US3401739A - Apparatus to be used with ingots - Google Patents

Description

B. OPLETAL.

4 iZneets-Sheetv 1 INVENTOR. 50/) u s /a'z/- fl v/efa/ BY Sept. 17, 1968 APPARATUS TO BE USED WITH INGOTS Filed Dec. 19, 1966 Sept. 17, 1968 I B. OPLETAL 3,401,739

APPARATUS I0 BE USED WITH INGOTS 4 Sheets-Sheet 2 Filed Dec. 19, 1966 fiu 5 /a1/' 0 9/m1/ INVENTOR.

Sept. 17, 1968 B. OPLETAL APPARATUS TO BE USED WITH INGOTS 4 Sheets-Sheet 3 Filed Dec. 19, 1966 muflurn n1n uui INVENTOR.

Sept. 17, 1968 B. OPLETAL APPARATUS TO BE USED WITH INGOTS Filed Dec.

4 Sheets-Sheet 4 50/; us /a u' fl o/efa/ INVENTOR.

United States Patent 3,401,739 APPARATUS TO BE USED WITH INGOTS Bohuslav Opletal, Brno, Czechoslovakia, assignor to CHEPOS Sdruzeni Chemickeho a Potravinarskeho Strojirenstvi, Brno, Czechoslovakia Filed Dec. 19, 1966, Ser. No. 602,901 Claims priority, application Czechoslovakia, Dec. 22, 1965, 7,687/65 Claims. (Cl. 164-408) ABSTRACT OF THE DISCLOSURE The apparatus of the invention includes a support means that has a main cylinder in which a main piston is slidable, said main cylinder extending vertically during use of the apparatus with the main piston which is slidable in the main cylinder being fixed to a piston rod that extends upwardly beyond the main cylinder and carries at its upper end a suspending means by which the piston rod and all of the remaining structure of the invention is suspended from a suitable lifting and lowering device, such as a crane. The main piston carries a nonreturn valve means which provides for flow of fluid from the space in the main cylinder beneath the main piston to the space in the main cylinder over the main piston, while preventing flow of fluid in the reverse direction from the space over the main piston to the space beneath the latter. A lower conduit communicates with the space in the main cylinder beneath the main piston, and a reservoir which contains a suitable hydraulic liquid is in permanent communication with the lower conduit which communicates permanently with the space in the main cylinder beneath the main piston therein. An upper conduit communicates permanently with the space in the main cylinder over the main piston, and a second nonreturn valve means is carried by and coacts with this upper conduit to provide for flow of fluid out of the space in the main cylinder over the main piston and through the upper conduit, while preventing flow of fluid in the reverse direction through the upper conduit into the space over the main piston.

Background of the invention The present invention relates to apparatus which is to be used with ingots. In particular, it relates to an apparatus which may be used for stripping ingot molds from ingots as well as for transporting ingot molds and ingots. The apparatus of this invention is particularly adapted for use with a lifting and lowering device, such as a crane which has a lifting capacity suflicient to carry the apparatus of the invention as well as the ingot and mold.

A primary object of the present invention is to provide a stripping apparatus capable of stripping an ingot mold from an ingot while operating exclusively in response to lifting and lowering movements of a crane or the like from which the apparatus of the invention is suspended.

Another object of the invention is to provide a device of the referred to type which is completely self-contained with its own closed hydraulic circuit and which is capable of automatically controlling the moving parts of the device in response to lifting and lowering movements.

A further object of the invention is to provide a device of the aforementioned type which is simple in construction and can be operated in a simple manner that does not require the use of any separate control assemblies.

Further, it is an object of the invention to provide a device of this type which can optionally be used for transporting ingots by themselves or for transporting molds by themselves.

A releasable holding means is provided to act on a part 3,401,739 Patented Sept. 17, 1968 which is to be worked on by the apparatus of the invention, and this releasable holding means is displaceable between a holding position holding this part and a release position releasing the latter part. An auxiliary cylinder is carried by the support means, and an auxiliary piston is slidable in the auxiliary cylinder and carries an auxiliary piston rod which coacts with the releasable holding means for displacing the latter between its release and holding positions in response to movement of the auxiliary piston and auxiliary cylinder one with respect to the other. An auxiliary conduit communicates with the auxiliary cylinder to direct fluid into and out of the latter during movement of the auxiliary piston in opposite directions therein. A return flow conduit communicates with the reservoir, and a distributing valve means of the invention communicates with the upper conduit, the auxiliary conduit, and the return flow conduit to provide in one position of the distributing valve means communication between the upper conduit and the auxiliary conduit, while preventing communication between the auxiliary conduit and the return flow conduit, so that during a reduction in the volume of the space in the main cylinder over the main piston therein the fluid will flow from the upper conduit through the distributing valve means into the auxiliary conduit to actuate the auxiliary piston. The distributing valve means has another position where it places the auxiliary conduit in communication with the return flow conduit while cutting ofl communication between the auxiliary conduit and the upper conduit, so that at this time fluid can return from the auxiliary cylinder to the reservoir.

A ram cylinder is also carried by the support means, this ram cylinder being situated at an elevation lower than the main cylinder and having in its interior a ram piston to which a ram means is fixedly connected, this ram means extending downwardly beyond the ram cylinder to the exterior thereof and pressing against a part which is to be worked upon by the apparatus of the invention during an increase in the volume of the space in the ram cylinder that is situated over the ram piston. The space in the ram cylinder beneath the ram piston communicates with the outer atmosphere, and a ram conduit communicates with the space in the ram cylinder over the ram piston and with the distributing valve means to receive fluid from the upper conduit through the distributing valve means when the latter is in its position providing communication between the auxiliary conduit and the return flow conduit, so that at this time fluid will flow from the space in the main cylinder over the main piston into the space in the ram cylinder over the ram piston. On the other hand, when the distributing valve means is in its position providing communication between the upper conduit and the auxiliary conduit, the distributing valve means simultaneously places the ram conduit in communication with the return flow conduit, so that at this time the fluid can flow out of the space in the ram cylinder over the ram piston and back to the reservoir. An actuating means is operatively connected on the one hand to the distributing valve means and on the other hand to the main piston rod for displacing the distributing valve means between its positions in response to movement of the main piston rod through a given stroke.

Summary of the invention-brief description of the drawings The invention is illustrated by way of example in the accompanying drawings which form part of this application and in which:

FIG. 1 is a sectional front elevation of one embodiment of a stripping apparatus according to the invention, this embodiment being adapted for stripping ingot molds from ingots where the ingot and mold taper so as to have upper ends which are smaller than the lower ends;

FIG. 2 is a fragmentary side elevation of the structure of FIG. 1;

FIG. 3 is a schematic illustration of the manner in which the structure of FIGS. 1 and 2 operates, the parts being shown during connection of the apparatus of the invention to an ingot mold;

FIG. 4 shows the position which the parts of FIG. 3 take, also in a schematic manner, during actual stripping of the mold from the ingot;

FIG. 5 is a partly sectional front elevation of a second embodiment of a stripping device in accordance with the invention, this embodiment being adapted for use with an ingot and mold assembly which have upper ends larger than the lower ends;

FIG. 6 is a partly sectional side elevation of the structure of FIG. 5;

FIG. 7 is a schematic representation of the manner in which the embodiment of FIGS. 5 and 6 operates during connection of the apparatus of the invention to an ingot;

FIG. 8 shows schematically the position which the parts of FIGS. 5-7 take during actual stripping of the mold from the ingot; and

FIG. 9 shows details, a ratchet and pawl arrangement and a distributing valve means and is explanatory of the connection of the ratchet to the distributing valve means.

Description of preferred embodiments Referring now to the drawings in greater detail and to FIGS. 14 in particular, the apparatus illustrated in FIGS. 1 to 4 includes a support means S which includes a main cylinder 5 that extends vertically during use of the apparatus. A main piston 3 is slidable within the main cylinder 5. A piston rod 2 is fixed to the main piston 3 and extends therefrom in a fluid-tight manner through the top wall of the cylinder 5 to an elevation above the latter where the upper end of the piston rod 2 is fixed to a suspending means 1 by means of which the entire apparatus is suspended from a lifting and lowering device C which may take the form of a crane having a hook to which the suspending means 1 can be attached. Thus, this suspending means 1 may take the form of a suitable shackle, eye, or the like, fixed to the top end of the piston rod 2 and receiving a hook of the lifting and lowering device C.

The piston 3 carries a nonreturn valve means 4 which provides for flow of hydraulic liquid or other suitable fluid from the space in the main cylinder 5 beneath the piston 3 therein to the space in the main cylinder 5 over the main piston 3, while this nonreturn valve means 4 prevents the reverse flow of fluid from the space over the piston 3 to the space beneath the latter.

A lower conduit 30 is in permanent communication with the space in the cylinder 5 beneath the piston 3 therein, and a reservoir 6 which surrounds the main cylinder 5 and which is carried by the support means S is in permanent communication with the lower conduit 30, as shown particularly in a schematic manner in FIGS. 3 and 4. In this way, in response to movement of the piston 3 and cylinder 5 one with respect to the other liquid can flow freely at any time into and out of the space in the cylinder 5 beneath the piston 3.

An upper conduit 32 communicates with the space in the main cylinder 5 over the piston 3 therein, and this upper conduit 32 carries a nonreturn valve means 19 which provides for flow of fluid out of the space in the cylinder 5 over the piston 3 and through the upper conduit 32. On the other hand, the nonreturn valve means 19 prevents the reverse flow of fluid from the upper conduit 32 into the main cylinder 5.

A ram cylinder 7 is fixedly carried by the support means S, and in the embodiment of FIGS. 14, this ram cylinder 7 is coaxial with the main cylinder 5 while being situated at an elevation lower than the main cylinder 5. A ram piston 8 is slidable in the ram cylinder 7, and a ram means 9 takes the form of a piston rod fixed to and extending from the piston 9 in a fluid-type manner through and beyond the bottom end of the ram cylinder 8, the lower end of the ram means 9 being adapted to directly engage and press against the top end of the ingot 21. A ram conduit 34 communicates permanently with the space in the ram cylinder 7 over the ram piston 8, while the space in the ram cylinder 7 beneath the piston 8 communicates permanently with the outer atmosphere as, for example, through an opening 36 shown in FIG. 3 and 4.

The support means S also carries a releasable holding means H for releasably holding a part which is to be worked on by the apparatus of the invention, this part being the ingot mold 20 in the example of FIGS. 1-4. The ingot mold 20 has at its top end a pair of opposed lugs 38 which are engaged by the releasable holding means H. This releasable holding means includes a pair of bell crank levers pivotally carried by a pair of opposed extensions which project from opposite sides of the cylinder 7, which forms part of the support means S. Each of these bell cranks of the releasable holding means includes a lever arm 10 of a substantially U-shaped configuration having a lower end portion adapted to extend beneath and engage a lug 38, and each of the bell cranks has an upper arm 11 which extends substantially horizontally, these arms being disposed at opposite sides of the cylinder 7 with the latter extending between the arms 11 of the pair of bell cranks. Furthermore, the bell cranks include projections 12, respectively, fixed to the arms 10 thereof and adapted to engage the upper end face of the mold 20 at opposed parts thereof, as described below.

The support means S fixedly carries over the pair of arms 11 of the pair of bell cranks a pair of auxiliary cylinders 13 which respectively have auxiliary pistons 14 slidable therein, and these pistons 14 are respectively fixed with a pair of auxiliary piston rods 40 the bottom ends of which engage the arms 11, respectively. An auxiliary conduit 42 communicates with each auxiliary cylinder 13 and more particularly with the space therein situated over the auxiliary piston 14, while the space in each cylinder 13 beneath the piston 14 communicates with the outer atmosphere, as through an opening 44 shown in FIG. 3.

A distributing valve means 15 is carried by the support means S directly next to the reservoir 6, and this distributing valve means 15, in addition to communicating with the upper conduit 32, the ram conduit 34, and the auxiliary conduit 42, communicates with a return flow conduit 46 which. is in permanent communication with the reservoir 6 for the hydraulic liquid. This distributing valve means 15 is displaceable between the positions thereof shown in FIGS. 3 and 4. In the position of FIG. 3 the distributing valve means 15 places the upper conduit 32 in communication with the auxiliary conduit 42, while the ram conduit 34 communicates with the return fiow conduit 46, and in the position of FIG. 4 the distributing valve means 15 places the auxiliary conduit 42 in communication with the return flow conduit 46 while at the same time placing the upper conduit 32 in communication with the ram conduit 34.

An actuating means A is provided for automatically actuating the distributing valve means 15 so as to successively displace it between the positions thereof shown in FIGS. 3 and 4. This actuating means A includes a ratchet wheel 16 which is operatively connected with the rotary valve member of the distributing valve means 15 and which is situated at the exterior of the latter, as shown in FIG. 1. A pawl 18 coacts with the ratchet wheel 16 and is carried by the lower end of one of a plurality of guide bars 17 which are fixed to and extend downwardly from the suspending means 1, these bars being guided through suitable openings in a flange projecting from the top end of the main cylinder 5, as shown in FIG. 1. Thus, the actuating means A is connected on the one hand to the distributing valve means 15 and on the other hand to the main piston rod 2 so that in response to a given stroke of the latter the actuating means will displace the distributing valve means 15 between its positions. Thus, referring to FIG. 1 it will be seen that when the piston rod 2 has been lowered sufliciently the pawl 18 will engage the ratchet wheel 16 and turn it through an increment which will displace the distributing valve means 15 between the positions thereof shown in FIGS. 3 and 4. During upward movement of the bars 17 the ratchet wheel 16 is not turned while during the next downward stroke of the piston rod 2 the pawl 18 will again actuate the ratchet wheel 16 so as to return the distributing valve means 15 back to the position it had prior to the previous actuation of the distributing valve means. Thus, this actuating means A of the invention will successively place the distributing valve means in the positions shown in FIGS. 3 and 4.

The above described structures operate in the following manner:

The apparatus of the invention is suspended by the suspending means 1 on a lifting and lowering device C, such as on the hook of a suitable crane, as indicated schematically at the upper part of FIG. 1. As a result of the force of gravity, the main cylinder 5 will simply slide downwardly along the main piston 3, and since the non-return valve means 4 is closed at this time liquid will flow from the reservoir 6 through the lower conduit 30 into the space of the cylinder 5 beneath the piston 3 so as to fill the space in the cylinder 5 beneath the piston 3 during an increase in the volume of this latter space. At the same time, with the distributing valve means 15 in the position of FIG. 3, the liquid which is displaced out of the space above the main piston 3 in the cylinder 5 flows through the upper conduit 32 and the distributing valve means 15 into the auxiliary conduit 42 so as to enter the space of each auxiliary cylinder 13 above the auxiliary piston 14 to displace the latter downwardly so that the piston rods 40 will turn the arms 11 downwardly, thus moving the arms outwardly away from each other and placing the releasable holding means H in its open; release position.

The apparatus of the invention is then lowered onto a mold 20 with the ram means 9 aligned with the top end of the ingot 21. When the ram 9 engages the ingot 21, the ram 9 and the ram piston 8 will remain stationary while the ram cylinder 7 together with the support means S and the main cylinder 5 are lowered so that the space in the ram cylinder 7 above the ram piston 8 diminishes in its volume and the liquid at this time is displaced out of this latter space through the ram conduit 34 and the distributing valve means 15, which still has the position of FIG. 3, into the return flow conduit 46 and thus back into the reservoir 6. This operation continues until the projections 12 engage the upper end face of the mold 20 at opposed parts thereof, and now with the projections 12 engaging the top end of the mold 20 the device C is actuated to continue the downward movement of the hook thereof, so that while the cylinders 5 and 7 remain stationary the piston 2 continues to move downwardly with the piston 3 approaching the bottom end of the cylinder 5 and the fluid in the latter flowing through the nonreturn valve 4 from the space beneath to the space above the piston 3. This operation is continued until the pawl 18 engages the ratchet wheel 16 so as to displace the distributing valve from the position of FIG. 3 into the position of FIG. 4. This will result in placing the auxiliary conduit 42 in communication with the return fiow conduit 46, and now because the arms 10 of the bell crank levers of the releasable holding means H are heavier than the arms 11 thereof, the bell crank levers will swing from the position of FIG. 3 into the position of FIG. 4 and the arms 11 will raise the piston rods 40 and the pistons 14 displacing the liquid out of the cylinders 13 through the conduits 42 and the return flow conduit 46 into the reservoir 6. In this way the arms 10 extend beneath and engage the lugs 38.

Now the operator will raise the hook of the lifting and lowering device C so that the piston 3 moves upwardly in the cylinder 5, and thus liquid is displaced out of the space in the cylinder 5 above the piston 3 through the upper conduit 32 and the distributing valve means 15 into the ram conduit 34 so as to be forced into the space of the ram cylinder 7 over the piston 8 therein, thus pressing the ram means 9 downwardly against the top end of the ingot 21 while simultaneously pulling up on the mold 20. In this way the mold 20 is stripped from the ingot 21.

If it should happen that the stroke of the piston 8 is insufficient to strip the mold 20 from the ingot 21, the operator can simply lower the piston 3 in the cylinder 5 so as to displace liquid through the nonreturn valve means 4 into the space over the piston 3, and this operation will take place because the nonreturn valve means 19 prevents fluid from entering through the conduit 32 into the cylinder 5. However, care is taken at this time to lower the piston rod 2 through a stroke which is too short to provide for displacement of the distributing valve means 15, so that the parts will remain in the position of FIG. 4. Now the operator can again raise the piston rod 2 so as to displace additional liquid into the ram cylinder 7 over the ram piston 8 so as to reliably strip the mold 20 from the ingot 21, in the event that such a second increment of movement of the ram means 9 and cylinder 7, one with respect to the other, is required.

When the mold has thus been stripped from the ingot, it is possible to transport the mold into the yard or the like where the molds are stored, using the apparatus of the invention, and then the mold 20 is simply lowered onto a suitable pad and the piston rod 2 is lowered until the actuating means A returns the distributing valve means 15 into the position of FIG. 3 so that during the immediately following raising of the piston rod 2 liquid will be displaced into the auxiliary cylinders 13 over the pistons 14 to lower the piston rods 40 and displace the releasable holding means to its release position releasing the mold 20.

Now the parts again have the position of FIG. 3, the previously stripped mold is released, and the apparatus can be placed over the next mold which is to be stripped, the releasable holding means H being in its release position so that it will extend over the top end of the mold as described above in connection with FIG. 3, and of course the cylinder 7 can simply be lowered downwardly along the piston 8 after the ram means 9 engages the top end of the next ingot 21. In this way the above operations will be repeated with the releasable holding means automatically assuming its holding position shown in FIG. 4 as soon as the actuating means A has displaced the valve means 15 from the position of FIG. 3 into that of FIG. 4 in the manner described above.

It is apparent that the structure of FIGS. 1-4 can also be used simply to transport molds 20 in which case the ram means 9 would simply remain in its position extending from the cylinder 7 without engaging any ingot and the structure otherwise operating in the manner described above. If desired, the structure can be designed simply as a mold transporting device, omitting the ram structure. In this event when the parts have the position of FIG. 4 and a mold has been transported to a desired location the piston rod 2 can be lowered until the actuating means A displaces the valve means 15 to the position of FIG. 3 whereupon the piston rod 2 is raised so as to displace the releasable holding means H to its open position, and the structure can now be placed on another mold to carry and transport the latter to a desired location in the manner described above. The ram structure simply will not participate in the operation at this time.

The embodiment of FIGS. 5-8 is adapted to be used with ingots and molds whose upper ends are larger than their lower ends, these ingots 21 having a dead head at its upper end. In this embodiment the releasable holding means H is in the form of a lazy tongs composed of the linkage which has upper links pivotally connected to the support means S and which have lower shear-type links pivotally connected by a vertically displaceable pivot pin which is connected to the bottom end of the piston rod 14a which projects from the auxiliary piston 14 in this embodiment. In this embodiment the pair of piston rods 14a are pivotally connected to opposite ends of the vertically displaceable pin of the lazy-tongs 10'. Moreover, there are a pair of ram cylinders 7 carrying ram pistons 8 and a pair of ram means 9 projecting therefrom to engage the upper face of the mold 20 at opposed parts thereof, as is particularly apparent from FIG. 6. The ram conduit 34 of this embodiment communicates with both of the cylinders 7 over the pistons 8, respectively, and in addition it will be noted from FIGS. 7 and 8 that in this embodiment the ram conduits 34 branch from the auxiliary conduits 42 which communicate with the spaces in the cylinders 13 over the pistons 14 therein. This embodiment also has additional auxiliary conduits 50 respectively communicating with the spaces in the cylinders 13 beneath the pistons 14 and with the distributing valve means 15, so that in this embodiment the cylinders 13 and pistons 14 are double-acting.

Except for the above differences the structure of FIGS. 58 is the same as that of FIGS. 1-4 and operates in the following manner:

Assuming that the apparatus of the invention is suspended on a crane and that the distributing valve means 15 has the position of FIG. 7, then as the main cylinder 5 moves downwardly with respect to the main piston 3, the liquid which is displaced through the upper conduit 32 enters into the space of the cylinders 13 beneath the pistons 14, through the auxiliary conduits 50, so as to raise the auxiliary pistons 14 and thus place the releasable holding means of this embodiment in its release position shown in FIG. 7. The apparatus is now lowered onto a mold with the pair of ram means 9 engaging the top end of the mold at opposed parts thereof, and as the cylinders 7 move downwardly with respect to the pistons 8 the fluid is displaced through the ram conduits 34 and the distributing valve means 15 along the return flow conduit 46 back to the reservoir 6. At the end of the downward movement of the support means S and the structure carried thereby, the piston rod 2 continues to move down so that the actuating means A actuates the distributing valve means 15 to displace it from the position of FIG. 7 into the position of FIG. 8.

When the crane is now lifted the upward movement of the piston 3 displaces liquid through the upper conduit 32 and the distributing valve means 15 on the one hand into the cylinders 13 over the pistons 14 and on the other hand into the cylinders 7 over the pistons 8, so that the releasable holding means H assumes its holding position gripping the top end of the ingot While simultaneously the pair of ram means 9 are pressed against the top end of the mold 20. The return flow conduit 46 at this time communicates with the lower spaces of the cylinders 13 to receive fluid from the conduits 50. Thus, the ingot 21 is stripped from the mold 241 and can be transported to any desired location after which the crane is again lowered so as to displace the piston rod 2 downwardly to cause the actuating means A to return the distributing valve means 15 to the position of FIG. 7, whereupon during the subsequent upward movement of the piston rod 2 the releasable holding means H will be returned to its release position releasing the ingot. Now the above operations can be repeated.

The diameters of the cylinders 5 and 7 and of rod 2 are selected so as to provide a proper the development of the force required to clamp and strip the mold therefrom. This force is automatically by the weight of the apparatus, that of the mold and ingot, without the use of the piston ratio for the ingot developed including any other driving structure. All of the stripping operations are brought about exclusively by the up and down movements of the lifting and lowering device C, which can be any suitable crane. Thus, the operation of the apparatus of the invention is exceedingly simple, and its structure is inexpensive.

The apparatus can be suspended from any standard lifting and lowering device. It can easily be removed from the crane which can then be used for other purposes. The crane can be provided with a turnable frame so that with the apparatus of the invention the molds can be turned, and thus a very expensive stripper crane can be replaced by the apparatus of the invention. It is apparent that the structure of the invention will save considerable investment as well as handling and maintenance costs.

The embodiment of FIGS. 5-8 also can be used only with the releasable holding means H and the auxiliary cylinders 13 and pistons 14 for actuating the releasable holding means, in which case the ram assemblies can either be omitted or simply not used. With such a construction the lazy tongs can simply be used for transporting ingots. With such an arrangement the tongs can be placed in the open position of FIG. 7 in the manner described above and lowered onto an ingot. When the tong levers engage the ingot and after the piston rod 2 has been lowered so that the actuating means A has displaced the distributing valve means 15 from the position of FIG. 7 into that of FIG. 8, the subsequent raising of the piston rod 2 will result in automatic gripping of the ingot which can then be transferred to any desired location. When the ingot has been transported in this way to a desired location in the yard or the like, the apparatus is lowered so that the distributing valve means 15 will be returned to the position of FIG. 7, thus resulting during subsequent raising of the piston rod 2 in opening of the tongs 10 and release of the ingot.

It will be noted that with this embodiment also the structure works in a fully automatic manner requiring no separate mechanical drive for the tongs. They are actuated exclusively by the lifting and lowering movements of the device C from which the apparatus of the invention can be easily removed whenever desired.

I claim:

1. In an apparatus which is to be used with ingots and the like:

(a) support means including a main cylinder which extends substantially vertically during use of the apparatus,

(b) a main piston slidable in said main cylinder so that said main cylinder and main piston are vertically displaceable one relative to the other,

(c) a main piston rod fixed to said main piston and extending from the latter upwardly beyond said main cylinder where said piston rod has an upper end situated at the exterior of said main cylinder,

(d) suspending means connected to said upper end of said piston rod for suspending the latter and said main piston therewith from a lifting and lowering device during use of the apparatus,

(e) nonreturn valve means carried by said main piston and providing communication between spaces in said main cylinder above and below said main piston, said nonreturn valve means providing for free flow of fluid from the space in said main cylinder beneath said main piston to the space in said main cylinder over said main piston during movement of said main piston and main cylinder one with respect to the other in a direction which reduces the volume of the space beneath said main piston while increasing the volume of the space thereover, said nonreturn valve means preventing flow of fluid from the space over said main piston back to the space beneath said main piston during movement of said main piston and main cylinder one with respect to the other in a direction which reduces the volume of the space over (f) a lower conduit (1) an auxiliary piston slidable said main piston while the volume therebeneath increases,

communicating permanently with the space in said main cylinder beneath said main piston,

(g) a reservoir communicating permanently with said lower conduit so that the space in said main cylinder beneath said main piston is in permanent communication with fluid in the reservoir through said lower conduit,

(h) an upper conduit communicating permanently with the space in said main cylinder over said rnain piston,

(i) second nonreturn valve means operatively con- (j) releasable holding means for releasably holding a part which is to be worked on by the apparatus, said releasable holding means being carried by said support means and being displaceable between a holding position where said releasable holding means securely holds the part and a release position where said releasable holding means releases the part,

(k) an auxiliary cylinder carried by said support means,

in said auxiliary cylinder and having an auxiliary piston rod fixed to said auxiliary piston and extending therefrom outwardly beyond said auxiliary cylinder, said auxiliary piston rod coacting at the exterior of said auxiliary cylinder with said releasable holding means for displacing the latter from one to the other of said positions thereof during movement of said auxiliary piston and said auxiliary cylinder one with respect to the other in one direction,

(m) an auxiliary conduit communicating with said auxiliary cylinder at one side of said auxiliary piston and providing for fluid flow into and out of said auxiliary cylinder at said one side of said auxiliary piston during movement of the latter and said auxiliary cylinder one with respect to the other in opposed directions, respectively,

(n) a return flow conduit communicating with said reservoir for returning fluid thereto, and

(o) distributing valve means communicating with said upper conduit, said auxiliary conduit, and said return flow conduit and having a pair of positions in one of which said distributing valve means directs fluid from said space over said main piston during a reduction in volume of the latter space to said auxiliary conduit to enter into said auxiliary cylinder for displacing said auxiliary piston to move said releasable holding means from one to the other of the positions thereof and in the other of which said distributing valve means prevents communication between said upper conduit and auxiliary conduit while providing communication between said auxiliary conduit and said return flow conduit so that said auxiliary piston can move in an opposite direction in said auxiliary cylinder during displacement of said releasable holding means back from said other to said one position thereof.

2. The combination of claim 1, further comprising: (p) a ram cylinder carried by said support means at an elevation lower than said main cylinder,

(q) a ram piston slidable in said ram cylinder, (r) ram means fixed to said ram piston and extending therefrom downwardly through and beyond said ram cylinder for pressing against a part which is to be worked on during an increase in the volume of the space in said ram cylinder which is situated over said ram piston, and

(s) a ram conduit communicating with the space in said ram cylinder over said ram piston and also communicating with said distributing valve means, said distributing valve means, when in said one posi tion thereof, interrupting communicating between said upper conduit and said ram conduit while directing fluid from said upper conduit to said auxiliary conduit and simultaneously providing communicating between said ram conduit and said return flow conduit, and said distributing valve means when in said other position thereof providing communication between said upper conduit and said ram conduit while directing fluid from said auxiliary conduit to said return flow conduit.

3. The combination of claim 2 and wherein the space in said ram cylinder beneath said ram piston communicates with the outer atmosphere.

4. The combination of claim 1 and wherein said auxiliary conduit communicates with the space in said auxiliary cylinder which is situated over said auxiliary piston, the space in said auxiliary cylinder beneath said auxiliary piston communicating with the outer atmosphere and said auxiliary conduit when receiving fluid from said upper conduit directing the fluid into said space of said auxiliary cylinder over said auxiliary piston to actuate said auxiliary piston rod to move said releasable holding means from said holding to said release position thereof.

5. The combination of claim 4 and further comprising: carried by said support (p) a ram cylinder fixedly means coaxially with said main cylinder and situated beneath the latter,

(q) a ram piston slidable in said ram cylinder,

(r) ram means carried by said ram piston and extending therefrom downwardly beyond said ram cylinder for engaging and pressing against the top end of an ingot during an increase in the volume of the space within said ram cylinder which is over said ram piston, and

(s) a ram conduit communicating with the space in said ram cylinder over said ram piston and also communicating with said distributing valve means, the space within said ram cylinder beneath said ram piston communicating with the outer atmosphere, and said distributing valve means when in said other position thereof directing fluid from said upper conduit to said ram conduit, while said auxiliary conduit communicates through said distributing valve means with said return flow conduit, said distributing valve means providing communication between said ram conduit and return flow conduit when said distributing valve means is in said one position providing communication between said upper conduit and said auxiliary conduit.

6. The combination of claim 5 and wherein said releasable holding means includes at least one bell crank pivotally carried by said support means, having one arm adapted to engage a lug of an ingot mold, and having another arm engaged by said auxiliary piston rod.

7. The combination of claim 5 and wherein an actuating means is operatively connected on the one hand with said distributing valve means and on the other hand with said main piston rod for responding to movement of the latter through a given stroke to displace said distributing valve means between said positions thereof.

8. The combination of claim 6 and wherein said releasable holding means includes a second bell crank having a lug-engaging arm for engaging a second lug of an ingot mold and having a second arm, a second auxiliary cylinder and auxiliary piston slidable therein with a second auxiliary piston rod engaging said second arm of said second bell crank, and a second auxiliary conduit communicating with said auxiliary cylinder and with said distributing valve means to be controlled simultaneously with and in the same way as said first mentioned auxiliary conduit to provide actuation of said second bell crank in unison with said first mentioned bell crank.

9. The combination of claim 1 and wherein said auxiliary cylinder has a space therein beneath said auxiliary piston communicating with said auxiliary conduit for raising said auxiliary piston rod when said auxiliary conduit communicates through said distributing valve means with said upper conduit, said releasable holding means having the construction of a lazy tongs the free ends of which are adapted to grip an end of an ingot, and said auxiliary piston rod coacting with said lazy tongs for displacing the latter to a release pOSitiOn during movement of said auxiliary piston in said auxiliary cylinder in an upward direction while said auxiliary conduit receives fluid from said upper conduit, and a second auxiliary conduit communicating with the space in said auxiliary cylinder over said auxiliary piston therein and also communicating with said distributing valve means to receive fluid from said upper conduit when said distributing valve means is in said other position connecting said first mentioned auxiliary conduit with said return flow conduit, whereby when said distributing valve means is in said other position thereof fluid under pressure will be received from said upper conduit and delivered to the space over said auxiliary piston to displace the latter downwardly for placing said lazy tongs in the gripping position thereof.

10. The combination of claim 9 and further comprising:

(p) a ram cylinder carried by said support means at an elevation lower than said main cylinder,

(q) a ram piston slidable in said ram cylinder,

(r) ram means fixed to said ram piston and extending therefrom downwardly beyond said ram cylinder for engaging an ingot mold and pressing against the latter during an increase in the volume of the space within said ram cylinder over said ram piston, and

(s) a ram conduit communicating with the space in said ram cylinder over said. ram piston and communicating with said second auxiliary conduit for directing fluid under pressure into said ram cylinder over said ram piston when fluid under pressure is delivered into said auxiliary cylinder over said auxiliary piston, the space in said ram cylinder beneath said ram piston communicating with the outer atmosphere.

11. The combination of claim 9 and wherein an actuating means is connected on the one hand to said distri-buting valve means and on the other hand to said main piston rod for displacing said distributing valve means between said positions thereof in response to movement of said main piston rod through a given stroke.

12. The combination of claim 1 and wherein an actuating means is connected on the one hand with said distributing valve means and on the other hand with said main piston rod for automatically displacing said distributing valve means between said positions thereof in response to movement of said main piston rod through a given stroke.

13. The combination of claim 12 and wherein said actuating means includes a rotary ratchet fixed to said distributing valve means for displacing the latter between said positions in response to turning of said ratchet, and a pawl actuating said ratchet and connected to said main piston rod for movement therewith.

14. The combination of claim 13 and wherein said actuating means includes an elongated bar carrying said pawl at one end thereof and carried at its other end by said main piston rod, and said support means guiding said bar for longitudinal movement to direct said pawl along a path where it Will engage said ratchet wheel.

15. The combination of claim 2 and wherein an actuating means is operatively connected on the one hand with said distributing valve means and on the other hand with said main piston rod for displacing said distributing valve means between said positions thereof in response to movement of said main piston rod through a given stroke.

References Cited UNITED STATES PATENTS 801,136 10/1905 Cheeuer 164408 2,641,806 6/1953 Leckrone 294-88 FOREIGN PATENTS 1,157,745 11/1963 Germany.

EDWARD A. SROKA, Primary Examiner. H. C. HORNSBY, Assistant Examiner.

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