US3248762A

US3248762A - Device for preparing the opened mould of a casting machine for the next casting operation

Info

Publication number: US3248762A
Application number: US236666A
Authority: US
Inventors: Wagner Ernst
Original assignee: FIRM Gebr ECKERT MASCHINENFABR
Current assignee: FIRM Gebr ECKERT MASCHINENFABR; Firm Gebr Eckert Maschinenfabrik
Priority date: 1961-11-11
Filing date: 1962-11-09
Publication date: 1966-05-03
Anticipated expiration: 1983-05-03
Also published as: DE1206551B; GB983094A; CH409254A

Description

y 3, 1966 E WAGNER 3,248,762

DEVICE FOR PREPARING THE OPENED 'MOULD OF A CASTING' MACHINE FOR THE NEXT CASTING OPERATION Filed Nov. 9, 1962 2 Sheets-Sheet 1 INVENTOR ERNST WAGNER BY W/MW A7773 ATTORNEYS y 1966 E. WAGNER 3,248,762

DEVICE FOR PREPARING THE OPENED MOULD OF A CASTING MACHINE FOR THE NEXT CASTING OPERATION Filed Nov. 9, 1962 2 Sheets-Sheet 2 33 J zsji 36 \52 INVENTOR ERNST WAGNER ATTORNEYS United States Patent 6 Claims. in. 22-94 The invention relates to a device for preparing the opened mould of a casting machine for the next casting operation and more particularly to an automatic mechanism for stripping the finished workpiece off the mould halves.

Such an arrangement can preferably be obtained by producing a stripper which is movable parallel to the plane of the mould parts and has on the end facing the mould a brush and a nozzle for lubricant. It is particularly advantageous to control such a stripper in accordance with the closing movement of the mould.

' To attain this, the stripper according to another feature of the invention, is arranged movable between two limit switches which are alternately in engagement with a control earn movable with the stripper, one of which switches controls the starting and stopping movements of the stripper and the other reversal thereof.

To prevent damage to the mould when closing, in the event of the stripper still being between the mould halves, the invention also proposes to control the limit switch which effects the starting and stopping of the stripper by another switch actuated independently of the movement of the mould parts.

According to another suggestion of the invention, the complete removal of the casting from the mould is ensured by controlling the closing movement of the mould with the aid of a weighing device which only releases this movement when it .registers that the casting to be removed from the mould has the'proper Weight.

The stripping device according to the invention may consist substantially of a piston and a cylinder with a container and a spraying device for the lubricant-air mixture, the actual stripper, the wire brush and the nozzles being arranged on the piston.

The device is moreover so constructed that, the lubricant-air mixture is produced during the movement of the piston towards the mould and expelled during the movement away from the mould.

To prevent the lubricant and pressure medium for actuating the device from becoming mixed, it is also proposed to provide the piston with alongitudinal central bore extending over a portion of its length for receiving a tightly fitting pressure medium feed pipe, thus enabling the spraying arrangement to lead into the space between the piston and cylinder remote from the mould.

The spraying arangement itself may consist of a bore arranged in the bottom of the lubricant container and provided with a check valve for closing the container, the discharge nozzle of an air admission pipe being arranged in the proximity of its mouth located in the container in such a manner that a lubricant-oil mixture is formed by injection effect by the suction effect away from the container prevailing in the outlet bore.

A machine according to the invention is hereinafter described by way of example with reference to the accompanying drawings, in which FIG. 1 is a diagrammatic view of the device according to the invention, partly in section, and

FIG. 2 is a wiring diagram for the electirc control of the device illustratedin FIG. 1.

3,248,762 Patented May 3, 1966 The stripping device itself consist-s substantially of a stationary cylinder 4 in which a piston 5 is preferably driven and controlled by electro-hydr-aulic means and shiftable in the mold parting plane between the mould parts. The piston 5 has a longitudinal central bore extending through a considerable portion of its length. This bore serves for accommodating a presure medium feed pipe 19 which is connected to the pressure medium supply conduit at 18 and terminates at the end of the piston 5 facing the mould in a space 20 which is arranged between the piston 5 and the end of the pressure medium feed pipe 19.

The piston 5 carries on its lower end a wire brush 6 which is so constructed that, when moving between the open mould halves 1 and 2 it sweeps completely over the surfaces thereof.

At the upper end of the cylinder 4 a container 7 is provided for the medium for lubricating the mould halves and has at its lower end a narrow outlet bore 8. This bore is connected to the end facing the piston 5 by a check valve 9 which closes the container 7.

The outlet bore 8 is widened at the mouth at the container end so that the end of an air admission pipe 10 can be so arranged that, on suction being produced in the outlet bore 8, lubricant mixture is sucked into the space of the cylinder 4. i

If therefore the piston Sis moved in downward direction in the drawing, a mixture of lubricant and air will collect above the upper end face of the piston which, when the piston moves in the opposite direction, that is in upward direction, will pass out through the bore 11 thereof and through the nozzle 12 mounted on the lower end of the piston and be sprayed on to the two mould halves.

Also coordinated to the stationary cylinder 4 are two

limit switches

13 and 14 which control the movement of the piston 5 through the intermediary of a switch or control cam 15 connected therewith.

The device alsocomprises a switch 16 controlled by the closing and opening movements of the casting machine, which switch is actuated by a cam 17.

The arangement operates in the following manner:

The control of the opening and closing movements of the mould as well as the mold stripping device is effected by electrical means. As long as the mould is not completely open, the circuit for actuating the stripping device 4, 5 is broken because the switch 16 is then in its inoperative position. Only when the mould is completely open, as shown in FIG. 1, can the cam 17, whichis moved simultaneously with the mould half 2, come into engagement with the switch 16 and close the circuit for actuating the stripping device 4, 5. A condition is that the piston 5 is in its extreme upper position so that the switching or controlling cam 15 is in contact with the switch 13.

The piston is now moved downwards by introducing pressure medium into passage 18, with the result that the casting 3 is first stripped off the ejector pins 21 by the lower end of the piston 5 coming into contact with the dead head cone.

As soon as the piston 5 and with it also the'control cam 15 reach the lower extreme position, the cam comes into engagement with the switch 14 with the result that the movement of the piston 5 is reversed so that it returns into its initial position. In so doing it has cleaned the mould halves with the brush 6 and sprayed them with lubricant discharged from the nozzles 12. As soon as'the piston 5 has reached its extreme upper position the pump is switched onto idle running by the cam 15 and the piston 5 remains under pressure so that it is held in its upper extreme position.

During the movement of the stripper between the mould halves, the machine cannot close because the stripper is only operated when the command mould open is set.

A guarantee that the stripper has actually removed the whole of the casting from the mould can be obtained by coupling the mould closing movement with an arrangement which automatically determines the weight of the dropped casting and prevents the stripper from moving in the case of underweight. At the same time it is immaterial whether the stripper has not functioned at all or only incompletely.

The manner in which the device is operated is hereinafter described with reference to the individual switching operations and control elements:

The wiring diagram illustrated in FIG. 2 comprises five cooperating circuits which are fed by a common source of current 22.

The circuit 1 comprises the

wires

23, 24, 25, 26, 27, 28, 29 and 30. It leads from the source of current 22 via the switch 16, actuated by the cam 17, to the switch 31, controlled by the relay 32, and back to the source of current 22 via the coil of the relay 33.

The circuit 2 comprises the

wires

23, 24, 25, 34, 35, 36, 37 and 30. It also leads over the switch 16, then over the switch 38, controlled by the relay 33 as well as over the coil of the magnet 64 which controls the piston of the hydraulic plant.

The circuit 3 comprises the

wires

23, 24, 34, 40, 41, 42, 43, 44, 29 and 30. It leads over the limit switch 16, the switch 45 controlled by the relay 33 and the coil'of the relay 32 to the source of current 22.

The circuit 4 comprises the

wires

23, 24, 25, 47, 48, the portion of the wire 42 at the top in FIG. 2 of the drawings, which leads back to the source of current 22 via the coil of the relay 32 and then via the wire 43. The

limit switch 16, the switch 49 controlled by the relay 32 and the relay 32 itself are arranged in this circuit 4.

For the electro-hydraulic operation (FIG. 1) the device according to the invention has a piston 66 which is guided in the cylinder 67 in which it can assume two extreme positions. It is actuated by the magnet 64 which operates against a pressure spring 68 which, when the magnet 64 is in the dead state shown, presses the piston 66 under pretension into the left-hand extreme position, whereas the magnet, when in operative state, shifts the piston 66 into the extreme position on the right-hand side of the drawing against the action of the spring 68.

In the right-hand extreme position the piston valve causes the pressure medium coming from the pump 80 to flow along the path 70, through the valve, into the conduit 72 which leads to the upper connection 73 of the piston 4. There the pressure medium in the space 20 causes the piston 5 to move downwards. The return flow of the pressure medium then takes place from the cylinder 4 through the connection 75, the conduit 76, the path 77 through the valve and then through the conduit 78 back to the pressure medium container 79.

When the piston 66 is in the left-hand extreme position, the

hydraulic conduits

69 and 76, as well as 78 and 72 are interconnected so that the hydraulic circuit is reversed and the piston is pushed upwards.

The device operates in the following manner taking into consideration the individual switching operations and control elements:

When the piston 5 is in its extreme upper position its upper limit switch 13 is closed but can only become operative on the plant when the switch 54 in the circuit 5 is also closed.

As long as the mould is open the cam 17 acts on the limit switch 16 (FIGS. 1 and 2) with the result that the circuit 1 is closed. As the switch 31 of the relay 32 is closed when the relay 32 is currentless, the relay 33 is energized and closes the circuit 2 through the intermediary of the switch 38 so that the coil of the magnet 64 is energized and shifts the piston 66 towards the right (FIG. 1 of the drawing) against the action of the spring 68, with the result that the valve is set according to the through- 4 flow diagram on the right of the drawing so that the piston 5 is moved downwards.

As long as the magnet 64 holds the valve piston 66 in this position, the piston 5 moves downwards.

Simultaneously with the switch 38, the switch in the circuit 3 is also closed by the relay 33 so that this circuit is prepared for subsequent operation.

As the piston 5 commences its downward movement, the upper limit switch 13 is opened.

At the end of the downward movement, the piston 5 brings the cam 15 into contact with the limit switch 14 and closes it. However, this also effects the simultaneous closing of the circuit 3 because the switch 45 has already been previously closed by the relay 33. The relay 32 now receives current and closes the switches 49 and 54 and at the same time opens the switch 31, thereby breaking the circuit 1.

Another result is that the relay 33 becomes currentless and the

switches

38 and 45 open. As on the opening of the switch 38 the magnet 64 becomes currentless, the

spring 68 will bring the piston 66 into its left-hand extreme position whereby the hydraulic conduits from and to the cylinder 5 are so switched that the piston is loaded from below and is consequently moved upwards.

Simultaneously with the opening of the switch 31, the switches 49 and 54 were also closed with the result that the relay 32 holds back through the intermediary of the switch 49 while no effect is caused for the time being by the closing of the switch 54 because the upper limit switch 13 in the circuit 5 is still open.

As the relay 32 holds through the intermediary of the switch 49 itself, the previous opening of the switch after the closing of the lower limit switch 14 could cause no change in the positions of the

switches

31, 49 and 54.

At the commencement of the downward movement of the piston 5, the limit switch 14 returns to its initial position with the result, however, that it has no effect on the electric system at first because the switch 45 is already open.

As soon as the piston reaches its uppermost poistion it closes the upper limit switch 13 through the intermediary of the cam 15.

As the switch 54 is already closed, the coil is energized with the result that further control functions necessary for the sequence of operations of the casting machine can be carried out, for example, through the intermediary of the

switches

81 and 82. For example, the first circuit for closing the mould can be prepared by these contacts so that the mould closing movement can be initiated either automatically or by further manual operation.

Finally, however, it is also possible to control an electrically operating weighing device with the

switches

81 and 82 so that the mould closing movement can only take place when the stripping cylinder has arrived in its upper extreme position and when it has been ensured through the weighing device that the stripped casting has its correct weight and been removed from the weighing device.

If the mould is closed, the limit switch 16 also passes into its open initial position and thus breaks the circuit 4. The relay 32 can then drop and thus close the switch 31, opening at the same time the switches 49 and 54.

Through the opening of the switch 54, the relay 55 becomes currentless, its operation being now no longer necessary. At the same time, however, by the closing of the switch 31, the circuit 1 for repeating the operation of the stripping cylinder is prepared and can immediately be introduced again when the limit switch 16 again closes the circuit 1 with the mould completely open.

What is claimed is:

1. Apparatus for automatically stripping, cleaning and lubricating the mold halves of a casting machine between each molding cycle thereof comprising:

(A) a stripper member located adjacent to and reciprocable between the mold halves in the mold parting plane, said member carrying a brush surrounding said member and a nozzle, said nozzle being located at the outer end of said member and said brush being spaced therefrom;

(B) means operable only when the mold is open to cause said member to move between the mold halves to strip and clean the molding surfaces;

(C) means for retracting said member to its initial position beyond the mold halves;

(D) and means operable in response to said last mentioned means for spraying the mold halves with a lubricant through said nozzle as said member is retracted; so that the mold is first stripped and brushed and then lubricated.

2. Apparatus for automatically stripping, cleaning and lubricating the mold halves of a casting machine between each molding cycle thereof comprising:

(A) a cylinder having a piston therein, said piston extending out'of one end of said cylinder and positioned adjacent to and for movement between the mold halves in the mold parting plane, said piston including a nozzle at its outermost-end;

(B) a brush mounted on and surrounding said piston and positioned between said nozzle and said cylinder;

(C) valve means for admitting fluid under pressure to one end of said cylinder when the mold halves are separated for moving said piston outwardly thereof and past the mold halves to strip and brush the mold halves;

(D) means for admitting fluid under pressure to the, other end of said cylinder for retracting said piston to its starting position;

(E) and means operable only during retraction of said piston .to spray lubricant through said nozzle on said mold halves.

3. Apparatus as defined by claim 2 and including a lubricant reservoir in fluid communication with said one end of said cylinder so that movement of said piston out of said cylinder is eifective to draw lubricant into said end of said cylinder; and means connecting said nozzle to said end of said cylinder whereby when said piston is retracted, lubricant under pressure is forced through said nozzle.

4. Apparatus as defined by claim 1 including an electrical inter-lock between said valve means and the casting machine permitting operation of said piston only when the mould halves are separated from each other.

5. Apparatus as defined by claim 2 and including limit 6 switches positioned adjacent the ends of travel of said piston and connected to control said valve means.

6. Apparatus for automatically stripping, cleaning and lubricating the mold halves of a casting machine between each molding cycle thereof comprising:

(A) a cylinder having a hollow piston therein, said piston extending out of one end of said cylinder and terminating in a nozzle, said pistons being positioned adjacent to and for movement between the mold halves in the mold parting planes;

(B) brush means surrounding said piston and positioned between said nozzle and said cylinder, said brush being so sized, shaped and positioned that it will clean the mould halves during operation of said piston therebetween;

(C) means defining a fluid passageway through said piston opening to said nozzle and to the opposite end of said piston within said cylinder;

(D) a lubricant reservoir in fluid communication with said cylinder adjacent that end of said piston remote from said nozzle;

(E)' check valve means between said cylinder and said reservoir so that movement of said piston outwardly of said cylinder draws lubricant into said cylinder and movement of said piston into said cylinder forces lubricant through said passageway and out of said nozzle;

(F) and valve means for controlling the admission of fluid under pressure to opposite sides of said piston and said cylinder.

References Cited by the Examiner UNITED STATES PATENTS 327,033 1885 Stevens 22192 373,1 86 1887 Illingworth 22-192 805,299 11/1905 Kastenhuber.

1,643,392 9/1927 Mullaney.

2,253,651 9/1941 Ring 2294 2,347,972 5/1944 Scott et a1.

2,754,562 7/ 1956 Webb.

2,814,083 11/ 1957 Beyer 22-94 3,081,486 3/ 1963 Skvorc 22-94 .I. SPENCER OVERHOLSER, Primary Examiner.

M. U. 'LYONS, V. RISING, Assistant Examiners.

Claims

1. APPARATUS FOR AUTOMATICALLY STRIPPING, CLEANING AND LUBRICATING THE MOLD HALVES OF A CASTING MACHINE BETWEEN EACH MOLDING CYCLE THEREOF COMPRISING: (A) A STRIPPER MEMBER LOCATED ADJACENT TO AND RECIPROCABLE BETWEEN THE MOLD HALVES IN THE MOLD PARTING PLATE, SAID MEMBER CARRYING A BRUSH SURROUNDING SAID MEMBER AND A NOZZLE, SAID NOZZLE BEING LOCATED AT THE OUTER END OF SAID MEMBER AND SAID BRUSH BEING SPACED THEREFROM; (B) MEANS OPERABLE ONLY WHEN THE MOLD IS OPEN TO CAUSE SAID MEMBER TO MOVE BETWEEN THE MOLD HALVES TO STRIP AND CLEAN THE MOLDING SURFACES; (C) MEANS FOR RETRACTING SAID MEMBER TO ITS INITIAL POSITION BEYOND THE MOLD HALVES; (D) AND MEANS OPERABLE IN RESPONSE TO SAID LAST MENTIONED MEANS FOR SPRAYING THE MOLD HALVES WITH A LUBRICANT THROUGH SAID NOZZLE AS SAID MEMBER IS REAND THEN LUBRICATED.