US3811808A

US3811808A - Weighed charge system for a brick press

Info

Publication number: US3811808A
Application number: US00117587A
Authority: US
Inventors: R Platt
Original assignee: Dresser Industries Inc
Current assignee: Dresser Industries Inc
Priority date: 1971-02-22
Filing date: 1971-02-22
Publication date: 1974-05-21
Anticipated expiration: 1991-05-21

Abstract

A system to deliver a weighed charge to the mold box of a brick press so that the material is uniformly distributed in the mold is disclosed. Specifically, a weighed charge is conveyed to the mold by conventional means, but is distributed in the mold by the coordinated synchronous movement of both the lower press pad''s downward motion and the reciprocating action of the charger during the charging sequence.

Description

United- States Patent [191 Platt [111 3,811,808 [451 -May 21, 1974 WEIGHED CHARGE SYSTEM FOR A BRICK PRESS [75] Inventor: Richard O. Platt, Bethel Park, Pa. [73] Assignee: Dresser 1ndustries,1nc., Dallas, Tex. [22] Filed: Feb. 22, 1971 [21 App]. No.: 117,587

[52] US. Cl. 425/167, 425/352 [51 Int. Cl. B29c 3/06 [58] Field of Search 425/253, 255, 356, 412, 425/413, 344, 351 398, 406, 352, 354, 355, 148, 77, 78,422, 260, 411, DIG. 33, 416; 264/294, 109; 25/103 [56] References Cited UNITED STATES PATENTS 297,218 4/1884 Andrus 425/344 478,915 7/1892 'Burkman 425/344 X 642,581 2/1900 C allaway 425/344 985,153 2/1911 Flood 425/344 1,241,398 9/1917 Kespohl 425/344 X 3,213,511 10/1965 Petruzzi 425/448'X 1,000,823 7 8/1911 Leflaive r 425/352 3,050,809 8/1962 Kupha...- 425/352 10/1966 Neubauer 425/355 ?25,939 9/1885 Kennedy 425/344 X 480,818 8/1892 Koch 425/344 X 3,187,401 6/1965 ODonnell... 425/148 3,690,805 9/1972 Kopicko 425/344 X 987,124 3/1911 Flood 425/344 X 2,888,731 6/1959 McElroy 425/167 X 3,107,410 ,10/1963 Davis 425/159 3,368,254 2/1968 Schacht 425/167 3,563,654 2/1971 Steingroever.... 425/411 X 3,397,435 8/1968 .lelesiewicz 425/411 X 3,555,621 1/1971 Hara 425/78 X Primary Examiner--J. Spencer Overholser Assistant Examiner-John S. Brown [5 7] ABSTRACT 4 Claims, 7 Drawing Figures P ENIEnm 21 1924 3.81 1.808

SHEET 2 UF 2 I7 l8 I II l4 FIG. 5

RICHARD O. PLATT INVENTOR ATTORNEY l WEIGHED CHARGE SYSTEM .FOR A BRICK PRESS 1 Many of the important properties of. refractory bricks are governed by their bulk density, the control of which will depend on the success in feeding'the same weight sequence by adjusting the one of the modifications of the Boyd-type press accordof uniformly mixed material to each mold box at each pressing. However, with ,many of the present brick press charging devices, segregation of the batch or uneven mold filling occurs which results in pressed brick of nonuniform properties. In addition, poor mold filling can result in an excess of entrapped air in the batch which can lead to problems such as cracking during and after the pressing cycle.

Accordingly, it is among the objects of this invention to provide a method and apparatus for uniformly filling a mold box with a refractory batch. It is another object of the invention to provide apparatus for modification of existing brickmaking presses, whereby brick of substantially uniform thickness, density and porosity can be made from a given refractory batch.

Briefly, according to this invention, there is provided apparatus for modification of a brick press, whereby brick of substantially uniform properties can be obtained from a givenrefractory batch. The apparatus includes means arranged to deliver accurately weighed quantities of granulated brick material to a mold'charging system which evenly distributes the material in the mold box. An example of a mechanical brick press, which can be modified according to this invention, is shown, for example, in U.S. Pat. No. 987,124. This is sometimes called a Boyd-type press.

Other objects and further features and advantages of the invention will become apparent to those skilled in the art from a study of the following detailed description, with reference to the drawings. In these drawings:

FIG. 1 is a side elevation in partial section of apparatus according to this inventionusedwith a brick press;

FIGS. 2'to 5 are partial cross'sectional views of the mold box charging arid'pressing area illustrating four stages of the pressing cycle;

FIG. 6 is a hydraulic schematic diagram showing a series of solenoids and valves for actuationof the lower 'press pad situatedin the mold box and for the charging cylinder; and,

FIG. 7 is anelectrical diagram illustrating a means for synchronizing the'operation of the press.

Those portions of a Boyd-type mechanical brick press which are shown in FIG. 1 include a worktable 15 provided with a rectangular molding cavity or mold box 16. The pressing of brick shapes in the mold box is accomplished by the movement of the upper and lower pressure plates or

pads

18 and 19 attached to the upper and lower plungers l7 and 20, respectively. The lower plunger rests on a saddle plate 21 which in turn is disposed on a lower crosshead 22. The upper plunger is moved vertically by a crosshead (not shown) slidably mounted in guides (not shown)at opposite sides of the press frame (not shown). An exemplaryconstruction for the upper portion of a brick press in shown in U. S. Pat. No. 2,893,101, and it is incorporated herein by reference.

In order to control the brick size in a conventional Boyd-type press, the operator would have adjusted, by a mechanical linkage, the depth of the mold for the fill ing to my invention. A hydraulic cylinder 24 is installed in the lower crosshead in place of the usual springs and mechanical linkage to control the downward motion to the saddle plate during the charging sequence. The bydraulic cylinder (saddle cylinder) 24 with an extended piston rod 23 and a mounting flange 25 at the rod end is mounted at the bottom of and on the centerlines of the lower crosshead 22. The top of the rod is connected to the saddle plate via a threaded hole 26. This arrangement allows the control of the travel of the lower pad which aids the brick mix in being uniformly distributed in the mold cavity.-

The automatic batch feeding system comprises an automatic scale and hopper 10 which dispenses a desired amount of material 11 onto a conveyor comprising an endless belt feeder 12. The belt feeder delivers the material to the charger 14 and may be supported by the frame of the brick press or independently. The horizontal movement of the charger is controlled by the charger-cylinder 13, which provides reciprocating movement of the charger back and fourth across the mold box which, in combination with the controlled downward movement of the lower pad, is the crux of this invention. The cylinder 13 contains a piston 30 and rod 31 which may be reciprocated by hydraulic fluid schematically illustrated in FIG. 6 or compressed air.

In FIG. 2, the lower pad 19 is raised to a relatively high position in the mold. box. As the sequence is begun, the charger 14 distributes material 11 into the mold box 16 on the first stroke of the cylinder 13. The charger on the initial stroke delivers only a portion of the charge to themold. After this first pass, the lower pad begins its descent which is synchronized with the reciprocating speed of cylinder 13 and mold box 16. The charger, on thefirst stroke, is moved horizontally so that the rear side has passed the mold centerline. At this time the saddle cylinder 24 lowers the saddle plate 21 slowly to provide more space forthe material in the mold- At the same time the charger on its second stroke, moves horizontally until the front side has passed the centerline as shown in FIG. 3. Simultaneous lowering of the saddle and reciprocating motion of the charger is continued, and the mold is more completely filled. The sequential charging operation with synchronized lower pad positioning is continued until the mold is completely filled with layered portions.

. In FIG. 2, the space 32 between the top of the crosshead 22 and the saddle 21 indicates that the saddle cylinder piston rod 23 is at the upward end of its stroke, whereas in FIG. 3 the saddle cylinder piston rod is near the lower end of its stroke. In FIG. 4, the mold has been completely filled, and the upper pad has descended and has compressed the material between it and the lower pad 19. The saddle 21 now rests on top of the crosshead 22. In FIG. 5, the pressed brick is being ejected by simultaneous upward motion of the lower crosshead through the controlled upward motion of the saddle the press cycle continues. The lower crosshead drops and, during its downward travel, the saddle cylinder piston rod moves up elevating the lower pad to a relatively high position in the mold so that the first charger stroke partially fills the mold. The charger starts reciprocating strokes distributing material in the mold while the lower pad is simultaneously lowered by the saddle cylinder piston rod and so on.

The

cylinders

13 and 24 which have double acting pistons may be actuated as shown by the schematic diagram of FIG. 6. The

cylinders

13 and 24 contain

pistons

30 and 34 and attached

rods

31 and 35, respectively. For the cylinder 24, the hydraulic fluid is fed to the cylinder under pressure from a reservoir 36 by a conventional pump 37. The fluid passes through a directional control valve 38 for the controlling of the direction of motion of the cylinder piston (up or down). This action of this valve may be controlled by solenoid 39. From valve 38, the fluid passes into one of the

flow control valves

40 or 41. Valve 40 controls the downward motion of the lower pad. Valve 41 controls the upward motion of the lower pad when the pressed brick is being ejected.

For the cylinder 13, the hydraulic fluid also passes through a directional control valve 42 controlled by a solenoid 43. However, here, the fluid passes directly into the cylinder since the mold box reciprocates rapidly with reference to the lower pad.

The hydraulic system could contain other components, i.e., pressure gauge, pressure relief valves, other solenoids, a fluid accumulator, filter and the like. However, these are not shown or discussed for the sake of brevity and since these are well known in the art. Many different hydraulic systems could be used to control the action of the pistons within the cylinders.

As mentioned previously, all of the steps in pressing brick shapes are synchronized for sequential operation. H6. 6 illustrates an exemplary schematic electrical circuit for controlling the sequence of steps. A multiple cam timing switch is represented by three earns 50, 52 and 53. Each cam actuates

valves

42, 38 and clutch 44, respectively, through their

respective solenoids

43, 39 and 45. In practice, the cams may be mounted on a common shaft for rotation thereon. A voltage (V) is applied across the circuit from a source separate from that normally associated with the press. This circuit may be integrated with the press circuit and other components attached to the press. However, modifications would have tobe made to the entire circuit as is well known in the art, and various other operative circuity is possible.

When the operator at the press starts the switch for operation, all cams on the common shaft will rotate together. Cam 50 with the lead contact (a) will first close the switch and cause the charger 14 to move forward over the mold box 16. The opening of the switch will cause the charger to move back across the mold box to its starting position. The repeated opening and closing of the switch throughout the half cycle of this cam provides the reciprocal movement of the charger.

Shortly after the contact (a) of cam 50 closes the switch, contact (b) of cam 52 closes a switch and causes the descent of lower pad 19. This descent is slow and continuous throughout an approximate half cycle of this cam.

When the descent is complete, contact (c) of cam 53 will activate a clutch on the clutch on the press which will in turn activate the mechanical linkages in the press to cause the upper pad 18 to descend and compress the material in the mold box. (For example, see U. 8. Pat. No. 2,893,101.) The opening of the switch causes the pad 18 to retract. v

At this point, contact (d) of cam 52 closes a switch which, through the hydraulic system, forces the lower pad upward to eject the compressed shape and position itself for the next cycle.

While illustrating my invention in connection with a Boyd-type mechanical press, it is readily applicable to other presses, whether mechanical or hydraulic type.

Having thus described the invention in detail and with sufficient particularity as to enable those skilled in the art to practice it, what is desired to have protected by Letters Patent is set forth in the following claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In combination with a brick press having a mold box and a vertically movable upper press pad, means for accurately weighing quantities of granular material, means for charging said weighed material to the mold box by continuous reciprocal movement, a vertically movable lower press pad within the mold box, electrical means synchronized with the reciprocation of the charging means for lowering the lower press pad while the mold box is being filled by the charging means with a series of continuous reciprocating strokes, means for lowering the upper pad into the mold box after the lower pad has ceased descending to compress the grandular material into a shape between the upper and lower pads, means for raising the upper pad and means for raising the lower pad to eject the compressed shape.

2. The combination of claim 1 which includes means for synchronizing sequential movement of the charging means, lower press pad and upper press pad.

3. The combination of claim 1 in which the vertical movement of the lower pad and the reciprocal movement of the charging means is provided by a double action piston contained within a pressure cylinder.

4. The combination of claim 3 in which the pressure is provided by hydraulic fluid.