US 3013321 A
Description (OCR text may contain errors)
Dec. 19, 1961 R. H. MCELROY 3,013,321
BRICK PRESS Filed Feb. 20, 1959 22 7 Sheets-Sheet l JNVENTOR. Roy H. 5). k
Dec. 19, 1961 R. H. McELROY 3,013,321
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BRICK PRESS Filed Feb. 20, 1959 7 Sheets-Sheet 7 INVENTOR. 1 H. McEZ 20/ A TTWZNE rs 3,013,321 Patented Dec. 19, 1961 pawl 3,013,321 BRICK PRESS Roy H. McElroy, Dayton, Ohio, assignor to International Clay Machinery of Delaware, Inc., Dayton, Ohio, a corporation of Delaware Filed Feb. 29, 1959, Ser. No. 794,719 2 Claims. (Cl. 2541) This invention relates to a compacting press and in particular to a com acting press for forming bricks or briquettes.
The present invention represents a further extension in development and refinement of the general inventive concept disclosed in applications: McElroy et a1. Serial No. 386,621, now abandoned, for: Press and Method of Operation, filed October 16, 1953; and McElroy Serial No. 418,863, now Patent No. 2,909,226, for: Method and Apparatus for Compacting Granular Material filed March In the applications identified above there are disclosed arrangements for compacting granular material by vibratory techniques so that the usual extremely heavy pressing arrangements that have been employed heretofore for forming bricks are eliminated.
The usual pressing arrangement has hydraulic or mechanical pressing arrangements and the compacting of the material is carried out simply by exerting an extremely high pressure against the granular material. In the applications identified above as well as with the arrangement of the present invention, the compacting of the granular material is accomplished by bringing a compacting memher to rest on the granular material and then vibrating the compacting material which brings about compacting of the material.
The devices of the pending applications referred to above have been characterized in having a compacting plunger attached to a cross head that is guided in the press frame. It has been found, however, that this arrangement results in the forming of crooked bricks since the compacting member tends to become misaligned.
A primary object of the present invention accordingly is the provision of an arrangement forcompacting granular material by vibration of a compacting member in which the compacting member is so guided as to prevent tilting thereof and accordingly bricks of a proper shape will be produced. 7
In the usual type of compacting press, including those referred to in the above identified applications, it is many times extremely difficult to replace the molds in which the bricks are made. This made it clifiicult to change the press from one type of brick product to another type.
Thus, a still further object of the present invention is the provision of a press arrangement in which the changing of molds and dies and the like becomes an extremely simple matter.
Another object of this invention is the provision of a control arrangement for a vibratory compactingpress in which the charging mechanism that delivers the material to the mold that is to be compacted therein is adjusted automatically so that bricks of the proper dimensions can be produced without close attention by the machine operator.
It is also an object of this invention to provide a greatly simplified press structure in which substantially all of the load on the press is carried by an inner frame than can easily be fabricated. I
A still further object of this invention is to provide a simplified hydraulic system for operating the machine and including an electrical control arrangement therefor.
Referring to the drawings somewhat more in detail:
, FIGURE 1 is a vertical sectional view through a press according to the present invention and is indicated by line 1--1 on FIGURE 2;
FIGURE 2 is a vertical section through the machine as indicated by line 2-2 on FIGURE 1;
FIGURE 3 is a plan sectional view indicated by line 3-3 on FIGURE 2;
FlGURE 4 is a plan sectional view taken through the press further down and is indicated by line 44 on FIG- URE 2;
PEGURE 5 is a perspective view showing the upper portion of the press partly broken away indicating the main cross head of the press and the vibratory cross head;
FIGURE 6 is a perspective view showing the bottom of the press and indicating the manner in which the ejector is guided and located in the press;
EGURE 7 is a perspective view showing one of the removable stop bars on which the ejector comes to rest during a pressing operation;
FIGURE 8 is a sectional view indicated by line 8-8 on FIGURE 2 showing a portion of the automatic charge adjuster of the machine;
FEGURE 9 is a diagrammatic representation of the electric control circuit; and
FEGURE 10 is a diagrammatic representation of the hydraulic circuit for actuating the machine.
Referring to the drawings somewhat more in detail, and in particular to FIGURES 1 through 6, the press according to the present invention comprises a frame which consists of four vertically extending column members 10 located at the corners of the press and which may consist of angles placed together as illustrated and welded along their abutting edges. At the top of the press there are short beams 12 extending from front to back and interconnecting the front and back column members 10.
At their bottoms the column members 10 are interconnected by the fabricated beams 14 which are welded to the columns with the beams being interconnected by a central beam element 16 keyed to beams 14 by keys 18 and attached thereto by cap screws 20.
The beams 12 at the top of the press are interconnected by a plate 22 and the sides of the press are enclosed by the large plate members 24 fixed to columns 10 and with there being feet 26 at the bottom of the plates 24 on which the press rests with the lower end of the press extending into the pit.
The plates 24 have apertures therein in which are mounted support members 28 which have portions extending through the plates 24 and notched at their inner end for receiving the rails 30. Bolts 32 through members 28 engage the rails and by placing shims as at 34 beneath the heads of members 28 the rails 30 can be precisely positioned inside the press frame.
These rails are availed of for guiding the press cross head and the ejector within the press frame in their vertical movements.
Intermediate the top and bottom of the press is a stationary frame 35 adapted for receiving or supporting the mold within which the bricks being formed are to be compacted.
A simple mold at 36 is illustrated but it is understood that the mold could comprise substantially any configuration and there could be a plurality of cavities in the mold if desired.
Beneath mold 36 is an ejector platen 38 having V-shaped portions 40 at the sides that engage the rails 30. This will best be seen in FIGURE 7. The ejector has a plunger 42 connected therewith which extends into a cylinder 44 which is connected at its bottom to the mid point of beam 16. The ejector platen is adapted for supporting member 46 that forms the bottom for the mold.
The ejector, when in its FIGURE 1 position comes to rest against bars 48 which have the replaceable wear plates 51') on opposite sides thereof. Bars 48 are clamped in position by the clamp members 52 and bolts 54 which thread into the brackets '6 provided therefor on the insides of beams 14. The bars 48 rest on top of beams 3.4 and when the ejector platen is fully retracted it engages the tops of the bars thus giving it a fixed lowermost position.
The hydraulic motor consisting of the plunger 42, the piston on the end thereof, and cylinder 44 is availed of for moving the ejector platen upwardly so that member 56 which forms the mold bottom will push compacted workpieces up to the top of the mold 36 from which position the bricks can be manually removed or will be pushed off the mold when the charging box subsequently to be described advances to supply another charge to the mold.
in the upper portion of the press is a main cross head 6% which has V-shaped guide elements 62 at the sides thereof engaging the rails St for guiding the cross head in the press frame.
The cross head is fabricated by welding plates together and there is formed therein a cavity 64 of substantial size. Attached to the bottom wall of the cavity is a plunger 66 extending into a cylinder 63 and there is a piston on the end of the plunger within the cylinder. The cylinder is attached to plate 22 forming the top member of the press frame. By use of the hydraulic motor described the main cross head can be raised and lowered. Located within cavity 64 are two stacks of weights 7t) which are retained in position by the bolts 74. Weights 7 t} provide the compasting pressure so that none of the pressing force is derived from the hydraulic motor attached to the main cross head.
The actual compacting cross head is beneath the main cross head and is indicated at 80. The compacting cross head comprises a lower plate member 82 upstanding from which are the V-shaped members 84 engaging rails 30 and braced relative to plate 62. by gusset plates 36. The compacting cross head 80 is suspended from the main cross head by four distributed bolts 38 having heads 96 beneath plate 8?. and nuts 92 on the. upper ends above the bottom plate of the main cross head. Springs 94 above the bottom plate of the main cross head and springs 96 beneath the said lower plate provide a resilient connection between the cross heads.
Tubular guide elements Welded to plate 82 surround the bolts 88 and form supports which the lower ends of springs )6 engage. The arrangement is such that the lower cross head will move with the upper cross head with the springs 94 and 96 permitting vibration of the lower cross head without requiring that the upper cross head vibrate in unison with it. At the same time the weight of the upper cross head, which may amount to as much as 2500 pounds, is exerted on the lower cross head though the springs 96.
Mounted on the plate 32 of the lower cross head is a vibrator arrangement consisting of the two counter rotating or? center masses Hit and a hydraulic drive motor geared thereto at Hi2. When the motor 102 is energized the off center masses ltil) will rotate in opposite directions and vibratory forces in the vertical direction will be established in the lower cross head but lateral vibratory forces will be substantially non-existent.
Attached to the back of the press frame is a sub-frame arrangement 134 which has guide rails 106 which extend into the press frame along the sides of the mold. These guide rails movably support a charging box 108 which is reciprocated along the rails by a hydraulic motor 113.
When the charging box is positioned over the mold the material in the charging box, and which is the granulated material that is to be compacted, will drop into the mold cavity and when the charging box is retracted it will strike the mold oft across the top thus giving a relatively accurate As will be seen hereinaiter, the position of the ejector cross head will determine the amount of fill so that brick of the proper size will be formed. The advancing movement of the charging box can be utilized for pushing the previously formed bricks from their position on top of the mold bottom on to a receiving platform 112 which extends out the front of the press from the mold. Any suitable means can be provided for maintaining the charging box filled with granulated material and this may include automatic controls if desired or there may simply be provided a filling chute as indicated in the dot-dash outline at 114.
in the charging of the mold cavity, the charging box 1% is advanced while the ejector platen 38 is in its uppermost position. When the ejector platen is in this position the stop screws 116 carried thereby abut the bottom of the mold support frame 3-4. This positions member 46 carried by the ejector platen so that it is flush with the top of the mold.
After the charging box has been advanced so that it is positioned over the mold cavity, the ejector platen is retracted until a cam element 118 carried thereby engages and actuates a limit switch LS4. This halts the downward movement of the ejector platen and member 46 carried thereby and determines the amount of material supplied to the mold cavity.
The charging box is then retracted and the material in the mold cavity is struck oil level with the top thereof.
After the charging box is completely retracted the ejector platen continues downwardly to the bottom of the stroke and the main cross head and compacting cross head are then lowered until the compacting member carried by the compacting cross head engages the material in the mold cavity whereupon the vibrator is placed in operation and the material is compacted by the vibrating action.
in connection with the halting of the ejector platen to determine the amount of material delivered to the mold cavity, limit switch LS4 is mounted on a block 12 which is adjustable by the apparatus best seen in FIGURES 2 and 6, and particularly in FlGURE 8.
In FIGURE 8 it will be seen that block 120 is slidable on a rod 122 and is screw threaded with a threaded rod 124. Rod 124 is rotatable in a lower support block 126 and in an upper support member 128. There is a hand wheel attached to the threaded rod for manual rotation thereof and the rod is also connected by a jaw clutch 132 with the output shaft of a geared head reversible electric motor 134.
Normally, motor 134 is operated to rotate rod 124 thereby to adjust the vertical position of block 120 and thereby to adjust the position of limit switch LS4 carried by the block which in turn adjusts the amount of material supplied to the mold cavity. Should it become necessary to rotate rod 124 manually, the jaw clutch 132 is disconnected and the rod can thereafter be rotated by hand wheel 1%.
An important feature of the structure described above is in connection with the bars 48 which form stops for the ejector platen. By removing these blocks, the ejector platen can be lowered to withdraw member 46 from the mold cavity whereby the changing of the mold at any time becomes extremely simple.
These bars also form stop members for the ejector platen to abut when in its lowermost position and whereby an absolutely solid mold bottom is provided against which the material within the mold cavity is compacted.
Another extremely important feature of the described structure is in the independent guiding of the compacting or vibrator cross head. This cross head is supported and guided independently or" the main cross head and is thus supported against any tendency to tilt or deflect which might occur in connection with the extremely heavy main cross head. Even if the main cross head does bind or tilt, the relatively light compacting cross head with its extremely long guide surfaces will be supported in the press frame without tilting. Thus, the combination of the absolutely solidly supported mold bottom member 46 and the extremely strongly and accurately guided compacting cross head member, produce bricks which have absolutely parallel sides and which are thus superior to bricks produced in other manners.
It will be noted that all Compacting thrusts are imposed on the four comer columns of the press structure whereby the side plates and other elements of the press structure are relieved from working stresses.
Referring now to the electric and hydraulic circuits of FIGURES 9 and 10,- the fiuid pressure for the system is supplied by a pump 14% which discharges pressure fluid into a conduit 142. This conduit leads to the inlet of a reversing valve 144 normally urged into one position by spring 146 and shiftable into a second position by energization of a solenoid S1.
The conduit that is under pressure when the solenoid is tie-energized leads to a pilot operated check valve 148 and through which fluid can flow freely to the lower end of cylinder 68. The upper end of cylinder 63 is connected with the tank and valve 144 and check valve 148 thus provides complete control of movements or" plunger 66 of cylinder 68. g
The conduit leading from valve 144 which is under pressure when solenoid S1 is energized leads to the inlet of a valve 150 which is normally closed by a spring 152 but which is opened by energization of a solenoid S2 to supply pressure to a conduit 154 leading to a check valve 156. Check valve 156 is normally closed by the pressure in conduit 154 and there is a conduit 158 leading from the check valve to hydraulic motor 102.
Check valve 148 is adapted for being opened to permit flow out of the cylinder 68 by actuation of a pilot plunger 160 and check valve 156 similarly is adapted for being opened to permit a supply of fluid to conduit 15S and motor 102 by actuation of a pilot plunger 162.
The pilot plungers are both connected to be actuated by pressure supplied thereto by conduit 1&4 which is connected with the side of valve 144 that is under pressure when solenoid S1 is actuated.
Pressure conduit 142 is also connected through a pilot operated valve'166 with a conduit 16-8. Valve 166 is adapted for being opened when the pressure supplied thereto from conduit 142 reaches a predetermined amount, say, 2,000 pounds. Conduit 168 leads to the inlet of a four-way reversing valve 170 which is normally centered by springs 172 and which is adapted for being shifted into position to supply pressure to a conduit 174 by energization of a solenoid S3, and is adapted for being shifted into position to supply pressure to a conduit 1'76 by energization of a solenoid S4.
, When both of the solenoids are de-energized the pressure conduit 168 is blocked from both of conduits 174 and 176.
Conduit 174 leads to the lower end of the ejector cylinder 44 and conduit 176 leads to the upper end thereof. Each conduit has therein a check valve 178 opening toward the cylinder and each check valve is by-passed normally by closed valve 180 adapted for being piloted to open position'by pressure from the cylinder side thereof by means of pilot conduit 182.
Each valve 180 may be set to open at a pressure, say,
Conduit 168 also leads to the inlet of a four-way revers position when the pressure in conduit 190' reaches a predetermined amount.
Draining of the pressure switch is accomplished through a valve 194 adapted for being piloted into open position when conduit 188 is under pressure.
In operation, de-energization of solenoid S1 will be accomplished by a shift of valve 144 to supply lluid to raise plunger 66. At the same time solenoid S3 is energized to supply pressure through conduit 174 to cylinder 44 to raise the ejector to its uppermost position. Thereafter, solenoid S5 is energized and this supplies iiuid to the advancing side of charging box cylinder so that the charging box advances.
Thereafter solenoid S3 is de-energized and solenoid S4 is energized and the ejector plunger lowers a predetermined amount until it engages a charge control switch LS4 whereupon both of the solenoids S3 and S4 are de-energized to halt the said plunger.
Thereafter, solenoid S5 is de-energized so that pressure is supplied to conduit 188 and the charge box retracts.
At about the time the charge box is retracted, solenoid S1 is energized so that check valve 148 is piloted open and the cross heads and plunger 66 drop. Simultaneously, solenoid S4 is energized and the ejector plunger again moves downwardly to its lowermost position. At about the time the cross heads and plunger 66 have dropped far enough for the compacting plunger to engage the material in the mold, solenoid S2 will be energized and there will be a supply of fluid to vibrator motor 102.
After a predetermined length of time, assuming the charge to be the right amount, limit switch LS1 will be actuated and a new cycle will commence.
If the charge is too large, the electric control circuit provides adjustment of the position of switch LS4 and for interrupting of the cycle for the commencement of a new cycle.
Referring now to the electric control circuit of FIG- URE 9, power lines L-l, L2 and L3 are arranged for energizing drive motor 200 for pump upon closing a relay M2.
The power lines are also connected to drive motor 134 pertaining to the adjustment of the charge control limit switch LS4 in the forward direction upon closing of a relay MIF and to operate the motor in the opposite direction upon energization of a relay MIR.
Power for operating the relay solenoids, the various timers in the circuit and the valve solenoids, is supplied from the secondary of a transformer 202. v
The secondary has leading therefrom wires 204 and 206 between which are connected the various relay solenoids and timers.
In series with a selector switch SS2 is a normally open blade of a push button P131, a normally closed blade of a push button PB2, a normally closed blade of relay MIR and the solenoid of relay MIF.
Also in series with switch SS2 is a normally closed blade of push button PBI, a normally open blade of push button PB2, and a normally closed blade of relay MIF and the solenoid of relay MIR.
In by-passing relation with switch SS2 the normally closed blade of P131 and the normally open blade of PBZ is a branch containing a normally closed blade of a relay CR7 and a normally open blade of relay TR4.
Leading from line 204 to line 206 is another branch containing a normally closed push button P33 and a normally open push button PB4 and, in parallel, the solenoids of relay M2 and a relay CRM.
PB4 is by-passed by a normally open blade of relay M2. Line204 is then connected through a normally open blade of CRM and a normally closed push button PBS with a wire 208. Wire 208 is connected through a normally open blade of a push button PB6, a normally closed limit switch LS1 and a normally closed blade of a relay CR8 with the solenoid of a relay CRA.
The said normally open blade of P136 is bypassed by a normally open blade of relay CRA.
Wire is connected to another normally open blade of PS6, a. selector switch SS3, and a normally closed push button PB! with the solenoid of a relay CR1. A normally open blade of relay CR1 is connected from between the first mentioned blade of P136 and LS1 to a point between switch SS3 and P37. From the last mentioned point there is still another open blade of CR1 connected back to line 263.
Also leading from wire 2% is another branch through a normally open blade of relay CRA to a wire 216. This branch also leads through a normally open limit switch LS2 and normally closed blade of relays CR4 and CR5 to the coil of a relay CR2. Switch LS2 is by-passed by a normally open blade of CR2 and the circuit through the said blade of CR2 also leads through a normally open limit switch LS3 and a normally closed blade of relay CR5 to the coil of a relay CR3.
The coil of relay CR2 is also directly connected between wires 206 and 208 by a wire 212 leading directly through a normally open push button PBS.
Leading from wire 2H) to a point between limit switch 1.53 and the said normally closed blade of CR5 is a wire which includes a normally open blade of relay CR3.
Leading from wire 210 is a branch containing a normally open pressure switch PS1, a normally closed blade of CR5 and the solenoid of a relay CR4. Pressure switch PS1 is by-passed by a normally open blade of relay CR4. Wire 298 is also connected through a normally open push button PR9 with the coil of relay CR4. There is also a branch leading from wire Zltl through a normally open blade of a relay CR6 to the coil of relay CR4.
Also leading from wire 219- is a branch containing a normally open limit switch LS4, a normally closed blade of CR2 and the coil of a relay CR5.
Switch is by-passed by a normally open blade of relay CR5.
Also leading from wire 21% is a branch containing another normally open blade of CR5 and a timer TRl. The last mentioned normally open blade of CR5 is bypassed by a normally open blade of the said timer TRl.
Also leading from wire 210 is a branch containing a normally open blade of time TRl and the coil of a. relay CR6 and the said timer blade is by-passed by a normally open blade of the said relay.
Still another blade of said relay CR6 is connected between wire 210 and wire 206 in series with a second timer TRZ and a normally open blade of said timer by-passes the said blade of relay CR6.
Still another branch leading from wire 2143 contains a selector switch SS2, another normally open blade of CR6 and a third timer TR3 with there being a holding circuit for the timer provided by a normally open blade thereof.
Still another normally open blade of the timer is con, nected between wire 21% and 206 in series with a fourth timer TR i and TR4 has a blade thereon providing a holding circuit.
The final branch leading from wire 210 contains a normally open blade of timer TR4 and the coil of a relay CR7.
Connected between wire 208 and wire 206 is a normally open blade of CR7 and the coil of a relay CR8.
Also leading from the secondary of transformer 232 is a wire 2.12 between which wire 2% are connected the valve solenoids referred to in connection with the hydraulic circuit.
Solenoid S3 that causes the ejector to raise is in series with a normally open blade of CR2.
Solenoid S5 which causes the charger to advance is in series with a normally open blade of CR3. Solenoid S4 which causes the ejector to lower is in series with a normally open blade of CR4. Solenoid S1 235 which causes the cross heads to drop is in series with a normally open blade of CR5, and solenoid S2 which causes the vibrator motor to run is in series with a normally open blade of timer TRZ.
The overall operation of the press can now be described as follows:
With the ejector in its lower position, a gauge block of the same thickness as the brick to be made is placed on the ejector and then the cross heads are permitted to drop until the compacting plunger rests on the gauge blocks.
The adjustable actuator 215 (seen in FIGURE 1) is then adjusted until limit switch LS1 opens. The selector switch S52 is then closed and push buttons PB and PB2 are availed of for adjusting the charge control limit switch LS4 to about the proper position for the fill desired and preferably with the fill being slightly greater than necessary.
Single cycle is then carried out as follows:
Selector switch SS3 is open and the cycle is then commenced by closing PR6.
The sequence of events is then as follows:
(a) CRA is then energized to provide an interlock.
(1)) Relay CR2 is energized thus energizing solenoid S3 for causing the ejector to raise to the top of its stroke.
(c) LS3 is closed by the ejector at the top of its stroke energizing relay CR3 which causes energization of S5 and advance of the charger to the front.
(0?) When the charger reaches the front pressure switch PS is actuated and this causes energization of relay CR4 which drops out CR2 to de-energize S3 and causes energization of S4 to lower the ejector.
(e) The ejector lowers until charge control switch LS4 is tripped which causes energization of CR5.
(f) Energization of CR5 (is-energizes CR4 thus de-energizing S4 and stopping lowering movement of the ejector while simultaneously timer TRl is energized.
(g) The timer closes its timed contacts to energize relay CRd just before the charger reaches the end of its retraction stroke and energization of relay CR6 energizes S1 so that the cross heads drop. CR6 also energizes timer TR3.
(h) The ejector moves down against its lower stops while the cross head is dropping.
(i) The timed contacts of TR2 close and this energizes S2 so that the vibrator motor 102 now operates. This occurs about the same time as the compacting plunger enters the mold box. The speed of the compacting motor can be adjusted by a valve 216 in series therewith.
(k) If the charge in the mold is not too great switch LS1 will be tripped open in about 5 seconds which will break the circuit to relay CRA and this will drop out all of the relays and the cross heads will return to their upper position. A new single cycle can thereafter be commenced by depressing push button P136.
(1) Should the limit switch LS1 fail to open in a predetermined time, say, 10 to 15 seconds, indicating too great a charge, the timed contacts of timer TR3 will close and energize timing relay TR4.
(m) Timing relay TR4 closes its blade and in circuit with the coil of relay MIR it starts the charge motor 134 in a direction to raise limit switch LS4 and reduce the charge. The relay is set to revolve the lead screw about A revolution.
(n) The timer contacts of relay TR4 then close and energize relay CR7.
(0) Relay CR7 closes tie-energizing the charge motor 134 while simultaneously energizing relay CR8.
1) Energization of relay CR8 (lo-energizes relay CRA dropping out all relays when the cross heads return to their upper position.
For continuous cycle operation selector switch SS3 is closed and this energizes relay CR1 so that PB6 is bypassed and the cycle of the press will be continuous until 9 the cycle stop PB7 is opened which will drop out relay CR1.
It will be seen from the foregoing that the present invention provides for a brick press in which a relatively light press is capable of performing work operations that formely required a large heavy press with a great deal of power being supplied thereto.
The press is constructed so that the stresses are confined to the corner columns of the press frame and the vibrator cross head is independently guided from the main cross head so that bricks of accurate shape are produced. The ejector platen is arranged to be retracted below its normal lowermost position to facilitate inserting and removing molds.
The hydraulic circuit is relatively simple and the electric control circuit provides for single cycle or automatic operation while including the feature of automatic adjustment of the charge when the bricks are more than a predetermined amount oversize.
It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions; and, accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.
1. In a brick press; a press frame, said frame comprising four vertical corner columns interconnected at the top and bottom, guide members adjustably mounted in said press frame, a stationary member in the press frame for supporting a mold, a mold having cavity and including a mold bottom mounted on said stationary member, a Weighted main cross head slidable on said guides members above said mold cavity, hydraulic means operable for elevating said main cross head above the mold cavity, means for releasing said cross head to cause it to drop toward the mold cavity, a compacting cross head beneath the main cross head adapted for carrying a pressing plunger to engage material in the mold cavity, said plunger resting on the material with the force of gravity only, rods connecting the compacting plunger with the main plunger, springs between the rods and one of the cross heads, and vibration creating means carried by said compacting cross head which is operable upon energization thereof to cause vertical vibration of the compacting cross head, said vibration creating means comprising a variable speed hydraulic drive motor.
2. In a brick press; a press frame, said frame comprising four corner columns extending vertically and interconnected at the top and bottom of the press frame, guides extending vertically inside the press frame, means fixed in the press frame defining a mold cavity including a mold bottom in the press frame for said mold cavity, a weighted main cross head slidable on the guides above the mold cavity, a motor connected between the press frame and said main cross head operable to thrust upwardly only on said main cross head, a compacting cross head resiliently suspended beneath the main cross head and independently guided on said guides, vibration creating means comprising a motor and ofif-center masses which are rotated in opposite directions and carried by the compacting cross head for vibrating the compacting cross head to cause compacting of material in the mold cavity against the mold bottom, a lower cross head guided on said guides supporting the mold bottom and operable to cause upward movement thereof in the mold cavity to eject formed brick shapes from the cavity, and means providing a lower stopped position for the lower cross head to support said mold bottom during compacting operations, the last-mentioned means comprising stop members detachably connected with said corner columns whereby all working stresses in the press are confined to the said columns.
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