US3579757A - Fly press for producing ceramic tiles - Google Patents

Abstract

A fly press for manufacturing ceramic tiles or like articles is disclosed, which comprises an additional flywheel capable of being engaged, at the proper instant, by the usual flywheel solid with the pressing screw, so as to effect the moulding, deaerating and final compression stages as single step process.

Description

United States Patent [54] FLY PRESS FOR PRODUCING CERAMIC TILES 6 Claims, 4 Drawing Figs. [52] [1.8. Cl 25/45, 25/83, 192/888 [51] Int. Cl B28b 3/02 [50] Field of Search 100/(Inquired);

[56] References Cited UNITED STATES PATENTS 1,553,243 9/1925 lvens 25/45 1,758,772 5/1930 Yingling 25/45 2,141,645 12/1938 Fawick 92/8813) 3,097,411 7/1963 Gerster..... 25/83X 3,479,905 1 1/1969 Helrigel 74/572 Primary Examiner-J. Spencer Overholser Assistant Examiner-Ben D. Tobor Attorney-Stevens, Davis, Miller and Mosher ABSTRACT: A fly press for manufacturing ceramic tiles or like articles is disclosed, which comprises an additional flywheel capable of being engaged, at the proper instant, by the usual flywheel solid with the pressing screw, so as to elfect the moulding, deaerating and final compression stages as single step process.

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SHEET 1 0F 4 INVENTOR nu. RELIO Mill 60777 ATTORNEYS PATENTED HAYZS l97l SHEET 2 UP 4 PATENTEU HAYZS l97l SHEET 3 [IF 4 ATTORNEYS 1 FLY PRESS FOR PRODUCING CERAMIC TILES As is known, in the majority of the ceramic industries for the production of tiles both for floors and facing, fly presses are used which are conventionally equipped with a screw and a crosshead, in which the momentum stored by a rotating flywheel is utilized an in which a quick-thread screw is fastened to the flywheel to convert the rotary motion into a translation linear motion. A crosshead slidable onto the pillars of the machine is connected to the screw by rods or other means adapted to the purpose and acts as a striking mass.

Usually, in order to impart the rotary motion to the flywheel in either direction of rotation (to obtain either a lifting or a depressional movement), two discs, keyed to a control shaft, are used. An electric motor imparts the energy of rotation to the discs, whereas the axial shift of the discs can be obtained in several ways, either automatically, or manually, by means of levers.

The discs, coming sequentially into contact with the flywheel, impart thereto a rotary motion in one sense and then in the opposite one so that the screw imparts the lifting and depressional motion to the striking mass. It is known that, to produce pressed tiles, moulds having the desired shape are used. The moulds generally comprise a die affixed to the bedplate of the machine, a lower pad housed within the die and arranged at a level lower than that of the upper edge of the die and arranged at a level lower than that of the upper edge of the die so as to allow for a free headroom adapted to receive the amount of powder which is necessary to form the tile, and an upper pad.

The lower pad is slidable within the die and is actuated by specially provided devices for driving out, during the lifting motion, the tile as formed by the die and has thus the function of an ejector.

The powder to be compressed is usually brought'to'the die by a special carriage having a grid and positioned in the rear portion of the machine and which, passing between the die and the upper pad as the latter is being lifted, draws out the pressed tile as this has been ejected from the die by the agency of the lower pad.

The upper pad affixed to the crosshead penetrates into the die during the descent and compresses the powder which is thus converted into a compact tile capable of withstanding subsequent handling. a

It is known that, to obtain an improved cohesion of the pressed stock, it is necessary that the powder contains a certain amount of water evenly distributed throughout its mass.

The compression of the powders, irrespective of the kind of machine available, should be carried out in two stages, inasmuch, as is known, as in the interstice between a granule and another, void spaces are present: these are filled by air which should be necessarily driven off to obtain particle cohesion. In order that this deaeration step may be accomplished, it it thus imperative to carry out, at the outset, a quick and not too intense compressive action, in order to cause the granules to approach one another and expel the air occluded amidst the powder granules. Obviously, the air, being driven from the inside of the mass, tends to be urged towards the ends of the mould, where it finds natural escape ways through the gap existing between the die and the pads. Concurrently, however, air, in its motion, tends to entrain with the lightest fractions of the powder and thus to clog the gap between the die and the pads, thus giving rise to compressed air pockets. In order that the air which is left, compressed within the die, between the pads an the compressed powder, may be driven off, it is necessary that the upper pad be lightly lifted so as to allow the air to escape at the die edges, whereafter the upper pad is depressed again and a new powerful stroke of the crosshead completes the compressive action.

If the compressive action were conducted without lifting the upper pad form the compressed stock, the tiles would crumble since the entrapped air would form a pocket within the tile.

Summing up, any conventional machine as used heretofore for compressing powders, requires that the compressive step be carried out in two stages, that is, descent of the crosshead for the first compressive action, reversal of the motion, lifting the crosshead to deaerate, reversal of motion, descent o the crosshead for the second pressing operation and then reversal to rotational lifting of the crosshead to restart a cycle.

As can be seen, the time taken for carrying out said double sequence of operations is a down time an the number of additional cycles per hourand the continuous reversals of motion overheat the component parts which are in frictional relationship with one another and wear them out.

An object of the present invention is to permit that the compression of powders for manufacturing tiles from a ceramic or other material with fly-presses of any kind, by adopting a single compression stage, that is to say, to obtain the compression of the powders with a single descent of the striking mass.

This object is achieved, according to the invention by a fly press which is substantially characterized in that the screw connected to the striking mass carries, integral therewith, a first flywheel which can be actuated by the two discs and, freely rotatable, a second flywheel, mutual engaging means being provided between said flywheels so as to permit a rotational movement, though restricted, therebetween.

In order to illustrate the operation of the invention, it is understood herein that it is not necessary to control the lifting of the striking mass in order to obtain deaeration, since in the conventional presses it has been noted that, after the preliminary compressing stage, if the screw is slightly separated from crosshead at the point where the crosshead gives the impact, the crosshead is lifted by the air pressure originated during the initial compression stage, and thus air tends to be expelled naturally.

It is obvious that in a conventional fly press the striking mass cannot be lifted at all without reversal of the movement of the screw. It is necessary, in addition, to have the flywheel being lifted by a height corresponding, at least, to one'quarter of revolution so as to give the flywheel the time and the space which are necessary to invert the direction of its motion and storing the momentum which is required to carry out the second sintering stroke.

The above mentioned down times have been done away with in the fly press according to the invention. As a matter of fact, the flywheel affixed to the screw receives its drive from the descent disc and is driven to rotation at a gradually increasing speed and, through the connection means, entrains with it the second flywheel which is idle on the screw. In the instant of impact of the upper pad with the powder to be sintered, the first flywheel integral with the screw receives a counterblow which tends to invert the direction of motion of the flywheel and thus to lift the screw again and to lift it from the crosshead whereas the second, idle, flywheel continues for a fractional time to be freely rotated prior to contacting the first, fixed, flywheel again. During this fractional time, it happens that the air, left compressed within the die, lifts by virtue of its expansion the upper pad and the crosshead therewith and is driven off through the natural paths.

The invention will be more detailedly disclosed hereinafter with reference to the accompanying drawings, which are illustrated by way of example only and without any implied limitations in connection with two possible embodiments thereof.

FIG. 1 is a diagrammatical elevational view, partly in section, of the flywheel according to the invention.

FIG. 2 is an axial sectional view of the twin-flywheel, taken along line II-ll of FIG. 3..

FIG. 3 is a cross-sectional view taken along the line IllIIl of FIG. 2, and

FIG. 4 is a sectional view, similar to that of FIG. 2, of a twin flywheel having engagement means according to an alternative embodiment.

The fly press shown in FIG. 1 is of a well known type per se and are illustrated and described herein only those component parts which are essential for understanding the invention properly. It is understood that all the component parts which are not shown or particularly pointed out in the specification to follow can be embodied in any way according to the known art. The press has a bedplate l with pillars 2: these support a bracket 3. In a central screw threaded vertical bore of the bracket 3 a screw 4 is screwed which carries in its upper portion an idle collar 5. To this, two rods 6 are affixed which are freely slidable through bores formed in the bracket 3 and are connected at their lower portion, to a crosshead 7. The crosshead 7 is slidable guided onto the pillars 2.

The crosshead 7 carries the upper movable pad 8 which is adapted to enter the die 9 affixed to the bedplate l. The bottom of the die is the lower pad 10.

The upper end of the screw 4 carries two flywheels I1 and 12, a first of which is fixedly keyed to the screw 4, whereas the second flywheel is idly mounted by means of ball bearings 13.

At the upper ends of the bracket 3 is journaled a shaft 14 which carries tow discs 15 and I6. A sheave, rigid with the disc 15, receives, through a belt drive, its rotational drive from an electric motor 17 mounted on the bracket 3.

The shaft 14 with the discs 15 and I6 can be axially shifted by the agency of means not shown herein, to bring, at will, either disc into contact with a leather lining mounted on the peripheral surface of the flywheel 11. the latter being fastened to the screw 4.

In the embodiment shown in FIGS. 2 and 3, there is, between the hub of the flywheel I1 and the body of the flywheel 12, an annular gap 18 into which shaped teeth 19 protrude, which are solid with the hub of the flywheel 11, matching shaped teeth 20 being solid with the body of of the flywheel 12. These teeth are a mechanical connection between the flywheel ll affixed to the screw 4, and the flywheel l2, idling on said screw, a free mutual rotation being allowed between the flywheels through a limited angle (see more particularly FIG. 3). More accurately, the teeth 19 with their front faces 21 can contact the front faces 22 of the teeth 20, or, as an alternative, the front faces 23 of the teeth 19 can contact the front faces 24 of the teeth 20. Spring biased plungers 25, are provided for in the front faces 23 of the teeth I9.

The operation of this embodiment of the fly press is as follows.

Starting from the position where the striking mass (crosshead 7 and upper pad 8) is completely lifted (see FIG. I) and where the die 9 has been loaded with the necessary amount of powder to be sintered, the shaft 14 is shifted so as to bring the disc 15 into contact with the flywheel II. By so doing, the flywheel l1 enters rotation and rotates the screw 4 so that the striking mass is lowered. The direction of rotation during this stage is shown in FIG. 3 by the arrows 26. The front faces 21 of the teeth 19 solid with the flywheel II engage the front faces 22 of the teeth 20 solid with the flywheel l2 and cause the flywheel 12 to be driven to rotation in the same direction. At the instant of impact of the upper pad 8 with the powder contained in the die 9, the flywheel 11, whose weight is somewhat less than that of the flywheel 12, carries out the first pressing operation of the powder and receives a counterblow. By virtue of this counterblow, the light flywheel 11 tends to invert its sense of rotation and thus to lift the screw 4 solid therewith, separating the screw from its contact with the crosshead 7.

Meanwhile, the heavy flywheel 12, as its teeth 20 are brought out of contact with the teeth 19 of the flywheel ll, continues its rotation by inertia in the direction of the arrows 26 (FIG. 3) through the entire space which is left free within the gap 18. During this fractional time, the air which was left compressed within the die 9 lifts, with its expansion force, the upper pad 8 and the crosshead 7 and is dumped outside through the gap existing between the die and the upper pad.

As the teeth 20 of the flywheel 12 have gone through the free space in the gap 18, they strike abruptly with their faces 24 the spring biased plungers as brought in registry with the faces 23 by the teeth I9 solid with the flywheel I I. The spring biased plungers 25 fulfill the task of damping the first impact as received from the teeth 20 of the flywheel l2 and of bringing the screw 4 in contact with the crosshead 7 again. The final impact of the teeth 20 against the teeth 19 thus originates a direct transfer of the force onto the upper pad 8 and thereby onto the material to be compressed, this last stage giving a well compressed tile as a result.

The working cycle is completed by the return of the striking mass to its lifted position. To obtain such a return, the disc 16 is brought into contact with the flywheel 11 and the latter is thus rotated .in the opposite direction and entrains the flywheel 12 by the agency of the teeth 19 contacting the front faces 24 of the teeth 20. As it reaches its dead center, the flywheel 11 is stopped whereas the flywheel 12, by inertia, is restored to its staring position with the faces 22 of the teeth 20 in contact with the faces 21 of the teeth 19.

FIG. 4 is illustrative of another embodiment which is distinguished from the one described hereinbefore only in that the means for engaging the second flywheel I2 idly mounted on the screw 4 with the flywheel 11 solid with said screw, consist in a clutch of conventional make. As clearly shown in FIG. 4, this clutch, generally shown at 27, comprises an inflatable member 29 solid to a shape sheet metal ring 30 which is affixed by screws 31 to the interior of the flywheel 11. A piping 28, connected to a source of compressed air through a stop valve (not shown), is connected, in turn, to a distributor 32 mounted in axial position at the free end of the screw 4. From this distributor 32 starts a tube 33 which is connected to the inflatable member 29 and follows the flywheel 11 in itsrotation about the axis of the screw 4. It is obvious that, by feeding with compressed air the pipings 28, 33 the inflatable member 29 is expanded and brought into contact with the second member 34 of the friction clutch, afiixed to the peripheral surface of the idle flywheel 12. By so doing, the clutch 27 becomes engaged and the flywheels I1 and 12 are coupled. By releasing the pressure from the pipes 28, 33,- the clutch is disengaged. I

The operation of the embodiment just now described is as follows.

Upon the descent of the striking mass, the friction clutch 27 becomes operative and the disc I5 is brought into contact with the flywheel 11: the latter, through the engaged friction clutch, drives to rotation the flywheel 12 also.

At the instant of impact of the upper pad 8 with the powder held in the die 9, the clutch 27 becomes disengaged and the disc 15 is brought away of the flywheel 11. The flywheel 11, by transferring its angular momentum to the screw 4, brings about the initial compression stage and receives a counterblow: the same effects are experienced as hasbeen seen for the first embodiment as described above. In the meanwhile, the flywheel l2 freely continues its rotation by inertia.

Theclutch 27 is engaged again so that the flywheel 12 is made integral with the flywheel 11 once again and also it becomes solid with the screw 4 to transfer thereto the angular momentum of the flywheel 12 so as to effect the second compression stage.

To restore the striking mass to its lifted position, the clutch 27 is disengaged and the disc 16 is brought into contact with the flywheel II.

It can now be appreciated that by adopting the twin flywheel, either flywheel being idle on the screw, it has been possible to do away with the down times which were required in the conventional presses by the necessity of inverting the direction of rotation of the screw in order to carry out the deaeration of the powder after the initial stroke.

It is obvious that the invention is not limited by the embodiment illustrated herein, since many modifications can be in troduced within the scope of the present invention.

I claim:

I. A fly'press for the production of ceramic tiles or the like, comprising a die for receiving the powder to be compressed, a vertically movable pad integral with a striking mass, a screw for controlling the depressional movements and the lifting movements of the striking mass, a first flywheel solid with said screw and two discs rotatable in the same direction and adapted to be altematingly brought into contact with diametrically opposite peripheral areas of said flywheel, charac terized in that on the screw a second flywheel is idly mounted, means being provided for causing the engagement between the flywheel affixed to the screw and the idle flywheel, said engaging means permitting at least a limited rotational movement of either flywheel relatively to the other flywheel, the first flywheel being lighter in weight than the second flywheel.

2. A fly press according to claim 1, characterized in that the engagement means consist of a tooth clutch.

3. A fly press according to claim 2, characterized in that the teeth of said clutch are, respectively, solid with the flywheel affixed to thescrew and the idle flywheel and that a free gap exists between the respective teeth so as to permit mutual rotational movements of either flywheel relatively to the other flywheel.

4. Afly press according to claim 3, characterized in that the teeth solid with the flywheel which is affixed to the screw carry spring biased plungers in registry with their rear front surfaces as referred to the sense of rotation of the flywheel which causes the depressional movement of the striking mass to occur.

5. A fly press according to claim 1, characterized in that the engagement means consist of a clutch.

6. A fly press according to claim 5, characterized in that the clutch comprises an inflatable member which can be inflated by compressed air and is aflixed to the interior of the flywheel which is solid with the screw, and a second member affixed to the exterior of the idle flywheel.

Claims (6)

1. A fly press for the production of ceramic tiles or the like, comprising a die for receiving the powder to be compressed, a vertically movable pad integral with a striking mass, a screw for controlling the depressional movements and the lifting movements of the striking mass, a first flywheel solid with said screw and two discs rotatable in the same direction and adapted to be alternatingly brought into contact with diametrically opposite peripheral areas of said flywheel, characterized in that on the screw a second flywheel is idly mounted, means being provided for causing the engagement between the flywheel affixed to the screw and the idle flywheel, said engaging means permitting at least a limited rotational movement of either flywheel relatively to the other flywheel, the first flywheel being lighter in weight than the second flywheel.

2. A fly press according to claim 1, characterized in that the engagement means consist of a tooth clutch.

3. A fly press according to claim 2, characterized in that the teeth of said clutch are, respectively, solid with the flywheel affixed to the screw and the idle flywheel and that a free gap exists between the respective teeth so as to permit mutual rotational movements of either flywheel relatively to the other flywheel.

4. A fly press according to claim 3, characterized in that the teeth solid with the flywheel which is affixed to the screw carry spring biased plungers in registry with their rear front surfaces as referred to the sense of rotation of the flywheel which causes the depressional movement of the striking mass to occur.

5. A fly press according to claim 1, characterized in that the engagement means consist of a clutch.

6. A fly press according to claim 5, characterized in that the clutch comprises an inflatable member which can be inflated by compressed air and is affixed to the interior of the flywheel which is solid with the screw, and a second member affixed to the exterior of the idle flywheel.

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