US3863705A

US3863705A - Sand blow reservoir for a foundry molding machine

Info

Publication number: US3863705A
Application number: US298297A
Authority: US
Inventors: Barry G Leeson
Original assignee: Sherwin Williams Co
Current assignee: Sherwin Williams Co
Priority date: 1972-10-17
Filing date: 1972-10-17
Publication date: 1975-02-04
Anticipated expiration: 1992-02-04

Abstract

A foundry mold or core blowing machine which includes a blow reservoir from which sand is blown into a mold or core box, the reservoir including a fixed top and bottom with a cylindrical housing journalled for axial rotation therebetween, and fixed scraper blades mounted adjacent the interior of the housing with arms on the blades projecting inwardly to maintain the sand therein in flowable condition.

Description

United States Patent 1191 1111 3,863,705 Leeson [4 1 Feb. 4, 1975 [54] SAND BLOWRESERVOIR FOR A FOUNDRY 2,943,656 7/1960 Wakeman 144/208 B MOLDING MACHINE 3,080,898 3/1963 Schnyder 1 144/208 B 3,253,304 5/1966 Hatch 164/12 Inventor: Barry Leeson, y Village, 1 3,288,441 11/1966 Bergstrom 259/88 x Assignee: The sherwimwiuiams p y 3,556,195 l/l97l Lund.... 164/201 X Cleveland, Ohio P E F S H rtmary xammerranc1s usar [22] Flled: 1972 Assistant Examiner-John S. Brown [211 App] 293,297 Attorney, Agent, or Firm-Donnelly, Maky, Renner &

Otto

[52] US. Cl 164/202, 259/88, 432/118 [51] Int. Cl. 1322c 15/24 [57] ABSTRACT [58] held of 2 9 3 25 A foundry mold or core blowing machine which in- 164/ 6 Z cludes a blow reservoir from which sand is blown into a mold or core box, the reservoir including a fixed top and bottom with a cylindrical housing journalled for [56] References cued axial rotation therebetween, and fixed scraper blades UNITED STATES PATENTS mounted adjacent the interior of the housing with 131,821 10/1872 Hutchins 259/88 X arms on the blades projecting inwardly to maintain the 2,045,170 6/1936 Whipperman 432/118 X sand therein in flowable condition. 2,774,236 12/1956 Gill 259/88 X 2,838,290 6/1958 Simpson 259/88 X 12 Claims, 5 Drawing Figures This invention relatesgenerally as indicated to a foundry molding machine and more particularly to a foundry mold or core blowing machine of the type wherein sand is blown from a reservoir into a mold or core box. Reference may be made to Hatch US. Pat. No. 3,253,304 dated May 31, I966 for a disclosure of a machine of the type in which the present invention may find utility.

In mold or core blowing machines sand is usually mixed with a resin or binder which cures after formation of the mold or core to provide a sand article which may be handled. Certain sand binders such as sodium silicate make the sand mix particularly difficult to blow from the reservoir into the mold or core box. One of the problems encountered in such machines is sand buildup on the walls of the reservoir which chokes down the center opening to the extent that sand does not feed properly through the reservoir refilling the same, particularly above the blow plate. Attempts have been made in the past to solve these problems by providing the reservoir with interior agitator blades or arms which rotate. Rotary internal agitators are seen,

for example, in Herbruggen US Pat. No. 3,439,733

dated Apr. 22, 1969. Such mechanisms generally require shafts or gears projecting into the reservoir and in many cases, because of space limitations, such interior rotating agitators cannot be provided.

The present invention provides a satisfactory solution to the problem by incorporating stationary scraper blades in the reservoir and rotating the cylindrical housing thereof.

A principal object of the present invention is the provision of a machine which will make high quality molds or cores from hard to blow sand mixes.

Another principal object is the provision ofa mold or core blowing machine having a blow reservoir which prevents sand build-up on the interior of the reservoir wall.

It is also an object to provide such machine wherein the reservoir rotates and the arms or blades therein are stationary.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

FIG. 1 is a top plan view of the reservoir carriage of the foundry mold or core blowing machine in accordance with the present invention, the reservoir carriage plate being shown in phantom lines;

FIG. 2, is a side elevation of the reservoir carriage of FIG. 1, partially broken away and in section seen from the line 2-2 of FIG. 1;

FIG. 3 is a fragmentary end elevation of the reservoir carriage as seen from line 33 of FIG. 2;

FIG. 4 is a horizontal section of one of the reservoirs in the carriage as seen from the line 4-4 of FIG. 2; and

FIG. 5 is a fragmentary vertical section of the reservoir of FIG. 4 taken substantially on the line 5-5 thereof. 4

Referring first to FIGS. 1, 2 and 3, it will be seen that the machine of the present invention includes a carriage plate 10, from which sand reservoir II is dependently mounted. The reservoir I! actually is two side by side reservoirs I2 and I3, as seen more clearly in FIGS. 1 and 3. As seen in FIG. 3, the carriage plate 10 includes lateral extensions 15 on each side thereof, supporting the carriage plate between rails 16 which ride on rollers 17 mounted on fixed rails 18. Accordingly, the reservoir II, as well as the carriage plate 10 is mounted for movement to the right and left as viewed in FIGS. 1 and 2, and toward and away from the viewer, as viewed in FIG. 3. Shuttling movement of the carriage as aforesaid, is accomplished by a piston cylinder assembly, not shown, alternately to position the carriage plate openings 19, one for each of the reservoirs, beneath a sand source and a blow valve. When beneath the blow valve assembly, the mold or core box is clamped against the

blow plates

21 and 22, on the reservoirs l2 and 13, respectively, and this clamping action also clamps the reservoir against the blow valve assembly. This aspect of the operation of the machine is the same as in the aforenoted Hatch US Pat. No. 3,253,304. Reference may be had to such Hatch patent for a complete disclosure of the sand source, blow valve assembly, the shuttling carriage, and the clamping action.

Each of the two reservoirs includes an upper rectangular plate 25, a lower rectangular plate 26 and a barrel or cylindrical housing 27, journalled therebetween as seen in FIG. 2. The upper plate 25 is secured to the carriage plate 10 by suitable large fasteners 28. A ball bearing assembly 29 is held in place by bearing retainer 30, held to the upper plate 25 by fasteners 31. A seal is provided at 32 between the plate 25 and the upper end of the barrel 27.

Similarly, the ball bearing assembly 34 is provided between the lower end of the barrel and the plate 26 held in place by bearing retainer 35, which is secured by fasteners 36 to the lower plate 26. A seal 37 is provided between the lower plate 26 and the lower end of the barrel 27.

The upper and lower plates of each reservoir are firmly held relative to each other by four corner tie rods 40, the upper ends of which fit within collars 41, while the lower ends are shouldered and threaded into collars 42, such collars being welded to the upper and lower plates, respectively. Fasteners 43 secure the tie rods to the upper plate. Such tie rods eliminate axial or lateral loading of the bearings 29 and 34 during the clamping, the blow, or the shuttling of the carriage.

Secured to the underside of each plate 26 is a flared housing 45 of the weldment construction shown in FIG. 2, to which the blow plate assembly 22 is secured. As seen, the housing may be of a double-wall construction to permit circulation of a cooling fluid therethrough, which may be supplied through the nipples indicated at 46. The blow plate assembly may also be provided with coolant passages seen at 47 which extend in a serpentine fashion about a plurality of sand nozzles 48.

Each barrel 27 has welded to the OD thereof a drivechain sprocket seen at 50, the sprockets on each barrel being horizontally aligned. Such sprockets are also horizontally aligned with drive sprocket 51 which is mounted on the output shaft 52 of worm gear reducer 53. The input shaft of the reducer seen at 54 is connected through coupling 55 to the shaft 56 of drive motor 57. The reducer is supported at each end by

brackets

59 and 60 from plate 61 while the motor is dependently supported by brackets 62 from the same plate, the motor being secured to the brackets by fasteners 63 incorporating suitable motor mounts.

A take-up idler sprocket 65 is mounted for rotation on the end of take-up slide 66, which is adjustably secured in take-up bracket 67. Two clamping fasteners 68, extend through an elongated slot 69 in the take-up slide. The bracket 67 also includes an adjusting screw 70, the tip of which bears against the slide. The position of the take-up sprocket 65 may be controlled by loosening the clamping fasteners 68, repositioning the slide with the aid of the adjusting screw 70, and then tightening the clamping fasteners. The take-up sprocket 65 is, of course, horizontally aligned with the sprockets 50 on the OD of the two barrels 27, and also the main drive sprocket 51. A roller-type drive chain 72, seen in FIG. 1, having the heart-shape path indicated connects the various sprockets to rotate the barrels 27 of the two reservoirs in the direction of the arrows 73 and 74, when the drive sprocket 51 rotates in the direction of the arrow 75. Such rotation is, of course, controlled by energization and de-energization of the motor 57.

As seen more clearly in FIGS. 4 and 5, each reservoir is provided with two scraper arms indicated at 76 and 77. Such scraper arms are generally L-shape with the relatively short lower leg of each being secured by the fasteners 78 to the under side of the lower plate 26. The major vertical extent 79 of each blade includes a knife edge seen at 80 in FIG. 4, which is formed by relieving the radially interior side only of the blade. Each blade is also provided with two horizontally extending arms, indicated at 82 and 83 for the blade 76, and at 84 and 85 for the blade 77. In elevation the blades thus alternate from side to side. Each such horizontal blade or arm 82 through 85 is provided with a knife edge 86, facing against the direction of rotation of the barrel 27, as indicated by the arrow 74. Aside from the difference in elevation of the horizontal arms, the

scraper arm assemblies

76 and 77 are identical in form.

In operation the dual reservoir, when retracted, will be filled with sand through the plate openings 19, usually with a metered amount. The reservoir will then be shuttled to a position beneath the blow valve assembly whereupon the mold or core box is clamped against the blow plate assembly, which in turn clamps the reservoir against the blow valve assembly. At this point, the blow valve is opened forcing the sand through the nozzle openings 48 into the vented mold or core box. The blow portion of the cycle may last approximately 2 seconds and the speed of the drive is selected to obtain preferably, one complete revolution of the barrels for such two second blow interval. This may be accomplished by obtaining a drive speed of approximately 30 revolutions per minute. Accordingly, in preferred form, a control system is provided so that the reservoir barrels will begin to rotate with the initiation of the blow and will stop when the reservoir has completely exhausted.

In any event, there is provided a foundry molding machine utilizing an improved blow reservoir which will prevent sand build-up on the walls of the reservoir, which would normally tend to choke down the center opening. It has been found that with the present invention the machine will efficiently utilize difficult to blow sand mixes such as those employing sodium silicate the binder.

What is claimed is:

l. A sand blow reservoir for a foundry molding or core blowing machine wherein said reservoir is initially charged with sand which is subsequently blown from said reservoir into a mold or core box. said reservoir comprising a selectively rotatable housing and agitation means in said housing fixed with respect thereto, said housing being rotated during said blowing to assist the agitation means in maintaining the sand in said housing in a flowable condition, thereby uniformly to feed the sand to the mold or core box, said agitation means including scraper arms mounted on one of said ends and positioned closely adjacent the interior of said cylindrical housing, and radially inwardly extending blades on said scraper arms.

2. A reservoir as set forth in claim 1 wherein said scraper blade has a leading surface tapered radially inwardly in the direction of housing rotation, such tapered surface having a knife edge immediately adjacent the interior surface of the housing to force the sand radially inwardly during housing rotation.

3. A foundry molding machine having side by side sand reservoirs to receive sand to be blown into a mold or core box, each reservoir including a cylindrical member with stationary scraper blades being mounted to extend into the cylindrical member adjacent the interior surface thereof, and a single drive means to rotate the cylindrical member of each reservoir during sand blowing to assist the scraper blades in maintaining the sand in a flowable condition in such housing.

4. A machine as set forth in claim 3, wherein said drive means comprises a drive motor and a drive chain interconnecting said motor and said cylindrical members, said drive chain extending around both said cylindrical members.

5. A machine as set forth in claim 4, including aligned sprockets secured to the exterior of each cylindrical member, said drive chain being in mesh therewith.

6. A foundry molding machine having side by side sand reservoirs to receive sand to be blown into a mold or core box, each reservoir including a cylindrical member with stationary scraper blades being mounted to extend into the cylindrical member adjacent the interior surface thereof, drive means to rotate the cylindrical member of each reservoir, said drive means comprising a drive motor and a drive chain interconnecting said motor and said cylindrical members, said drive chain extending around both said cylindrical members, aligned sprockets secured to the exterior of each cylindrical member, said drive chain being in mesh therewith, and a take-up sprocket between said cylindrical members to form a heart-shape path for said chain around said cylindrical members.

7. A sand blow reservoir for a foundry molding machine comprising ends vertically spatially fixed one above the other, the lower of said ends including a blow plate and the upper a fill opening through which the reservoir is charged with sand, a cylindrical housing journalled for rotation between said ends, and at least one fixed scraper blade secured to one of said ends and extending from said one end axially into said housing adjacent the interior surface thereof.

6 tive to rotate said housing.

11. A reservoir as set forth in claim 7, including tie rods extending between said ends to hold the same in fixed spatial relation.

12. A reservoir as set forth in claim 7, including means mounting said reservoir on a carriage for horizontal shuttling alternately between a sand fill and sand blow position.

Claims

1. A sand blow reservoir for a foundry molding or core blowing machine wherein said reservoir is initially charged with sand which is subsequently blown from said reservoir into a mold or core box, said reservoir comprising a selectively rotatable housing and agitation means in said hoUsing fixed with respect thereto, said housing being rotated during said blowing to assist the agitation means in maintaining the sand in said housing in a flowable condition, thereby uniformly to feed the sand to the mold or core box, said agitation means including scraper arms mounted on one of said ends and positioned closely adjacent the interior of said cylindrical housing, and radially inwardly extending blades on said scraper arms.

8. A reservoir as set forth in claim 7 wherein said scraper blade has one tapered surface adjacent the interior cylindrical surface of the housing to force the sand inwardly during rotation of such housing.

9. A reservoir as set forth in claim 7 wherein said scraper blade includes radially inwardly extending arms.

10. A reservoir as set forth in claim 7 wherein said housing includes a sprocket secured to the exterior thereof, and drive means engaging said sprocket operative to rotate said housing.