US2535127A

US2535127A - Vibkatory conveyer for packing

Info

Publication number: US2535127A
Authority: US
Publication date: 1950-12-26
Anticipated expiration: 1967-12-26

Description

Dec. 26, 1950 J. FREl, JR

VIBRATORY CONVEYER FOR PACKING Filed May 2, 1947 Patented Dec. 26, 1950 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to a vibratory conveyor for packing finely divided material.

While the conveyor of my invention may be advantageously employed for the shaking down and packing of various types of divided material, it is particularly well adapted for use in connection with silica sand or the like, which is employed to form a mold for use in casting operations. When the article to be cast must be of precise dimensions and the material of which the articles are cast is extremely hard, it is important that they be cast accurately so that a minimum of grinding or other cleaning operations are required, since such operations are difficult, time-consuming and expensive. It is desirable, therefore, to prepare a mold which will provide a mold cavity having a smooth surface and a surface free of hollows produced by entrapped fluids, such as air or liquids, which attach themselves to the pattern during the formation of the mold. When the finely divided investment material, which is employed to form the mold, is distributed in fluid form about the pattern in a flask, bubbles of air or other gas entrapped in the investment material may attach themselves to the pattern and thereby displace the investment material at that location. Thereafter, when the mold-containing flask is heated to melt or burn out the pattern, the mold cavity has one or more unwanted hollows which will be filled with molten metal during the casting operation, with the result that the casting is imperfect. Expensive cutting or grinding operations may then be required to put the casting in usable form, or else it may be necessary to discard the casting entirely.

It is a principal object of my invention to remove from the investment material, as it is setting about the pattern, all gases which might spoil the configuration of the casting.

It is another object of my invention to cause the investment material to be closely and firmly packed throughout the mold and especially about the pattern so that the mold will be strong and so that a smooth casting will be produced.

In the accomplishment of the foregoing objects, I cause the mold-containing flask to be vibrated more strongly at first and then in diminishing amounts. The initial rougher vibrations are desirable for driving out entrapped gases, but are not as satisfactory for settling and packing the investment material in the flasks. By reducing the degree of vibration after gases have been eliminated from the mold, it is possible toform a densely and uniformly packed mold 2 and to bring excess liquid to the surface of the mold.

It is another object of my invention to provide means for consistently producing many molds of uniform density and accuracy. In accomplishing the foregoing object, I provide mechanism which subjects each mold to the same amount of vibration for the same periods of time.

It is still another object of my invention to provide vibrating mechanism, the degree of vibration of which may be varied for different mixtures of liquid and varying sizes of finely divided particles of investment material. Other objects, uses and advantages of my invention will become apparent from the following description when taken with the accompanying drawings in which:

Figure 1 is an elevational view of the vibratory conveyor of my invention together with driving means therefor; and

Figure 2 is a sectional view on line 2-2 of Figure 1.

Referring now to the drawings, the vibratory mechanism, which will be referred to as a vibratory conveyor, is indicated generally by the reference numeral ID. A mounting plate or board l2, adapted to be rested upon or secured to a supporting surface, has a plurality of vertically extending pairs of posts l4, I4, I6, l6 and I8, I8. Each of the posts has an extension of reduced diameter at its upper end which extension is threaded. The extensions 20 of the posts l4 may carry nuts 22 while the extensions 24 of posts l6 and extensions 26 on the posts 18

carry nuts

28 and 30, respectively. The

nuts

22, 28 and 30 are usually located with their upper surfaces in a common, horizontal plane so as to support a plate 32 in horizontal position, when it is not being vibrated. Apertures through the margin of the plate 32 permit said plate to be positioned over the threaded

extensions

20, 24 and 26 so that it rests on the

nuts

22, 28 and 36. Above the board on each threaded extension are positioned a pair of lock nuts, which, when in engagement with each other, prevent both nuts of each pair from being vibrated from their selected position. The pairs of lock nuts for each of the pairs of posts M, It and [8 are indicated by the

reference numerals

34, 36 and 38, respectively.

The distance between the nuts 30 and cooperating lock nuts 38 of the posts I8 is greater than the corresponding distance between the

nuts

28 and 36 of posts I6, and the nuts 22 and 34 of posts l4. Also, the distance between

nuts

28 and 36 of the intermediate posts [6 is greater than that between the nuts 22 and 34 of posts l4. Consequently vertical movement of plate 32 along the

extensions

20, 24 and 26 of the supporting posts, is permissible with the right-hand end of the plate, as viewed in Figure 1, being permitted the greatest amount of vertical movement, and the mid-portion of the plate 32 being permitted an amount of vertical movement about one-half of that permitted at the posts I8.

Vibrating means, indicated generally by. the reference numeral 44, is secured to the underside of the plate 32 nearer the end of the plate which is permitted the greater amount of vertical movement. The vibrating mechanism, by

way of example, may comprise an electric motor 46 having a pulley wheel 58 carried by the drive shaft, which pulley wheel carries a pin 50.

pivoted to the periphery of the pulley wheel 28. The pin 50 forms an eccentric and thereby causes the motor and its frame-to vibrate when the motor 4'6 is running, with the result thatthe plate 32 is vibrated. The force of the vibrations may be varied by varying the length of the-pin. The plate is vibrated primarily in a vertical direction because the'apertures inthe margin of the plate 32 are substantially the same width as tire diameter of th extensions on the posts i l, l5 and 18. However, some lateral .motion tends to be transmitted to the plate-32 during the. onerationof said motor. Although I have shown the vibrating means M as being fastened to the under side of the plate 32, other means may be employed to impart a vibratory motion to the plate-and said; other means need not be supportedrdirectly by the plate 32. It will be understood that in the preferred" form ofmy invention, whatever the vibrating means may be, it will be-applied nearer the end of the plate which is permitted the greater amount of vibratory movement.

An endless conveyor belt Elguidedby idling rollers 54 and driven by the shaft 55 passes over the-upper surface --of the plate 32. Mechanism for driving th drive shafttii isindicated generally; by the reference numeral and may take any" one of a'number of'forms. In the illustrated embodiment shaft as is connected-with thelarge pulley wheel 58 which; through pulley belt 62,-is'connected with a smaller pulley wheel (not shown) carried by a shaft'of a gear reduction unit-54. The gear reduction unit can directly connected with the drive shaft of anelectric motor 66. It will be noted that the conveyor belt 52 moves in the direction indicatedby the arrow A, that is, in a direction such that it enters-upon 'the surface of the vibratory plat -32 at that end which is permitted the greater amount of vibratory movement. Pairs of posts d5 along opposite longitudinal marginsof the-plate 32 s port a pair of parallel guide rails 62 for g flasks, such as flasks H5, in their movement along plate 32. Thebelt 52 passes between the posts dll and may be guided therebyin its passage across the plate. At the left-hand end of th vibratory conveyor it, there may be positioned a board or-table 58 which is sufficiently close to the belt 52*at the'end of its horizontal travel that objects carried by said conveyor belt may readily pass onto said table $8;

As will be readily apparent, the plate 32 vibrates at the right-hand end; as viewed in Figure 1, to a greater extentthan-it does at any other part, and the extent of the vibrations supplied will depend upon the nature of the object to b'e vibrateda Where a:moldcontainingdiask I5 is being passed along the board 32, the amount of vibration selected will depend in part upon the mixture of liquid and mold forming material. The granular size of the sand or other investment material will be another factor governing the amount of vibration desired.

In the operation of m vibratory conveyor, the vibrating means 4 will be started and the driving means 58 for the conveyor belt 52 will be started, so that the belt will be traveling over the board at a predetermined uniform rate of speed. Flasks containing freshly poured investment material will be placed upon the plate 32 at its right-hand end, as viewed in Figure 1, so that initially the flasks will be vibrated extensively and to such a degree that air and other gases will be driven from'the investment material. As the belt .52 carries the flask along the plate 32, the vibrations will be of decreasing amount since, once the gases are driven .from the investment material; the. investment material will be better settled and packed about the pattern when vibrated a lesser amount. I have found that clearance between the plate and nuts of of an inch at the posts [8, A of an inch atthe intermediate posts It, and ofan inch at the posts i l will provide the proper vibration of mold-containing flasks as they pass along the plate 32. Rails 42 provided along the longitudinal margins of the plate 32 prevent the flasks from sliding oif sideways and becoming spilled or broken. Iprefer to employ the vibratory conveyor in such fashion that flasks are continually being added at the end of the plate having. the greatest amount of vibratory movement while, at the end having the least amount of movement, th vibrated flasks are being removed or collected on an adjacent table, such as table 68. Whilethe force of vibrations transmitted from the vibrating mechanism at to the plate 32 may be varied by varying the.

length of the pin 59, which is secured to the pulle wheel 58 of motor GE, the extent of the vibrations;-willstill be controlled by the location of the nuts on the-threaded extension on the pairs ofsupportingposts l4, l6 and- I8.

Thecadvantageof having a conveyor belt transporting the flasks across the plate 32 resides inthefact that :a uniform rate of passage acrcss the plate 32 istherebypossible. This results in each mold being of uniform density and accuracy, a great advantage in the production of precision castings in quantity. Howeventhe flasks could be. transmitted along. the vibrating board without the conveyor belt'521if the. lower nuts. 22;. 28 and 33 on the posts l4; l6 and l8irespectively, were so adjusted -relative to each other that the common plane of their upper surfaces werev at an angle with respect to the. horizontal and inclined downwardly toward-the'lelt hand end, as viewed in-Figure 1, ofthe vibratory plate 32'. Gravity would, in this arrangement; cause the flasks to pass along thevibrating-plate 32 from the end having the greater amountof vibration, to the end having the lesser amount. Causin the flasks to travel in this manner will not, however, result inv their being vibrated a uniform amount because offthe. rate of -th'eirrpassage along the plate 32will not be uniform.

Although I'have illustrated a preferred embodimentofmyinvention, I do. not intend to be limited theret except insofar as the appended claims are soulimited, since modificationcoming within the scopepf the claims will suggest themselves to others =byreason of this-disclosure.

I claim:

Vibrating mechanism comprising, in combination, a longitudinally extending plate adapted to be vibrated, a retainer rail along each side of the plate, supporting posts positioned adjacent the ends and the middle of the plate and having threaded extensions of reduced diameter passing through apertures in the margins of the plate, adjustable nuts carried on said extensions to control vertical movement of the plate on the extensions of the supporting posts, said nuts being adjusted to permit greater vibratory movement of said plate at its one end than at its other end, vibrating means for vibrating the plate, and an endless conveyor passing over the plate between the retainer rails and adapted to carry objects to be vibrated along said plate from the end having the greater vibratory movement to the end having the lesser vibratory movement.

JOHN FREI, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS