US2661513A

US2661513A - Core blower

Info

Publication number: US2661513A
Application number: US244411A
Authority: US
Inventors: Relfe N Brewer
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1951-08-30
Filing date: 1951-08-30
Publication date: 1953-12-08
Anticipated expiration: 1970-12-08

Description

Dec. 8, 1953 R. N. BREWER 2,661,513

CORE BLOWER Filed Au 50, 1951 IN V EN TOR.

fiE/fe fY. Brewer BY Mai M M his zzarneys Patented Dec. 8, 1953 UNITED s TAT E s. PAT orrlcs Relfe N. Brewerf lfni:r: n?::fassignor ,m, Gen;

eral Motors Corporation, DetroitgMich -a cor.- porafion ofDelaware AppIicationAugust130, iesig ser iamol 244,411

1 Claim. (.01.. 32-

, 1 Thi'siinvention relates, 'toa coreblower used to blow sand into a "core mold which is inaccessible for tamping.

It is, therefore, the main object of the invention to provide a core blower which will uniformly eject a core sand mixture therefrom into a core mold.

A further object of the invention is to provide a core blower comprising an elongate tube having a predetermined inner diameter with an outlet at one end thereof to form a chamber, which may be filled with a core sand mixture. An upper attachment cap including an air nozzl is provided, which air nozzle emits pressurized air into the chamber in a direction horizontal to th main axis of the chamber whereby said mixture is uniformly forced into the outlet without channelling.

Further objects and advantages of the present invention will be apparent from the following description, wherein reference is made to the accompanying drawing, which shows in section a core blower in place on the core mold.

In the manufacture of cores for use in the casting of metals, core sand is mixed with molasses or some other suitable adhesive material and is placed in core molds and baked in order to form a baked sand core which may then be used to core out articles to be subsequently cast from metal. A distinct problem in the manufacture of baked sand cores is to uniformly fill molds which include reentrant angles therein, it being very diflicult to tamp the core sand mixture into the mold uniformly whereby the baked cores are nonuniform and often crumbly due to the fact that the density of the mixture as placed in the mold is non-uniform.

For this purpose, it is desirable to have a core sand blower wherein the molds are filled under pressure, which provides greater uniformity together with reduced production cost.

In order to provide a satisfactory core blower, it is necessary to design the apparatus so that the core sand mixture placed in the blower is uniformly emitted therefrom without channelling and the like, since it is quite apparent that if the mixture is channelled due to non-uniform pressure, the portion remaining in the blower hardens and is not as easily fiowable as other portions thereof, whereby non-uniformity is the obvious result.

In order to accomplish the ends desired, I have designed a core blower 20 shown in the drawing as assembled to a core mold 2| having a cavity 23 therein which is to be filled with core sand. The

blower; 24! consists of an elongate tubularmember 2:25 which provides aeavity .24 therein. .At the upper end of the member 22 there is a cap 26 which is locked to the tube 22 through any suitable means such as bayonet joint shown at 28. The cap 26 includes a fitting 30 threaded therein which is attached at its outer end by a tube 32 to a pressure source such as a compressor or the like. It is apparent that valve means, not shown, may be provided in the pressure tube 32 for controlling the action of the device. The fitting 30 is hollowed out at 34 and this portion of the fitting extends into the cavity 24. This lower portion has a plurality of apertures 36 spaced around the vertical walls thereof. In other words, pressurized air which is emitted from the fitting 30, passes in a direction perpendicular to the longitudinal axis of the cavity 24. Thus the upper portion of the cavity 24 i pressurized whereby sand therein is forced through the outlet opening 38 at the opposite end thereof into the cavity 23. The outlet 38 is merely an apertur in the tapered end of the tube 22, which end is tapered to provide satisfactory flow of sand and likewise to permit an easy attachment to the core mold orifice.

The direction of air emission from the fitting 30 is important to the success of the invention. If an aperture were provided in the end of the fitting 30, the pressurized air would tend to channel the sand, thereby forcing the center portion of the sand held in the cavity 24 through the outlet 38 while permitting the remainder of the charge to stay in the blower cavity 24. Obviously, if the sand mixtur includes a binder, this will tend to become dried out in view of the constant passage of air thereover, making the mixture of different flow characteristics whereby non-uni formity would be apparent in the cores. Also, it would be impossible to empty the cavity 24 of the sand therein, thereby causing considerable waste or necessitating mixing the remaining sand in the cavity with an additional charge in order to obtain a full cavity.

By having the orifices 36 perpendicular to the longitudinal axis of the cavity 24, the pressurized air in effect acts as a piston over the charge in said cavity 24 and uniformly forces the entire charge downwardly through the outlet 38.

Specifically, a core blower 10" long is preferably provided with an internal cavity diameter of about 1%. This diameter is of some importance since if the diameter is much greater than 1%", the piston effect of the air charge is lost. The specific length of the cavity is not too important but the diameter is a definite limitation which must be adhered to if satisfactory operation is to be obtained. For these reasons, a limit of the diameter of the core blower cavity to a diameter not greater than 1%" is necessary with the design shown, it being a proven fact that when the diameter of the cavity exceeds this figure, channelling becomes apparent and the core blower is of little use commercially.

While the embodiments of the present invention as herein disclosed, constitute preferred forms, it is to be understood that other forms Y References Cited in the file of this patent might be adopted.

What is claimed is as follows:

A core blower for use in filling core molds, comprising in combination; an elongate charging tube having an unrestricted internal diameter not in excess of 1 /2", open atone end and having 7.

an outlet orifice at the other end thereof,v a removable cap for said tube for closing the open end ting being closed at its inner end and including a plurality of radially located apertures in the extended wall thereof, said fitting being adapted to have the other end connected to a source of fluid pressure whereby fluid under pressure will enter said fitting and be directed into the tube perpendicularly to the longitudinal axis thereof so as to force the contents of the charging tube longitudinally wtihout channeling into a core mold.

RELFE N. BREWER.

UNITED STATES PATENTS Number Name Date 1,563,156 Burman Nov. 24, 1925, 1,910,417 Zeman May 23, 1933 2,556,618 Harrison et al June 12, 1951 FOREIGN PATENTS Number Country Date 601514 Great Britain May 11, 1948