US2978760A - Core making machine - Google Patents

Description

April 1961 G. BARRALLON 2,978,760

CORE MAKING MACHINE Filed July 11, 1958 5 Sheets-Sheet 1 ew es BARRALLON INVENTOR April 11, 1961 e. BARRALLON CORE MAKING MACHINE 5 Sheets-Sheet 2 Filed July 11, 1958 I NVENTOR Gan es L A ril 11, 1961 G. BARRALLON 2,978,760

CORE MAKING MACHINE Filed July 11, 1958 5 Sheets-Sheet 5 Fig.5

Geor es BARRALLUN INVENTOR April 19$1 G. BARRALLON 2,978,760

CORE MAKING MACHINE Filed July 11, 1958 5 Sheets-Sheet 4 INUENTUR s BARRALLON April 1951 G. BARRALLON 2,978,760

CORE MAKING MACHINE Filed July 11, 1958 5 Sheets-Sheet 5 Gm," BARRALLON R INVENTO CORE MAKING MACHINE Georges Barrallon, Firminy, France, assignor to Compagnie des Ateliers et Forges de la Loire, Paris, France, a corporation of France Filed July 11, 1958, Ser. No. 748,571

Claims priority, application France July '16, 1957 Claims. (Cl. 22-10) This invention relates to machines for making foundry cores and it is an object of the invention to provide an improved automatic core making machine which will operate efliciently, reliably and simply to provide an increased output of well-formed cores with a minimum amount of manpower. Another object is to provide such a machine which will be especially well-suited for work with core compositions of the type comprising mixtures of sand and synthetic polymerizable resins which are quickly settable by the application of heat to the core molds, or other quick setting means. Further objects will appear as the description proceeds.

The machine of the invention generally applies the conventional core-making method which involves discharging sand from a sand receptacle into a core-mold or corebox, by means of a blast of high-pressure air at a pressure of about 5 to 6 kg. per sq. cm. According to an object of the invention, however, improved structure is provided whereby this conventional step is performed by fully automatic means in operative relationship with other steps of a complete core-making process.

According to an important aspect of the invention there is provided in a core making machine, in combination, a first turntable having a vertical axis and supporting a circumferential array of sand receptacles, second turntable means having a vertical axis horizontally displaced from the first axis and supporting a circumferential array of core-boxes, said arrays being substantially tangent as seen on a horizontal plane and defining a corefilling station at their point of tangency, means for synchronously imparting steps of rotation to both turntables so as simultaneously to present a receptacle and a corebox said station with a bottom outlet of the receptacle directly overlying an upper inlet of the core-box, a sand tank, and means filling each receptacle with a charge of sand from the tank prior to presentation of the receptacle to said station, air blast means positioned substantially at said station above said receptacles and cooperable with each filled receptacle presented to said station for discharging the charge of sand thereof into said core-box, and means for automatically operating said turntable rotating means and said air blast means in timed sequence for filling sand into the successive core-boxes of said array.

An exemplary embodiment of the invention will now be described for purposes of illustration but not of limitation with reference to the accompanying drawings,where- Fig. l is a general perspective view of the machine;

Fig. 2. is a vertical axial section of the sand tank, assembly showing the air blower units, the core-box clamping vice jaws (the core-box sections are not shown) and the core receiver table;

Fig. 3 is a plan view of the sand tank showing the scrapers for filling the core-boxes and related mechanism;

Fig. 4 is a sectional elevation of the blower head;

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Fig. 5 is a plan view of the sand tank rotating means; and

Fig. 6 is a perspective view of the assembly including the clamping device and core-box means.

As shown in Figs. 1, 2 and 5, sand is adapted to be contained in a generally cylindrical tank 10 having a central hub part 11 which is journalled about a vertical shaft 12 and is rotated by a drive system comprising a piston 13 movable in a cylinder 13c and connected with a piston rod 13d. The rod 13d is pivoted to a pair of integrally inter-connected spaced flanges 132. A pawl 13a pivoted to a flange 13e is engageable with the ratchet teeth of annulus 13b secured to hub 11, and the pawl is applied into engagement with the ratchet 13b by a spring 13 When pressure fluid, e.g. air, is delivered into the cylinder through inlet 13g, on the side of the cylinder through which the piston rod 13d extends, the other cylinder side being exhausted, the piston 13 is driven to the right (Fig. 5) and pawl 13a drives ratchet 13b to impart an incremental rotation to sand tank 10 about its axis.

Supported from the under wall 10a of the sand tank and spaced at equal angular intervals around a common circumference, are a number of blower units or cans 14 which are each adapted to be filled with a charge of sand during rotation of the sand tank by the action of scrapers 15 secured to cross links 15a. The cross links in turn are secured to a flange connected to the cylinder 13c serving to rotate the sand tank, see Fig. 3, so that on rotation of the tank the scrapers force sand into the blower cans 14, filling the latter.

A latch 16 engageable with sockets 17 carried at the under wall of the sand tank positively locates the tank at each of the successive angular positions in which a blower is in operative position in relation to a core-box, as will presently be described, the latch is actuated by a piston 1611 working in a cylinder 16b having a pressure inlet 16c to which compressed air is selectively delivered so that latch 16 will be depressed or retracted to allow rotation of the sand tank 10 and will be lifted to latching position to block rotation of the tank.

Each blower can 14 is mounted in the bottom wall 16:: of sand tank 10 so as to be vertically slidab-le therein, in such a way that its discharge outlet will be applied into engagement with the opening in the core-box when the blower unit is urged downwards by the blower head, as will be described. A spring .18 constantly biases the blower to its downward or extended position.

The system so far described constitutes a first turntable assembly which is bodily adjustable in the vertical direction by means of a handwheel 21 to enable its being adapted to varying vertical dimensions of core-boxes.

Arranged centrally below the sand tank is one of the pair of core-box clamping vices 19, actuated by a com pressed-air piston 20.

A table 22 serves to receive the finished cores and is secured on a central hub 23 rotatable about a vertical shaft 24 displaced horizontally from shaft 12, under the action of a system 25 similar to the system described above for rotating the sand tank. As with the sand .tank, the proper angular positions of the table are deter mined by a piston-actuated latch. Mounted on the table are core supports of a suitable shape corresponding to that of the type of cores to be made and shown in detail in Fig. 6. Each support comprises in the illustrated form, a flat plate 41 secured to the table 22, and having points 42 projecting upwards from it in positions corresponding to the portions of the cores 43 to be made, which points serve to retain the core contained in core-box 44 in a vertical upstanding condition when the box is removed from the core, and prevent displacement of the core relative to the table and its dropping ofi the table on rotation of the latter. The core supports are arranged at regular intervals around a circumference which is substantially tangent, as seen in vertical projection, to the circumference around which the blower cans 14 are spaced.

The receiver table constitutes a second turntable assembly which is bodily adjustable vertically in accordance with the vertical size of the core-boxes.

Disposed above the table 22 is a further clamping vice 26 which supports the other section of the core-box, and

which vice is actuated with a compressed-air piston 27.

Vice-actuating pistons and 27 are operated to eifect automatic opening and closure of the core-boxes in properly timed sequence. One of these two pistons is provided to develop a greater force than the other and the length of its operating stroke is adjustable so that the plane of junction of the core box sections will at all times be positioned in axial alignment with the blower can M in operative position. The vices '19 and 26 are mounted at a fixed vertical elevation, one being supported on the shaft 24 on which the table is rotatable, and the other on the shaft 12 on which the sand tank is rotatable.

A blower head 28 is provided for blowing sand from each 14 into acore-box, and comprises a cylinder 29 connectable to a source of compressed air and itself providing a store of air under pressure. The cylinder 29 is sealed at its lower end by a valve 30 operated by a shank 31. The valve shank 31 is actuated through a rocker 32 by a piston 33. This assembly is bodily displaceable vertically up or down by means of a rack 34 secured to cylinder 29 and operable by gears 34' and 35. The gear 35 further meshes with racks 36 and 37 actuated from air pistons 38 and 39.

Piston 33 when operated in its cylinder causes downward movement of the blower cylinder 29 to bring it into engagement with the sand-filled blower can 14 which has been advanced into operative position under it. The blower cans are spring mounted as already described so that, under the pressure exerted upon the can by the blower cylinder, the nozzle is moved down into engagement with the core-box aperture. After the blowing operation has been efiected, piston 39 is actuated to cause the subsequent upward movement of the blower cylinder.

The sand tank then has a further step of rotation imparted to it to bring the next blower can into operative position over a core-box for making a further core.

The operation of the various actuating pistons in the proper timed sequence is effected by any suitable timing control means such as a system of cams for example, acting on the various air-valves and driven from a suitable source of power such as a motor and speed-variator unit 49. Such timed control systems are well-known for various purposes of automatic control and hence do not require further description.

According to one advantageous form of the invention, the automatic operating means may be set to provide the following sequence of steps:

(1) Opening the core- box clamping vices 19 and 26 to open a core-box and release a finished core;

(2) Simultaneous incremental rotation of receiver table 22 and sand tank iii and concurrent actuation of the latching means for properly locating the table and tank at the fresh operating position;

(3) Closure of vices 19 and 26 to clamp the core-box in place;

(4) Lowering the blower cylinder 29;

(5) Discharge of sand from the blower can into the core-box; and

(6) Return of blower cylinder to its idle upper posi tion.

Advantageously, the motor and speed variator system operating the automatic timing systems, may be controlled through pneumatic switching means, such as a .latch operated by a mercury switch, for automatically stopping and starting the motor at the end and beginning of .each operating cycle.

It will be understood that in the specification and claims the word sand is used to designated any of the pulverulent compositions usable in making cores.

What I claim is:

1. In a machine for foundry cores, the combination comprising a first table rotatable about a vertical axis, a series of sand receptacles having lower and upper openings supported by said table along the circumference thereof, a second table rotatable about a vertical axis offset from the axis of said first table, a core box having an upper opening supported by said second table comprising two half boxes opening and closing in a vertical plane, a pair of camping devices located respectively in general vertical alignment with said two vertical axes, each half box being fixed to one of said clamping devices, means for synchronizing the rotation movements of said two tables, means for operating said clamping devices for closing and opening said two half boxes when a sand receptacle is directly above said core box thereby defining a filling station for said box when the axis of a receptacle is located in the closing plane of said core box with a lower opening of the receptacle directly superposed to said upper opening of said core box, a reservoir for sand, means for filling each receptacle with a charge of sand from said sand reservoir before said station, means for blowing air located above said receptacle and operable at the same time that each receptacle is presented to said station for the discharge of the sand from the receptacle into said core box, means for operating said two tables and said means for blowing air to fill with sand said core box at said filling station.

2. The combination claimed in claim 1, wherein said sand receptacle is supported on said first table above said receptacles and scraper means are provided in said tank for filling sand into said receptacles on rotation of the first table.

3. The combination claimed in claim 1, wherein said means for blowing air is vertically displaceable at said filling station between an idle upper position an an operative lower position in engagement with a receptacle presented to said station.

4. The combination claimed in claim 1, wherein said receptacles are mounted for vertical sliding displacement relative to said first table, between an idle upper position and an operative lower position and wherein said lower opening of the receptacle is engageable with the upper orifice of a core-box, spring means biasing the receptacles to said idle position, and said air blowing means in their movement towards their lower active position maintaining said receptacles in engagement with the upper opening of the core box against said spring.

5. In the combination claimed in claim 1 wherein positioning latch means releasably engage said tables for positively locating said tables in their correct positions in relation to said station.

References Qited in the file of this patent UNITED STATES PATENTS 819,883 Hewlett et al May 8, 1906 1,458,903 Holmquist June 12, 1923 1,573,436 Anderson Feb. 16, 1924 2,196,403 Thompson Apr. 9, 1940 2,791,012 Miller May 7, 1957 FOREIGN PATENTS 779,926 France Jan. 24, 1935

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