Patent US6155428A successfully refreshed from Google Patents.
US6155428A
Expired / Lapsed
US
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Vibratory screening machine
Assignee: Varco IP Inc
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Filing: 1997-10-15
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Granted: 2000-12-05
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Expires: 2017-10-15
Abstract
Abstract A vibratory screening machine such as used for separating solid particulate material from drilling mud to allow the latter to be re-used, is described. The general form of the construction is similar to that of the VSM100 shaker machine as supplied by the applicant company, but significant differences in the design and construction of the new unit allow a higher throughput of mud to be accommodated. An upper filtering screen (88) extends generally horizontally and serves to separate out the larger particles from the rest. The slurry which passes down to the lower screen (90) (of finer mesh than the upper screen) is further filtered and a mud-like residue of particulate material slowly accumulates on the lower screen (90) and migrates up the screen--to be discharged at the upper outlet end thereof, while liquid material filters through the screen to be recovered in a sump below. The drive (14, 16) for the machine comprises two pairs of rotating clump weights, mounted with their individual motors on a platform which spans the basket within which the screens are fitted. The two pairs of clump weights occupy a plane which is generally parallel to the upper (horizontal) screen (88), close to the latter, so keeping the center of gravity low, which enhances the vibration characteristics of the system.
Inventors
- 👤 Arthur Robert Bailey
- 👤 George Alexander Burnett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:12
CPC Classifications
B; B07; B07B; B07B1/00; B07B1/46; B01; B01D; B01D33/00; B01D33/01; B01D33/03; B01D33/0346; B01D33/35; B01D33/41; B01D33/70; B01D33/76; B01D33/763; B07B1/28; B07B1/284; B07B1/42
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
208 words
A vibratory screening machine having a rigid housing within which is resiliently mounted a rigid screening basket having upper and lower screens mounted therein, the upper screen being of a coarser mesh than the lower, and drive means for vibrating the basket relative to the housing which comprises a pair of counter-rotating masses mounted for rotation about two spaced apart parallel axes between the sides of the basket, wherein: (1) the spacing between the two spaced apart parallel axes or their precise positioning relative to the mean operational centre of gravity of the basket is selected so that the resultant force is of the desired type, and makes a desired angle relative to the screens; (2) the axes of the counter-rotating masses both occupy a plane which is substantially parallel to the plane of the upper screen and spaced thereabove, to keep the centre of gravity low; (3) the lower screen forms a continuous ramp which is uniformly sloped upwardly from input end to discharge end and makes an acute angle with the upper screen, and (4) the rotational moment produced by one of the counter-rotating weights is different from that produced by the other, thereby to produce an elliptical motion of the basket relative to the housing.
Claim 2
Dependent Claim
208 words
A vibratory screening machine having a rigid housing within which is resiliently mounted a rigid screening basket having upper and lower screens mounted therein, the upper screen being of a coarser mesh than the lower, and drive means for vibrating the basket relative to the housing which comprises a pair of counter-rotating masses mounted for rotation about two spaced apart parallel axes between the sides of the basket, wherein: (1) the spacing between the two spaced apart parallel axes or their precise positioning relative to the mean operational centre of gravity of the basket is selected so that the resultant force is of the desired type, and makes a desired angle relative to the screens; (2) the axes of the counter-rotating masses both occupy a plane which is substantially parallel to the plane of the upper screen and spaced thereabove, to keep the centre of gravity low; (3) the lower screen forms a continuous ramp which is uniformly sloped upwardly from input end to discharge end and makes an acute angle with the upper screen, and (4) the rotational moment produced by one of the counter-rotating weights is different from that produced by the other, thereby to produce an elliptical motion of the basket relative to the housing.
Claim 3
Dependent Claim
43 words
A vibratory screening machine as claimed in claim 1, wherein each mass comprises a pair of similar weights which are mounted on opposite sides of the drive unit therefor, and the drive and weights are located on a bridge which spans the basket.
Claim 4
Dependent Claim
35 words
A vibratory screening machine as claimed in claim 2, wherein the bridge is located beyond the midway point measured along the length of the basket nearer to the discharge end than the input end thereof.
Claim 5
Dependent Claim
69 words
A vibratory screening machine as claimed in claim 1 wherein the position of the assembly of weights in the drives relative to the basket is such that the angle of the major axis of the elliptical motion produced by the counter-rotating masses tends to pass through the centre of gravity of the basket and to subtend an acute angle in an upward sense relative to the lower inclined screen.
Claim 6
Dependent Claim
21 words
A vibratory screening machine as claimed in claim 1 wherein in use the upper screen of coarser mesh is substantially horizontal.
Claim 7
Dependent Claim
31 words
A vibratory screening machine as claimed in claim 1 wherein the acute angle between the plane of the lower screen and that of the upper screen lies between 2° and 30°.
Claim 8
Dependent Claim
40 words
A vibratory screening machine as claimed in claim 1, wherein the lower screen is adapted to be self-cleaning so as to reduce the risk of fines becoming permanently lodged between the interstices of the smaller mesh of the lower screen.
Claim 9
Dependent Claim
48 words
A vibratory screening machine as claimed in claim 7, wherein the lower screen comprises two screen cloths, one laid above the other over a rigid frame, which are pre-tensioned during manufacture so that the tension in the lower cloth is greater than the tension in the upper cloth.
Claim 10
Dependent Claim
47 words
A vibratory screening machine as claimed in claim 8, wherein the cloths are formed from woven wire having different mesh sizes and the woven wire cloths are adhesively bonded at least around their periphery to rigid frames by which the screen is mounted within the shaker basket.
Claim 11
Dependent Claim
21 words
A vibratory screening machine as claimed in claim 1 wherein both the upper and lower screens are removable from the basket.
Claim 12
Dependent Claim
30 words
A vibratory screening machine as claimed in claim 1 wherein the screens are removable from the end of the basket over which the solids and fines are discharged in use.
Claim 13
Dependent Claim
45 words
A vibratory screening machine as claimed in claim 1 wherein the basket is mounted on four helical springs which support the weight of the basket and are adapted to vibrate substantially freely with small amplitudes up to a few millimeters relative to the rigid housing.
Claim 14
Dependent Claim
35 words
A vibratory screening machine as claimed in claim 1 wherein opposite sides of the rigid housing are parallel and upright when the machine is mounted for use and nothing protrudes laterally of the rigid housing.
Claim 15
Dependent Claim
48 words
A vibratory screening machine as claimed in claim 1 wherein each said drive means comprises a motor mounted centrally of a bridge with an output shaft extending axially in both directions therefrom and weights are mounted eccentrically on the two output shafts on opposite sides of each motor.
Claim 16
Dependent Claim
37 words
A vibratory screening machine as claimed in claim 14, wherein bearings are provided to support the output shafts between the motors and the eccentrically rotating masses, and further bearings are provided outboard of the eccentrically mounted masses.
Claim 17
Dependent Claim
39 words
A vibratory screening machine as claimed in claim 1 wherein flexible couplings are provided between the drives and the counter-rotating eccentric masses so that forces generated by the rotating eccentrically mounted masses are not transmitted to the motor bearings.
Claim 18
Dependent Claim
136 words
A vibratory screening machine comprising a basket having an inclined screen, drive means for vibrating the basket to cause solid material deposited on the screen to migrate there along up the incline to the upper discharge end of the screen from which the solid material is discharged, wherein the drive means comprises a pair of counter-rotating masses respectively mounted for rotation about two spaced apart parallel axes between the sides of the basket, whereby the drive means exerts on the basket a resultant force along a line which passes through or near the centre of gravity of the basket when the latter is unloaded, and wherein the inclination of the screen is such that the centre of gravity of the basket continues to lie on or near the said line for different loadings of the basket.
Claim 19
Dependent Claim
136 words
A vibratory screening machine comprising a basket having an inclined screen, drive means for vibrating the basket to cause solid material deposited on the screen to migrate there along up the incline to the upper discharge end of the screen from which the solid material is discharged, wherein the drive means comprises a pair of counter-rotating masses respectively mounted for rotation about two spaced apart parallel axes between the sides of the basket, whereby the drive means exerts on the basket a resultant force along a line which passes through or near the centre of gravity of the basket when the latter is unloaded, and wherein the inclination of the screen is such that the centre of gravity of the basket continues to lie on or near the said line for different loadings of the basket.
Claim 20
Dependent Claim
90 words
A vibratory screening machine as claimed in claim 17, wherein the counter-rotating masses comprise two pairs of weights and including two drives therefor, each drive being located centrally between its associated pair of masses, each pair of masses being mounted for eccentric rotation about its associated drive axis, the masses being counter-rotated by their respective drives, and wherein the said line along which the resultant force acts joins the centre of gravity of the basket under normal loading conditions to the centre of action of the two pairs of masses.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-12-05 | 2004-06-05 | 2004-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-12-05 | 2008-06-05 | 2008-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-12-05 | 2012-06-05 | 2012-12-05 | $7700.00 | Window Closed / Lapsed |