US 3179998 A
Description (OCR text may contain errors)
April 27, 1965 H. w. LAMB 3,179,998
VARIABLE IMPACT TI LE PRESS Filed Oct. 12, 1962 6 Sheets-Sheet 1 3 Harold 11! Lamb INVENTOR.
A fil 27,1965
Filed Oct. 12, 1962 H. W. LAMB VARIABLE IMPACT TILE PRESS 6 Sheets-Sheet 2 Harold VTLamb INV EN TOR.
April 27, 1965 H. w. LAMB 3,179,998
VARIABLE IMPACT TILE PRESS Filed Oct. 12, 1962 6 Sheets-Sheet 3 V 3f m u l 38 40 16 M Harold 1 Lamb A INVEN TOR.
HTTORNE) April 27, 1965 H. w., LAMB VARIABLE IMPACT TILE PRESS 6 Sheets-Sheet 4 Filed Oct. 12, 1962 rd mvi w wwk Harold W. Lamb INVENTOR.
April 27, 1965 H. w. LAMB 3,179,998
VARIABLE IMPACT TILE PRESS Filed Oct. 12, 1962 6 Sheets-Sheet 5 LL] I I 66 46 g Harold PV. Lamb INVEN TOR.
April 27, 1965 H. w. LAMB 3,179,998
VARIABLE IMPACT TILE PRESS Filed Oct. 12, 1962 6 Sheets-Sheet 6 Harold WTLCWnb INVHVTOR.
BY .114 wax,
n T ram/5y United States Patent Jersey Filed Oct. 12, 1962, Ser. No. 230,044 3 Claims. ((Il. 25-84) This invention relates to power presses of the general type employed in compressing pulverized clay or other pulverized material into tile or other compact products adaptable to such press and die operations.
In presses of the type referred to the die cavity is formed by means of a die case surrounding and slidable on a vertical stationary die member in a telescopic manner and the tile is ejected from the cavity by lowering the die case. The clay dust for a new tile is supplied to the die cavity by means of a rectangular dustbox or tray which first pushes the previously completed tile from the cavity area, after which the die case is immediately raised and the cavity formed thereby is filled with clay dust by sweeping or Wiping action of the dust box, as it passes over the cavity. The dust box is then returned to its starting position and the ram member of the press shaped for close fitting insertion into the die cavity is lowered into the cavity to compact the clay dust therein into a tile.
In previous presses of the type mentioned the impact of the ram member on the clay dust in the die cavity is effected by mechanical power, and has been found to have the serious disadvantage of trapping air in the clay dust due to the rapidity and force of the impact, and thereby resulting in defective tile.
Therefore, one of the principal objects of the present invention is to provide a tile press having means for effecting an initial retarded impact on the clay dust for forcing the air from the dust, followed immediately by a more rapid and heavier impact for forming the completed tile. For the purposes of this invention I employ two heavy impact members one above the other, the lowermost of which is suspended from the other in vertically spaced and movable relation and from which the ram depends; and the uppermost of which is attached to the piston rod of an air cylinder having electrical control valve means for simultaneously admitting air pres sure into both ends of the cylinder for effecting a retarded lowering of both impact members until the ram slightly presses the dust in the die cavity, and then releasing the air pressure from the lower end of the cylinder while maintaining the air pressure in the upper end thereby effecting accelerated and heavy impact of the uppermost impact member upon the lowermost member, the force of which impact is transmitted to the ram and the clay dust in the die cavity. The initial force exerted by the ram as it comes into the clay dust and compresses it is adjustable and controllable by the weight and cooperation of the lowermost or suspended member, and by the speed with which it is lowered, which, in turn, is determined by the speed and length'of travel between this member in its upper starting position and its position upon contact of the uppermost member therewith.
The speed of the simultaneous downward movement of the impact members is controlled by a differential of air pressure above and below the piston to which the uppermost impact member is attached, and/or also the transverse area or diameter of the piston rod, which traverses the bottom portion of the cylinder, and the diameter oi the piston and creates a preponderance of pres sure above the piston, whichmay be further varied by means of regulators in the air pressure lines.
Thevertical space between the lowermost and uppermost impact members may also be varied as required by 3,179,998 Patented Apr. 2'7, 1965 ICC the axial adjustment of the rods upon which they are slidably mounted. The greater the spacing the more acceleration of movement of the uppermost member and, consequently, the greater the force of impact of the uppermost upon the lowermost member.
In previous presses of the type mentioned the dust box is supplied with clay dust at only one side of the press, so that after the initial stroke or horizontal movement of the dust box across the die cavity, to deposit therein the clay dust for the next tile, the dust box is returned to its starting position for another supply of dust. In order to ensure a complete filling of the die cavity the dust box is necessarily supplied with a greater quantity of clay dust than that required to fill the die cavity. Consequently, in its return passage over the die cavity the back end of the box drags and impacts more dust into that already in the die cavity, especially toward the front edge of the cavity, resulting in a tile of uneven thickness and compactness.
Therefore, another, and important, object of this invention is to provide a tile press of the character referred to having means for supplying clay dust to the dust box on each side of the press, so that the die cavity is filled with clay dust by a single stroke of the dust box across the cavity, resulting in an even, uniform filling of the cavity.
Other objects and advantages of my improved tile press will be apparent or pointed out in the following specifications in which reference is had to the accompanying drawing forming a part thereof, and in which FIG. 1 is a front elevation of a tile press in accordance with the present invention, with some of the parts omitted in the illustration;
FIG. 2 is a section taken on the line 22 of FIG. 1;
FIG. 3 is a section taken on the line 3-3 of FIG. 1;
FIG. 4 is a section taken on the line 44- of FIG. 3, with the air cylinder shown exteriorly;
FIG. 5 is a section taken on the line 55 of FIG. 4, with the air cylinder also shown exteriorly;
FIG. 6 is a section taken on the line 66 of FIG. 2;
FIG. 7 is a detail section similar to FIG. 2 and showing the initial impact of the press ram;
FIG. 8 is a similar detail View showing the completion of a tile;
FIG. 9 is a similar view showing a completed tile being pushed by the clay dust box from the area of the die caivty; and
PEG. 10 is a schematic diagram showing the arrangement of the several air cylinders, electrical air pressure control valves and switches employed in the press illus-' trated.
Referring to the drawing in which like reference characters designate like parts in the several views, 10 is a vertical press base upon which is slidably mounted a pairv of heavy metal impact members 12 and 14 one above the other. The lowermost impact member 14 is suspended from the uppermost member 12 in vertically spaced and unrestrained slidable relation on a plurality of rods 1:6 which are threaded into the member 14 to provide means for adjusting the space between the two members, each of which is notched on one edge, as indicated at 18 (FIGS, 3 and 5) for engagement with a V-shaped guide member Zil mounted on the press base 16.
The uppermost impact member 12 is rigidly attached to the piston rod 22 of an air cylinder A, the ends of which are closed and in communication with a source of air pressure through pipes 24 and 26 having air pressure regulators 2S and 27 and electrical control valves Al and A4. The press ram 28 is rigidly attached to the-lowermost impact member 14 in depending relation therewith. One edge of the uppermost member 12 is provided with a socket fail for engagement therein of horizontal latch bar 32 which is attached to the piston rod 34 of an air cylinder B mounted on the press base 10 and the ends of which are in communication with a source of air pressure through pipes 38 and 40 provided with electrical control valves B1 and B3. This latch bar is slidably inserted into the socket to hold the members 12 and 14 in their uppermost starting positions and is withdrawn to permit downward movement of those members. The members 12 and 14 may be made of cast iron and provided with steel contact plates 12:: and 14a. The bottom of the inner end of the bar is inclined as shown at 33 (FIG. 4) and upon the upward movement of member 12 is retracted by contact with a beveled portion 35 in the upper edge of the member 12.
A stationary and vertically elongated die member 42 is mounted on a horizontal portion 44 of the press base, and a die case 46 is slidably or telescopically mounted over the die member 42 for forming a die cavity below the ram 28. The die case 46 is attached through rods 48 and yoke 50 to the piston rod 52 of an air cylinder C, the ends of which are in communication with a source of air pressure through pipes 54 and 56 having electrical control valves.C1 and C4. The upward movement of the piston rod 52 and die case 46 is limited by an adjustable wedge device 58 operated by a handle 60. The downward movement of the piston rod 52 is limited by vertical rods 62 adjustably mounted at their lower ends in a plate 64 on the bottom of the cylinder C and in abutting engagement at their upper ends with the yoke 50.
A horizontal plate or platform 66 is rigidly attached to the die case 46 with its top surface flush with that of the die case and extends a substantial distance forwardly and rearwardly of the die case. A rectangular clay dust box or tray 68 having an open bottom is mounted on the platform for slidable movement thereon across a die cavity formed by the stationary member 42 and the die case 46 in either direction. The dust box has projecting portions or bumpers 70 and 72 at its ends for pushing completed tile from the die cavity in advance of the arrival of the dust box. over the die cavity. One end of the dust box is attached to the piston rod 74 of an air cylinder D having communication at its ends with a source of air pressure through pipes 80 and 82 which are provided with electrical control valves D1 and D3.
As illustrated, the dust box is supplied with clay dust at each end of its stroke from hoppers 84 and 86 in which their outlet ends are closed by pivotally mounted gates 88 and 90 provided with operating levers 92 and 94 which are connected, respectively, to the piston rods 96 and 98 of air cylinders E and P which are in communication with a source of air pressure through pipes 100, 102, 104 and 106 having electrical control valves E1, E3, F1 and F3.
The diagram FIG. 10 schematically indicates the arrangement of the various air cylinders, electrical control valves and switches at the end of one stroke of the dust box 68, after pushing a completed tile T from the die cavity and filling the die cavity with clay dust 108 as shown in FIG. 2. The connection of the switches with the electrical valves are indicated in broken linking lines. As show in the diagram, air pressure is on the bottom of cylinder A through switch A5 and contact A6, having returned the piston P, together with the impact members 12 and 14 to their uppermost or starting positions. Air pressure is on the back of cylinder B through switch B4 and contact B5, having inserted the latch bar 32 into the socket 30 in the upper impact member 12. Air pressure is on the bottom of cylinder C through switch C2, contact C3 and valve C1 holding the die case 46 in its raised or cavity forming position. Air pressure is on the front of cylinder D through switch D2, contact D5 and valve D1, holding dust box 68 in its starting position. Air pressure is on the back ends of cylinders E and F through switch E2 and contact E5 and through switch F2 and contact F5, holding the gates 88 and 90 in closed posicos .4 tion. Although the electrical valves and switches are shown schematically in separate relation, in actual practice they are all coordinated into an automatic timing switch unit connected in the electrical circuit EC, so that when started into operation by closing a switch 110 the air cylinder will function in cooperative sequence until the switch is again opened. Since such timing units are conventional and form no part of the present invention, illustration of details is omitted in the drawing.
FIG. 7 shows the ram 28 upon its initial retarded impact on the clay dust 108 in the die cavity. In this phase of a cycle the latch bar 32 will have been withdrawn from the socket 30, thereby releasing impact members 12 and 14 for downward movement, and both valves A1 and A4 of cylinder A will be open and admitting air pressure into each end of the cylinder. As previously mentioned, due to the transverse area of the piston rod 22, which extends through a packing in the bottom end of the cylinder, thereby causes a preponderance of pressure against the upper end of the piston P, which forces the impact members 12 and 14 downwardly at a retarded rate of speed to effect a light impact of the ram 28 on the clay dust 108 in the die cavity. During this stage the gate W of hopper 84 is opened by cylinder E to deposit a quantity of clay dust 108 into the dust box 68, which is still held in its starting position by the piston in cylinder D.
FIG. 8 shows the ram 28 upon completion of the formation of a tile T. In this stage the air pressure has been released from the bottom portion of cylinder A thereby applying the full air pressure against the top of the piston P, thereby accelerating member 12 downwardly and bringing contact plate 12a against contact plate 14a with great force which is transmitted to the ram 28 to complete the pressing of clay dust 108 into a tile T. As previously mentioned, the force of impact by mem- 'ber 12 is determined by acceleration of member 12 and to the vertical distance between contact plates 12a and 14a as governed by the axially adjustable rods 16. Further variations may be effected by the weight of member 12 and the air pressure regulators 25 and 27. At this stage the dust box 68, now filled with clay dust, is still held in its starting position.
FIG. 9 shows the start of the dust box with its charge of clay dust 108 on its stroke across the die member 42, pushing the completed tile T therefrom. The air pressure has been released from the top of cylinder A through va lve A1 and the pressure applied to the bottom of the cylinder through valve A4. At this time the latch bar 32 is forced into the socket 20 by cylinder B under air pressure through valve B3. Immediately before the clay dust in the dust box 68 reaches the edge of the die member 42 the air pressure is released from the top of cylinder C, through valve C4, and the pressure applied to the bottom of the cylinder through valve C1, which raises the die case 46 to form the die cavity. As the dust box 68 continues its stroke the cavity will be evenly filled with clay dust through sweeping or wiping action of the following end of the dust box, which will continue its stroke until stopped under the hopper 86 to receive a supply of clay dust, which will be deposited in the die cavity upon its return stroke to its starting position, as shown in FIG. 2, to begin a new cycle of operation, as already described. The dust box 68 may be stopped at each end of its stroke by means of a collar 112 on a rod 114 attached to the piston rod 72 and abutments 116 on the platform 70, or by other suitable means.
From the foregoing description it will be seen that I have provided a tile press having the following outstanding advantages over previous designs, namely (1) means for pressing tile without the employment of cams, screws or other conventional means, a press in which the preliminary operation of expelling the air from the clay dust in the die cavity and the final pressing operation are almost simultaneous, and, because of the speed of movement of the impact members, this press operates much faster than presses of previous designs; (2) both the air expelling operation and the final impact operation are completely adjustable as to both force and speed; (3) the great forces required to compact tile are obtained through acceleration of weight, without the necessity of heavy motors and other expensive power equipment; (4) due to the action of this press all applied forces are utilized in compacting the tile, and not dissipated; and (5) means for eliminating the return stroke of the dust box, thereby preventing the dragging of additional clay dust into the die cavity after it has been evenly filled during the initial stroke of the dust box over the die cavity, thereby ensuring a uniform deposit of clay dust in the die cavity and a resulting uniform thickness and compactness of the tile.
The important features mentioned are simple, efiicient and economical, resulting in a high tonnage press at eX- ceptionally low cost.
Obviously, various modifications or changes may be made in my improved press without departing from the spirit or scope of my invention. Therefore, it should be understood that the embodiment of my invention shown and described is intended to be illustrative, only, and restricted only by the appended claims.
1. In a tile press including a stationary die for containing clay dust, a cylinder having a piston, and a piston rod projecting from its lower end, said press also including an upper impact member carried by said piston rod' and a lower impact member having means for suspending it from said upper member in initially spaced and limited unrestrained, vertically movable relation of said upper member toward and from said lower member, the unrestrained movement of said upper member toward said lower member being limited only by contact with said lower member and its unrestrained movement from said lower member being limited only by the means for suspending the lower member therefrom; and a ram carried by said lower impact member for impact on clay dust in said stationary die; means for efiiecting a retarded and relatively light impact of said ram on said clay dust followed by a rapid and heavier impact on said dust, and the immediate retraction of said ram from contact therewith, said means comprising, in combination, a pipe in communication with the upper end of said cylinder and a source of relatively high air pressure, and a pipe in communication with the lower end of said cylinder and a source of a lower air pressure, and electrically actuated air pressure flow control valve means in said pipes for simultaneously admitting air pressure from both air pressure sources into the respective ends of said cylinder for effecting a retarded simultaneous downward movement of said impact members until the initial impact of the ram on said clay dust and then immediately releasing the air pressure from the lower end of said cylinder while maintaining the same air pressure in the upper end of said cylinder for effecting a more rapid and heavier impact of the upper impact member upon said lower member immediately following said initial impact, and immediately thereafter releasing the air pressure from the upper end of the cylinder and admitting air pressure into its lower end to retract said ram.
2. A tile press as in claim 1 and including pressure regulating means in the pipes communicating with the ends of the cylinder, for varying the air pressure in said pipes.
3. A tile press as in claim 1 and including means cooperative with the means for suspending the lower impact member from the upper impact member for adjusting the maximum space between said members.
References Cited by the Examiner UNITED STATES PATENTS 1,288,472 12/18 Barr -269 1,460,287 6/23 Stevenson 2555 1,652,883 12/27 Ackermann 25103 2,383,736 8/45 Rembert et a1. 25-103 2,398,227 4/46 Hubbert 25-91 2,584,534 2/52 Barnhardtson 192-129 2,613,409 10/52 Miller 25-103 2,674,008 4/54 Van Der Pyl 25103 2,770,862 11/56 Miller 25--84 2,855,628 10/58 Lassman 25-102 2,888,731 6/59 McElroy et a1 25-102 3,060,540 10/ 62 Lapidus 25-103 ROBERT F. WHITE, Primary Examiner.