US1728148A - Machine for casting printing plates without a riser - Google Patents

Description

Sept. 10, 1929. H. A. w. WOOD MACHINE FOR CASTING PRINTING PLATES WITHOUT A RISER Filed April 30, 1926 3 hee -Sheet 1 i i L -J TQM fl m kr k\ 1 F ATTORN EYJ' Sept. 10, 1929. H. A. w. WOOD MACHINE FOR CASTING PRINTING PLATES WITHOUT A RISER Filed April 30. 1926 3 Sheets-Sheet 2 Wake 700?,

ATTO F! N EYS Sept. 10, I929. w WQOD 1,728,148

MACHINE FOR CASTING PRINTING PLATES WITHOUT A RISER Filed April 30, 1926 5 Sheets-Sheet 3 INVENTOR "79am Q 5 ATTO H N EYS Patented Sept. 10, 1929.

UNITED STATES PATENT OFFICE.

HENRY A. WISE WOOD, OF NEW YORK, N. Y., ASSIGNOR TO 7001) NEWSPAPER MA- CHINERY CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF VIRGINIA.

MACHINE FOR CASTING PRINTING PLATES WITHOUT A RISER.

Application filed April 30, 1926. Serial No. 105,819.

This is in part a division of my applicametal enters, showing an intermediate step tion Serial No. 7 21,272 filed June, 20, 192s, of the operation of separating the still molnow patent 1,673,857, issued June 19, 1928, ten riser from the plate; but contains additional matter. Fig. 4 is a sectional view of the mold and 5 This invention relates to an apparatus for plate showing one plate ejected from the the casting of printing plates without a mold and ready to be removed and another riser in a solid state attached to the plate plate just starting to be cast, the parts of When cast. the riser separating means being in a dif- The principal objects of the invention are ierent position :trom those shown in Figs. 10 to provide means for eliminating entirely 1 and 3;

the presence of the riser on the plate when Fig. 5 is a similar view showing the posicast without sacrificing any of the advantion of the parts when the whole operation tages which an ordinary riser provides so .is completed and the second plate is fully as to do away with the use of the mechacast and its riser entirely separated; and

15 nism ordinarily employed for sawing otl' Fig. 6 is an enlarged sectional view a solid riser and yet leave the edge of the similar to Fig. 3 showing a modification. plate in a smooth condition and ot' the de- The conventional method of casting plates sired contour; to provide a machine which for rotary printing presses is to pour molten will avoid the loss of time and the slowing metal into a mold, in which a matrix has 20 down in the production of plates necessitated been placed. This mold is generally closed by the sawing otl' oi the riser, and also to on all sides and edges except the edge provide means for avoiding the necessity of through which the metal is poured. On this waiting until the plate is chilled before the edge a riser is formed, which serves the riser cutting operation can be started, and purpose of a feeder, from which the shrink- 2 at the same time to produce a plate of less age within the plate during the cooling prolength than the matrix in which it is cast, cess is supplied. This riser is generally so and of no greater length than a similar proportioned that it remains in a molten plate from which the riser has been severed state while the plate is solidifying, so that a while cold; to provide for the automatic and reservoir of molten metal is being mainrepeated operation of the machine; to protained during that process. 80

vide for quick and automatic separation of From this it will be seen that it eventualthe plate from the core; to produce the ly becomes necessary to rid the cast plate of plates ready to go on the press at a rapid this riser, so that the plate may be produced rate; to strip the plate from the core by with a straight finished edge instead of the the co-operation of the means for eliminating irregularly shaped mass, found thereon by the riser; and to provide for completing the the riser. This makes it necessary to proplates without producing chips or sawdust vide a device for severing the riser from which sometimes cause trouble in the the plate proper, usually in the shape of a mechanism. cutting mechanism of one form or another,

40 Additional objects and advantages of the according to the idea of the designer and invention will appear hereinafter. the demands of the machine. The process Reference is to be had to the accompanyof cutting off the riser after it has solidiing drawings in which fied produces a quantity of chips or saw- 1 is a cross section of one form of dust which are apt to clog the working parts casting mold and metal pump and pot with of the machine and interfere with its operaa preferred embodiment of this invention tion. It also serves to slow down the proapplied thereto; duction of plates, since a certain number of Fig. 2 is a plan of the same; seconds is required for the act of cutting Fig. 3 is a sectional view on enlarged oil the riser. scale of the portion of the mold at which the It has been suggested that the riser While it still is in the molten state, can be cut of by means of a rotating valve or the like. This method has proved defective, however, because among other objections, no way has been found of cutting olf the molten riser of a printing plate close enough to the edge of the type matter to avoid reducing the number of lines.

This has been because the valve devices proposed have never been able to sever the molten riser at a point nearer to the type than the edge of the matrix, which is used to secure the matrix in the mold. Thus, a blank space has had to be left on the plate edge equal in width to the clamping edge of the matrix which shortens the type surface of the plate by as many lines of type at least as the clamping edge of the matrix is wide.

As the shortening of the printing surface of a newspaper plate, in the direction of its curvature, reduces the number of type lines the page may carry, and as advertising is sold by the line, it has been necessary to bring the type area of a page to the utter- Inost edge of the printing plate. It is this limitation that has largely made impracticable the otherwise desirable method of cutting off the riser while in its molten state.

The invention is capable of use with an ordinary melting pot 1 located in a furnace casing 2 provided with a grate 3 or burners 4 under the pot as may be desired. The molten metal, as is well understood, is maintained at a level indicated by 5 in the melting pot. In this case it is pumped into a hopper 6 from which it is delivered into the mold. For the purpose of raising the metal from the pot 1 into the hopper 6 I have shown a pump 7 of the gear type driven by a shaft 8 from a sprocket 9 and chain 10 connected with a motor not shown. Of course any type of pump may be employed as that is not a feature of this invention.

' The metal enters the pump 7 at a point 11 from the interior of the pot 1. It is forced up through a pipe 12 into the hopper 6 in which a level is maintained by an adjustable gate 13 past which any overflow may return to the pot 1 through an overflow tube 14 extending below the level 5. I have also shown a means for emptying the hopper comprising a valve 15, rod 16 and lever 17 for opening a port below and allowing the metal to flow backinto the pot preferably under the level 5. An ordinary mixer 18 on the shaft 8 is indicated for the usual purpose.

The hopper 6 is provided with a spout 19 through which the metal is allowed to flow directly into the mold. The inside of the hopper 6 and the spout 19 are shown as provided with electrical heating elements 20 so that the temperature of the metal within may be maintained at any desired degree. Feeding wires 21 are shown for conducting a current to them, but if desired any other means may be employed. This constitutes 7a the metal delivering means.

The mold comprises a casting box 22 which in this case is shown as forming the concave wall for receiving the matrix M and intended to be lowered to open the mold. This box is shown as having a horizontal axis and as provided with matrix bars and clips 24 on its two upper edges. These hold the clamping edges of the matrix M and are arranged to strip the matrix from the cast to plate when the casting box is lowered from the pouring position in the usual manner by an arm 44;.

I have shown a core or cylinder 25 arranged to rotate about its own axis, and the ts axis of the casting box when in casting position, and forming the other side of the mold.

T have not shown any specific means for rotating this core or for raising or lowering the box 22 as any means well known in this fi art can be employed.

The mold is so located with respect to the end of the spout 19, which is provided with a cylindrical end 19 concentric with the curvature of the mold, that the metal will be delivered from the hopper 6 through this spout by gravity directly into the mold cavity between the core 25 and box 22 at one edge and preferably all along that edge. The matrix is clamped at each straight edge .199 as shown in Fig. 3 between the edge of the bar 23 and clip 24 which covers the upper and inner edge of the matrix. Above it is the spout 19 which registers with it.

The mold provided with an oscillating shutter or valve 29 adapted to su'ir' w. the surface of the core 25 about that core. It extends thron of the spou or nozzle 19. T operated by a lint: 30, lever 31. hr.

cam from the driving shalt l-l the cam is mounted. The letter link is shown as hating a roll co-opera .urposo.

(fl move the h will be poin I find it advisab effect of the us l cylinder 25 the metal contained witl tw the plate P and 1102. e 19. One means for this the provision of the cyliiuler o" 25 with an insulating area in the form cored hole 36, which when filled w.="

solid well. Another "way to .0 shown ll (3. in which a much thic r solid wall is ci'nployed sothat it will longer for the heat to be dispersed through it. it any 1W rate some means is employed for insulating this part of the mold from the cooling, devices which I have not illustrated herein. but which are ordinarily employed in this kind of mold.

Of course the printing; plate P is provided on its inner face with finishing strips 3) which are cast in suitable grooves 39 in the core for that purpose. On account of the proximity of the adjacent group of grooves around the cylinder I find it advisahlt-i to provide a lip 40 at the lower edge of the shutter 29 projecting downwardly to prevent metal from running; upwardly into the grooves of the upper half of the cylinder.

4 shows the position of the parts when the metal is being poured. It will be seen that the metal is free to flow into the mold cavity from the hopper and entirely fill it. At this time the shutter 29 is in its uppermost positoin so that the channel into the mold is unobstructed. Now when it is desired to sever the connection between the partly cooled metal within the mold and the molten metal within the passage of the spout 19 the shutter 29 is brought downward by the action of the cam 33. timed as stated to perform this operation at the exact instantindicated by the existing conditions. The shutter 29 swings down around the axis of the core from the position shown in Fig. to that shown in Fig. 3. thus partly closing the channel for the passage of meta] between the mold and spout. The plate P is nearly solidified by this time, which action may be hastened by the usual cooling methods. The shutter starts to move before the solidifying action is entirely completed.

Under the old conditions the metal in the riser was kept in a molten condition on account of the greater cross sectional area of the riser so that the shrinkage of the metal in the mold was compensated for by the necessary descent of the metal into the mold from the riser. In the present case, however, this shrinkage is compensated for by the descent of the shutter 29 into the mold and the forcing of the metal ahead of itinwardly toward the center of the mold cavity if the shrinkage is such as to permit it to do so. If not, the shutter continues to advance until the surplus metal is forced out along the side of it as indicated by the curved arrow in F ig. 3 when such metal goes back into the hopper. The operation, of the shutter. of course, is so timed as to synchronize with the rate of cooling of the metal being used at that time. It does not shut the mold passage instantaneously. but there is some dwell so that the surplus metal can be forced out. The timing is such that when the plate P becomes completely solidified and there is no further need of supplying it with molten metal for the purpose of replenishing the shrinkage incident to cooling. the shutter at that instant comes to its final position shown in Figs. 1 and 5. At that time it shuts off all communication between the mold and hopper 6 and the molten metal supply between the mold and the interior of the spout is forced out of the way by the advancing inclined edge of the shutter from the position shown in Fig. 3 to that shown in Fig. 5. In this way the supply of metal is entirely separated from the plate without the production of any riser at all. although all the ad- 'antages of a riser have been maintained through the various states of the cooling and solidifying action. Because of the construction shown there is no limitation placed upon the point to which the shutter 29 may descend. All metal but that actually used in the formation of the printing plate is dis placed and eliminated from the plate. The metal in the spout 19 is maintained in a molten state whenever that is necessary by the heating elements 20. The riser edge of the plate is cast against the surface of the parts 2-jland 29 which are finished to the proper shape to form the desired shape of this edge to permit it to be clamped properly on the cylinder of the press.

Fig. 1 shows the mold closed by the action of a cam 35, on the shaft 3%, on the bell crank lat, or lever connection. The shutter 29 closes all communication between the hopper 6 and the mold cavity and is ready to rise by the action of the cam 33. When the shutter rises to the position shown in Fig. 4 the metal will flow in as indicated in that figure. Now as the plate cools and the cam 38 rotates the latter will act to move the shutter 29 down from the position shown in Fig. 4 to that shown in Figs. 1, 3 and 5 just as the metal reaches the proper stage for that action as described above. When the shutter rises again the casting box 22 drops away from the cylinder and the matrixds stripped by the parts 23 and 24. Now the cylinder or core 25 turns through a half revolution in the usual way so that the newly cast plate is delivered on its upper half. lVhen this occurs the preceding plate P meets a projection on the shutter 29 and is thereby lifted during its turning action away from the surface of the core 25. The plate is turned positively with the core and kept against its surface throughout its turning action up to this point by a notch 43 in the core which of course is tilled by a projection on the plate. By the time the parts get to this position the shutter 29 has opened as shown in Fig. 4 so that a new plate P may be cast while the precedinp; plate P is being removed from the machine by hand or otherwise. l Vhen the plate is delivered it may or may not be shaved along its inner ribs before being clamped down on the cylinder of the press. As there is no riser and that edge of the plate is cast true against the surfaces of the parts 29 and 24 the entire finishing operation may in some instances be dispensed with.

In this way it will be seen that the riser sawing mechanism can be entirely elimi nated and even the shaving means in some cases; that although the riser is not present and does not have to be manipulated, sawed off or delivered, yet none of the advantages of the riser are lost. Furthermore, notwithstanding that the metal supply is separated from the cast plate while the former is in a fluid condition the plate is of no greater length than a similar plate from which the riser has been sawed while cold. Neither is any blank space necessary on the edge of the plate Conforming to the width of the clamping edge of the matrix and thus the type surface of the plate does not have to be shortened. Furthermore the connection of the plate with the metal supply or riser is done away with without producing chips or sawdust which might clog the working parts of the machine and interfere with its operation. This invention is also carried out with a corresponding increase in rate of production.

I do not claim herein the method or product as they are claimed in my original application, Serial No. 721,272. Although I have illustrated and described only a single form of the invention and shown it as applied to a well known type of casting box and melting pot I am aware of the fact that modifications can be made in the invention itself and that it can be used with other types of casting boxes and melting pots without departing from the scope of the invention as expressed inthe claims.

Therefore I do not wish to be limited in these respects, but what I do claim is 1. In a casting machine, the combination with a mold, means for supplying molten metal thereto, and means for opening and closing the mold, of means connected with the opening and closing means for automatically cutting off the supply of metal to the mold and ejecting the metal from the sprue.

2. In a casting machine, the combination with a mold having a passage leading to the mold cavity through which passage the metal flows to fill the mold, and means for closing the mold, of means for forcing the metal out of said passage when the mold cavity proper is filled and means for operating said last mentioned means.

3. In a casting machine, the combination with a mold having a passage leading to the mold cavity through which passa e the metal flows to fill the mold, and means for closing the mold, of means for forcing the metal out of said passage when the mold cavity proper is filled, and applying pressure to the metal in the mold cavity, whereby the edge 5. In a machine for casting a stereotype printing plate without a riser, the combination with the core and back, of a movable member between the core and back at the point at which the metal enters the mold,

and means for moving said member into the mold after it is filled to eject the metal lying between the mold proper and the source of supply.

6. In a device for casting a stereotype printing plate, the combination with a mold having a matrix holding device, and means for supplying molten metal thereto, of a movable member, and means for introducing the movable member into the mold to a position between the matrix holding device and the opposite side of the mold cavity to eject the metal at that point and cast a plate without blank end located along said matrix holding device.

7. In a device for casting a stereotype printing plate, the combination with a mold having a matrix holding device, and means for supplying molten metal thereto, of a gate, and means for moving the gate up to the edge of the character forming areaof the matrix to separate the cast plate from its riser close to the printing surface of the plate.

8. In a machine for casting a stereotype printing plate, the combination of a mold and a gate located at the intake edge thereof, with a hopper for containing molten metal located above the mold with a conduit at its bottom leading directly to the mold, and means for moving the gate into the conduit to close the conduit and prevent metal solidifying therein.

9. The combination with a mold for a stereotype printing plate having a space for the introduction of molten metal, of means movable bodily in a direction for stopping the flow of metal, forcing extra metal into the mold to supply any deficiency due to shrinkage, and cutting off the supply of metal at a point to prevent the formation of a riser.

10. The combination with a mold consisting of two parts having a space between them and means communicating with said space for introducing molten metal thereinto, of a shutter movable in a direction traverse to the adjacent side surfaces of the two parts of the mold toward the body of the mold, and means for moving said shutter inwardly after the mold has been filled and the metal therein partially solidified for the purpose described.

11. In a machine for casting stereotype printing plates, the combination with a mold con'iprisiug two parts having at one edge a space through which metal can be introduced to lill the space between them, of a shutter movable along the surface of one of said parts toward the mold cavity through said space whereby the metal can flow into the mold when the shutter is with drawn and means for forcing the shutter in toward the mold while the metal therein is only partly solidified to expel the surplus metal and cut it oli' from the cast plate.

12. In an apparatus for casting stereotype printing plates, the combination with a concave back and a convex core co-operating therewith to provide a mold space between them for a plate, of a spout having a surface constituting a continuation of the inside surface of said back and located adjacent thereto, means for supplying metal to the interior of said mold through the spout, and a shutter located between said surface of the spout and the convex surface of the core movable inwardly toward the mold cavity to cut oil the interior of the spout entirely from the mold cavity.

18. In a device for casting molten metal for a printing plate, the combination with a concave back and a convex core spaced apart to form a mold for a curved stereotype printing plate, oi. a spout fitting against said back and spared from said core the same distance as the back, whereby metal is free to flow through said spout into one ed e at mold cavity to till the same and Ioi'in a cast plate, and a shutter in the space between the surfaces of the spout and core outside the mold to close that space at that point, said shutter being movable inwardly along the surface of the core in engagement with the core to shut otl all communication between the spout and plate cavity, said shutter having a lip at its edge to prevent metal from running into the grooves of the upper half of said core.

14. In a device for casting molten metal for a printing plate, the combination with a concave back and a convex core spaced apart tc form a mold for stereotype printing plate, a spout fitting against said back and spaced from said core, and a shutter in the space between the spout and core to close that space at that point, said shutter being movable inwardly along the surface of the core to shut off all communication between the spout and plate cavity and mold the plate without a riser, of a matrix clamp on the same edge of the back, a clip for holding the edge of the matrix and molding a part of the surface of the edge of the plate, said shutter being constructed and arranged to fit against the edge of said clamp and mold the balance of the edge surface of the plate.

15. In a stereotype plate casting machine, the combination with a concave back and a cylindrical double core therein, of means for introducing the molten metal into the space between the back and core, means for shutting ol'l' the metal from the mold cavity and supplying surplus metal to prevent the formation of a riser, said core having on each of its halves a notch so as to form a projection on the plate inside and cause theplate to be turned around with the core positively when the core is rotated.

16. In a stereotype plate casting machine, the combination with a concave back and a rotatable cylindrical double core therein, of means for introducing the molten metal into the space between the back and core, means for shutting off the metal from the mold cavity and supplying surplus metal to prevent the formation of a riser, said core having on each of its halves a notch so as to form a projection on the plate inside and cause the plate to be turned around with the core positively when the core is rotated, said shutter having means thereon for engaging the advance edge oi the plate when ejected from the mold by the rotation of the core and separating it from the core ready to be detached.

17. In a device for casting molten metal for a printing plate, the combination with a back and core spaced apart to form a mold for a stereotype printing plate, a spout fitting against said back and spaced from said core, and a shutter in the space between the surfaces of the spout and the core to close that space at that point, said shutter being movable inwardly to shut oll all communication between the spout and plate cavity and mold the plate without a riser, of means for cooling the interior of the core and means for retarding the conveying of heat from the parts of the mold cavity adjacent to the entrance point for the molten metal in order to keep that part of the casting at a molten temperature alter the rest of the casting is solidified.

18. In a device for casting molten metal for a printing plate, the combination with a back and core spaced apart to form a mold for a stereotype printing plate, of means for cooling the interior of the core and means for retarding the conveying of heat from the parts of the mold cavity adjacent to the entrance point for the molten metal in order to keep that partof the casting at a molten temperature after the rest of the casting is solidified.

19. In a mold for casting printing plates for rotary printing presses, the combination with the ingate funnel in said mold, of a reciprocable pressure plate movable in a path in said mold adjacent to said funnel.

20. A mold of the character described having an ingate funnel and an adjacent guide passage therein, and a pressure plate i eciprocable in said guide passage.

In testimony whereof I have hereunto affixed my signature.

HENRY A. WISE WVOOD.

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