stripper on a new mold to carry out another stripping operation as described above.

Should the hook 5 be raised when the key 19 is unlocked with no control, the pin 4 may come down to the bottom end of the slot 7 and may receive such a great stress that it may be broken. The links 27, 27 act to prevent such an incident by stopping the lowering of the pin 4 by the brake shoes 29, 29 which are adapted to engage with the sides of the links 30, 30 before the pin 4 reaches the bottom end of the slot 7.

However, the stripper of FIGS. 1 and 2 cannot be used for stripping an ingot from a mold when Ithe mold is tapered downwardly or has a larger cross section at the top. In order to eliminate this disadvantage, the 2nd embodiment as illustrated in FIGS. 6 and 7 is contrived.

In this embodiment, a hook 105 is connected with the top end of a lazy tong linkage constituted by a pair of suspension levers 103, 103' including pin 106, the other ends of said levers are pivotally connected by pins 102, 102' with outer ends of a pair of arm levers 101, 101'. The other ends of the levers `101, 101 are connected at points 116, 116' to the opposite sides of a support member 108 integral with a base plate 109 which is adapted to be placed on a mold 117 tapered downwardly. Levers 112, 112 constitute the closing members of the lazy tong linkage. A pair of gripping arms or tongs 115, 115 of L-shape are crossed and pivoted by a pin 104 at the crossing point.

The upper ends of the tongs are connected to the lower ends of a pair of links 127, 127 the top ends of which are pivoted together by a pin 128. Links 127, 127' and gripping tongs 115 and 115 constitute a scissor linkage for engaging the ingot. The support member 108 has an upper slot 137 and a lower slot 107 and the pin 128 joining top ends of the links 127, 127 is slidably inserted in the upper slot 137 while the pin 104 joining the tongs 115, 115' at their intersecting point is slidably inserted in the lower slot 107. 'Ihe top ends of a pair of connecting rods 112, 112 are piyoted on the pin 128 and the lower ends of said rods are pivotally connected to the levers 101, 101' at their intermediate points 113, 113 as shown in FIG. 6. A tongs key 119 having the construction -similar to the tongs key 19 of FIGS. 3-5 is iixed to the top ends of the links 127, 127 and a key lock chamber 120 is provided below the tongs key 119 in the support member 108. When the key 119 is lowered, it enters the key lock chamber, and is locked or unlocked by the rotation of the key spindle v126 as already explained with reference to FIGS. 3-5.

From the construction as described above, it will be evident that when the key 119 is locked in the key look chamber 120, the distance between the two pins 104 and 128 is limi-ted and the tongs 115, 115 are maintained in open condition.

The operation of the stripper is las follows:

Now assume that the key 119 is locked in the lock chamber 120 and the tongs 115, 115 are open. When this stripper is lowered onto a mold 117 lfrom which the feeder head 132 of an ingot 132 is projected, passing through a hole provided in base plate 109 of the support member 132, the feeder head 132 will come between the tongs 1,15, 115. After placing the base plate 109 on the mold 117, the hook 105 is lifted. When the hook' is lifted, the pin 128 is lifted through the links 103, 101, 112 and 103', 101', 112. This lift of the pin :128 causes the rotation of the key spindle 126 of the key 119 to unlock said key and hence, the lifting of the pin 128 may be continued until the tongs 115, 115 clamp the feeder head 132 of the ingot. After the grip of the feeder head 132', the hook 105 continues to be lifted, and the pins 102, 102' of the lever arms 101, 101 are lifted. Accordingly said levers tend to rotate around the pins 113, 113 as the fulcrums.

The length between the pin 113 and the inner end 116 of the lever is much smaller than the length between the pin 113 and the outer end 102 of the lever, and hence the pressing force applied to the mold 117 through the support member 108 and the pressure plate 109 will be greatly intensified. The ingot 132 is pulled up by the tongs 115, 115 while the mold 117 is pressed down by the inner ends 116, 116 of the levers 101, 101', and consequently the stripping of an ingot from a mold tapered downwardly can be eifected.

When the stripper having the key 1 19 unlocked is lowered again on a mold, the key 1.19 `will enter in the key lock chamber 120 and the key spindle 126 is rotated to loc-k the key in the key lock chamber 120, and when the hook 105 is lifted, the tongs 115, 1115 are kept in open condition and the stripper may be transported by a crane to a new mold to carry out the stripping operation in respect of said mold.

As explained above, the stripper of the present invention has a tongs key which can be separated entirely from an associated key lock chamber and the construction can be made much simpler than the stripper of the former invention in which the tongs key must alrways be located in a key lock chamber. Furthermore,

the stripper of the present invention can be used for the stripping of an ingot from a mold irrespective of whether the mold is tapered upwardly or downwardly or is not tapered at all different from the stripper of the former which cannot be used when the mold is tapered downwardly.

What I claim is:

l. Apparatus for separating mold and ingot members comprising a plurality of links pivotally connected together to form a lazy tong linkage, said linkage being movable between extended Iand retracted positions, means for engaging said mem-bers to exert forces thereon to separate the same, the latter said means being coupled to the lazy tong linkage for separating said members as the lazy tong linkage is extended, and means for locking the lazy tong linkage to said latter means with the lazy tong linkage in retracted position to enable positioning of said latter means relative to said members so that said latter means can separate said members as said lazy tong linkage is extended, said means for locking the lazy tong linkage to said latter means including a tongs key coupled to said lazy tong linkage and movable therewith, said key including a pair of axially aligned cam surfaces in spaced relation and a key spindle in part between said cam surfaces and adapted to move axially therebetween; said means for engaging said members defining a chamber which is aligned with said key spindle, said key spindle being lockable in said chamber to lock the lazy tong linkage to said latter means, said key spindle bein-g locked and unlocked in said chamber in accordance with respective movement of said cam surfaces relative to said key spindle, said movement of said cam surfaces being controlled solely by extending and retracting said lazy tong linkage.

2. Apparatus as claimed in claim l wherein said means for engaging said members includes a support adapted for being positioned on one of said members yand a pair of tongs pivotally supported on said support for engaging said one member in gripping relation, said chamber for Iaccommodating said key spindle being provided in said support.

3. Apparatus as claimed in claim l wherein said means for engaging said members includes a support adapted for being positioned on one of said members, a pin operatively coupled to the lazy tong linkage and supported for mo'vement in said support in accordance with extension and retraction of said lazy tong linkage, a scissors linkage connected to said pin for opening and closing in accordance with movements in opposite direction of said pin, said scissors linkage including gripping means for engaging the other of said members.

4. Apparatus as claimed in claim 2 wherein said support is provided with a slot, a pin pivotally connecting a pair of the links of said lazy tong linkage and slidably supported in the slot in the support, a pair of levers pivotally connected together at said support, each lever being pivotally connected to one of said pair of links of the lazy tong linkage whereby said pin moves in said support in -accordance with extension and retraction of said lazy tong linkage.

5. Apparatus as claimed in claim 3 ycomprising a further pin connecting said scissors linkage, the latter being slid-ably supported in said support in aligned relation with the iirst said pin, said tongs key being supported for movement with the first said pin, said chamber being associated with the further pin for movement Itherewith.

6. Apparatus as claimed lin claim 4 comprising a cam on said pin and positioned between said pair of tongs for 7 engaging the same with the pin in a position corresponding to the retracted position of said lazy tong linkage such that said tongs are spaced from said one member.

7. Apparatus as claimed in claim 4 comprising a ram rod on said pin `and movable therewith, said ram rod engaging the other of said members with said pair of tongs gripping said one member whereby said members are separated as said lazy tong linkage is extended, said one member remaining gripped by said tongs.

8. Apparatus as claimed in claim 4 comprising brake means coupled to said lazy tong linkage and said support for locking said linkage in the extended position with said pin in an intermediate position in the slot in the support.

9. Apparatus as claimed in claim 8 wherein said brake means comprises a pair of rst restraint links, each having one end pivotally connected to one of the links of the lazy tong linkage, a brake shoe on each restraint link at an end remote from the first said ends, said brake shoes being adapted to engage said lazy tong linkage to limit extension thereof, and a pair of second restraint links, each having one end pivotally connected to a corresponding first restraint link intermediate the ends thereof, each second restraint link having an end remote from the tirst said end thereof and pivotally connected to said support.

References Cited in the lile of this patent UNITED STATES PATENTS 472,436 Cornelius Apr. 5, 1892 2,063,656 Bigler et al. Dec. 8, 1936 2,148,625 Joliet Feb. 28, 1939 FOREIGN PATENTS 740,544 Germany Oct. 22, 1943 908,665 Germany Apr. 8, 1954

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