US3078540A - Hydraulic press - Google Patents

Description

Feb. 26, 1963 Filed Jan. 16, 1961 J. E. BUSH HYDRAULIC PRESS l0 Sheets-Shet 1 Feb. 2s, 1963 J. E. BUSH 3,078,540

HYDRAULc PRESS Filed Jan. 1e, 1961 lo sheets-sheet 2 lNvEN-roR BY Q J. E. BUSH HYDRAULIC PRESS Feb. 26, 1963 1 0 Sheets-Sheet 3 Filed Jan. 16, 1961 Feb. 26, 1963 J. E. BUSH 3,078,540

HYDRAULIC PRESS I Filed Jan. 16, 1961 10 Sheets-Sheet 4 Feb.`26, 1963 J. E. BUSH 3,078,540

HYDRAULIC PRESS Filed Jan. le, 1961 1o 'sheets-sheet 5 Feb. 26, 1963 J. E. BUSH 3,078,540

HYDRAULIC PRESS Filed Jan. 1e, 1961 1o sheets-sheet e NVENTOR Feb. 26, 1963 J. E. BUSH 3,078,540

HYDRAULIC PRESS Filed Jan. 16, 1961 10 Sheets-Sheet 7 Feb. 26, 1963 J. BUSH HYDRAULIC PRESS Filed Jan. 16, 1961 10 Sheets-Sheet 8 INVENTOR cfa/ 5 m Feb. 26, 1963 J. E. BUSH 3,078,540

HYDRAULIC PRESS Filed Jan. 16, 1961 10 Sheets-Sheet 9 INVENTOR Feb. ze, 1963 J. E. BUSH 3,078,540

HYDRAULIC PRESS v Filed Jan. 16, 1961 10 Sheets-Sheet 10 l i Kga; /ZZ

ai Z0.

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i l 05- u 0%/ 7 202 2 l (f ,Z021 j Vania Filed Jan. 16, 1961, Ser. No. 83,095 6 Claims. (El. 25-91.)

The present invention relates to hydraulic presses of the character which are suitable for molding particles into molded objects, particularly intended for brick-making presses, briquetting presses, powder metallurgy molding presses and tableting presses.

The present application is a continuation-impart of my copending application Serial No. 854,639, led November 23, 1959 for Hydraulic Press, now abandoned.

A purpose of the invention is to greatly simplify the construction of a hydraulic press of the character under discussion and particulany reduce the complexity of the hydraulic operating mechanism.

further purpose in a press of the character described is to interconnect the top head and lower platen together so that they move as a unit, to provide auxiliary hydraulic means to manipulate the top head and lower platen from a press base containing a mold box, to provide a bottom punch for the mold box interconnected with the bottom platen and to provide a crosshead and top punch which is moved by a hydraulic cylinder and ram on the top head.

A further purpose at the time of molding is to apply pressure from the main cylinder on the to-p head to advance the upper punch in the mold box and concurrently to apply pressure on the auxiliary cylinders to advance the bottom punch in opposition to the top punch.

A further purpose is to strip the mold by raising the top head and lower platen in unison until the bo-ttom punch is iiush with the top of the mold bo-x, thus extracting the previously molded object from the mold box, and then to push the previously molded object ofi laterally and bring a bottomless hopper into position on the lower punch, and then lower the top head and bottom platen and the bottom punch to form a mold cavity and discharge the contents of the hopper into the mold cavity.

A further purpose is to interconnect the top head and the lower platen by columns which are surrounded by and guided on the outer frame, the column cross-section desirably being deep in the direction transverse to the direction toward the opposite column and narrow in the direction toward the opposite column.

A further purpose is to provide a gate at one side of the mold cavity and a gate lock which can be inserted to close the gate, so that the mold box can be withdrawn laterally when the gate lock is withdrawn vertically.

A further purpose is to provide improved structure at the sides of the molded object by moving the entablature (the combination of thetop head and lower platen) axially while pressure is building up between the upper and lower punches under the action of the main cylinder and desirably also the prepressure cylinders.

A further purpose is to control the position of the entablature by stops in opposite directions; also to control the position of the upper moving platen with respect t the entablature by stops.

Further purposes appear in the specification and in the claims.

`In the drawings I have chosen to illustrate a few only of the numerous embodiments in which the invention may appear, selecting the forms shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

Describing in illustration out not in limitation and referring to the drawings:

atteste Patented Feb. 26, i963 FIGURE 1 is a diagrammatic end elevation of the device of the invention partially broken away to show the interior of one of the auxiliary cylinders.

FIGURE 2 is a section on the line 2-2 of FIGURE 1.

FIGURE 3 is a plan section on the line 3 3 of FIG- URE 1.

FIGURE 4 is a fragmentary section on the line tr-4 of FIGURE 3.

FIGURES 5, 6 and 7 are central vertical sectional diagrams showing the operation of the press of the invention in molding a brick.

FlGURE 8 is a diagram showing a hydraulic system of the device of the invention.

FIGURE 9 is a view similar to FIGURE 3 showing a modified form of the invention.

FIGURE 10 is a fragmentary section on the line lll- 1li of FlGURE 9.

FIGURES 11 to 17 illustrate a further embodiment of the invention.

FIGURE 11 is a front elevation of the modied press partly in vertical section.

FIGURE l2 is an end elevation of the press of FIG- URE l1 partly in vertical section.

FIGURES 13 to 16 inclusive are diagrammatic ceutral vertical sections showing the operation of the press of FlGURES 11 and 12.

FIGURE 17 is a hydraulic diagram showing also a diagrammatic section of the press of FlGURES 11 and 12.

FIGURES 17 to 20 illustrate a modified form of the evice of the invention in which the columns of the entablature are within and guided on the outer frame.

FGURE 17 is a fragmentary front elevation of the modified press partly broken away to show the guiding of the columns.

FIGURE 18 is a fragmentary end elevation of the press of FIGURE 17.

FIGURE 19 is a section on the line lil-19 of FlG- URE 17.

FIGURE 20 is a section on the line 2li-Ztl of FlG- URE i7.

in the prior art, in making brick molding presses and the like, it has been usual to employ rather complicated and expensive hydraulic mechanism, which adds greatly to the cost of the equipment.

ln accordance with the present invention, it is possible to perform the required functions of a brick molding press by using only two sets of hydraulic cylinders, namely, a main double-acting cylinder and an auxiliary single-acting set of cylinders.

In accordance with the invention, the press base provides guides for columns and the columns are interconnected at the top and bottom to a top head and a lower platen which operate as a unit. The lower platen carries a bottom punch which enters the bottom of the mold box.

The top head c rries the main cylinder, and the main cylinder ram carries the upper moving platen which is interconnected with the upper punch. The combination of the top head and lower platen is raised and lowered by interconnection with a combination of single-acting auxiliary cylinders and rams.

One great advantage of the press of the invention is that .auxiliary equipment including mold feeding andv bracket handling equipment can readily be mounted en the mold box in the press of the invention, since the mold box is stationary. The molded bracket is always discharged at the same height and this cooperates very errect-ively with conveyors to remove the bracket. of the invention readily adapts itself to different depths of ill of the mold activity.

A great advantage of the preferred embodiment of thedevice -of the invention is that it is possible to obtain the effect of active pressure applied to the upper and The pressV 3 lower punches even though there is only one main ram. This is accomplished by moving the entablature axially so that both punches are moving axially together through space while they are moving toward one another.

Accurate control of both limiting positions of the entablature and of the downward position of the upper moving platen is accomplished by means of stops.

In one desirable embodiment in the device of the invention, the columns which interconnect the top head and the lower platen to form the moving entablature are surrounded and guided on the outer frame, so that they very firmly resist distortion and are capable of withstanding eccentric loading. This capability is further increased by making the dimension of the columns in the direction of the other column less than one-third of the dimension transverse to the direction of the other column.

FIGURES l and 2 of the drawings illustrate the main components of the invention which consist of a stationary mold table 20, a top moving platen 21, a top head 22, a lower platen 23, and columns 24 interconnecting the tophead and lower platen. The mold table 20 has a base 25 extending horizontally and having sides 26 and ends 27. Tapped holes 2S, here shown as two, extend suitably through each side of the base and receive piston rods 30 extending vertically upward from the base. The base 25 is suitably secured to a foundation (not shown) in any suitable manner as by imbedding, bolting or the like. Mold beam sections consisting of side beams 31 and and end beam 32 extend vertically upward from the base and are suitably of rectangular cross section.

These mold beam sections are integral with the base and form part of the casting. The mold beams frame is a rectangle which has at its corners tubular guides 33 having machined inner surfaces 34 suitable for receiving columns 24 as will be later explained. The tubular guides 33 are of desirably greater depth than the mold beams as shown in FIGURES 1 and 2, and are suitably cast integral with the beam sections and base. The tubular guides at one end of the press have vertical key grooves at 36 and 37 on their exterior surfaces which receive tongues 38 and 40 on gate 41 which forms the end beam section opposite end beam 32.

In the modified form of the device shown in FIGURES 9 and l0, the tubular guides have vertical key grooves at 36 and 37 on their exterior surfaces which receive tongues 3S and 40 on gate 39 which forms the side beam section opposite side beam 31'.

The mold beam sections have recesses at 42 along the inside of the mold beams and have recesses 43 and 44 in the end beams which form a cavity for the mold 45.

Side removable liners 46 and end removable liners 47 and 48 are suitably attached to the inner sides of the eam sections by tlat head screws 50 passing through the liners and tapped in the mold beams. The inner sides of the side removable liners 46 have a dovetail recess 51 extending along the inner side of the liners and lying in a vertical plane. All the liners have a tapering side 51 which converges toward the mold beam section walls from a thick end at 52 to a thin end at 53. Wedges 54 bear dovetails 55 which lit into dovetail recesses 51 and engage the mold 45. Wedges 54 slidably t between the liners and the mold. The mold suitably consisting of sides 56 and ends 57 has extending about the outside of the sides and ends a tongue 56' which engages groove 57 on the wedges 54. Set screws S pass through threaded holes 60 which line up longitudinally with each of the wedges and bear against the thick end of the wedges 54. A moldcavity 61 extends through the center of the mold 45. A suitable recess 62 extends through the mold table in continuation of the mold cavity to provide an unobstructed opening through the mold table.

In the modilied form of the device shown in FIGURES 9 and 10, rectangular liners 46' and 47 are secured by screws 50 alongside beam 31 and end beam 32. The mold box 45 has tongues 56 which engage grooves 57 in liners 46 and 47'.

Passing through tubular guides 33 on the mold table 20 are columns 24. These..columns are of a suitably smooth outer surface and of adequate cross section for suicient strength. At the upper end of each column, a shoulder 63 ts against abutment 64 and the column extends through the head and is secured at the upper end by a nut 66 which retains the head 22 against the shoulder 63; A main hydraulic cylinder 67 having a dome 63 at the upper end and a port 70 at the upper end and a port 71 at the lower end is formed in the center of the top head. The cylinder is open a-t the lower end. A main hydraulic ram 72 having piston rings 73 is in the cylinder and has a piston rod 74 extending from the top head 22. A follower 75 is suitably threaded at 76 to the top head 22 and retains packing '77 about the piston rod 74.

At the end remote from the piston the piston rod 74 is attached to the top moving platen 21. The top moving platen 21 is guided by the columns 24 which extend through the openings in the crosshead portion 81. An upper punch or die 82 is suitably secured to the crosshead portion 81 and extends into the mold cavity 61, when platen 81 is in down position.

At the lower end of the columns 24 shoulders 83 abut against the lower platen 23 at 84 and the columns 24 extend through openings 85 in the lower platen. Nuts 86 threaded on the columns 24 at the lower end securely hold the lower platen against the shoulders 83 of the columns 24. A lower punch 87 conforming to the mold cavity is suitably attached to the lower platen and extends through passage 62 into mold cavity 61.

In the hydraulic system as shown in FIGURE 8, a high pressure low volume constant delivery pump 87 has a suction line 88 which leads from reservoir 90 containing suitable hydraulic oil 91. Conduit 92 leads from the discharge of pump 87 to a pressure relief valve 93 having discharge pipe 94 leading to reservoir 90. Flow pipe 95 leads from valve 93 to a three-way valve 96l A low pressure high capacity constant delivery pump 97 takes oil through suction plpe 98 and discharges through pipe 100 through pressure relief valve 101. A relief line 102 leads from valve 101 to reservoir 90. The discharge pipe 100 leads to three-way valve 96 and three-way valve 103. A ow line 104 connects three-way valve 96 to a four-way valve 105. Flow line 106 connects to the port 'l0 at the upper end of the main hydraulic cylinder 67 and the tlow line 107 connects four-way valve to the port 71 at the lower end of the main hydraulic cylinder 67. A discharge line 108 leads from valve 10S to reservoir 90. Flow line 110 connects four-way valve 103 to port 70' of the auxiliary hydraulic cylinders 67. Flow line 106 leads from ow line 106 to check valve 1062. Flow line 112 passes through throttle valve 113 to port 70 in auxiliary cylinder 67'. Discharge line 114 connects valve 103 to reservoir 90.

Feed hopper 115, as shown in FIGURES 6 and 7, has a bottomless container 116 mounted on the end of rod 117 which is connected to double acting cylinder and ram In the operation of the device of FIGURES 1 to l0, the mold is lirst inserted in the mold table at the beginmng of the brick pressing operation. The gate 41 is out of the mold table and held suspended above the mold table 20by crosshead 81 which is secured to a hook screwed in tapped hole 41 by a suitable wire, rope, sling or the like (not shown). The mold 45 is inserted. Wedges 54 bearing dovetails 55 slidably engage the dovetails 1n the liners 46 and 47. The wedges 54 having grooves 57 receive the tongues 56' of the mold box 45 which is positioned in the mold table.

Gate 41 is then lowered into position in recess 42 at the end of the mold table remote from the fixed end' beam by means of the sling and hook which connects the gate to the upper movable plates. Tongues 38 on the gate engage grooves 36 and 37 on the tubular guides 33. The gate is allowed to seat on the mold. table at act/aseo surface 42. The sling and hook are disengaged from the gate and crosshead after the gate is in place.

The top moving platen 2l is then lowered and mold 45 is positioned to coincide with upper punch 82 by longitudinally shifting the wedges 5ft which are free to slide between the mold sides 55 and 57 and the mold beam section liners de, 47 and dit. Set screws 53 are adjusted to mo-ve and hold the wedges in position. It will be seen that the mold 45 will be held from horizontal movement by the wedges and mold beam sections while the mold will be held from vertical movement by the tongue and groove interlock between the mold 45 and the wedges 54 along the sides 57 of the mold. The wedges will be interlocked with liners 5l which are secured to the mold beam sections by the dovetail lit at 55. In this position the mold is securely held for pressing of the bri-ck.

in the modilied form of the device shown in FIGURES 9 and l0, the mold 45 is inserted from the side of the mold table Zt while the gate 39 is being held in a raised position. The tongue 56' along one side and one end of the mold t5 engages groove 57 in the liners 46 and 47. Wedges 54 are inserted in the remaining side and end and adjustment of the mold made with adjusting screws 58.

After the mold d5 is in position and locked, the press is ready to form the bricks through its cycle of operation. ln FGURE 6 the press head and the lower platen are shown in the fully raised position. it will be evident that the press head 22 and the lower platen 23 will move as a single unit due to the tie rod arrangement between the columns 2d having shoulders 63 which receive the top head and lower platen which are held in position by upper nuts 65 and lower nuts 8d. The top head and lower platen will be held in the uppermost position by the hydraulic fluid lll which enters auxiliary cylinder 67 through port il and acts against piston 72 which is in fixed position at the end of stationary piston rods 3h which are mounted in tapped holes 23 and extend vertically upward from the base 2S. The hydraulic iluid 9i has been pumped from reservoir hit through high capacity pump 97 through line Mill, through valve w3 and through line liti into port 7d.

Main hydraulic ram 72 is in its uppermost position in the main hydraulic cylinder 67. Piston rod 74, connected to ram 72, holds crosshead S1 and mounting punch Si?. in an upward retracted position. In this position the lower punch 37 has passed through the mold tab-le recess 62; and into the mold cavity 6l. The top lid of the lower punch is flush with the top M9 of the mold.

A feed hopper IllS filled with a loose aggregate of Ibrick-forming material lZZ is translated across the smooth surface composed or upper surface il@ of lower punch 87 and upper surface 119 of the mold 45 as shown in FIGURE 6. The end l2@ of the feed hopper cornes in contact `vith a brick mi previously made and pushes the brick from the mold table 2d. When the bottomless container ille of the feed hopper 115 is in position over the mold cavity, the upper and lower platens descend. Valve lids is manipulated to close line lull from the pump y? and open flow line ilu from the port 7h to the discharge pipe ildand allow fluid 91 trapped in auxiliary cylinder 67 to escape and permit the top head and lower platen to descend on pistons 72'. When the lower platen 23 descends it carries with it lower punch 87 which forms the bottom of the mold cavity. This allows the brick-forming material 122 to descend into the mold cavity 6l as sho-wn in FIGURE 7. The feed hopper ll is then retracted by double-acting hydraulic cylinder and ram M5. lt will be understood that the top moving platen 2l is in its retracted position with respect to press head 22. This is accomplished by introducing fluid 91 from low pressure high capacity delivery pump 97 through line iti-ti, through valve 96 and o through valve 165 to line lo? which leads to port 71. This forces main hydraulic ram 72 upward in the cylinder 67 along with crosshead 3l.

It will be noted that fluid from the opposite side of hydraulic ram 72 flows out through port 7i), through line lilo, through valve 155, to discharge line 193 into reser- Voir @il when the entablature is moving relatively downward on the hydraulic ram.

At the position of FGURE 7 and after the retraction of the feed hop er from the hydraulic press, fluid from low pressure high capacity constant delivery pump 97 is delivered to the upper port Fitl through flow line lil@ of valve 95, flow line lilo, valve lilS, and flow line lilo; The hydraulic ram 72 moves rapidly downward with upper punch 82 contacting the brick-forming material .1.22. t a preset position subsequent to the initial contact with the brickforming material 122 by the upper punch 2-, valve Sio shuts off the llow from liow line tu@ and passes the flow from feed line from the high pressure low capacity pump S7 to feed line 10d through valve 165 to line lido connecting with port 7d in the top of the main hydraulic cylinder. The ram is forced downward under high pressure and forces upper punch S2 into the mold cavity 6l to form the pressed brick lill. The hydraulic tluid below the double acting main hydraulic ram 72 is allowed to escape in the downward movement of the ram through port 7l, line 167, through four-way valveylilS and discharge line i655.

During the time the main ram 72 is being forced downward by the hydraulic fluid under high pressure, iiuid from line lud is passed through line lilo', through check valve w62, through line M2, through throttle valve M3, through line lill into port 76 of the auxiliary cylinders 67. rl`his will cause the top head and lower platen to slowly rise and thereby move the lower punch d'7, forming the bottom of the mold, slowly upward in the mold cavity, while the top moving platen 2i descends, carrying the upper punch 82 into the mold cavity. This will give the effect of opposing moving punches and will etectively apply live pressure at the top and bottom of the brick-forming material 1.22. When the brick has been pressed to its desired size as shown in FlGURE 5, the high pressure iluid is cut ofi by valve 96 to ow line lil@ and fluid from low pressure high capacity pump 97 is passed through valve lo to valve E65. Valve lil is so manipulated as to pass fluid through line lil? which enters port 7l at the lower end of the main hydraulic cylinder o7. Line lilo from the cylinder 67 is connected by valve "itlS to discharge line 168 and the duid above ram 72 is allowed to pass to reservoir 90. The fluid will not pass through line lilo to line H2 and into auxiliary cylinder o7 since the iiuid in auxiliary cylinder o7" is under a higher pressure than the iiuid being discharged through line iM. The fluid under pressure in cylinder 67 is prevented from iiowing through line M2 and line lilo into lilo by check valve lil-62.

Also during the time of the retraction of main ram 72 into upper platen 22, valve lil is passing fluid from low pressure high capacity constant delivery pump 97' through line lili; to line il@ which leads to port 7h' in auxiliary cylinder o7'. This acts to move the upper and lower platens upward, since piston '72 is stationary onv piston rod 3o connected to stationary base 25. Lower platen Z3 carryingy lower punch d'1' moves upward and ejects the finished brick lll upward. The brick is held on top of the lower punch lid flush with the top of the mold table il@ at the fully raised position of the top head and lower platen. The feed hopper is about to be moved in on a side table L23 to push the nished brick off the press and to carry to the mold the new batch of bricklorming material i152. The cycle is now ready to repeat itself. r

ln ETL/.EURES ll to 17 inclusive l illustrate a desirable form of the press of the invention, omitting however the features of the construction of the mold box and omitting in many cases the feeding hopper or shuttle box,

7 which have already been illustrated in detail in respect to the form of FIGURES 1 to 8, and 9 and 10.

In FIGURES 1l to 17, the mold table 2G is supported on a foundation 139. As in the form previously mentioned, an entablature consisting of a top head 22 and a lower platen 23 is connected together by columns 24 which are supported and guided for vertical motion on the mold table 20.

Single acting auxiliary hydraulic cylinders 67 mounted on the top head 22 of the entablature act on rods S0 which are mounted on the mold table. The top moving platen 21 is guided on the columns 24 and operated by main ram 72 as already described, and the top moving platen carries the upper punches 82 while the lower platen 23 carries the lower punches 87 which enter the mold cavities 61.

In this form of the invention, double-acting prepressure rams 131 in prepressure cylinders 132 act on the top moving platen, the cylinders being mounted on the top head, while the rams are connected to the top moving platen and act parallel to the main ram.

By reference to the hydraulic system of FIGURE 17 it is there noted that an electric motor 133 drives a solenoid controlled pump 134 which provides alternate outgoing pressure lines 140 and 141 to a pretill valve 142 which includes the following features:

The prell valve as shown on the drawing in the conventional valve illustration consists of a main large orifice valve and seat which permits large volume ow by means of suction. This valve is closed by means of an internally contained pilot-pressure-operated three-way valve which permits oil to be admitted into the large area of a cylinder in which a ram opens the main oritice. The same three-way valve will admit oil to the differential area in the operating cylinder within the pretill valve to open the valve. Also contained in the three-way pretill valve is a port which opens and permits flow to the prell tank. The prell valve shown is entirely conventional in the art.

From the prell valve there is a line 16D passing to the main ram cylinder 67, a line 161 connected to both pump lines 140 and 141, and connected to the full area side of the prepressure cylinders 132 and also connected to a check valve 162 closing in the direction away from cylinders 132 and connected at the opposite side to sump 163. The prell valve also has a line 164 to sump 163.

Prepressure cylinders 132 on the diterential pressure side are connected by line 167 to one side of holdup valve 168, the opposite side of which is connected to line 166. Line 166 is also connected to line 180, one side of which is connected to holdup valve 181 which connects by line 190 to auxiliary hydraulic cylinders 67 and the other side of holdup valve 181 connects ythrough check valve 191 to sump 163.

Holdup valves 168 and 181 are suitably identical and are conventional valves which have the following features as shown by the conventional valve illustration on the drawing. They consist of an integral pilot operated threeway valve and an integral pilot operated two-way valve which together permit holding pressure on the inlet line at a preset pressure and also free ow through the valve from the inlet to the outlet side.

Line 180 at the opposite end connects to two-way valve 192, the opposite side of which connects through line 193 to sump 163.

The two-way valve 192 is suitably a conventional valve in the art which has the following eharacterLtics as shown by the conventional valve illustration on the drawing. This valve is of spool type construction with the spool being operated by pilot pressure exerted on a small double acting cylinder.

ln operation of the form of FIGURES 11 to 17, start ing with the structure in the position of FIGURE 13, the entablature including the top head and lower platen is raised. This has been accomplished by opening holdup valve 181 and admitting hydraulic liquid into the auxil- 8 iary hydraulic cylinder 67. This has raised the lower punches 87 until the molded brick 121 is level with the top of the table 20. As the brick nears the top of the mold cavity, hydraulic liquid has been directed to the differential area of prepressure rams 131, causing the top moving platen 21 and the upper punch 82 to move upwardly more rapidly than the lower punch 87 rises.

The upper punch thus reaches its upper position before the lower punch reaches its topmost position.

The upper position of the lower punch which makes it flush with the top of the mold table 2t] is determined when the collarlike column stops 194 engage the bottom of the mold table as shown in FIGURE 13. The charging box not shown in this form but operating as shown in FIGURES 1 to 8 pushes the molded bricks 121 out of the press and brings new charges to positions above the mold cavities.

With the top head and lower platen in upper position las shown in FIGURE 13, and the top moving platen also in raised position and the prepressure rams 131 fully retracted, the next step in the operation as shown in FIG' URE 14 is achieved by opening holdup valve 181. Hydraulic liquid from auxiliary hydraulic cylinders 67' is drained through line 190 and holdup valve 181 and bypassing the pumps goes through line 180 and two-way valve 192 in open position, allowing the entablature with the top head and lower platen to move down. By the time the filling hopper is over the mold cavities, the lower punches 87 have dropped to a preset filling position at which adjustable stops 195 in the top head, which suitably screw up and down therein for adjustment, encounter stop bumpers 196 on the mold table. The adjustment of the stops 195 is desirably accomplished by remote control, suitably through electric motors, not shown.

Pump 134 applies pressure through line 140 and applies suction to line 141 and this pressure is diverted through pretill valve 142 to the full pressure area side of prepressure cylinders 132. However holdup valve 168 is open, permitting hydraulic liquid to escape from the differential pressure side of prepressure cylinders 132, so that in effect the top moving platen 21 descends by gravity. The motion downward of the top moving platen has been retarded with respect to the motion downward ofthe top head and lower platen because of delay in releasing pressure from the differential area of the prepressure cylinders 132.

As top moving platen 21 moves downward it encounters a limit switch 197 which causes holdup valve 168 to close, and pressure which has already been supplied through line to the full area side of prepressure rams 131 now begins to force the prepressure rams against the charge, to the limit of the pressure of the prepressure rams, eliminating air before the application of the main pressure.

The rapid advance of the upper moving platen between the position of FIGURE 14 and the position of FIGURE 15 is accomplished and controlled as hydraulic liquid is pumped from the differential area of the prepressure .cylinder 132, the upper moving platen moving down by gravity.

In the meantime the main cylinder 67 is preflling through prell valve 142.

The relationship at the time of applying main cylinder pressure is shown in FIGURE 15.

A pressure switch 198 is then actuated, which shifts pretill valve 142 connecting ports 4 and 1 to the main cylinder, and full pressure is applied.

During both the prepressing and final pressing stroke, two-way valves 192 and 202 are maintained normally closed andrhold up valve 181 is open permitting ow of lluid through line into auxiliary hydraulic cylinders 67', applying pressure through line 190 to auxiliary hydraulic cylinders 67' which slowly raises the entire entablature and the top moving platen mounted on it by means of the auxiliary cylinders moving slowly upward. This causes a wiping action under pressure between the mix in the mold and the sides of the mold cavity and the eect is as i-f live pressure were being applied to both the top and the bottom of the material in the mold. The two punches advance toward one another compacting the molded material, and this greatly improves the quality of the surface of the side of the molded product and is valuable not only in brick molding but in molding powder metallurgy metal compacts, salt blocks, abrasive articles and the like.

The two punches advance toward one another until as `shown in FlGURE 16, top moving platen 21 encounters stops 198 which suitably surround columns 24.

The stops 195 determine the thickness of the brick or other molded object. When stops 195 are encountered movement effectively stops and pressure continues to build up.

At the ultimate pressure, pressure switch ltltl operates preiill valve 142 and the pressure switch reverses pump 134 so that it pumps out through line 166 and sucks in through line 140, the pumping ow passing through holdup valve 1.63 into the differential area of prepressure rams 131. The pump arrangement of the character described by which reversal between pressure and suction on two lines lis accomplished is a conventional device well known in the art as shown by the conventional illustration on the drawing. 'Ihis returns the top moving platen at full speed to raised position as shown in FIGURE 13,

feeding the brick or other molded object from any downward acting pressure.

The small pump 164 keeps pumping into auxiliary hydraulic cylinders 67 and oil from pumps 134 is diverted into line l'tl'll through line 166 by the opening of ltwo-way valve 202 until stop 194 engages the bottom of the mold table, at which point pressure switch 201 disconnects motor 16S on small' pump 164'.

The use of a separate motor and separate pump for the auxiliary cylinders is very desirable as i't starts moving the entire entablature upward while molding is taking place to improve the grain structure at the side of fthe molded object.

The form of FIGURES 17 to 20 provides an overhead structure Zti surrounded by standards 201 which are secured to outer frame members ZtlZ which extend vertically and are mounted by bolts 203 from the stationary mold table 2t) supported on the foundation as previously described, as by columns 204.

The outside frame members 202 at the ends are crossconnected at the top by front and back frame members 26S as best seen in FIGURES 17 and 19.

rille general components of the press are as previously described. The entablature yin this case comprises a top head 22 and a lower platen 23 which are connected together by vertical columns 24', one at each end which are keyed and bolted at the top and bottom in suitable manner. Each of the columns 2li is desirably of rectangular form as best seen in FIGURES 19 and 20, having a dimension in the direction toward the opposite column which is less than one third the dimension transverse 'thereto thus providing for great resistance to deformation from load which is applied with the center relatively forward of or relatively rearward of the center of the mold activity.

The vertical outside frame elements 262' at the ends have a vertical groove recess 2&6 best seen in FIGURES 17, 19 and 2O which receives and guides the columns 24' there being guiding shoes 237 at the corners between the outside frame and members Ztl@ and the columns 2d'.

At the positions opposite the top moving platen 21 the columns 24 are chamfered at ZtlS and engaged by antifrictio-n metal guides 21@ secured on guiding sho-es 211 which are suitably fastened to the top moving platen.' The first component for guiding of the top moving platen urges the columns 2st toward engagement with the guiding elements on lthe outer frame end members 2h12 thus further pressing the column elements 24'.

lt will thus be evident that the column elements are 10 really surrounded by the outer frame end members thus assuring an extremely strong construction.

ln this form brackets 212 extend through Windows 213 in the outside frame end members 202 and connect with auxiliary cylinder rams 30' which operate in auxiliary hydraulic cylinders 6,7' mounted on brackets 21e on the outside frame.

In the device of FIGURES 17 to 20 stops 194' secured to the columns perform the functions of stops 194 and stops 1% or secured to the columns performs the functions. of stops 198.

The outward motion of the entablature is adjustably controlled by screw stops 195 mounted on the entablature and engaging abutments 196' mounted on the outer frame.

ln operation the form of FIGURES 17 to 20 is similar to that already described except for the fact that the columns are surrounded by and guided by the outer frame, through the length between the top and the stationary mold, and also for a distance below the stationary mold as best seen in FGURES 17 and 19 and the stops are somewhat differently constructed as shown.

The stops 19S' may be suitably intergeared as desired so that the screws can be adjusted in unison.

It will be evident that one of the great advantages of the invention is that it is not necessary to place any type of hydraulic mechanism beneath the mold table. This has been a frequent source of dificulty in prior art devices.

ltA will also be evident that whereas the press of the invention has only one main ram, it will give the same pressing action as a press which has both upper and lower full tonnage main rams.

In view of my invention and disclosure, variations and modications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the structure shown, and I, therefore, claim all such insofar as they fall within the reasonable spirit and scope of my claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

l. In a hydraulic press for molding brick and the like, including a base, a mold box having an open bottom end and an open top supported on the base, columns, a top head mounted on the upper end of the columns, a lower platen mounted on the lower end of the columns, the top head and lower platen moving together as an entablature, bottom punch on the lower platen extending into the mold box, a main cylinder on the top head, a main ram in the main cylinder, and atop punch ultimately connected to the main ram and adapted to enter the mold box in combination with guides on the base for the columns, means including auxiliary cylinders, pistons and piston rods interconnecting the top head with the base and adapted to move the entablature vertically, in combination with a cross-head connected to the main ram and guided to move vertically, pre-pressure cylinders mounted on the top head and having pistons and rods connected to the cross-head, means for energizing the pre-pressure cylinders in opposite directions and means for applying pressure to the auxiliary cylinders to raise the entablature and cause wiping action between the work and the side of the mold while the main cylinders and the pre-pressure cylinders are applying pressure to the top and bottom punches to move the top and bottom punches toward one another.

2. A hydraulic press for molding brick and the like, including a base, a mold box having an open bottom end and an open top supported on the base, columns, a top head mounted at the upper end of the columns, a lower platen mounted on the lower end of the columns, the top head, the columns and the lower platen moving together as an entablature, a bottom punch on the bottom platen extending into the bottom of the mold box and forming the bottom of the mold cavity, a main cylinder on the top head and movable with the entablature, a main ram in the main cylinder, a top punch mounted ultimately on the main ram and entering the mold box, the main cylinder and ram applying pressure to the top punch and to the bottom punch so as to mold the work, in combination with means for guiding the columns on the base, and means including auxiliary cylinders, pistons and piston rods interconnecting the entablature with the base and moving the top punch and the bottom punch both in the same direction at the same time that the top punch and the bottom punch are moving toward one another and applying molding pressure to the work.

3. A hydraulic press having a base, a mold box having an open bottom end and open top supported on the base, columns at opposite ends of the press, a top head mounted at upper ends of the columns, a lower platen mounted at the lower ends of the columns, the top head and the lower platen moving together as an entablature, means for moving the entablature, a bottom punch on the lower platen, a main cylinder on the top head, a main ram in the main cylinder and a top punch ultimate- 1y connected to the main ram and adapted to enter the mold box, in combination with an outside frame including vertical members on both ends of the press, there being a vertical groove at each end of the press in the outside frame, guides for the columns in the vertical grooves of the outside frame, said columns having a dimension parallel to the direction defined by a line connecting the columns at opposite ends of the press which is less than one-third the transverse dimension, and a crosshead connected to the main ram and guiding the top punch.

4. A hydraulic press of claim 3, having windows through the outside frame at the ends, and brackets on the columns extending through the windows and means for moving the entablature including cylinders and rams mounted outside the frame and interconnected with the brackets.

5. A hydraulic press for molding brick and the like including a base, a mold box having an open bottom end and an open top supported on the base, columns, a top head mounted on the upper ends of the columns, a lower platen mounted on the lower ends of the columns, the top head, lower platen and the columns moving together as an entablature, a bottom punch on the lower platen extending into the mold box, a main cylinder on the top 12 head, a main ram in the main cylinder, a top punch ultimately mounted on the main ram and adapted to enter the mold box, in combination with means for guiding the columns on the base, means including auxiliary Vpistons and piston rods interconnecting the top head with the base and moving the entablature vertically, a crosshead connected to the main ram and guided to move vertically, and pre-pressure cylinders mounted on the top head and having pistons and rods connected to the crosshead and double-acting means for energizing the pre-pres sure cylinders, said auxiliary cylinders lowering the entablature to open the mold cavity while the top punch is raised for lilling the mold, said pre-pressure cylinders lowering the top punch and applying pressure between the top and bottom punches to begin molding the work, said main cylinder applying pressure to the top and bottom punches to complete the molding of the work and said auxiliary cylinders moving the top and bottom punches upwardly in the mold while the top and bottom punches are moving toward one another.

6. A press of claim 5, in combination with means acting between the lower platen and the base for restricting the upper movement of the entablature to place the top of the bottom punch on a level with the top of the mold box.

References Cited in the file of this patent UNITED STATES PATENTS 1,003,987 Cotton et al Sept. 26, 1911 1,765,626 Stacy June 24, 1930 1,860,075 Byerlein May 24, 1932 1,958,199 Morin May 8, 1934 2,309,944 Flowers Feb. 2, 1943 2,320,759 Stacy June 1, 1943 2,398,227 Hubbert Apr. 9, 1946 2,569,226 Carter Sept. 25, 1951 2,775,016 Dubois et al. Dec. 25, 1956 2,831,230 Neth et al. Apr. 22, 1958 2,877,531 Heine Mar. 17, 1959 2,962,790 Daniel Dec. 6, 1960 FOREIGN PATENTS 16,808 Great Britain Oct. 22, 1890 101,065

Australia Mar. 27, 1937

Claims (1)

1. IN A HYDRAULIC PRESS FOR MOLDING BRICK AND THE LIKE, INCLUDING A BASE, A MOLD BOX HAVING AN OPEN BOTTOM END AND AN OPEN TOP SUPPORTED ON THE BASE, COLUMNS, A TOP HEAD MOUNTED ON THE UPPER END OF THE COLUMNS, A LOWER PLATEN MOUNTED ON THE LOWER END OF THE COLUMNS, THE TOP HEAD AND LOWER PLATEN MOVING TOGETHER AS AN ENTABLATURE, BOTTOM PUNCH ON THE LOWER PLATEN EXTENDING INTO THE MOLD BOX, A MAIN CYLINDER ON THE TOP HEAD, A MAIN RAM IN THE MAIN CYLINDER, AND A TOP PUNCH ULTIMATELY CONNECTED TO THE MAIN RAM AND ADAPTED TO ENTER THE MOLD BOX IN COMBINATION WITH GUIDES ON THE BASE FOR THE COLUMNS, MEANS INCLUDING AUXILIARY CYLINDERS, PISTONS AND PISTON RODS INTERCONNECTING THE TOP HEAD WITH THE BASE AND ADAPTED TO MOVE THE ENTABLATURE VERTICALLY, IN COMBINATION WITH A CROSS-HEAD CONNECTED TO THE MAIN RAM AND GUIDED TO MOVE VERTICALLY, PRE-PRESSURE CYLINDERS MOUNTED ON THE TOP HEAD AND HAVING PISTONS AND RODS CONNECTED TO THE CROSS-HEAD, MEANS FOR ENERGIZING THE PRE-PRESSURE CYLINDERS IN OPPOSITE DIRECTIONS AND MEANS FOR APPLYING PRESSURE TO THE AUXILIARY CYLINDERS TO RAISE THE ENTABLATURE AND CAUSE WIPING ACTION BETWEEN THE WORK AND THE SIDE OF THE MOLD WHILE THE MAIN CYLINDERS AND THE PRE-PRESSURE CYLINDERS ARE APPLYING PRESSURE TO THE TOP AND BOTTOM PUNCHES TO MOVE THE TOP AND BOTTOM PUNCHES TOWARD ONE ANOTHER.

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