US2447101A - Die casting machine - Google Patents

Description

ugo i?, 1948.

Flled Dec 30, 1944 6 Sheets-Shea?I 2 Filed Dec. 30, 1944 I mw wm m mm mm m.

A77'ORNEY ug. W, 1948. H. A. STOCK 2,447,101

DIE CASTING MACHINE Filed Dec. 50, 1944 6 Sheets-Sheet 3 I gll 35 l im 37 /AvENTo/z A77'ORNEY Aug. E7, i948'. H. A. s'rocK 2,447,101

DIE CASTING MACHINE Filed Dec. 30, 1944 6 Sheets-Sheet 4 /N VEN TO R A 77'ORNEY Aug. 17, 1948. H. A. STOCK DIE CASTING MACHINE 6 Sheets-Shea?I 5 Filed Dec. 30, 1944 Y ug. 17, 1948.

H. A. sTocK 2,447,101 DIE CASTING MACHINE Filed Dec. 50, 1944 6 'Sheets-Sheet 6 Patented Aug. 17, 1948 DIE CASTING MACHINE Hubert Arthur Stock, Peterborough, England Application December 30, 1944, Serial No. 570,668 In Great Britain February 15, 1944 9 Claims.

The present invention relates to die casting machines lfor moulding materials which can, for the purpose of manipulation, be temporarily reduced to a plastic consistency. Thus inter alia the machine may be used for moulding plastics in general, including thermo-plastic and th'ermosetting materials and metals.

According to the invention the machine comprises ia plurality of injection cylinders which can be selectively brought into position for use, by rotation in turret fashion about a xed axis. The injection cylinders may be fed from a common hopper or from separate hoppers, with predetermined measured quantities of material. Thus while one injection cylinder is in use for filling a mould, another cylinder may be undergoing relling, ready for use while the rst cylinder is being refilled. Preferably there are a. series of nozzles, with their injection cylinders, which are successively brought into operation, suitable means being provided for indexing the turret for this purpose.

According to a further feature of the invention provision may be made for fixing the turret when desired, and also for adjusting two of the injection cylinders, as by rotation of parts thereof so that both' of their nozzles are simultaneously engaged with separate filling orifices of the mould, thus permitting the ejection of twice the quantity of plasticized material, for example, as compared with a single cylinder.

The invention also includes the provision of means for locking the divided mould parts together as by means of wedges mechanically or hydraulically forced into position :after passage of the movable mould or its supporting platen beyond a predetermined point. By this means it is rendered unnecessary to maintain the closing pressure on the mould parts during the injection operation.

In order that the invention may be more clearly understood and readily carried into practice, reference will now be made, by way of example only, to the accompanying drawings, which illustrate one construction of machine according to the invention. In the drawings- Figure 1 is a side view in elevation of the machine;

Figure lA is a detail view in section, tofan enlarged scale;

Figure 2 is a plan view of the machine;

Figure 2A is a lateral view in section to a larger scale;

Figure 3 is a cross section on the line Ill-| Il of Figure 1, but to a larger scale;

Figure 4 is a large scale detail view illustrating the locking action for the moving mould platen;

Figures 5 and 6 are respectively a plan view and a side elevation of the ratchet gear of the turret indexing mechanism;

Figure 7 is a vertical section through the multihead turret type of lling mechanism;

Figure 8 is a part sectional view showing kthe ejector mechanism;

.Figure 9 is a plan view of the ejector mechanism and VFigure 10 is a diagrammatic elevation .of a modified form of machine.

Referring to the drawings, the machine comprises a hollow box-like bed A, which serves Vto support an upper frame comprising la 4pressure head B and a support head C. The former comprises a hydraulic cylinder 3 operating the moving mould part, and the latter contains a springloaded carriage for supporting the stationary mould part and also has the mould filling mechanism associated therewith. Between th'e two heads B and C extend four parallel rods -l'l which serve to guide the mould carriers or platens in their closing and opening movements. The front Iand rear heads B and C are connected together by an overhead beam 8 which merges into an open frame 9 at the top of the support h'ead C through which the mould lling apparatus extends upwardly.

The half moulds Mi, M2 (Figure 8) for producing the object or article to be moulded are mounted on carriers consisting of platens .I :and 2, of which' the platen 2 is substantially stationary, whilst the platen EI canbeadvancedtowards platen 2 until the vmould parts are closed-together by the hydraulic cylinder 3. The platens l and 2 are slidably engaged with the guide rods l 'I and where guide rods Il' pass through the front wall of carriage 23 bores are enlarged to receive springs .di which' bear against the back of platen 2 and tend to -force the platen 2 away from carriage 23, until it comes up against stop-collars lia, on guide ,rods I1 (see Figure 2A).

The platen l is adjustably connected to a bolster .plate d .by four screw pillars 5 (Figure 1A) which can ,be .rotated to adjust the spacing between bolster il and platen l to suit different mould thicknesses. When adjusted the screws 5 are prevented irom rotation by the lock nut colla-rs 5a.

The bolster l itself always assumes the same =forward position and on its rear face are moulded four U-sliaped Wedge vpieces 6 Whose inner edges fit round the edges of slots 6a cut in platen 'l and f .loolsterplatenit As it moves forwardlyy the bolster 4 travels along and beyond four fixed buttresses 1 which are carried by the overhead beam 8 and bed 9 respectively and are slidably engaged with the four slots 6a. When the bolster platen 4 reaches its constant forward position shown in dotted lines in Figure 1, four hardened steel wedges 9a, are driven by hydraulic cylinders 1a between the ends of the fixed buttresses 1 and the wedge pieces 6 on the bolster platen. This effects a positive lock which prevents backward movement of the bolster platen 4 and therefore precludes -any possibility of the mould opening by a force acting between the mould parts.

Behind the platen 2 and with support head C ls a carriage 23 which carries the mould filling `mechanism. The edges of carriage 23 slide along.

the top of bed 9 between guide channels along the interior of the side .plates of the head C (see Figure 7).

The raw material is supplied from a hopper 25 .(Figures l and 7 into a tube 56 having at its lower end ports which are covered by slides 26 having inclined channels 28, the size of which is chosen to accommodate varying quantities according to the work being done. Normally said slides 26 are pressed upwardly by springs 21 acting on the lower ends, but as the hydraulic ram 51 operating the filling plunger 29 descends, a bar 36 projecting laterally therefrom engages the ends of rod 3| projecting upwardly from slide 26 and carries the slide 26 downwardly, thus shutting off the channel 28 from the hopper tube 56 and eventually bringing it into register with the upper end of passage 58, Whose lower end opens into an inclined passage leading to a port in the upper part of the wall of the injection cylinder 59. ri'he passage 35 is closed at its lower end by the injection piston 29 until the piston has been withdrawn from the injection cylinder, whereupon the material in the passage 35 can fall by gravity into the injection cylinder 59 Where plasticizing or softening takes place as by means of heat applied to the walls of cylinder 59, for example electrically or by steam or gas heating.

There are a plurality of injection cylinders 59 mounted on a multi-cylinder turret head I3 which can rotate on a spindle 6D carried by carriage 23, so that the injection cylinders can be brought into use successively. If desired the number of cylinders and their arrangement on the turret may be such that more than one can be brought into operation at the same time, so that a greater amount of material may be forced into the mould in a given time. To facilitate the use of the injection cylinders in this manner, the lower parts 24 of the cylinder Walls may be rotatable in relation to the upper parts (Figure '7) so that the nozzles can be aligned with the mould filling openings and correctly seated thereon.

The turret plate I3 is adapted to be rotated or indexed by a hydraulic cylinder I9 which operates a rack bar 31 engaging a toothed pinion 36, coupled through a pawl drive 20 with the turret spindle 60 (Figures 5 and 6). The stroke of the piston of cylinder I9 is such as to rotate the turret plate I3 to the extent necessary to bring the next nozzle I I into mould filling position, whereafter the piston returns to the starting position ready for subsequent operation, the ratchet mechanism permitting this without backward rotation of the turret. When it reaches any of its setting positions the turret I3 is locked in position .by an index locking pin 2I operated by a hydraulic cylinder 22.

The turret plate I3 has at its rear end a tail piece I4 cushioned by springs I5 in relation to the rear end plate 6I of head C. After the mould parts come into contact the moving platen I continues to advance until the springs 4I (Figure 2A) are compressed and platen 2 beds up against carriage 23. Thereafter the whole carriage moves farther back compressing springs I5 sufficiently to establish the requisite sealing pressure of the nozzle I I in its seating in the die part carried by platen 2. After the dies have opened the carriage 23 is moved forwardly by springs I5 and platen I is then moved forward by springs 4I up to stop collars Ila. (Figure 2) on the cylinder rods I1.

Referring now toFigures 8 and 9, the moving mould part Mi is mounted on platen I and the stationary mould part M2 on platen 2, the moulded article being indicated by M. In the mould M1 :is a cavity 42 in which is disposed an ejector` plate 43 carrying two ejector pins 44 which t in holes opening into the interior of the moulding space, at suitable points, in the present instance behind the flange of the moulded object M. The ejector plate is mounted on two rods. 45 which pass through the platen I. On the hydraulic cyll inder 3 is mounted a double armed member or fork 46 which can be slidably adjusted along the cylinder and fastened by the nuts 41. At the forward ends of the arms of fork member 46 are plates 43. As the platen I and mould part M1 move backwards after moulding, t0 open the mould, the rods 45 strike the plates 48 and thus are brought to rest while the mould M1 continues its rearward movement. Consequently the ejector pins 44 push the moulded object out of the mould part M, as indicated in Figure 8.

The machine operates in the following manner:

The mould parts M1 and M2 having been fixed on the platens I and 2 the hydraulic cylinder 3 is operated to cause the platen I to travel towards platen 2, until the bolster platen 4 passes the four fixed buttresses 1. Thereafter the hydraulic cylinders 'la are operated to force the wedges 9a between buttresses 1, and the V-shaped wedge pieces 6 on the bolster platen. A positive lock is thus produced which prevents the mould parts Mi and M2 from moving apart, under the pressure produced in the interior thereof by the moulding material injected under pressure into the mould.

The mould is then filled with the plastic moulding material. As soon as the mould parts M1, M2 make contact they move forward, together with platen I, until the operative filling nozzle II engages in the seating in the mould part Mz. Further movement of platen I causes the turret plate I3 to recede, the springs I5 yielding to permit this and maintain sealing pressure of the nozzle I I in the mould inlet.

The appropriate plunger 29 is then operated to eject the material from nozzle II into the mould. After lling has been completed the wedges 9a are withdrawn and platen I is moved backwards by hydraulic cylinder 3 to its full extent.

The stationary platen 2 follows up this return movement under the action of springs 4I, until it comes up against stop collars I'Ia. As the platen I completes its return movement the ejector 44, 46, comes into action, as already explained,

The indexing-mechanism I9, etc., is then operated to rotate the turret plate I3 and bring the next injection cylinder 59 into position for the next filling operation. During this time the injection cylinder 59, last used becomes recharged amasar again, as already described. The above cycle of operation is. then repeated.

The invention is not limited to the particular construction of machine herein described and. illustrated in Figures 1-9, as it may take other forms without departing from the invention. For example as illustrated by Figure 10, instead of the mould4 lling cylinders being mounted on a capstan plate rotating about a vertical axis, they may be mounted torotate about a horizontal axis. In this case, as shown, the lling cylinders may be supported by a cylindrical member 49 rotatable in a bearing member 5B by means of a worm 5| meshing with teeth round the member 49. The hydraulic cylinders 5! for Operating the injection cylinders 59k are supported by a bearing ring 6&3 and a spindle 6i journalled in a bearing 62a By rotation of the cylindrical member 49. the discharge nozzles of any desired injection cylinder 59 can be brought into register with the aperture in platen 2 leading to the mouldv inletI opening. Itshould be appreciated that the invention is, not limited to the specific construction 0f machine and the details thereof herein described and illustrated in the drawings, the various gures should therefore only be taken in an illustrative and not in a limiting sense.

What I claim is:

1. Die casting machine for pressure moulding, comprising in combination a rotatable support and a plurality of injection cylinders mounted thereon, transfer passages formed to communicate with said injection cylinders, a plurality of injection plungers associated with said cylinders, a common lling hopper and an outlet passage therefrom, measuring slides, having cavities of predetermined capacities, movable from positions communicating with said outlet passage to positions communicating with said transfer passages, by action of said injection plungers when performing a filling stroke, and means associated with said injection plungers for thus moving said measuring slides.

2. Die casting machine for pressure moulding, comprising in combination, a rotatable support and a plurality of injection cylinders mounted thereon, transfer passages formed to communicate with said injection cylinders, a plurality of injection plungers associated with said cylinders,

which plungers, on performing a lling stroke, f-

close the ends of said transfer passages leading in-to said injection cylinders, a common filling hopper and an outlet passage therefrom, measuring slides, having cavities of predetermined capacities, movable from positions communicating with said outlet passage to positions communicating with said transfer passages, means associated with said injection plungers for positively moving said measuring slides, during a filling stroke of said plungers, from a position of communication with said hopper outlet passage to a position of communication with said transfer passages, and spring means for returning said slides to the position of communication with said hopper outlet passage on the withdrawal movement of said plungers after the filling stroke.

3. Die casting machine comprising, in combination, a spring cushioned stationary platen, a mould part carried by said platen, a movable platen carrying a complementary mould part, means adapted positively to lock said movable platen against backward movement when the mould parts are closed tightly together, a machine bed plate, a carriage slidable on said bed LlO 6i plate, a turret'. plate rotatable onV said; bed plate; a plurality of injection cylinders supported onsaid turret plate, spring means yieldingly spacing` said carriage from a part fixed to said bed plate,"v and spring meansi yieldingly spacing said stationary platen from said carriage.

4. Die casting machine for pressure moulding, comprising in combination, a bed, a mould sup.- ported by said bed, a pivot on said bed, a support rotatable on said pivot, and a` plurality of injection cylinders on said. support,v which by partial rotation of said support can be brought selectively into lling position in relation to said mould, each of said injection cylinders being formed of two parts, one of' which carries an injection nozzle with its axis projecting substantially radially from the cylinder and is rotatable in relation to the other part in order to allow adjustment ofthe radial orientation of the nozzle outlet in relation to the axisv of said injection cylinder.

5'. Die casting machine for pressure moulding comprising in combination, a die, a support'rotatable about a central axis, a plurality of injection cylinders mounted on said support and disposed in a circle concentric with said axis, which cylinders can be brought selectively into lling position in relation to the die of the machine by rotation of said support, and a plurality of hydraulic cylinders and rams individually associated with said injection cylinders and adapted to be selectively operated to inject material from said cylinders into the die.

6. Die casting machine according to claim 5, comprising injection cylinders of two part construction, one part carrying the injection nozzle and being rotatable with respect to the other part, whereby the injection cylinders may either be used one at a time, or a plurality of said injection cylinders may simultaneously be operatively connected with a die having a plurality of injection apertures.

7. Die casting machine for pressure moulding comprising, in combination, a horizontal frame, a spring cushioned stationary platen, a mould part carried by said platen, a platen movable along said frame and carrying a supplementary mould part, hydraulic means for closing said mould parts together, locking means and a drive therefor, operated when the mould parts are tightly closed together, positively to lock said movable platen against movement, a table supported by said frame and rotatable about a central vertical axis at right angles to said frame and on the side of said stationary platen opposite to said movable platen, a plurality of injection cylinders mounted on said support and disposed in a circle concentric with said axis, which cylinders can be brought selectively into filling position in relation to the die of the machine by rotation of said support, and a plurality of hydraulic cylinders and rams, individually associated with said injection cylinders, selectively operable to inject material from said cylinders into the die.

8. Die casting machine for pressure moulding comprising, in combination, a horizontal frame comprising horizontal guide rods, a spring-cushioned stationary platen through which said guide rods pass, a mould part carried by said stationary platen, a platen movable along said guide rods carrying a supplementary mould part, hydraulic means for closing said mould parts together, locking means and a drive therefor, operated, when the mould parts are tightly closed together, positively to lock said movable platen against movement, a table supported by said frame and 7 rotatable about a central vertical axis at right angles to said frame and on the side of said stationary platen opposite to said movable platen, a plurality of injection cylinders mountedron said support and disposed in a circle concentric with said axis, which cylinders can be brought selectively into filling position in relation to the die of the machine by rotation of said support, and a plurality of hydraulic cylinders and rams individually associated with said injection cylinders, selectively operable to inject material from said cylinders into the die.

9. Die casting machine for pressure moulding, comprising in combination, a bed, a mould supported by said bed, a pivot on said bed, a support rotatable on said pivot, a plurality of injection cylinders on said support, which by partial rotation of said support can be brought selectively into lling position in relation to said mould, and indexing means associated with said support, comprising a power driven reciprocable rack, a pinion in mesh with said rack, and a pawl drive between said pinion and said support for rotat-x ing the support to bring diferent injection cylinders selectively to mould-filling positions, and locking means separate from said rack and pinion drive means, releasably engageable with said support to lock it against rotation during a return movement of said reciprocable rack.

HUBERT ARTHUR STOCK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,952,241 Eckert Mar. 27, 1934 2,111,857 Jeffery Mar. 22, 1938 2,193,832 Morin et a1 Mar. 19, 1940 2,273,516 Dinzl Feb. 17, 1942 2,273,713 Lawyer Feb. 17, 1942 2,298,043 Dinzl Oct, 6, 1942 2,356,634 Von Opel Aug. 22, 1944

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