US1943680A

US1943680A - Die-casting machine

Info

Publication number: US1943680A
Application number: US491583A
Authority: US
Inventors: Lester Nathan
Original assignee: PREC CASTINGS Co Inc
Current assignee: PREC CASTINGS Co Inc; PRECISION CASTINGS COMPANY Inc
Priority date: 1930-10-27
Filing date: 1930-10-27
Publication date: 1934-01-16
Anticipated expiration: 1951-01-16

Description

Jan. 16, 1934. N. LESTER DIE CASTING MACHINE Filed Oct. 27, 1930 3 Sheets-Sheet 2 Z'TOR/YE Ys WIT/1E .s's

Jan. 16,1934.fi 'f N. LESTER, 1 1,943,630

DIE CASTING MACHINE Filed Oct. 27, 1950 3 Sheets-Sheet 3 Patented Jan. 16, 1934 UNITED STATES PATENT OFFICE DIE-CASTING MACHINE Application October 27, 1930. Serial No. 491,583

21 Claims.

This invention relates to certain new and useful improvements in die-casting machines, and pertains more particularly to that class of apparatus in which all of the working parts are actuated by fluid pressure.

The main objects of this invention are the production of a die-casting machine adapted to make castings from brass, aluminum or other materials, and which is'rigidly and durably constructed, is rapid and positive in operation and which may be readily and easily controlled.

In carrying out these objects, I have provided a vertically disposed, novelly constructed delivery pot in which is mounted for reciprocative movement, a discharge plunger actuated by fluid under pressure to positively force themolten metal into the die cavity. The die is positioned above the delivery pot and is moved vertically to bring it into and out of casting relation with the delivery pot.

The die is composed of two sections arranged in superposed relation and is mounted and actuated in such a manner that when the die is being moved away from the delivery pot to permit the entrance of a fresh supply of casting materials into the pot, the die. sections will be spaced to permit the removal of the casting fashioned therein, and as the die is moved into casting relation with the delivery pot, the die sections will again be brought into engagement With each other for receiving the charge of molten metal forced from the delivery pot by the plunger.

These movements of the die are effected by fluid under pressure acting upon the die through the medium of a piston and a toggle mechanism connecting the die with the piston in such a manner that when the die is in casting relation with the delivery pot, saidtoggle mechanism will form a lock for positively maintaining said die and pot in engagement during the casting operation and thereby premitting the molten metal to be forced into the die under high pressure and at a relatively low degree of temperature, thus eliminating substantially all air from the metal and thereby producing a more perfect casting.

A further advantage in this invention resides in the control which it affords of the molten metal during the casting operation in that the discharge of the metal from the pot may be instantaneously governed when the shot is being made and thereby providing means forthe elimination of serious accidents which might otherwise occur in case a die section should be accidentally omitted or if, for any reason, an inadequate connection exists between the die and delivery pot at the time of a discharge of the metal.

Another object is to provide a simply con- 0 structed unitary valve mechanism which may be quickly and easily operated for governing all of .the various moving units of the machine whereby they may be controlled in their regular order of operation.

Other objects and advantages relate to the form and relation of the details of the structure, all as will more fully appear from the following description taken in connection with the accompanying drawings in which:

Figure 1 is a front elevation of a die-casting machine embodying the various features of this invention and showing certain portions thereof broken away to more clearly illustrate the construction and operation thereof, and which is shown with the various members thereof in the open or inoperative position.

Figure 2 is a vertical sectional view of the machine taken substantially in the plane of the line 22, Figure 3, with the various members thereof in the casting position.

Figure 3 is a horizontal transverse sectional view taken substantially in the plane of the line 3-3, Figure 2. v

Figure 4 is an enlarged vertical sectional View taken on line 44, Figure 3, and illustrating the construction of a unitary valve mechanism for controlling the various moving elements of the apparatus.

Figure 5 is a sectional view taken on line 5-5, Figure 3, through one of the swivel joints.

Figure 6 is an enlarged detail sectional view taken on line 6-6, Figure 2.

Figure 7 is a vertical section taken in the plane of'the line'7-7, Figure 2.

The apparatus, as illustrated in the drawings, consists of a substantially rectangular base 1 adapted to be mounted upon a suitable supporting bed, not shown.

The base 1 has a pair of its opposite vertical '10o walls 2 provided with relatively large rectangular openings 3 therethrough while the upper portion of the base 1 is provided with a substantially flat horizontally disposed surface 4 which, in this instance, is made integral with the

side walls

2 and 5 of the base to form a convenient bed plate for the machine.

The central portion of the bed plate 4 is provided with a slightly raised portion or platform 6, rectangular in plan view and which has 1.10

the central portion thereof cut away to form a pair of flanges 7 which extend along opposite sides of the platform 6 transversely of the bed plate 4 in a direction extending between the vertical walls 5 of the base 1. The inner opposed vertical faces of the flanges 7 are arranged in parallel spaced relation to form guideways for a novel delivery pot or plunger box 8 which will hereinafter be more fully explained.

Secured to or made integral with the bed plate 4 is a pendant bracket 9 positioned centrally of the bed plate 4 and which is provided at its lower end with a rectangular plate 10 adapted to form one of the head members of a cylinder 11 and for this purpose, the central portion of the undersurface of the head plate 10 is recessed at 12 to receive one end of the cylinder 11.

A similar recessed head plate 13 is positioned at the other or lower end of the cylinder 11, and the cylinder and the two head plates 10 and '13 are clamped together in operative position by a plurality of, in this instance six, tie bolts 14 which pass through suitable holes provided in the lower end plate 13 and are screw-threaded in similar threaded holes in the upper head plate 10.

Each of these head plates '10 and 13 is provided with a respective passage or port 15 and 16. Each of these ports have one end thereof in communication with the interior of the cylinder 11, while each of their opposite ends is connected by respective conduits 17 and 18 with a novel unitary control valve 19 hereinafter more fully described.

In the cylinder 11 is mounted for reciprocative movement, a suitable piston 20 connected with the piston rod 21 which extends upwardly through a suitable opening 22 provided in the upper end plate 10 and has the upper end thereof rigidly connected with a discharge plunger.

23. The plunger 23, in this instance, is an elongated block of metal substantially square in cross section and extends upwardly through a similarly formed opening 24 provided at the center of the bed plate 4'and platform 6.

The delivery pot or plunger box 8 hereinbefore referred to, is composed of two similar half-portions 25 having their lower end edges provided with outwardly extending flanges 26 adapted to travel between the guide members 7 of the platform 6, said flanges 26 being of substantially the same thickness as the height of the guides '7 so that the plunger box sections 25 may be maintained in sliding relation with the platform 6 by means of a guide plate 27 secured by bolts or screws 28 to the upper face of each of the flange members 7.

Each of the plunger box sections 25 extend upwardly some distance beyond the upper face of the guide plates 2'7 and have their inner opposed vertical faces 29 formed substantially flat and smooth so that the sections may be brought into liquid-tight engagement with each other. Each of these faces 29 is also, provided with a vertically disposed centrally located V-slot 30 so constructed that when the plunger box sections 25 are brought into contact with the each other, said slots will form a substantially square opening 31 extending upwardly through the plunger box 8 of substantially the same cross sectional area as the plunger 23 for receiving said plunger upon the upward movement of the piston 20, and when the plunger 23 is in the lower position as illustrated in Figure 2, said opening 31 will form r a convenient delivery pot for receiving molten metal prior to the casting operation.

Each of these plunger box sections 25 is pivotally connected at 32 with one end of an operating link 33 which has the opposite end thereof pivotally mounted upon a pin 34 carried by the free ends of a pair of rock arms 35 which are positioned one at either side of the link 33 and are secured to a suitable rock shaft 36 pivotally mounted in a pair of brackets 37 which are secured at opposite sides of and extend upwardly from the base 1, as illustrated more clearly in Figure 3. V

' Each of the rock shafts 36 have one end thereof extending outwardly beyond the adjacent bracket 3'7 for receiving a respective crank arm 39 which is secured to the rock shaft 36 for rotating said shaft. Each of these rock arms have their outer or free ends pivotally connected at 40 to the upper end of a yoke 41 which, in turn, is connected with a piston rod 42 which extends downwardly from the rock arms 39 with the lower ends thereof positioned in a respective cylinder 43 and connected with a suitable piston 44 mounted in said cylinder.

Each of these pistons 43 is located at a respective side of the base 1 adjacent a vertical wall 5 thereof and is provided with a pair of susbstantially rectangular end plates 45 and 46 positionedone at either end of the cylinder.

The cylinder 43 and end plates 45 and 46 are clamped together by a plurality of, in this instance, four tie bolts 4'7 which extend upwardly through suitable openings provided in the head plate 46 positioned at the lower end of the cylinders 43 and screw-threaded in the upper positioned head plate 45. Each of the head plates 45 and 46 are also provided with respective passages or

ports

47 and 48 in communication with the interior of the cylinder 43.

The ports 4'7 and 48 positioned in the cylinder 43 located at the right hand side of the base 1, as viewed in Figures 1, 2 and 3, are connected respectively by

conduits

49 and 50 with a second pair of conduits 51 and 52 which, in turn, are

connected with the control valve 19 in a manner hereinafter more fully explained.

The

ports

47 and 48 positioned in the cylinder 43 located at the left hand side of the base 1 are, in like manner, connected by

respective conduits

53 and 54 with the conduits 51 and 52. Each of the upper positioned head plates 45 are provided with a suitable central opening therethrough for receiving the respective piston rods 42. The lower positioned head plates 46 are each provided with a relatively flat downwardly extending lug 55 which has an opening therethrough for receiving pins 56 which, in turn, are

mounted at their ends in a pair of respective outwardly projecting lugs 5'7 secured to or made integral with the adjacent vertical wall 5 of the base 1.

These

lugs

55 and 57, together with the pins 56 form a pivotal support for the respective cylinders 43 to permit the rocking movement of said cylinders during the swinging movement of the respective rock arms 39 which are moved by the action of the liquid in the cylinders 43 upon the respective pistons 44 for rotating the rock shafts 36 for the purpose of moving the plunger box sections 25 into and out of engagement with each other through the medium of the respective links 33 and rock arms 39 for the purpose of releasing any metal which may remain in the delivery pot 31 after the casting has been formed.

commences its downward movement and,- for' this reason, the plunger box sections 25 are each provided with a recess or groove 59 which extends around the V-shaped openings 30 near the upper end of the delivery pot 31. In other words, as the plunger 23 reaches the limit of its upward stroke after having forced the molten metal from the delivery pot 31 into the die as 60,.

whatever excess metal remains in the delivery pot will, of course, fill the groove 59 and will become solidified by the time the plunger 23 commences its downward movement, and therefore the excess metal will be maintained at the upper end of the delivery pot in connection with the sprue, so that as the die 60 is moved away from casting engagement with plunger box sections- 25, the excess metal held by said sections will be broken loose from the sprue, after which this metal is released by the sections for removal as said plunger box sections are moved outwardly by the action of the fluid upon the pistons in the cylinders 43.

The die 60, as is usual in this class of a machine, is constructed of two sections 60' and 60". The lower positioned die section 60' is provided with a gate or sprue-forming passage 61 therethrough which, whenthe dies are in the casting position, has one end in communication with the interior of the delivery pct 31 and the other end thereof communicating with the die 'cavity formed in the other die section 60".

The die section 60 containing the sprueforming passage, that is, the sprue die section, is secured by any suitable means, as by screws 62, to a die-supporting plate 63 which we will call the sprue die-supporting plate. The other die section 60" is provided with suitable openings therethrough for receiving a plurality of ejector pins 64 and, for this reason, we will term this portion of the die, the ejector die section. This ejector die section is secured by screws 65 or other suitable means, to a die-supporting plate 66 which we will term the ejector die-supporting plate. This ejector plate 66 is provided with suitable openings therethrough for receiving thefejector pins 64 which, in this instance, extend upwardly through the ejector plate 66 and are secured to and operated by an ejector head 67 which will hereinafter be more fully described.

The ejector plate 66, in this instance, is substantially rectangular in plan view and is pro-' vided at each outer corner thereof with an upwardly extending boss '70 each of which is provided with a vertically disposed opening for receiving a respective guide rail 71 which extends vertically upwardly from the base 1.

The guide rails 71 are arranged a uniform distance apart and are located at the comers of an imaginary rectangle near the outer corners of the bed plate 4 as illustrated in Figure 3. The rails are secured to and are supported by the base 1 and, for this reason, the lower ends 71' of the rails are reduced in diameter and extend downwardly through suitable openings in the base 1 and are secured to said base by nuts 72 screw-threaded on the lower ends of the rails.

The sprue die plate 63 is also rectangular in plan view and has secured thereto at each corner thereof an upwardly extending vertically disposed supporting rod 73 which have their lower ends reduced in diameter and extending through corresponding holes in die plate 63 to which the rodsare ,secured by nuts 74 screwthreaded on the lower end of the rods 73.

These supporting rods 73 extend upwardly from the die plate 63 through suitable openings provided in the die plate 66 and up through openings aligned with the openings in the die plate 66 provided in the die supporting head plate 75 to which the rods 73 are adjustably secured by means of nuts 76 screw-threaded on the upper ends of the rods 73 and positioned above and below the die-supporting head 75 for the purpose of properly positioning the sprue die section 60' in casting relation with the delivery pot 31 as will be hereinafter more apparent.

The die-supporting head 75, like the ejector die plate 66, is provided with, in this instance four, vertically disposed bosses 77 positioned at the corners of a rectangle and which are provided with openings therethrough for receiving a respective guide rail 71 upon which the head 75 is slidably mounted. This die-supporting head 75 also supports the ejector die section in' a manner hereinafter explained and which, in turn, is supported by the base 1 in the following manner: Upon each of the rock shafts 36 (see Figure 3) and positioned between the respective rock arms 34, is rotatably mounted a rock arm 79 which has a horizontally disposed opening therethrough for receiving the rock shaft 36 and another opening 79' positionedat one side and extending at right angles to the first-mentioned opening for receiving therethrough one end of a supporting rod 80.

These supporting rods 80 are each adjustably secured to the respective rock arms 79 by means of two nuts 81 screw-threaded on the rods and positioned one at either side of the respective rock arm 79.

These. supporting rods 80 extend upwardly from their respective supporting rock arms 79 and each rod has its upper end pivotally connected at 82 to one end of a respective rock arm 83 for the purpose of pivotally supporting the die-supporting head 75 and the operating mechanism connected therewith to permit the vertical movement of the die 60 in the following novel manner: Each of the rock arms 83 extend inwardly from the pivot 82 between a pair of spaced downwardly extending lugs 84 which are, in this instance, made integral with the underface of the die-supporting head 75 and the arms 83 are pivotally connected to the respective pairs of lugs and, therefore, to the head 75 by means of respective pins 85 which are secured to said lugs and upon which the rock arms 83 are pivotally mounted. These rock arms 83 also extend inwardly from each of their pivotal connections 85 with the head 75 and have their inner ends curved concentrically with the respective pins 85 and terminating in spaced relation.

These curved inner faces of the rock arms 83 are each provided with gear teeth '86 which are in meshing engagement with respective sides of a double-faced rack member 87. This rack member 87 is slidably mounted in a T guide slot 88 formed in one vertical face of an upwardly extending arm 89 secured to or made integral with the upper face of the ejector plate 66.

This rack member 87 is also connected with a piston 90 mounted for reciprocative movement in a cylinder 91 by means of a piston rod 92 which has the lower outer end thereof extended through a suitable opening provided in a lug 87 secured to or made integral with the outer face of the rack 87.

The rod 92 is adjustably secured to the lug 8'7 by means of nuts 94 screw-threaded on the lower end of the rod 92 and positioned at either side of the boss 8'7.

The cylinder 91, in this instance, is positioned above the die-supporting head 75, which has an upwardly extending bracket 95 secured to or made integral with the upper face of said head. The upper end 95' of this bracket 95 is substantially square in plan view and is provided with an annular recess 95" in which is positioned one end of the cylinder 91 to form one head plate therefor. The other end of the cylinder 91 is provided with a head plate 96 similar in plan view to the end plate 95' of the bracket 95 and which is also provided with an annular recess 96' for receiving the outer end of the cylinder 91.

The cylinder 91 and the head plate 96 are secured in operative relation with each other and with the bracket 95 and, therefore, with the die-supporting head by means of four clamping bolts 9'7, which extend through suitable openings provided in the head plate 96 near the corners thereof and screw-threaded into the upper end of the bracket 95.

.The head plate 96, in this instance, is provided with a passage or port 98 communicating with .the interior of the cylinder and which is connected by a suitable conduit 99 with the valve member 19. The cylinder 91 is also provided with another port 100 located in the side wall thereof near the other or inner end of the cylinder and which is connected by a conduit 101 with the said valve 19.

The outer end 95' of the bracket 95 is provided with a suitable central opening for receiving the piston rod 92 which extends downwardly to the rack 8'7 through an opening 102 provided in the die-supporting head '75. This opening is also large enough to permit the rack 8'7 to pass therethrough during the upward movement of said rack.

It may now be clearly understood that with the piston 90 and rack 87 positioned at the end of the downward stroke and with the teeth of the rack engaging the teeth 86 of the rock arms 83, as illustrated in Figure 2, that the die-supporting head '75 will be maintained a predetermined distance from the bed plate 4 by the supporting rods 80. If, however, pressure is applied to the lower face of the piston 90 to cause said piston to move upwardly in the cylinder 91, it is also evident that the die-supporting head will be,moved upwardly along the guide rails '71 by the action of the rack upon the rock arms 83 but to a lesser degree due to the rack 8'7 causing said arms 83 to rock upwardly about the pivots 82 which will, of course, carry the pivotal pins and, therefore, the die-supporting head '15 upwardly. This upward movement of the die-supporting head '75 will be of a less distance than the upward movement of the piston and rack 87, due to the difference in the radial distance of the teeth 86 and the pins 85 from the respective pivots 82. In other words, the distance from the pivotal pins 82 to the respective teeth 8'7 being greater than the distance from said pivots to the pins 85, the rack 8'7 will, of course, have to move upwardly a greater distance than the pins 85 in order to bring the pins 85 to a predetermined height.

It will be noted that during this vertical movement of the die-supporting head '75 along the guide rails '71 that pins 85 upon which the rock arms 83 are rotatably mounted, will travel in straight parallel planes and that as the rock arms 83 and die-supporting head '75 move upwardly or downwardly vertically, said rock arms will rock about the axis of the pins 85 and cause a slight rocking movement of the supportin rods 80. This rocking movement of the rods 80 is permitted by the pivotal mounting of the rock arm '79 uponthe respective shafts 36 and, therefore, upon the base 1. This vertical movement of the die-supporting head will produce a like movement of the sprue die section 60 through the medium of the sprue die plate 63 and the tie rods '73 for bringing the sprue die into and out of casting relation with the delivery pct 31 and will also produce a vertical movement of the ejector die section 60 and the ejector die plate 66 relatively to the delivery pot 31 and also to the sprue die section 60' through the medium of a toggle mechanism 103 in the following manner: One end of each of the pins 85 is extended outwardly beyond the respective supporting lugs 84 and has pivotally mounted thereon a link member 104 which has pivotally connected therewith at 105 one end of an arm 106 which extends downwardly some distance from the pivot 105 and has the other end thereof pivotally connected at 107 to one end of a second link 108 which, in turn, is pivotally connected at 109 to upwardly projecting lugs 110 made integral with the upper face of the ejector die plate 66.

To each of the arms 106 intermediate the ends thereof, is pivotally secured at 111 an ejector head member 6'7 which is positioned intermediate the arms 106 and is provided with a T- flange 112 on the rear vertical face thereof which is slidably mounted in the T-guide 88 provided in the arm 89 so that the ejector head 67 is free to move vertically upwardly or downwardly and, at the same time, provides a pivotal support for the arms 106 at 111 about which said arms may rock during the flexing movement of the toggle mechanism.

The adjacent ends of each of the arms 106 and links 108 are provided with abutting shoulders 106' and 108' adapted, when the pivots of the links 104 and 108 and arms 106 are in the same straight line for preventing the movement of said links and arms in one direction.

It will be noted by referring to Figures 2 and 6 that the links 104 are connected with the respective rock arm 83 by means of a pair of shouldered screws 114 which pass through elongated slots 115 provided in the arms 83 and are screw-threaded in the adjacent portion of the links 104 to permit an initial movement of the rock arms 83. In other words, the screw and slotted connection between the rock arms 83 and the links 104 is for the purpose of permitting a certain amount of rocking movement of the arms 83 to lift both die sections 60' and 60" a certain distance from the delivery pot 31 before the links 104 are actuated to collapse the toggle mechanism 103 and thereby produce a relative vertical movement of said die sections, for as is evident, as soon as the links 104 and 108 and the arm 106 begin the collapsible or folding movement, the ejector supporting plate 66 and therefore the ejector die 60" will be moved upwardly at a greater speed than that of the upward travel of the die-supporting head '75 and therefore, the sprue die section 60'.

This folding movement of the toggle mechanism will also produce a relative movement between the ejector die plate 66 and, therefore, the ejector die and the ejector head 67 which will cause the ejector plate 66 and the ejector die 60" to travel upwardly relatively to the ejector pins 64 which will cause said pins to extend downwardly through the ejector die 60" and thereby produce the ejection of the casting from said die, as illustrated in Figure 1.

It is also evident that as the toggle mechanism assumes the extended position as shown in Figure 2, with the

pivots

85, 105, 107 and 109 of each set of links and arms in the same vertical plane, that said toggle mechanism will constitute a rigid connection between the die-supporting head and the ejector die plate 66 which will constitute a lock for rigidly maintaining the ejector die section 60" in contact with the sprue die section 60' during the ejection of the molten metal from the delivery pot into,

the die cavity.

The control valve 19 hereinbefore mentioned, may be of any suitable construction for controlling the flow of the fluid to and from each of the cylinders of the machine but it is preferable that the valve should be so constructed that this ,control may be accomplished by actuating a single lever, and for this purpose, I have illustrated a simply constructed mechanism, as illustrated more particularly in Figure 4. This valve consists of a body member 118 which is substantially rectangular in cross section and is provided with a centrally located piston chamber 119 which extends longitudinally through said body.

The ends of the piston chamber 119 may be closed by any suitable means as by

gland members

120 and 121 which may be secured to the body 118 in any suitable manner as by screws 122.

One of the gland members as 121 is provided with a suitable longitudinal opening therethrough for receiving a piston rod 123 which has the inner end thereof secured to a suitable piston 124 and the other or outer end of the rod is secured to a suitable actuating member such as the rack 125 which, in this instance, is guided in a longitudinal opening 126 formed in a lug 127 secured to or made integral with a suitable lever-supporting bracket as 128 which, in this instance, may be secured to or made integral with the gland member 121.

The body 118 of the valve 19 is also provided with an inlet port 130 which extends through the upper wall of the body midway between the ends thereof and two outlet ports 131 positioned in the lower portion of the body 118 adjacent the ends of the piston chamber 119. These outlet ports 131 communicate with a common passage 132 which is connected to an outlet pipe as 133 for returning the fluid to the source of supply.

In the upper portion of the body 118 there is also formed a plurality of, in this instance six, control ports 134 which are formed in two groups consisting of three ports each, with a group positioned at each side of the inlet port 130 longitudinally of the body 118. The inlet port 130 and each of the control ports 134 communicate with the interior of the piston chamber 119 through the medium of annular recesses or

grooves

135 and 136 respectively.

The piston 124 is substantially smaller in diameterthan the piston chamberllQ with the exception of two annular outwardly extending port control flanges 124' and 124" positioned near the ends of the piston 124 and spaced apart a distance substantially equal to the distance between the outer edge of either one of the outer positioned control port openings 136 and the opposite face of the inlet port opening 135, it being understood that the ports 134 are spaced substantially equal distances apart and from the inlet port 130 so that the intervening flanges or ribs 138 formed by the

recesses

135 and 136 are substantially equal in width and that the port control flanges 124' and 124" on the piston 124 are each substantially equal in width to the width of the ribs 138, so that when the piston 124 is in the extreme position at one end or the other of the piston chamber 119, all of the control ports at the end of the body 118 in which the piston is located, will be in communication through the piston chamber 119 with the intake port 130 while all of the control ports 134 positioned at the opposite side of the inletport 130 will be in communication with the outlet or exhaust port 131. It is, therefore, evident that as the piston 124 is moved toward the opposite end of the piston chamber 119, that the control ports formerly in communication with the inlet port 130, will be successively cut off from the inlet port and connected with the exhaust port 130 positioned at the adjacent end of the piston chamber while the control ports formerly in communication with the exhaust port will be successively cut oil from the exhaust port and brought into communication with the inlet port 130.

This movement of the piston 124 from one position to another is accomplished, in this instance, by a simply constructed control lever 140 pivoted at 141 to the bracket 128. The lever 140 extends below the pivot 141 and has the inner end thereof made concentric with the pivot 140 and provided with gear teeth 142 which are in meshing engagement with the teeth of the rack 125.

The bracket 128 is provided with a circular slot 143 positioned above the pivot 141 and made concentric therewith for receiving an L-shaped latch pawl 144 which is slidably mounted in a groove 145 provided in the lever 140. The upper periphery of the slot 143 is provided with a plurality of, in this instance four, radial slots 143 corresponding to the number of diiferent positions the piston 124 is to assume so that the piston may be maintained in a predetermined position by the latch 144 engaging a respective slot 143.

The latch 144 may be yieldingly maintained in any one of these slots 143 by means of a spring 146 and rod 147 slidably mounted in the lever 140 and connected with the latch 144.

In order to permit the pivotal movement of the cylinders 43 for controlling the positioning of the plunger box sections 25 and the vertical movements of the cylinder 91 necessary for operating the

die sections

60 and 60", it is necessary to provide the conduits leading from said cylinders to the control valve 19 with means for permitting the relative pivotal movements of certain portions of said conduits and for this purpose, there is provided at advantageous points in said conduits a desired number of swivel joints as 150.

In the operation of a die-casting machine of this class, it has been found diflicult to provide a suitable swivel joint to permit the free relative movements of the conduit and, at the same time, prevent leakage of the fluid at these points due 150 to the extremely high pressure in which the fluid is used. Figure 5, however, illustrates a simply constructed swivel joint which has been found to meet the requirements. This joint consists of a body 151 having one end thereof rigidly connected with one end of a conduit as C, while a companion conduit C having its inner end provided with an annular flange 152 is journaled in the opposite end of the body 151 with the flange extending beyond and in contact with an inwardly extending annular flange 153 formed in the body 151 intermediate the ends thereof.

Suitable packing as 154 is positioned at the opposite side of the flange 153 and maintained in a fluid-tight manner with the walls of the conduit 0' by means of a follower nut 165 screwthreaded in the adjacent end of the body 151.

Operation It will be noted that each of the

cylinders

11, 43 and 91 have one end port thereof connected with a control port in the control valve 19 positioned at one side of the inlet port 130 while the ports positioned in the other ends of these cylinders are each connected with a respective control port positioned .at the opposite side of the control valve inlet port. For instance, the plunger operating cylinder 11 has the upper or rod end thereof connected to the control valve 19 by the conduit 1'7 which is connected with the control port positioned next to the inlet port of the control valve at the left hand side thereof, while the conduit 18 leading from the port 16 at the opposite end of the cylinder 11 is jointed with the control port positioned fartherest from the inlet port 130 in the group positioned at the right.

hand side of said inlet port.

The conduit 51 which is connected with the

conduits

49 and 53 leading from the respective ports 47 of the plunger box operating cylinders 43, is connected with the control port located in the group at the left of the inlet port and with the specific control port positioned fartherest from said inlet port, while the

conduits

50 and 54 connected with said cylinder ports 48 are united with a common conduit 52 connected with the group at the right of the inlet port and with the control port positioned adjacent the inlet port 130; likewise the die operating cylinder 91 has its

ports

98 and 100 connected by

conduits

99 and 101 with the centrally located control ports in the groups positioned at the right and at the left of the inlet port 130 respectively.

Now, by considering the machine to be in the position illustrated in Figure 2, the control valve 19 will be in the position illustrated in Figure 4; that is, with the conduits 17, 52 and 99 in communication through the piston chamber 119 with the inlet port 130 and with said inlet port connected with a suitable conduit as 130' with a suitable source of liquid supply, such as oil under high pressure. Said pressure will be exerted through the respective cylinder ports 15. 48 and 98 to the corresponding ends of said cylinders which will maintain the plunger 23, the plunger box sections 25 and the die 60 in the position illustrated in Figure 2, ready to form a casting; that is, the pistons 44 in the cylinders 43 will be in the up position maintaining the plunger box sections 25 in flrm contact with each other and thereby maintain the grooves 30 of said sections in registration with each other to maintain the delivery pot 31 intact.

The piston 20 in the cylinder 11 and, therefore, the plunger 23 will be maintained in the 19Wermost position with the upper end of the plunger 23 at the lower portion of the delivery pct 31 to form the bottom wall of said pot, it being understood that the grooves 30 in the plunger box sections 25 are so constructed that the plunger 23 will have a close sliding fit in the delivery pot so that as the plunger is moved upwardly through the delivery pot to force the molten metal from the pot into the die, all of the molten metal will be carried along by the upward movement of the plunger. Likewise the sprue die section 60 will be firmly maintained in contact with the upper face of the plunger box sections 25 with the gate or sprue-forming passages 61 in communication with the upper end of the delivery pot 31 for receiving the molten metal therethrough as the plunger is moved upwardly, by the action of the fluid under pressure on the upper end of the piston 90, exerting a downward pressure upon the inner adjacent ends of the rock arms 83 through the medium of the rack 87. This action will exercise a greater downward thrust upon the die-supporting head '75 than the upward thrust produced thereon in the cylinder 91 due to the leverage obtained by the particularpivotal arrangement of the rock arms 83.

The ejector die'section 60" will also be positioned and maintained in operative engagement with the sprue die section 60' by the toggle mechanism 103 which will have been extended by' the rotating movement of the rock arms 83 in a manner hereinbefore described and the ejector pins 64 will be positioned with their lower ends in registration with thewall of the die cavity to form a substantially smooth continuous surface therein. Now, by assuming that the delivery pct 31 is approximately full of molten metal, it is evident that by manipulating the lever 140 to move the piston 124 in the piston chamber 119 to the right in Figure 4 to the limit of its inward stroke that the upper end of the plunger cylinder 11 will be cut off from the pressure inlet 130 and be connected with the adjacent exhaust port 131 and, at the same time, the other or lower end of the cylinder will be connected with the pressure fluid entering through the valve inlet port 130 which will cause the piston 20 and, therefore, the plunger 23 to be moved upwardly and thereby positively force the molten metal from the delivery pot through the gate 61 into the die cavity.

This upward movement of the piston 20 will continue until the die cavity has been completely filled with the molten metal at which time the upward movement of the plunger and piston will be arrested, which will maintain the molten metal in the die under a very high degree of pressure and thus force out any air from the molten metal which may have been collected therein during the previous operations and thereby produce a very high'grade of castin: having an especially smooth surface and which is free from air holes.

Although the cylinder 11 and piston 20 for operating the plunger 23 are much larger in diameter than the cylinders 91 and piston 90 for operating the die 60 and maintaining said die in casting relation with the delivery pot, it will be remembered that both of these cylinders are connected with the same source of pressure supply at the control valve 19 and, therefore, each of the

pistons

20 and 90 are actuated from liquid, as oil, having the same pressure per square inch which will cause the piston 90 and the die 60 connected therewith to resist the upward thrust of the piston 20 and the plunger 23 and cause said piston 20 and plunger 23 to come to an at rest position as the two

pistons

20 and 90 reach a balanced or static condition, even though the smaller piston 90 did not operate as it does through the leverage afforded by the pivotal arrangement of of the rock arms 83.

After the casting has been formed, the lever 140 will be manipulated to move the piston 124 to the opposite end of the piston chamber 119.

As the piston moves along the chamber '119, thepiston 20 and plunger 23 will first be returned to the normal down position due to the port 16 being cut ofi from the pressure side of the valve 19 and connected with the exhaust port 131 and the cylinder port 15 and conduit 17 connected with the valve inlet port 130. By the time the plunger commences its return downward stroke, what excess metal remains in the delivery not after the die cavity has been filled, will be solidified and as a portion of the metal will, of course collect in the recess 59 at the upper end of the deliverypot, this metal will remain at the upper portion of said pot in contact with the sprue contained in the sprue passage 61.

As the control valve piston 124 continues its return movement, liquid under high pressure will next be admitted through the conduit 101 to the lower end of the die-actuating cylinder 91 which will cause the pistons 90 to travel upwardly and thereby lift the die 60 from the upper face of the plunger box sections 25 wherein remains the surplus metal not used in making the casting. As this surplus metal is by now solidified, it will be rigidly held in the plunger box by the recess 59, and the sprue will be broken therefrom at its smallest sectional area.

At about the time the die 60 has traveled far enough to cause this breaking of the sprue, the screws 114 connected with the lings 104 will have traveled the length of the elongated slots 115 in the rock arms 83 and this will cause the links 104 to be rocked about the pins 85 with the rock arms 83 during the remainder of the travel of said arms which will cause the ejector die section 60" to travel upwardly away from the sprue die section 60 due to the folding action of the toggle mechanism 103 thereby opening the die 60 and as the piston reaches the end of its upward stroke cause the casting to be removed from the die by the action of the ejector pin 64 in the manner hereinbefore described. In the meantime, as the control valve piston 124 reaches the limit of its outward stroke, fluid under pressure will be admitted through the ports 47 to the upper ends of the respective cylinders 43 thereby causing the downward movement of the pistons 44 contained in said cylinders and the consequent outward movement of the respective plunger box sections 25 which will release the excess casting material collected in the upper portion of the delivery pot in the manner hereinbefore described.

The machine is now ready to begin the operation for making the next casting.

The lever 140 is first actuated to move the piston 124 inwardly to connect the lower ports 48 of each of the plunger box actuating section cylinders 43 with the pressure side of the valve 19. This will cause the upward movement of the pistons 44 contained therein and the return of the plunger box sections 25 into cooperative relation to form the delivery pot 31. Molten metal may now be poured by any suitable means, herein not necessary to describe, into the delivery pot 31 after which the piston 124 is moved to connect the upper end of the die-actuating cylinder 91 with the fluid under pressure which will cause the

die sections

60 and 60 to return to the casting relation with the delivery pot and with each other.

The machine is now in the position illustrated in Figure 2 and the cycle of movement just described may be repeated for each casting desired.

Although there has been shown and-particularly described the preferred embodiment of this invention, it is not wished to be limited to the exact details and arrangement of the construction shown as various changes may readily be made without departing from the spirit of this invention as set forth in the appended claims.

I claim:

1. ma die-casting machine, a delivery pot having an outlet opening and comprising a plurality of box sections, means for moving the said sections into co-operative relation to form the delivery pot, a die movable into and out of casting relation with the delivery pot and adapted to form a closure'for the outlet opening, and a plunger adapted when the box sections are in cooperative relation, to eject metal from the pot into said die.

2. In a die-casting machine, a base, a plunger mounted for longitudinal movement in said base, a plunger box provided with an opening therethrough to form a delivery pot having substantially the same cross sectional area as the plunger for receiving said plunger, a die movable into casting relation with one end of said delivery pot to form a closure therefor, and means for maintaining the die in casting relation with the delivery pot during the movement of the plunger.

3. In a die-casting machine, a sectional delivery pot having an outlet, a die having a sprue opening, means for moving said die to bring the sprue opening thereof into casting relation with said outlet, a plunger mounted for reciprocative movement in the delivery pot for ejecting molten metal from said pot through the sprue opening into the die, means provided in the delivery pot for maintaining the excess metal at the forward end thereof during the return movement of the plunger, and means for actuating said delivery pot sections to release said excess metal.

4. In a die-casting machine, a sectional delivery pot having one end normally open, a die having a sprue opening, means for moving said die to form a closure for the delivery pot and to bring the sprue opening thereof into registration with said pot, means for ejecting the molten metal from the delivery pot through the sprue opening into the die, means provided in the delivery pot for maintaining the excess metal in the pot as the die is moved from engagement therewith, and means for actuating said delivery pot to release said excess metal.

5. In a die-casting machine, a base, a delivery pot, a sectional die member and a die-supporting head mounted on said base for rectilinear movement toward and from said pot, means securing one of the die sections to the head in fixed spaced relation thereto, means slidably supporting the other die section intermediate the firsimentioned section in said head, operating means including a toggle mechanism connecting the head with said second-mentioned die section for producing relative movements of the die sections toward and from each other, and separate means actuated by the operating means and pivotally connected to the base and to the head for actuating said head to bring the die sections into casting relation with the pot.

6. In a die-casting machine, a base, a delivery pot, a sectional die member, die-supporting means mounted on the base and movable toward and from said pot, operating means connected with the die-supporting means for moving said die sections into and out of cooperative relation with each other, and separate means pivotally connected with the base and with the supporting means and actuated by said operating means for bringing the die sections into casting relation with the pot.

'7. In a die-casting machine, a base, a delivery pot supported by the base, a sectional die member, guide means mounted on the base, a die supporting head mounted on said guide, means for longitudinal movement toward and from said pot, means rigidly connecting said head with one 01' the die sections, a toggle mechanism connecting the head with the other die section, operating means mounted on the head for actuating the toggle mechanism to produce a relative movement of the die sections toward and from each other, and means pivotally connecting said head with a fixed support and operably connected with the operating means for actuating said head to move the die sections into and out of casting relation with the delivery pot.

8. In a die-casting machine, a base, a delivery pot supported by said base, a sectional die member, a die-supporting head mounted for longitudinal movement towards and from said pot, means rigidly connecting said head with one of the die sections, a toggle mechanism connecting the head with the other die section, actuating means mounted on said head, a rock armoperably connected with the actuating means and pivotally connected with said head and with the base to cause the die sections to be moved into and out of casting relation with the delivery pot, and means connecting the rock arm with the toggle mechanism for operating said toggle to produce a relative movement 01' the die sections and permit an initial movement of the die sections in unison as said sections are moved out of engagement with the delivery pot.

9. In a die-casting machine. a movable sprue die-supporting plate, a movable ejector die-supporting plate, a plurality of guide rails, a head member mounted for longitudinal reciprocative movement upon the guide rails, said head being rigidly connected with one of said plates to move therewith, a tog le mechanism connecting the head with the other die-supporting plate, a cylinder mounted on the head, a piston movable in said cylinder, pivoted supporting rock arms rotatably mounted on said head and operably connected with said piston to produce a retarded relative movement of the head and piston to thereby effect the movement of the head and die-supporting plates along said rails, means connecting said rock arms with the toggle mechanism whereby said toggle mechanism will be actuated to effect a relative movement of said die plates after an initial movement of said rock arms, and means for actuating said pistons.

10. In a die-casting machine, plunger box sections adapted to be moved into operative relation to form a delivery pot, a die movable into casting relation with said delivery pot when said sections are in operative relation, a plunger adapted to eject metal from the delivery pot into said die, separate fluid pressure actuated means connected with said die, plunger and each of the plunger box sections, and a single valve mechanism adapted to control the flow of the fluid to cause the successive operations of said plunger, die and plunger box sections.

11. In a die-casting machine, a delivery pot having an outlet and comprising a plurality of box sections, means for moving said sections into cooperative relation to form the delivery pot, a die adapted to form a closure for said outlet, and means for ejecting the metal from the delivery pot. when said sections are in operative relation into said die.

12. In a die-casting machine, a delivery pot having an outlet and comprising a plurality of box sections movable into and out of cooperative relation to form the delivery pot, a die adapted to form a closure for said outlet, means for releasably locking said sections against relative movement when in their cooperative relation, and means for ejecting the metal from the delivery pot when said sections are in operative relation.

13. In a die-casting machine, a base, a delivery pot having an outlet opening and comprising a plurality of box sections slidably mounted on said base, means for simultaneously moving said sections into and out of cooperative relation to form the delivery pot, a die adapted to form a closure for said outlet, and a plunger mounted in said base adapted to eject the metal from the pot when said delivery pots are in cooperative relation.

14. In a die-casting machine, a base, a delivery pot comprising a plurality of sections slidably mounted on said base, rock arms pivotally mounted on the base at the outside of said sections, links pivotally connecting said arms with a delivery pot section, means for rocking said arms to bring the delivery pot sections into and out of cooperative relation, and means for limiting the pivotal movement of the arms in one di-- rection when said arms and links are in the extended position for releasably locking said sections against relative movement when in their cooperative relation, and means for ejecting metal from the pot when the die sections are in cooperative relation.

15. In a die-casting machine, a base, a delivery pot comprising a plurality of sections slidably mounted on said base, rock arms pivotally mounted on the base at the outside of said sections, links pivotally connecting said arms with a delivery pot section, fluid-actuated means connected'with said arms and means for admitting fluid under pressure to said fluid-actuated means to cause the delivery pot sections to move into and out of cooperative relation, and means for ejecting the metal from the pot when the die sections are in operative relation.

16. In a die-casting machine, a base, a delivery pot comprising a plurality of sections slidably mounted on said base, rock arms pivotally mounted on said base at the outside of said sections, links pivotally connecting said arms with the delivery pot section, cylinders pivotally connected with the base, pistons movable in said I cylinders and pivotally connected with said arms, and means for simultaneously admitting fluid under pressure into said cylinders to cause the delivery pot sections to simultaneously move into and out of cooperative relation.

17. In a die-casting machine, a movable sprue die-supporting plate, a movable ejector die-supporting plate, a plurality of guide rails, a head member mounted for longitudinal reciprocative movement upon the guide rails, said head being rigidly connected with one of said plates to move therewith, a toggle mechanism connecting the head with the other die-supporting plate, a cylinder mounted on the head, a piston movable in said cylinder, a rack secured to the piston to move therewith, pivoted supporting rock arms rotatably mounted on said head and having gear teeth meshing with said rack to produce a retarded relative movement of the head and piston to thereby effect the movement of the head and die-supporting plates along said rails, means connecting said rock arms with the toggle mechanism whereby said toggle mechanism will be actuated to efiect a relative movement of said die plates, and means for actuating said piston.

18. In a die-casting machine, a movable sprue die-supporting plate, a movable ejector diesupporting plate, a plurality of guide rails, a head member mounted for longitudinal reciprocative movement upon the guide rails, said head being rigidly connected with one of said plates to move therewith, a toggle mechanism connecting the head with the other die-supporting plate, a. cylinder mounted on the head, a piston movable in said cylinder, a rack secured to the piston to move therewith, pivoted supporting rock arms rotatably mounted on said head and having gear teeth meshing with said rack to produce a retarded relative movement of the head and piston to thereby efiect the movement of the head and die-supporting plates along said rails, said rock arm having a pin and slot connection with the toggle mechanism whereby said toggle mechanism will be actuated to efiect a relative movement of said die plates after an initial movement of said rock arms, and means for actuating said piston.

19. In a die-casting machine, a base, a plurality of guide rails mounted on said base, a head member mounted for longitudinal reciprocative movement upon the guide rails, a sprue diesupporting plate rigidly secured to said head to move therewith, an ejector die-supporting plate slidably mounted on said guide rails, a toggle mechanism connecting the head with the ejector die-supporting plate, a cylinder mounted on the head, a piston movable in said cylinder, a rack secured to the piston to move therewith, supporting rock arms pivotally connected with the base and rotatably mounted on said head, said rock arms having teeth meshing with said rack to produce a retarded relative movement of the head and piston to thereby effect the movement of the head and die-supporting plates along said rails, means connecting said rock arms with the toggle mechanism whereby said toggle mechanism will be actuated to efiect a relative movement of said die plates, and means for actuating said piston.

20. In a die-casting machine, a plurality of box sections mounted for movement toward and from each other, a plunger mounted intermediate said sections, means for producing relative movement of the box sections and plunger to form a delivery pot having an outlet, and means for actuating said plunger to eject metal from the pot through said outlet.

21. In a die-casting machine, a plurality of box sections mounted for movement toward and from each other, a plunger mounted intermediate said sections, and operating means for successively producing relative movement of the box sections and plunger to form a delivery pot having an outlet and for actuating said plunger to eject metal from the pot through said outlets.

NATHAN LESTER.