US3589433A

US3589433A - Two-piece squeeze plate in a sand moulding machine

Info

Publication number: US3589433A
Application number: US769594A
Authority: US
Inventors: Olof Johan Gerhard Hedberg
Original assignee: Malcus Industri AB
Current assignee: Malcus Industri AB
Priority date: 1967-10-30
Filing date: 1968-10-22
Publication date: 1971-06-29
Anticipated expiration: 1988-06-29
Also published as: GB1242556A; FR1587211A; SE333435B; DE1800750A1

Abstract

A molding machine in which a pressure plate and a support plate for a mold box are movable toward each other for compacting molding sand in a mold box placed upon the support plate comprises a pressure plate composed of two complementary parts. These plate parts can be selectively moved either into an engaged position in which they form a continuous pressure plate or into a spaced-apart position. In the latter position the two plate parts open a discharge for feeding molding sand into the box through a feed duct in a housing part of the machine.

Description

United States Patent Inventor 010! John Gerhard Hedberg llalmstad, Sweden Appl, No. 769,594 Filed Oct. 22, 1968 Patented June 29, 1971 Assignee Mllcus lndustri Alttiebolag, llalmstad, Sweden Priority Oct. 30, 1967 Sweden 1 TWO-PIECE SQUEEZE PLATE IN A SAND MOULDING MACHINE 7 Claims, 11 Drawing Figs.

[1.5. CI 164/207, 100/229, 25/103, 164/37 Int. Cl. B22c 15/02 Field of Search 164/37, 40, 207, 212; 18/16 C, 16 11,22,18 F; 100/229; 25/103 Primary Examiner-J. Spencer Overholser Assistant Examiner-R. Spencer Annear I Attorney-Bane & Baxley ABSTRACT: A molding machine in which a pressure plate and a support plate for a mold box are movable toward each other for compacting molding sand in a mold box placed upon the support plate comprises a pressure plate composed of two complementary parts. These plate parts can be selectively moved either into an engaged position in which they fonn a continuous pressure plate or into a spaced-apart position. In the latter position the two plate parts open a discharge for feeding molding sand into the box through a feed duct in a housing part of the machine.

PATENTEU JUN29 I97; 3. 589 .433

I sum 1 0r 5 INVHNTOR OLOF JOHAN BERNARD HEDBERG 6 Y 71 (dun I4 7 ATTOHNIIYG PATENTEDJUNPQIQYI 3,589,433

SHEET u UF 5 INVENTOR OLOF JOHAN GERHARD HEDBIJRG PAIENIEQJuuesm: 3.589.433

SHEET 5 OF 5 3f ZNVENTOR OLOF JOHAN GERHARD HIIDBERG 6 '7 WWW 644 ATTORNEYS TWO-PIECE SQUEEZE PLATE IN A SAND MOULDING MACHINE The present invention relates to sand-molding machines for foundries, and particularly to a two-piece squeeze plate in a molding machine.

Common to known molding machines is that they contain two horizontal tables or plates which are vertically opposite each other in the working position, between which a mold is prepared. The lower plate is then connected to a pneumatic lifting and jolting device and constitutes the base on which the pattern for the mold is set up, as well as a pattern frame or molding box, into which the molding material, usually sand, is filled. In the final molding stage, the mold and sand is pressed between said lower plate, which is raised from its original position and subjected to jolting, and the upper plate, the squeeze plate, which thus-functions as a counterholder during the final molding phase. When filling sand into the mold for the molding operation, which filling takes place by sand being allowed to fall freely from a sand container above the machine to a socalled sand beater and thereafter substantially vertically is fed into the mold, the squeeze plate must be moved away laterally in order to allow the sand to pass. In known machines, this squeeze plate is made in the form of one coherentunit, usually having a considerable weight, which with its supporting devices takes up a large portion of the totalweight of the machine and the power consumption. At the high production tempo at which mechanized foundries work, the time available for the various molding stages is necessarily very short. Under such circumstances, it will be realized that the time required to move a coherent, heavy squeeze plate out of the way and back into position again can be comparatively long, and can to a high degree influence the total time for the molding procedure. It will moreover be realized that the unsymmetrical movement to be effected by an undivided, heavy squeeze plate out of and back into its working position involves special requirements for the designing of the machine, e.g. as regards dimensioning, balancing etc. all of which contributes towards an increase in weight and complexity of the machine.

One purpose of the present invention is to create a squeeze plate for a sand-molding machine, which squeeze plate is divided substantially in a vertical symmetry plane so that the passage for filling in sand can be arranged by the two halves of the squeeze plate being moved symmetrically in opposite directions from the dividing plane between them. A considerable saving of time can thereby be made, in that, totally seen, less work is required for the opening and closing of the passage, compared with the circumstances when an undivided squeeze plate is used, even when it has the same size and weight, as well as a considerable saving in weight and dimensioning of the machine, owing to the more favorable dimensioning requirements which are a result of said symmetrical movement.

Another purpose of the invention is to create a squeeze plate intended for molding machines, which is divided into two substantially symmetrical halves through a dividing plane at right angles to the end surface and thereby constitutes a new element which provides for the creation of new solutions within the field of sand-molding machines.

In the following, the present invention will be described in more detail with reference to the attached drawings, in which FIG. 1 shows in perspective and obliquely from below the main parts of a molding machine provided with a two-piece squeeze plate according to the invention, the halves of the squeeze plate being in the process of moving away from each other in order to open a sand passage, in which FIG. 2 shows the design, in principle, of an embodiment of a squeeze plate according to the invention and the mounting devices for same, in which I FIG. 3 shows the main parts of a molding machine with a squeeze plate according to the invention in a certain working phase, in which FIG. 4 shows the same molding machine in a working phase following the working phase shown in FIG. 3, in which FIG. 5 shows the same molding machine in the final phase ofa molding procedure, in which FIG. 6 shows in detail a certain type of divided squeeze plate and a mold in the same final phase of the molding procedure as in FIG. 5, in which FIG. 7 shows a modified form of squeeze plate in the same final phase of the molding procedure, in which FIG. 8 shows a modified form of squeeze plate together with another type of mold, in which FIG. 9 shows still another modified form of a divided squeeze plate together with still another type of mold, in which FIG. 10 shows a molding machine of a conventional kind with a squeeze plate according to the invention, and in which FIG. 11 shows another molding machine provided with a squeeze plate according to the invention.

FIG. ll shows the two head parts I and 2 of a molding machine between which the preparation of the mold takes place.

The head part 1 consists of a horizontal pressing table or pressing plate 3, which is fixed to the outer end of the vertically movable piston rod 4, belonging to a hydraulic or pneumatic joltingand lifting device 5. On the pressing plate 3, a pattern'plate 6 with a pattern 6a and a mold 7 are placed in the usual way.

The head part 2, which is located right over the head part 1, consists, according to the present invention, of a horizontal squeeze table or squeeze plate, which has generally been given the reference designation 8 and which is vertically opposite the pressing plate 3 and the mold placed on same. The squeeze plate 8 consists of two symmetrically identical parts and 8b, which are supported so that they are displaceable horizontally in a housing 9. The

parts

8a and 8b, according to what is suitable in the individual case, can be compact'or hollow or have the form of boxes that are open upwards or boxes that are open at sides facing each other.

The

halves

8a and 8b of the squeeze plates can be supported in the housing 9 in any suitable way whatsoever. In FIG. 1 and for the rest in the figures, as well as in this description, an alternative for a support is used which is such that a horizontal strip 10 is arranged at the top of each side of the squeeze plate halves that is parallel to their movement, which strips are supported in horizontal straight grooves 11 on the insides of the sidewalls in said housing 9, as is also shown in FIG. 2.

From FIG. 2 it will moreover be noted that the

halves

8a and 8b of the squeeze plate are each provided with fastening members 12a and 12b for the ends of piston rods 13a and 13b, respectively, of hydraulic or

pneumatic pump cylinders

14a and 14b, respectively, the cylinder ends of which are fastened in holders 15a, and 15b, respectively, on the insides of the end walls of the housing 9.

FIG. 2 also shows how a so-called sand beater, generally designated I6, can be arranged in the housing 9 immediately above the squeeze plate 8 and how the housing 9 is arranged to constitute an intake 17 for sand 18 which is fed to the sand intake 17 in any conventional way whatsoever.

The functioning of the molding machine comprising the two head parts 1 and 2 and particularly the functioning of the head part 2, comprising the present invention, will now be described primarily in conjunction with FIGS. 3, 4 and 5. In FIG. 3, an empty mold 7 and possibly a new pattern plate 6 have been placed on the pressing plate 3, which has been raised part of the way towards the squeeze plate 8 ma position suitable for filling in sand. The

halves

8a and 8b are on their way to open up a passage for sand, in that the hydraulic or

pneumatic cylinders

14a and 14b pull them on their supports 10, I] to an outer position each in the housing 9.

In FIG. 4, the

halves

8a and 8b of the squeeze plate have reached their outer positions. Sand 18 is being fed from a sand scale 19 to the sand intake 17, being finely distributed while passing the sand beater l6, and is thereafter fed via the open sand passage between the

halves

8a and 8b of the squeeze plate to the mold 7. The mold 7 and the pattern plate 6 are then subjected to a jolting movement generated by the hydraulic or pneumatic jolting and lifting device 5.

When the feed of a weighed quantity of sand has ceased, the

halves

8a and 8b of the squeeze plate are returned by the

cylinders

14a and 14b, respectively, to their inner positions, which connect them to each other, as shown in FIG. 2, and the mold 7 is raised, during continued jolting, in that a pressure medium is fed to the jolting and lifting device 5, so that the sand will be pressed between the squeeze plate 8, i.e. the

halves

8a and 8b of the squeeze plate, on one side, and the pattern plate 6 and the mold 7 on the pressing plate 3 on the other side.

FIG. shows the final phase of the molding procedure, when the full pressing force has been attained and the sand has been made to tightly fill up the space in the mold above the pattern plate, the quantity of sand then, as the case preferably should be, having been adapted so that the squeeze plate 8 is inserted into the mold 7 to a minor extent.

Alternatively, the quantity of sand can be adapted so that, at the final phase of the molding, the mold 7 is pressed between a squeeze plate which in such a case has a larger pressing surface then the inner cross section area of a mold, and the pattern plate 6 on the pressing plate 3, as shown in FIG. 6.

An intermediate form 21 of the

squeeze plates

8 and 20 according to FIGS. 5 and 6, respectively, is shown in FIG. 7, which has a total cross section area which is larger than the inner cross section area of the mold, but a pressing surface which is somewhat smaller than or equal to the inner cross section area of the mold, and which extends from a shoulder 21a around the squeeze plate 20. This design of a squeeze plate is used particularly for so-called turning machines, when the mold rests on said shoulder of the squeeze plate during one working phase.

Particularly for large molds, reinforcement of the sand in the mold is required, which reinforcement can consist of transversal ribs 25, fixed in the upper part of the mold 24 to two opposite walls of the mold, or ofa network of

crossed ribs

28, 29, which joins all four walls of the mold 30 at their upper parts. FIG. 8 shows a squeeze plate 22 which is arranged with ribs 23 at its bottom, which can be inserted into the mold 24 between its reinforcing ribs 25. FIG. 9 again shows a squeeze plate 26 made with vertical bars or frames 27, arranged in a regular pattern of squares on the pressing surface, which frames fit and can be inserted between the

crossed ribs

28, 29 in the mold 30.

In the foregoing, a clear and explicit description has been given of the principle of the design and the embodiment, as well as the functioning ofa two-piece squeeze plate according to the invention as one of the two head parts of a sand molding machine. In FIG. 10, an illustration of such a molding machine 31, ofa substantially conventional type, is given. This molding machine, in addition to the actual molding procedure, is intended to execute a turning of the mold, and consists ofa turningframe 32, in which a molding frame 33 in the form of a two-pronged fork is rotatably supported on a horizontal axle 34, which axle forms the handle of said two-pronged fork. In one prong 35, a head part 1 with a lifting and jolting device 5 and a squeeze plate 3 is mounted, and in the other there is a head part 2 with a two-piece squeeze plate 8 according to the invention in a housing 9. The head parts 1 and 2 together function in identically the same way as has been previously described.

In FIG. 11 still another molding machine is shown, as an example of the use ofa two-piece squeeze plate according to the present invention. Also in this case it is a question of a socalled turning machine, but now not one of a conventional type but a particularly advantageous machine ofa new design, which has become possible only through the creation ofa twopiece squeeze plate according to the present invention. As is clearly shown in the figure, this machine consists of two parallel, circular turning discs, 37 38 which can be turned on rollers 39 in a machine frame 4 The discs are fixed together by means of an arrangement 41 with a lifting and jolting device near the periphery of the discs at the bottom of the figure, as well as diametrically opposite the last-mentioned part with an arrangement 42 with a two-piece squeeze plate according to the invention. As regards the molding procedure, and functioning of the new machine is identical to that of the one described above from the two head parts with a squeeze plate and a pressing plate.

Iclaim:

1. In a molding machine of the kind comprising a pressure plate and a support plate disposed in parallel relationship and movable toward each other for compacting loose molding material in a mold box placed between the two plates, the improvement comprising a pressure plate composed of two complementary parts selectively displaceable into an engaged position in which the two plate parts form a continuous pressure plate or into a position in which the two parts are spaced apart to define therebetween a passage for feeding molding material into the mold box placed between the two plates.

2. The molding machine according to claim 1 and further comprising a housing including a feed duct having an outlet for passage of molding material through the housing, said parts of the pressure plate being displaceably mounted in said housing so as to close the outlet of said feed duct when the plate parts are in the engaged position and to open said outlet when the plate parts are in the spaced apart position.

3. The molding machine according to claim 1 wherein said place parts are substantially alike and laterally displaceable in the plane of the pressure plate.

4. The molding machine according to claim 1 and comprising a mold box open on at least one side, and wherein the peripheral outline of the plate parts in the engaged position thereof overlies the rim on the open side of the mold box.

5. The molding machine according to claim 1 and comprising a mold box open on at least one side, and wherein said plate parts are set off on the side of the pressure plate facing the support plate, the setoff portions of the plate parts having a combined peripheral outline fittable into the open side of the mold box.

6. The molding machine according to claim 1 and comprising a mold box, the walls of said box and the side of the pressure plate facing the support plate having parallel mutually engageable ribs and grooves.

7. The molding machine according to claim 6 wherein said mold box walls and the pressure plate have additional parallel mutually engageable ribs and grooves crossing said aforementioned ribs and grooves.