US3897658A

US3897658A - Method and apparatus for finishing workpieces under high vibrating pressure (tentative)

Info

Publication number: US3897658A
Application number: US351966A
Authority: US
Inventors: Hisamine Kobayashi
Original assignee: Tipton Manufacturing Corp
Current assignee: Shikishima Tipton Manufacturing Co Ltd; Tipton Manufacturing Corp
Priority date: 1972-04-17
Filing date: 1973-04-17
Publication date: 1975-08-05
Anticipated expiration: 1992-08-05
Also published as: JPS5414795B2; JPS49897A; DE2319146A1; GB1401386A; CH579966A5; FR2199675A5; DE2319146B2; DE2319146C3

Abstract

A method and an apparatus for finishing workpieces which are caused to flow in a helical motion together with abrasive media within a circular vibratory finishing tub in the form of a hollow annulus closed at both ends, and more particularly for vibratory finishing of workpieces together with abrasive media in a heavily compressed condition and for separating the mass (a mixture of workpieces and abrasive media) into workpieces and abrasive media. The apparatus has a downwardly inclined or horizontal circular vibratory finishing tub having an opening at the top which is closed in operation, in the form of a hollow annulus, having the radially greatest sectional area at the central portion thereof and the sectional area being gradually smaller toward both ends thereof, so that the mass is caused to flow during vibration with an increased density resulting in a substantially compressed condition of the mass so that workpieces and abrasive media are caused to move in a closely spaced relation which would otherwise be eliminated at every vibrating. By this arrangement the vibrating pressure and action between workpieces and abrasive media are improved and the mass separating efficiency as well as the smoothness of the finished surfaces are also improved considerably.

Description

United States Patent Kobayashi 1 Aug. 5, 1975 l METHOD AND APPARATUS FOR FINISHING WORKPIECES UNDER HIGH |57| ABSTRACT VIBRATING PRESSURE (TENTATIVE) A method and an apparatus for finishing workpieces I lllvfimfll'i Hisflmine Kfibayashit N g ya. apan which are caused to flow in a helical motion together [73] Assigncci Shikishima Timon Mfg Co Lid with abrasive media within a circular vibratory finish- Nagoya Japan mg tub In the form of a hollow annulus closed at both ends, and more particularly for vibratory finishing of l Fllcdi P 1973 workpieces together with abrasive media in a heavily [2| I App No: 351966 compressed condition and for separating the mass (a mixture of workpieces and abrasive media) into work pieces and abrasive media. The apparatus has a downl Foreign pp n Priority D lfl wardly inclined or horizontal circular vibratory finish- Apr. I7, 1972 J'tlplll'l 47-38474 ng ub having an Opening at the top which is closed in operation in the form of a hollow annulus, having the [52] U.S. Cl. .I 5l/l63 ra ially greatest sectional area at the central portion [51 1 Int. Cl .I B24b 31/06 h r of n h sec ional re eing gradually smaller [52%| Field of Sear h 5 h3 7; 241/175 toward both ends thereof. so that the mass is caused to flow during vibration with an increased density result- [56] References Cit d ing in a substantially compressed condition of the UNITED STATES PATENTS mass so that workpieces and abrasive media are 3 24l l 2o 5/1966 Fosscn I. 5m x caused to q m u.cl.osely Spaced i wh'ch Lena-267 H971 Huhncrnm H63 would otherwise be eliminated at every vibrat ng By molly) 4/w74 Ftfill'itrll. .4 52/163 this arrangement the Vibrating Pressre and acllo" tween workpieces and abrasive media are improved FOREIGN PATENTS OR APPLICATIONS and the mass separating efficiency as well as the 224,(|5u 3/l97l United Kingdom 5l/l63 smoothness of the finished surfaces are also improved Primary I; .\'umim'rHarold Di Whitehead Armrm'r Agcn1 u! FirmWenderoth, Lind & Ponack considerably.

9 Claims, 8 Drawing Figures PATENTEU AUG 51975 SHEET Fig.7

PRIOR ART PATENTEU 5195 $2,897, 658

SHEET Fig 8 PRIOR ART f 1 4 51c1912a12 1 METHOD AND APPARATUS FOR FINISHING WORKPIECES UNDER HIGH VIBRATING PRESSURE (TENTATIVE) BACKGROUND OF THE INVENTION In a conventional finishing apparatus having a circular vibratory finishing tub, the finishing operations are performed with the tub open at the top to facilitate a visual inspection of the flowing mass. However, this causes the disadvantages of limiting the volume of workpieces which can be finished, causing damage or defects to the workpieces due to the impact thereof with each other, the media and the tub under strong vibration and reducing the mass separating efficiency due to the backflow of the mass.

There are conventional finishing apparatuses having a circular vibratory finishing tub, a rotary barrel or mill, a centrifugal barrel, or a vibratory finishing tub or box type in which the barrel or the like is closed in operation. However, all of those apparatuses provide only a means of closing the barrel or the like without which it would be impossible to operate the apparatus since the contents would otherwise be easily vibrated out, or a means of closing the barrel or the like to prevent water from the finishing compound from spattering out. In other words, this is simply a covering means, but not a means of finishing workpieces effectively by vibration under a heavily compressed condition as in this invention.

SUMMARY OF THE INVENTION With the method and apparatus according to the invention, an increased volume of workpieces can be finished, and the smoothness of the finished surfaces of workpieces is improved by placing the workpieces and abrasive media under a heavily compressed condition during vibration.

In order to meet these needs, the apparatus has a circular vibratory finishing tub having an opening at the top which is closed in operation, and has the radially greatest sectional area at a central portion thereof before a dam and the radially smallest sectional area at that portion thereof beyond said dam.

Consequently, contents of the mass are caused to move in a closely spaced relation, and are mutually subjected to a heavy force by the vibration while passing through the portion of the smallest sectional area.

According to the invention. the tub is a downwardly inclined or horizontal circular vibratory finishing tub in the form of a hollow annulus having an opening at the top which in operation is closed, having the radially greatest sectional area other than the mass separating portion, at that portion thereof before a dam and a sec tional area which is gradually smaller toward both ends thereof. one end having the smallest sectional area at that portion beyond or downstream of the dam and the other end having a medium sectional area at that portion connected to the mass separating portion, so that contents of the mass are caused to move in a closely spaced relation and are thus subjected to a heavy force by the vibration while moving inside the tub.

Consequently, it is possible to handle double the volume of the mass and improve the smoothness of the finished surfaces by reducing substantially by half the roughness thereof. This can thus protect workpieces from damage or defects due to the impact thereof with each other, the media or the apparatus. Furthermore,

these increased volume and improved smoothness bring the finishing efficiency to substantially four times that of the conventional apparatus. In using the ma chine for a mill, not only can the deviation of the milled particles from the desired sizes can be reduced, but the efficiency can be increased. This finishing efficiency cannot be obtained from the prior art vibratory finishing apparatuses for handling metals or ores or the like. In other words, these prior apparatuses are usually capable of increased efficiency for polishing, milling and mixing purposes, but for that increase must sacrifice the smoothness of the finished surfaces.

According to this invention, it is possible not only to increase the volume of the processing mass but also to improve the finishing efficiency and smoothness of the finished surfaces.

As has been described heretofore, the invention provides an improved finishing efficiency by increasing the smoothness of the finished surfaces, and also a reduction of substantially half the amount of deviation of the milled grain sizes from the desired sizes, in addition to an increased volume of workpieces which can be finished. Thus, it provides a completely novel performance by bringing the whole efficiency to substantially four times that of the prior art.

When the mass is fed by a charge port into the tub of the present apparatus, it is subjected to vibration and is caused to travel in a helical motion. During the finishing operation, the mass is caused to move upwardly along the dam and when the operation is completed, it is caused to move up to a sieve along a movable flap which has been moved downwardly and on the sieve the mass is separated into workpieces and abrasive media. The abrasive media is again fed through the sieve into the tub by action of gravity.

This invention is characterized in that the circular vibratory finishing tub having an opening at the top to be closed in operation comprises two portions with radially different sectional areas, so that the mass is caused to move inside the tub under a heavy compression force by the vibration.

As compared with the conventional apparatus having a vibratory finishing tub open or closed at the top by which the mass is uniformly subjected to vibration, the apparatus according to the invention is provided with a circular vibratory finishing tub having the radially greatest sectional area at that portion before the dam and the radially smallest sectional area at that portion over said dam, so that the mass flowing under vibration toward the smallest sectional area is subjected to compression from the barrel wall and substantially heavy compression force by vibration. When it is supposed that the greatest sectional area at that portion before the dam is E. the smaller sectional area at the portion after the mass separating portion F should preferably be smaller than F. but greater than 0.8 E, the optimum being more or less 0.9 E. Then, suppose the smallest sectional area is G, G should be within the range of 0.9 E G 0.5 E. the optimum being within the range of 0.8 E to 0.6 E.

Consequently, it is possible to obtain a considerably improved finishing efficiency by controlling values of these two sectional areas inside the tub.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS FIG. 1 is a front view of one apparatus according to this invention.

FIG. 2 is a plan view of the apparatus of FIG. 1.

FIG. 3 is a fragmental developed sectional view taken along the line A A of FIG. 2.

FIG. 4 is a front view of another apparatus according to this invention.

FIG. 5 is a plan view of the apparatus of FIG. 4.

FIG. 6 is a sectional view taken along the line B B of FIG. 1.

FIG. 7 is a front view of one conventional apparatus.

FIG. 8 is a front view of another conventional apparatus.

DETAILED DESCRIPTION OF THE INVENTION According to the invention. a dam is provided to separate a circular vibrating finishing tub into two portions, one having the radially greatest sectional area and the other having the radially smallest sectional area. so that the mass moving inside the tub can be finished or milled by vibration under a heavy compression force with a substantially improved efficiency.

In the drawings, in FIGS. 1 and 2 is shown the upper end I of a circular vibratory finishing tub placed in a downwardly inclined position as shown in FIGS. 1 and 2. The tub has a descending part 1a. an ascending part lb. and a separating part It, respectively.

In FIGS. 4 and 5 as shown a circular

vibratory finishing tub

21, 21a placed in a substantially horizontal position. which has an ascending part 2112 and a separating part 21c.

For the convenience of reference. two conventional apparatuses having a circular vibratory finishing tub open at the top are shown in FIGS. 7 and 8. In FIG. 7 the upwardly inclined tub has a lower end 41 open at the top, and ascending part 41a, an ascending part 4th over the dam and a separating part 410.

In FIG. 8, a horizontal circular

vibratory finishing tub

51, 51a is open at the top and has an ascending part 5112 over the dam and a separating part 510.

By referring to the reference numerals common to all drawings. we will illustrate the structure of the appara- The circular vibratory finishing tub is rigidly secured by a rib 3 to a flange 2 and mounted by a plurality of springs 5 on a pedestal 4. An electric motor 9 is vertically fixed to a flange 8 within a cylindrical housing 7.

When the motor 9 is started, it causes weights It), 10 rigidly secured to the motor shaft to rotate and then vibrate the tub and the mass therewith. A superposed portion 11 is provided for the descending portion of the tub of FIGS. 1 and 2, and for the ascending portion of the tub of FIG. 7. respectively.

A dam I2 is rigidly secured on said superposed portion II. A dam is also provided for the horizontal tub of FIGS. 4 and 8. This dam is preferably of an angular shape having an ascending part 12 and a descending part 12a. A dam having only one plate may be provided vertically. or only that portion of the angular-shape dam facing the flow direction of the mass may be provided with an ascending part.

Apart from the shape of the dam. the most important thing of the invention is that the ratio of the sectional area at one point to that at the other point inside the tub should be maintained within the range of a given value.

By the structure of the invention. it is possible to cause the mass to travel smoothly inside the tub and to reduce the vibrating width or amplitude of the mass to a small amount by increasing the density of the mass. thus subjecting the mass to heavy compression force during vibration.

A cover 6 encloses a plurality of helical springs S. A movable flap I3 is placed in such a position that it does not prevent movement of the mass. indicating a position which the flap I3 takes in turning on its shaft 14 when the mass is being separated. A sieve 15 is provided for separating the mass. A mass charging port 16 is provided with a cover 16a having a grip 1617. In operation. the port I6 is closed by the cover 16a. This port 16 is provided as indicated in FIG. 1 near to that portion of the tub where the mass is entering the finishing portion after passing through the separating portion.

When the mass is fed through the port 16 into the tub, it is subjected to vibration. flowing in a helical motion in the direction of the arrow 17b revolving inside the tub as indicated by the arrows l7 and 170. Then. the mass moves up along the dam as indicated by the arrow 18 and continues to flow beyond the dam as indicated by the arrow 19, where the mass receives the finishing operations.

When the finishing operations are completed. the flap 13 rotates on its shaft to the position as indicated by dot-dash lines 131: of FIGS. I and 3 to move the mass up to the sieve I5 where the mass is separated into workpieces and abrasive media. The media are screened through the sieve to be fed again into the tub. The finished workpieces are automatically ejected out of the tub as indicated by the arrow 20.

For the circular vibratory finishing tub open at the top as shown in FIGS. 7 and 8. there is no need of such a port for charging a mass. Motors. weights. and other component parts that are the same as in FIG. I are not indicated in FIGS. 7 and 8, but naturally these are also installed on the apparatus of FIGS. 7 and 8.

The invention is particularly characterized in that the circular vibratory finishing tub comprises one portion before the dam having the radially greatest sectional area and one portion over the dam having the radially smallest sectional area. so that the mass is caused to move under a heavy compression force during vibration. In the conventional apparatus having a circular vibratory finishing tub. open or closed at the top. vibration of the mass is caused uniformly. Accordingly to the invention. however. a circular vibratory finishing tub is provided in the form of a hollow tubular container having a gradually smaller sectional area toward both ends. having one portion before the dam having the radially greatest sectional area, one portion over the dam having the radially smallest sectional area. and one portion connecting to the separating portion having a radially medium sectional area. so that the vibration given to the whole exerts on the mass a substantially compressing force. The mass is thus caused to move under such heavy compressing force during vibration.

The widths E'. F. G of the tub at the various portions except the separating portion are the same as indicated in FIG. 2. The portion F of the tub before the dam hits the greatest in depth. and the depth of portion F after the separating portion should be smaller than E and greater than 0.8 E. the optimum being more or less 0.9 E. The depth of portion G over the dam should preferably be (1.9 E G 0.5 the optimum being within the range of 0.8 E to (1.6 E, namely E F G and accordingly EE' FF' GG'.

When the tub and the mass therein are subjected to vibration, i.e., a vibration equivalent to about 6 mm is amplitude, the vibrating width or amplitude is compressed so as to be substantially smaller than 6 mm and greater than 3 mm. In the conventional apparatus of this type, the amplitude generally ranges from 8 mm to 3 mm but in this invention, it is possible to obtain an amplitude of6 mm to 2 mm by compressing it by l mm to 3 mm. In this way, workpieces can be polished or finished under heavy compression force during vibration. The vibration thus obtained differs greatly from that of the prior art in the finishing efficicncy, since the former offers substantially four times higher performance than the latter.

As a result, it is possible to improve the finished surfaces of workpieces, doubling the efficiency for finishing workpieces and reducing the deviation of the sizes of milled grain from the desired size. This equals four times higher finishing efficicncy, which is evident from the tables I to 4 that follow hereinafter.

As can be seen from the above tables, the finishing efficicncy of the invention differs greatly from that of the conventional apparatus. which is due to the fact that the inner diameter D of the outer periphery of the tub and the outer diameter d of the inner periphery thereof have a common size, respectively, in all types,

the inside arcuate bottom being uniform, and that the radially sectional portions.

E, F'and G have the same width, while these portions have radially different sectional areas depending on the depth E, F and G thereof.

In the embodiments of the apparatus according to this invention, suppose the portion E is I, then the portions F and G should be E F 0.8 and E and 0.9 E G 0.5 E, respectively, resulting in E F G.

In this way, when the mass is charged in an amount sufficient to fill the greatest sectional space ahead of the darn it will thus be compressed in moving from the portion F toward the portion G over the dam having radially the smallest sectional area. However, in the apparatus according to one embodiment of the prior art (FIG. 7), E, F, and G are equal while in the apparatus according to the other embodiment of the prior art (FIG. 8), Fa, E, F and G are different and Fa E F G, the portion E note being the greatest in sectional area in this apparatus.

It is clear that the structure of these portions E, F, and G of the conventional apparatus differs from that of the apparatus of the invention.

According to the apparatus of the prior art, the structure and function are not such as to compress the moving mass during either the finishing or separating operations. Because of this, higher inner walls must be provided for the inner and outer peripheries of the tub so as to prevent the overflow of the mass moving onto the stationary and movable dams during the separating operations. This causes the mass to flow backward, resulting in a considerably decreased separating efficiency and more frequent damage or defects due to the impact thereof.

According to this invention, however, the two portions ahead of and over the dam are provided with a different radially sectional area i.e. E F G and the ratio among E, F and G is properly determined, so that the mass may be subjected to heavy compression force during vibration, namely the finishing operations can be performed under a high compression force. In addition, this invention can protect workpieces from any type of damage or defect due to the impact thereof, and can also minimize noises since in operation the tub is closed by a cover.

Tests have been effected under about the same finishing conditions with regard to these four apparatuses, in which three samples of brass, iron and stainless steel have been used. Then, comparison has been made with respect to the weight of workpieces to be finished and the smoothness of the finished surfaces thereof, on the basis of the capabilities of the conventional apparatuses, the results of which have been obtained, as follows: The weight according to the embodiments of the present invention has reached 209 to I53 respectively, as compared with that of the conventional apparatus, the surface roughness reaching [.5 to 0.7a. The apparatus of FIGS. I-3 in particular has shown the best results, i.e., a weight of 209 to I53 and the surface roughness of 1.3 to 0.7a.

Table 4 also shows the remarkably significant difference in the milling efficiency between the prior art apparatus of FIG. 7 and that of FIGS. 1-3 of the present invention.

In a milling test on bauxite ores (mined in Guinea) using the apparatus of FIGS, [-3 and continuing, the test was continued for 48 hours and in the resulting material the amount of deviation from the desired particle size ranged from lOp, to 2p. for 67% and from 60p. to 10p. for 2l% of the total amount of material respect vely, whereas in the apparatus of FIG. 7, the amount of deviation was only within the range of 60a to It) for 47% of the material.

However, in order to make the best use of these efficiencies for the finishing and milling operations, or for any amount of the mass remaining inside the tub, it is desirable to provide a plate H inside the tub for pre venting the backflow of the mass, as indicated in FIG. 6.

When the mass is moving upwardly along the ascending side 12 of the dam, the upper part P of the mass flowing on the inner peripheral side of the tub is apt to flow backward. As the volume of the mass becomes smaller after further separating operations, the remaining mass is more apt to flow backward.

The ratio in which a given volume of workpieces are mixed with abrasive media or the like is usually I to 3 or 2. When workpieces and abrasive media are mixed in this ratio, the finishing and separating operations are more easily performed in the apparatus of the invention. By providing the aforesaid plate for preventing the backflow of the mass, it is possible to improve the ratio further, i.e., the ratio of l for workpieces, and 2 or I for abrasive media. This means that the finishing and separating operations can be improved by substantially 50% and the time required for the separating operations can accordingly be reduced considerably.

Because of the presence of the plate H for preventing the backflow of the mass as shown in FIG. 6, the upper part M of the mass M forces the mass M to remain on the down stream side (side G of FIG. 4) of the plate H, keeping the mass filling the space between the portions E and G until the upper part M moves down to a level N on the upstream side (side F of FIG. 3) of the plate H. thus enabling the mass to be separated into workpieces and abrasive media effectively. At this stage. workpieces alone are ejected out of the tub.

The volume H of the mass that remains on the up stream and down stream sides of the plate H after completion of the separating operation will be equivalent to M/2, from which it is evident that the maximum separating volume MB of the conventional apparatus has been improved by substantially fifty percent.

The size. shape and position of installation of the plate H should be such that it is placed nearer to the portion E along the distance between the portions E and G and on the radially inside inner peripheral wall of the tub, having a width of about K/4 and a height of about K (K is width of the tub), the lower end portion 15 being inclined at an angle (more or less 60 )ohtained by intersecting a line passing through the center 0 of a circle K and a perpendicular line U as shown in FIG. 6. The plate H should also be such that the major por- Table l tion of the inside areuate bottom of the tub is not shut off but open. so as to force the mass up to the downstream side of the plate H thus preventing the mass from flowing back from the downstream side to the up- 5 stream side.

In the apparatus of the invention comprising a downwardly inclined circular vibratory finishing tub having an opening at the top to be closed during operation. a separating device is provided at the top of the upper portion of the tub indicated by of FlGS. l and 3. The distance between the sieve and the bottom of the tub is smaller than the width of the tub, which is equivalent to substantially half the distance between the separating device (indicated by 15 of FIGS. 7 and 8) and the bottom of the tub in the conventional apparatus. This makes it possible to avoid occurrence of damage to or defects in the workpieces due to the impact thereof. also providing a good finishing efficiency for aluminum bronze. zinc diecast and other soft metals.

Finishing Conditions Machine Capacity Frequency Amplitude Advance angle of Sample type cpm lower weight workpiece Disk Shape Quantity Brass. iron. (I IUOL I730 5 5mm 90 stainless mm X titmm 5 each steel (2) I, H H H n a (3) .y n H H n t. H H H H I, H

Charge Abrasive Compound 84 water AES- 3M0 kg GCL Sllg/Sltwaterl Type Diameter of Tub Depth of Tub Ratio Ratio l 920mm 460mm 240mm l 240mm 1 24Umm l mrn Ratio (2) 37() l 300 (L81 150 0.68 39H [.05 (3) 231) 207 0.) I41) Ufvl {4) 250 l 200 0.8 lXO ([78 NOTES FOR TABLE 1 I. As the inner diameter (D) of the outer circumference and the outer diameter (d) of the inner circumference are nearly the same for all types. the width E. F and G in the direction of the radius of the arcuate hottom of the tub is almost the same as 2-H) mm. The vertical section in the direction of the radius of the tub is 2. F,, denotes an exceptional case for type 3. Type (3) of this invention is superior in almost proportional to the depth E. F and G of the space inside the tub. except the separating portion.

(2) in which the depth inside the tub is greater than in E and F. finishing efiicicnc which is clear from the following experimental results. Table 2.

Table 2 Experimental Results Finishing Efi'tcieney Typetl) Typetll Stock Removal Brass lron Stainless Brass Iron Stainless Steel Steel mg '4 mg mg ii mg Z mg .i mg "i is! 27.5 13.9 lllll Z8 5 14.2 10.5 2nd 26.9 l5 7 ll R 37.2 I49 A I l.7 3rd 28.! I i 9.2 290 l-Lh HI I Average llKl I44 llXl Ill} lllll 28] HI? l-lh llll lllb Ill Surface Roughness 2.4;; l l 5a 1 F t Itlp. 1 7p TA Bl .E Z (ontinued m: (31 yp Stock Removal Brass lron Stainless Brass lron Stainless Steel Steel mg "/1 mg '7: mg /r mg Z mg Z mg q is! 57.5 25.7 lio 54.6 26.] 14.7 2nd 55.7 28.] m0 57.2 26.5 I56 3rd 59.2 28.0 I59 55.8 27.2 l5.0 Average 57,5 209 27.3 I89 l5.8 153 55.8 203 26.6 185 l5.l [47 Surface Roughness L3 0,8 (17 1.4;; 0.9;; 0.7

Table 3 Milling Condition Type Sample Media Water Description Shape Quantity l (alcinated Bauxite Ores Massive 3Ul Alumina Ball l (mined in Guinea) 10,000 to 100p mm 4). 60] (3) 30l 5| NOTES FOR TABLE 3 Note I l Type l is a conventional finishing apparatus having an upwardly inclined circular vibratory finishing tub with a step open at the top. Model (CL-I00. as sl-mwn in FIG. 7.

2) Type (2) is a conventional finishing apparatus having a horizontal circular vibratory finishing tub. open at the top. Model CL lOU. as shown in FIG. 8.

3 Type I 3) is a finishing apparatus according to the invention having a downwardly inclined circular vibratory finishing tub. Model CSS-I0O, as shown in FIG. 1, Z and 3.

4) Type 4) is a finishing apparatus of the invention having a horizontal circular vibratory finishing tub, Model C RS- 100, as shown in FIGS. 4 and 5.

The above four types l l to (4) are manufactured by Shikishima Tipton Mfg, Co. Ltd. Note 3 The experimental results have been obtained at the laboratory of this company.

Note 4 Test Time 30 minutes for each finishing test and 48 hours for each milling test.

Table 4 said tub for closing and charging opening, said finishing portion having an equal width throughout its circum- Experimental Results fcrential length and having a depth at said charging Milling Emciency opening and above said dam less than the depth adja- TW: 3; cent the bottom of said dam, and the depth of said finishing portion increasing gradually from said charging opening to the bottom of said dam and from the top to Grain 5 to a) 47% z to no, 67% the ot m f i m Disiwrsivn s g 1% lungellhun 12% 2. An apparatus as claimed in claim 1 in which the depth E of said finishing portion at the bottom of said dam, the depth F of said finishing portion adjacent said We claim: charging opening and the depth G above the top of said 1. An apparatus for vibrating finishing of workpieces dam are in the relationship E F G. under heavy compression force during vibration, com- 3. An apparatus as claimed in claim 2 in which said prising a substantially horizontally positioned circular 50 depths are in the relation E F O.8E and annular vibratory finishing tub, a base. a plurality of O.9E G O.5E.

springs on said base and supporting said tub thereon, 4. An apparatus as claimed in claim 3 in which said vibrating means on said base having a drive means and depth are in the relation F OQE and O.8E G ().6E. a vertical shaft having eccentric weights thereon with 5. An apparatus according to claim 1 in which the one end connected to said drive means and other end gs bottom of said tub is downwardly inclined.

connected to said tub, said tub being in the form of a i 6. An apparatus according to claim I in which a movhollow annulus having a mass separating portion and a able flap is pivotally mounted above the stationary dam finishing portion extending around the circumference and leaving the space above the dam in the tub open for of said tub from one end of the mass separating portion flow olthe mass when it is pivoted upwardly and blockofthc other end thereof. a stationary dam in the bottom ing said space above the dam for leading the mass up thereof at the end of said finishing portion adjacent said out of the tub when it is pivoted downwardly.

other end of said mass separating portion. mass sepa 7. An apparatus according to claim 1 in which the rating means in said means separating portion of said stationary dam has an ascending portion facing uptuh adjacent to and above the level of the top of said stream and a descending portion facing downstream.

stationary dam. said tub having a charging opening in 8. An apparatus according to claim 1 in which said the top of said finishing portion adjacent said one end mass separating portion has a sieve in the upper portion of said mass separating portion and a closure means on of said tub and the distance between the sieve and thc 12 inner peripheral wall of the tub and having u width of KM and at height of K. when K is the width of the tub. vertically and radially of the tub. respectively.

Claims

1. An apparatus for vibrating finishing of workpieces under heavy compression force during vibration, comprising a substantially horizontally positioned circular annular vibratory finishing tub, a base, a plurality of springs on said base and supporting said tub thereon, vibrating means on said base having a drive means and a vertical shaft having eccentric weights thereon with one end connected to said drive means and other end connected to said tub, said tub being in the form of a hollow annulus having a mass separating portion and a finishing portion extending around the circumference of said tub from one end of the mass separating portion of the other end thereof, a stationary dam in the bottom thereof at the end of said finishing portion adjacent said other end of said mass separating portion, mass separating means in said means separating portion of said tub adjacent to and above the level of the top of said stationary dam, said tub having a charging opening in the top of said finishing portion adjacent said one end of said mass separating portion and a closure means on said tub for closing and charging opening, said finishing portion having an equal width throughout its circumferential length and having a depth at said charging opening and above said dam less than the depth adjacent the bottom of said dam, and the depth of said finishing portion increasing gradually from said charging opening to the bottom of said dam and from the top to the bottom of said dam.

2. An apparatus as claimed in claim 1 in which the depth E of said finishing portion at the bottom of said dam, the depth F of said finishing portion adjacent said charging opening and the deptH G above the top of said dam are in the relationship E>F>G.

3. An apparatus as claimed in claim 2 in which said depths are in the relation E>F>0.8E and 0.9E>G>0.5E.

4. An apparatus as claimed in claim 3 in which said depth are in the relation F Congruent 0.9E and 0.8E>G>0.6E.

5. An apparatus according to claim 1 in which the bottom of said tub is downwardly inclined.

6. An apparatus according to claim 1 in which a movable flap is pivotally mounted above the stationary dam and leaving the space above the dam in the tub open for flow of the mass when it is pivoted upwardly and blocking said space above the dam for leading the mass up out of the tub when it is pivoted downwardly.

7. An apparatus according to claim 1 in which the stationary dam has an ascending portion facing upstream and a descending portion facing downstream.

8. An apparatus according to claim 1 in which said mass separating portion has a sieve in the upper portion of said tub and the distance between the sieve and the inside bottom of the tub is less than the width of the tub.

9. An apparatus according to claim 1 further comprising a plate in said tub for preventing the backflow of the mass, said plate being mounted on inside of the inner peripheral wall of the tub and having a width of K/4 and a height of K, when K is the width of the tub, vertically and radially of the tub, respectively.