US2376203A - Molding machine - Google Patents

Description

May 15, 1945.

H. STEMMLER ET AL MOLDING MACHINE Filed Aug. 4, 1942 2 Sheets-Sheet 1 fizz 6722072:

H. STEMMLER' ET AL 2,376,203

MOLDING MACHINE 'Fiied Aug. 4, 1.942 2 Sheets-Sheet 2 May 15, 1945.

- jizz/ei zizz;

- millimeters.

Patented May 15, 1945 I Hans Stemmler and KarlK Switzerland, assignors to Aktiengesellschaft der Eisenund Stahlwerke' vorma Geoig Fischer,

Schafihouse, Switzerland Application August 4, 1942, Serial No. 53,586

' In Switzerland November 24,1941

1 Claim. (Cl. 18- 16) This invention relates to molding machines comprising mold lifting pins which are arranged on a vertically displaceable supporting frame and are controllable from a single control position, each lifting pin being adapted to be forced against the underside of the casting box from below independently of the-other. pins. This arrangement I is intended to serve the purpose of initiating the rising movement of all the lifting pins at the same time so that the casting box is maintained parallelwith its initial position during the whole lifting operation.

, Adjusting devices for the lifting pins of molding machines that are controllable from a, single control position have already been proposed. Some of these propositions relate to arrangements with pistons which can v-be hydraulically or pneumatically actuated and the piston rod of which constitutes a'lifting pin of itself. If the pressure fluid conduits that are associated with such lifting pins of an individual molding machine are led to a single valve, common control of the pins is feasible. This arrangement has, however, not withstood the test of actual practice for the reason that, 'when the resistance opposed to the lifting operation varies, the pistons fail to rise at uniform speed so that the casting box is likely to assume an inclined position even from the start ofthe lifting whereby the mold is liable to be detrimentally affected. I 1 Other known proposals provide for lifting pins which are mounted on rotatable crank discs serving as cam discs. Said discs are rotated by means of press bolts that are operated from a single control position. The throw of such crank discs is restricted and is byall'means smaller than required for die carrier plates presently used, the thicknessof which averages about 100 Due to this fact the applicability of crank discs is subject to the requirement of compensating deficiency in length of throw in adaptation to excess thickness of the die carrier plates used, by applying exchangeable shimming blocks of different thicknesses to the lifting pins.

In contradistinction'thereto the arrangement according tothe present invention is"simplified in thatat least partof the lifting pins, each consist of two telescopically connected extensiblegand fixable" parts that are all spring biased upward direction, one ofsaid parts of each pln beinglockedin adifl'erent podtion ,of'height relative to the supporting frame at the end of travel of its associated spring means. arrangementdoes .away with lifting pins, which haskadily been preliminarily adjusted by hand to the thickness of die carrier plate required, further automatically adjusts itself to any uneven portion of the underside of the casting box that may be present and all the lift ing pins are locked in rigid relation to the supporting frame at the moment of beginning of the lifting so that all parts of the casting box share in the movements of the supp rting frame simultaneously.

Various embodiments of the molding machine according to the present invention are illustrated by way of example only in the accompanying drawings, in which Fig. 1 is a view of an assembled molding machine according to the invention inclusive of the lifting pins;

Fig. 2 is a part-view of a slightly modified embodiment of the invention compared to that shown in Fig. 1; I

Fig.3 is a longitudinal section of a lifting pin; Fig. 4 is a longitudinal section of a modified lifting pin;

Fig. 5 shows a detail of the clamping ring of Fig. 4;

Fig. 6 shows a cross section of a, lifting pin and modified lifting pin.

In Fig. 1, the outer forms of the machine standard I, and 0f the laterally rockable adjustable head piece 2 including a press plate 3 and a spindle 4 are illustrated. The base 5 provides-the mounting and the cylinder for the press plunger 6 carrying the molding plate I. On top of the die carrier plate 8 the casting box 9 comprising brackets 10 is placed. Lifting pins ,1 I supported by adjustable pivotal members I2 bear against the lower surfaceof the brackets I 0. The pivotal members l2 are firmly clamped to a supporting frame in pairs on either side of the molding machine by means of a screw l3 for each pair. The

supporting frame I4 is firmly connected to'a lifting plunger l5 interiorly of the machine standconduit [1, whereby the plunger' I5 is raised. An

upper bearing l8 guides the plunger l5 and the supporting frame I4 connected thereto in conjunction with a stufling box l9. On the backside This shimming blocks for the lifting pins. Each of the extensible of the supporting frame an ear 2| is arranged in which a screw spindle 21 carrying a hand wheel 22 is mounted; The screw spindle 2| bears Fig, 7 shows a longitudinal section of a further against an abutment 23 on the machine standard I, thereby forming an adjustable, lower limiting means for the travel of the supporting frame. Supply conduits 24 lead to the lifting pins ll via acheck member 25, the conduits being connected with the same source of pressure fluid as conduit l'l.

The lifting operationis'carried into effect as.

contact with the bottom of the casting box already in their initial positions. If the operator then actuates the plunger. 15 bymeans of pressure fluid, the fluid is also supplied to the con duits 24 and the locking plungers of the lifting pins H. The locking plungers of the lifting pins immediately effect rigidity of connection between the supporting frame it and the lifting pins Ii, thereby transmitting the lifting effect of the plunger l5 to the casting box. Due to the fact that the lifting pins I! have entered into contact with the casting box by action of the springs associated therewith prior to the locking having become effective-the casting box is raised by simultaneous action of all. the lifting pins as soon as the pressure fluid is projected onto the locking plungers. It will be seen that by this and the mold. The spring biased lifting pins means the absolute necessity for lifting the cast- .ing box exactly parallel to its initial position is complied with and thus the risk of injuring the mold is eliminated in that even very slight deviations from true parallelism might damage the mold.

The embodiment shown in Fig. 2 is. somewhat modified from that shown in Fig. 1 and differs from the latter as regards the manner in which the previously described lifting operation is carried out. The lifting pins 28 are connected to the supporting frame 29 and are each provided with a locking device actuated by means of pressure fluid also in this case. The supporting frame 29 is guided by means of bolts 30 which are firmly secured to a press plunger 3|. A collar 32 provides a lower limiting means for the travel of the supporting frame.- In a bearing 33 supporting levers 34 are mounted which are firmly urged against the arms of the supporting frame 29 in automatic manner by an elastic means. In lifting the press plunger 3| the supporting frame 29 is raised together with the lifting pins by the bolt 30.

Adjacent to the highest position fingers provided on the supporting levers 34 engage under the arms of the supporting frame'29 by snap action and remain in these positions until the compression is completed. In the meantime the Ill locking eifectof the lifting pins 28 is initiated by means of pressure fluid via a check' member 35 and supply conduits 36. During the subsedrawing. Alternatigely, the supporting levers piece into unlocking position.

may be reset by means of pressure fluid, or other meanssuch as an elastic tension device.

The longitudinal section of a lifting pin drawn to a larger scale in Fig. 3 shows by way of example the body 40 of they lifting pin to be integral with a pivotal member 4|. The extensible part of the lifting pin consists in a tube 42 having a-pointed bearing end 43 having a pressflt with the tube 42. A screw spindle 44 is firmly connected with the tube 42 by means of a. plug 45. A knurled adjusting nut 46 is carried by the screw spindle 44 andis connected to a sleeve ll.

The sleeve 41 carries a ring 48 which transmits the pressure of a, spring 49 to the adjusting nut 46. The lower end of the spring 49 bears on a I ).tact is ensured between the lifting pins and castxtend down to the bottom of the casting box r the ing box portions or heels that do not top of the die carrier plate. In placing 'the cast- -ing box in position the lifting pin portion 42, 63

is depressed together with the parts 46, W, and 49 until the underside of the casting box bears on the die carrier plate. The travel which the spring 49 performswhlle the lifting pin portion 42, 43 is depressed is always commensurate with theextent to which thepoint 43 of the lifting pin projects in the initial position above the top of the die carrier plate. As the casting box bears on the die carrier plate the lifting pins have arrived in their operating positions.

The lockingmeansijof the lifting pin shown in Fig. 3 consists in a braking block 5! which is actuated by fluid pressure and adapted to bear against the lifting pin. The pressure fluid enters through a pipe connection 52 for acting upon the unobstructed surface of a diaphragm 53. This diaphragm is forced against the braking-block 5| whereby the spring is compressed. In the compressed condition of the spring 54 the bralr ing block 5| bears against. the lifting pin, that is, the tube 42, thus preventing said pin from any further shifting movement within the body 663. As the pressure on the diaphragm 53 is removed the spring 54 resets the braking block 5| so as -to clear the tube 42. v 1

A similar form of lifting pin is shown in Fig. i. The pivotal member 55 is, forexample, integral with the body 56 of the lifting pin also in this case. The body 56 forms a guide for'the extensible part of the lifting pin which consists in a BI and a pipe connection 62 for the pressure fluid.

Compression springs 80 tend to press the braking Instead of the spring 41 in Fig. 3 a spring 63 as per Fig. 4 is provided which is however effective only for a lift of short length. This length is so chosen in this instance as to suillce, when the tube 51 is adjusted into a certain position, for compensating any difference of form of various kinds of casting boxes that are likely to enter into the question. To this end a spring housing 64 with a clamping ring 65 inserted therein must be displaced relative to the tube 51 as soon as a. different die carrier plate or a different kind of casting box is employed. For this purpose the pressure exerted by the clamping ring 65 is so adjusted by means of an adjusting screw 65, a spring 61 and a press ring 63 that the tube slides along the sleeve 6& if any tension or -compression. to which the tube 5'? is sub jected exceeds the effort of the'spring 63. A stop 69 and a screw cap 69' are provided for the purpose of retaining the sleeve 6d if the tube 51? is subjected, to tension. By this means the lifting tube i3 is gripped on opposite sides by the co-.

operating locking elements I4 and I5 which elements are forced. asunder to some extent by springs 16 in their initial positions. The locking element 14 is screwed together with the inlet pipe connection 11 so as to form a self-contained unit, a diaphragm 18 being interposed between said two parts. .To the side of the diaphragm 18 remote from the pressure fluid-a press piece 19 is fastened which transmits the deflection of the diaphragm. to the locking element 15. As the pressure fluid entersthe pressure chamber 80 compression forces acting onone hand on the locking element I5 through the press piece 19 and on other on the inlet pipe connection 11 are set up which connection transmits said forces to the locking element 14. After the springs 16 are I fixable parts, spring means for biasing at least overpowered the tube ,13 is locked to the pivotal member 10 by an effect similar to that produced y a. Pair of pincers.

A further form of lifting pin is shown in cross section in- Fig. 7 in which the pressure effect ex-'- erted by the entering pressure fluid is transmitted to the locking means by means of a leverage. In the instance shown the numeral refers to the body of the pivotal member which joins with a guide member 32 for a tube 83 of the lifting pin. A cylinder 86 containing a piston 85 is secured to the underside of the pivotal member at.

pressure fluid entering the pressure chamber 86 has the effect to compress a spring 87: by means of the piston 85, whereby the piston rod 88 is shifted in the direction toward the tube 83. In consequence thereof, a, lever 89 to which the rod 8% i851 pivotally connected turns about a pin Q0, thereby pressing the locking means ti against the tube 83. As the pressure fluid is discharged from the pressure chamber 86 again the spring 8i which bears against an annular abutment 92 shifts the piston 35 back into initial position. The rod 88, the lever 89} and the locking means 9! return together with the piston 85 into initial position.

We claim:

In a fluid pressure operated machine for forming molds in combination, a casting box, a press a actuated press motor for vertically displacing said frame, lifting pins for said'casting box carried by said supporting frame and each comprising two telescopically connected, relatively shiftable, and

one of said shiftable parts upwardly into contact with the casting box before actuation of the press motor, a braking motor intercalated between each pair of telescopically connected lifting pin parts, a source of pressure fluid, and means connecting the fluid press motor and also the braking means with said source of fluid pressure, the lifting pins thus being locked in their respective positions heights HANSSTEMMLER.

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