US2301819A

US2301819A - Knockout for die casting machines

Info

Publication number: US2301819A
Application number: US335814A
Authority: US
Inventors: Frank J Sambrook
Original assignee: Ternstedt Manufacturing Co
Current assignee: Ternstedt Manufacturing Co
Priority date: 1940-05-17
Filing date: 1940-05-17
Publication date: 1942-11-10
Anticipated expiration: 1959-11-10

Description

Nov. 10, 1942. J SAMABRQOK 2,301,819

KNOCKOU'I' FOR DIE CASTING MACHINES Filed May 17, 1940 2 Sheets-Sheet l Zinncntor Nov. 10, 1942. 'F'. J. sAMBRooK 2;30 l,8l9

KNOCKOUT FOR DIE CASTING MACHINES Filed May 17, 1940 2 Sheets-Sheet 2 Patented Nov. 10, 1942 z sorslc harem truce KNOCKOUT FGR DIE! CASTING MACHINES Frank J. Sambrook, Dearhorn, Mich, assignor to Ternsted-t Manufacturing Company, Detroit, Mich, a corporation of llfiichigan Application May 17, 1940, Serial No. 335,814

1 Claim.

This invention relates to an improved and si plifiedform of ejector and knock-out mechanism for die casting machines. An object of g the invention is to provide an ejector device which can be easily applied to existing machines and which will not only separate the finished casting from the die but will free it completely from the machine at the end of the operating cycle without the usual manual removal and handling of the casting which normally delays the succeeding casting operation and slows down production output.

A further object of the invention is to provide for the complete dislodgment of the casting from the machine by the use of two or more pins moving together at a uniform rate initially to avoid bending of the casting as its bond to the die is broken and thereafter at relatively different rates and to different extent for breaking the smaller surface bonds between the ejected casting and the ejector pins.

Additional objects and advantages will become apparent during the course of the following specification having reference to the accompanying drawings wherein Figure 1 is a side elevation with parts in section of a portion of a die casting machine having the invention applied thereto; Figure 2 is an enlarged sectional view showing the dies and ejector mechanism in fully opened position and Figures 3 and 4 are detailed sectional views taken, respectively, on lines 3-3 and 4-4 of Figure 2.

The invention is especially adapted for use with the well known type of die casting machine having a vertical parting lin for the two part die and an automatic operating cycle which includes, in timed sequence, the closing of the dies, the injection of hot metal, the opening of the dies and the ejection of the casting from the die cavity. When the die halves are parted the casting sticks to one of the mold halves and also to the ends of the ejector pins exposed to the die cavity but is pushed out of the cavity by the automatic projection of the ejector pins. 01'- dinarily, the casting remains suspended within the space between the open dies until its bond on the pins is broken, usually by means of a suitable tool in the hands of the workman who needs to leave the controls at the rear of the machine and step up and lean toward the parted dies to take hold and remove the casting and then return to the controls for again putting the machine into operation. The elimination of this manual operation in accordance with the present invention will reduce hazard and work for the J operator as well as the time interval between succeeding casting operations and the resultant greater output per machine cuts down overhead costs and investments in additional equipment and floor space.

The machine illustrated in the drawings consists essentially of a pair of relatively movable die blocks I and 2 with the die 2 fixedly mounted on the frame upright 3 and provided with a sprue opening through which molten metal is delivered to the die cavity from the nozzle 4. In the closed position of the die a spreader 5 carried by the movable die I extends into the sprue opening and distributes incoming metal throughout the multiple die cavity. The movable die carriage 6 is slidably mounted on a number of horizontal guide bars I fastened at opposite ends in the frame upright 3 and a similar upright 8 and is actuated through a plunger 9 from a suitable power source such as a piston motor, for example.

The forwardly projecting die support IE! on the reciprocatory carriage 6 has an enlarged hollow head, in the front shouldered portion of which is mounted, as by set screws I I, the die block I and in the space I2 immediately behind the die block is slidably positioned the ejector plate It. Extending rearwardly from the plate I3 through suitable guide openings in th support It), is a rod I4 having a series of gear teeth on one side in mesh with a gear I5 located within a slot in the support I #3. The gear I5 is mounted on a stud or trunnion shaft I6 and is pinned or otherwise secured to a rock lover I! which extends beyond the support I!) and has its outer end coupled through a connecting rod I8 with the fixed upright 3. By reason of this operating connection the opening and closing movements of the dies are transmitted to project and retract the ejector plate It.

This ejector plate carries one or more ejector pins I9 directly connected thereto by threading an end of each pin into the plate, the projecting portion thereof being slidable in an opening through the movable die I and of such length that its tip or outer surface will lie flush with the die cavity when the pin is retracted. Another ejector or knock-out pin 20 is slidably mounted in the die block I and is projected forwardly by the ejector plate I3 through a motion moditying lever. Here again the relation of the parts is such that the tip surface of th pin 20 lies flush with the die cavity in retracted position and the pin is moved to this retracted position upon closing of the dies by its engagement with the tip of a pusher pin 2|, aligned therewith and fastened in the stationary die 2.

The opening in the movable die 8, which slidably receives the pin 20, is counterbored at its rear end and the resulting shoulder affords a stop to be engaged by a peripheral flange 22 on the pin to limit outward movement of the pin. At its inner end the pin 20 engages the free end of a lever 23 located within a pocket in the rear face of the die i and fulcrumed on a pivot stud 24 carried by an insert or mounting bracket 25 fixed to the die I. The rear edge of the lever 23 is formed to V-shape and the point of convergence afiords an abutment pad indicated at 26 for engagement with the ejector plate l3 at a predetermined point in the range of forward movement of the ejector plate l3. At the fully retracted position of the ejector plate the pad 26 is out of contact and the ejector plate is in engagement with the free end of the lever as shown in Figure 1.

After the hot metal has been injected into the die cavity the dies are parted and the relative movement is transmitted to the ejector plate through the link l8 causing it to move forward. In the initial portion of the range of travel the motion is transmitted from the plate [3 directly to the ejector pins l9 and 20 so that the several pins are projected outwardly in unison at the same rate to dislodge the casting from the die cavity as indicated by the broken lines in Figure 2. As the lever 23 is swung forward through this initial range, the abutment pad 26 is brought into engagement with the ejector plate and thereafter the action of the lever multiplies the motion transmitted to the pin 29 and the pin 20 moves faster and farther than do the pins I9. In this final portion of the range of travel of the ejector plate l3 the differential movement of the ejector pins cocks or tilts the casting with reference to the tip surfaces of the pins and causes the bond of the casting to the pins to be broken in the manner shown by the full lines in Figure 2. Thereupon the casting drops from between the dies and falls into a suitable receiver, such as a tray 2?, in the nature of an inclined chute on which the casting can slide laterally from the machine into a quenching tank or the like.

As soon as the operating cycle is complete the machine is ready for the next casting operation and there is eliminated any need for the operator to leave his controls at the rear of the machine. From his control station the operator may look into the dies and observe the condition of the casting and the action of the ejection mechanism by the use of a suitable mirror (not shown) positioned opposite the parting line at the proper angle to give the reflected image.

I claim:

In a die casting machine having separable dies to one of which dies the formed castings have a tendency to cling, means operable after die-separation for positively dislodging the formed casting from the die to which it tends to cling, comprising; a plurality of ejector pins projectable with respect to the matrix surface of said die, means for effecting initial identical projection of said pins for incipient dislodgment of said casting, and pin-motion-modifying means actuated by said last-mentioned means after said incipient casting dislodgment for efiecting subsequent projection of one of said equally-initially-projected pins at a materially greater rate than others thereof to positvely cook the casting and effect its facile final dislodgment from said die.

FRANK J. SAMBROOK.