US1392697A - Molding-machine - Google Patents

Description

1. B NEESHAM.

MOLDING MACHINE.

APPLICATION FILED JUNE 10. 1919.

1,392,697, Patented 001;. 4, 1921.

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JOHN BIRCH NEESHAM, OF GLASGOW, SCOTLAND.

MOLDING-MACHINE.

To all whom it may concern:

Be it known that I, JOHN BIRcH NEE- SHAM, 36 Cumlodden Drive, Maryhill, Glasgow, Scotland, a subject of the K ng of Great Britain, have invented certain new and useful Improvements in .Molding-lilachines, of which the following is a speclfication;

This invention relates to molding machines, ior foundry use, of the jarring type in which there is a main jarring table and a turnover table the jarring table being operated by means of fluid pressure controlled by a jarring valve which latter is, itself, controlled by a pilotvalve.

In the specification of my prior United States Patent No. 1,318,101, dated October 7, 1919, there is described an arrangement in connection with the jarring valve whereby, when pressure fluid is admitted to the usual side cylinders of the machine to raise the turnover table, fluid pressure is automatically and simultaneously supplied directly to the jarring valve and caused to act thereon in such manner that the jarring valve is locked, thereby rendering the machine I"oolproof by preventing possibility of the jarring valve being operated accidentally or otherwise by the admission of pressure fluid to the pilot valve. 4

The present invention relates to an improvement on the aforesaid invention and it consists in providing means whereby the pilot valve can be easily and readily locked, to prevent the jarring valve being operated at the times when fluid pressure is admitted to the side cylinders for the purpose of raising the turnover table preparatory to the drawing of a pattern or otherwise.

Under this invention the pilot valve is positively locked, simultaneously with the admission of fluid pressure to the side cylinders of the machine, by means of a piston or equivalent working in a small cylinder formed on or secured to the pilot valve casing this piston having a pin or projection capable of engaging in a hole or recess in the pilot valve. The piston is normally held out of action by means of a spring or equivalent and can be forced into action by the fluid pressure, as the same is admitted to the side cylinders of the machine. The cylinder within which the piston works is preferably connected for this purpose by a pipe connection or otherwise with the side cylin- Specification of Letters Patent.

Patented Uct. 4t, 1921.

1919. Serial No. 303,106.

ders or with the source of fluid pressure supply thereto.

in order that the invention may be clearly understood 1 have hereunto appended an eX- planatory drawing showing, in vertical section, the jarring valve with its pilot valve having my improvements applied thereto.

6n the drawings F is the jarring valve casing, a the jarring valve which is of the shuttle pattern and works within said casing, 0 a spring normally holding the valve depressed, b and limiting screws, 6 the fluid pressure inlet port and e the exhaust port. is the pilot valve, k a slot therein and 76 the limiting screw whose inner end is capable of engaging in said groove. 70 is the sand cap. J is a pipe for supplying compressed air to the underside of the pilot valve. m is a port at the bottom of the pilot valve, m a port common to the jarring valve casing and the pilot valve casing and communicating with the underside of the jarring valve, m a reduced part on the pilot valve and m a port in the casing G of the pilot valve.

Under the present invention I make the pilot valve casing with a cylindrical extension 0 having a passage 0 at one end communicating with the groove 70 in the pilot valve and an opening 0 at the other end communicating with a pipe D, indicated in dotted lines, which conveys fluid pressure (compressed air) to the side cylinders (not shown) of the machine. Slidably fitted in the cylinder 0 is a piston 10 which is normally held in the position shown by the action of a spring 9. The piston 39 has a reduced extension p which constitutes a lock mg pin.

It is obvious, with the arrangement shown, that when fluid pressure is admitted to the side cylinders of the machine by means of the pipe D the fluid pressure will simultaneously act upon the back of the piston p and force the piston inward against the action of the spring 9 thereby causing the pin p to enter the slot 7: and lock the pilot valve 70 against upward movement so that it will then be impossible for fluid admitted through the pipe J, by accident or otherwise, to act on the pilot valve 76 and raise it up to such an extent as to supply pressure fluid through the ports m and m to the jarring valve casing and so operate the arring valve a as to cause it to rise and open the exhaust 6 leading to the main cylinder of the machine (not shown) by passages. It 1s equally obvious that When the pressure in theplpe D is relieved the piston 39 will move back to its original position under the action of the spring g and thereby free the pilot valve 70 so that it can be operated in the usual manner.

Having now fully described my invention What I claim as my invention and desire to secure by Letters Patent is 1. In a molding machine of the type speci fled, a pilot valve and means, operable by fluid pressure, for positively locking same.

2., In a molding machine of the type specifled, a pilot valve having a slot therein, a locking pin and means, operable by fluid pressure, for causing the locking pin to engage the aforesaid slot.

3. In a molding machine of the type specified, a casing, a cylindrical extension in connection therewith, a pilot valve in said casing, a piston in said extension, means Whereby fluid under pressure may be admitted to said extension for operating said piston and means in connection with said piston for positively locking said pilot valve on the operation of the piston.

4:. In a molding machine of the type specifled, a pilot valve and spring controlled means, operable by fluid pressure, for positively locking same.

5. In a molding machine of the type specified, a pilot valve having a slot therein, a spring controlled locking pin and means, operable by fluid pressure, for moving the locking pin, against the action of said spring, into engagement with said slot.

6. In a molding machine of the type specilied, a pilot valve, means for limiting the movement thereof, and means, operable by fluid pressure, for positively locking said valve. v

7. In a molding machine of the type specified, a casing, a pilot valve in said casing having a slot therein, a cylindrical extension in connection With said casing, a piston in said extension, a locking pin in connection with said piston adapted to engage in said slot, means for admitting fluid under pressure to said casing and means for admitting fluid under pressure to said extension for operating the piston.

In testimony whereof I aflix my signature in presence of'two Witnesses.

' JOHN BIRCH NEESHAM;

Witnesses:

H. D; F ITZPA'IRIGK, MARY GREEN.

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