US1565883A

US1565883A - Screen

Info

Publication number: US1565883A
Application number: US641327A
Authority: US
Inventors: Alfred L Adrianson; Axel L Bengtson
Original assignee: Individual
Current assignee: Individual
Priority date: 1923-05-25
Filing date: 1923-05-25
Publication date: 1925-12-15
Anticipated expiration: 1942-12-15

Description

Dec 15, 1925- 1,565,883

'A. L.. ADREANSON ET AL scnm'm Filed May 25, 1923 2 Siwets-Sheet 1 Dec. 15, 1925- 1,565,883 A. -L. ADRIANSON ET AL SCR-EEN 2 Sheets-Shut 12 Filed May 25, 1923 Z. Jdrz tented Uec. 1:), was.

UNITED STATES PATENT OFFICE.

ALFRED L. ADRIANSON AND AXEL L. BENGTSON, OF RACINE, WISCONSIN.

SCREEN.

Application filed May 25, 1923.

To all whom it may concern:

Be it known that we, ALFRED L. ADRIAN- SON and Axnr. L. BENGTSON, citizens of the United States, residing at Racine, in the county of Racine and State of lVisconsin, have invented certain new and useful Improvements in Screens, of which the following is a specification.

Our invention relates to screens of the type which are used for screening or grading gravel, crushed rock and the like, the present invention having reference particularly to improvements in the screen which is shown in our application filed June 6, 1921, Serial No. 175,366.

The principal. objects of our invention are to improve the operating mechanism so that it is not affected by the stresses and strains to which the structure is subjected; to mount and reinforce the screen fabric so that it is capable of readily withstanding extreme wear and tear; and to provide an improved support for the driving mechanism and other parts of the structure so that the device is conveniently adaptable to Various operating conditions.

()n the drawings:

Fig.1 is a side view of a screen set up for use and embodying our improvements;

Fig. 2 a top view of the screen;

Fig. 3 an end view thereof;

Fig. at an enlarged fragmentary sectional view on the line 4el of Fig. 2;

Fig. 5 a similar view showing a modified form of screen or shaker section; and

Fig. 6 a view partly in section showing the bearing for the vibrator shaft.

Referring to the drawings, the reference numeral 1 indicates the supporting base which is preferably composed of a pair of spaced side rails or sills which are su1tably connected together to form a solid frame work. Mounted on the supporting base 1 is an inclined frame comprising a pair of side rails 2 which are connected together in spaced relation by cross members 3, and have their lower ends connected to the side rails of the base 1 by bolts 4, the side rails of the base 1 being preferably provided with a number of apertures 5 so as to afford an adjustable connection of the lower end of the inclined frame with the base 1. The upper end of the inclined frame is carried by a strut comprising a pair of side mem: bers 6 which are suitably secured together by cross braces 7 and have their lower ends Serial No. 641,327.

connected to the side rails of the base 1 by bolts 8, a number of apertures 9 being pref e ably provided in the side rails of the base to afford an adjustable connection of the strut with the base. The upper ends of the side members 6 are connected by bolts 10 to blocks 11 which latter are secured to the under side of the side rails 2 of the inclined frame, a number of bolt holes 12 being pro vided in the side members 6 for affording an adjustable connection of the upper end of the strut with the inclined frame.

By reason of the construction just de scribed, ample adjustment is afforded whercby the inclined frame 2*?) which supports the shaker or screen section, may be arranged in substantially any desired angular position to suit the particular requirements of each case without the necessity of providing a special frame or cutting and fitting the parts to afford the desired inclination to the screen.

The shaker section which carries the screen, comprises a pair of laterally spaced elongated side walls 13 which are connected across the top by a plurality of channel irons 1 1-, spaced at intervals throughout the length of the shaker section, and provided with downturned ends 15 which are secured by bolts 16 to the outer sides of the side walls 13. The lower portions of these side walls are connected together at their ends by transverse f'anie members 16 and intermediate of the ends by cross rods 17 which pass through spacer tubes 18, these intermediate connections being preferably located at the same points as the overhead braces 14:.

The screen 19 which is preferably a wire fabric of suitable mesh, is located somewhat above the lower edges or extremities of the side walls 18 as shown in Figs. 8 and 4t and has the opposite edges clamped between the inwardly extending flanges of upper and lower angle irons 20 by bolts 21. The upright flanges of the angle irons 20 extend respectively above and below the screen 19 as shown in Fig. 1, and are secured to the side walls 13 of the shaker section by the bolts 22, the provision of the bolts above and below this screen making it possible to effect a direct pull on the screen 19 so that there is no bend in the screen along the inner edge of the angle iron which occurs in some structures where the connection is only above or below the screen. The width of the screen 19 and the position of the angle irons 2O thereon is such that there is a gap between the upright flanges of the angle irons and the side walls of the shaker section, this being desirable so as to afford ample oppor tunity to take up slack in the screen 19 and draw the latter up to the required tension. To prevent the material escaping through the gap between the angle irons 20 and the side walls 13, and to avoid accumulation in this gap which would interfere with the proper drawing up of the screen, a half round 23 or other suitable shield is secured along the inner side of the side wall 13 in contact with the upper edge of the upper angle iron as shown in Fig. 4, so that the latter when drawn outwardly, bears against this head and this closes the top of the gap.

The operation of the vibrating mechanism hereinafter described imposes or imparts an up and down vibratory movement to the screen 19, and in screens of the usual width it is impossible to draw the latter up tight enough so that the center of the screen does not yield somewhat under the vibration .and weight of the material thereon.- This not only decreases the eiiiciency of the screen on account of insufficient vibration at the cen ter, but also causes the screen to break and wear out in a short time. To avoid this detrimental yielding of the center portion of the screen, we have provided a center reinforcing comprising a channel iron 2-1 and strap 25 which extend lengthwise of and on the upper and lower sides respectively of the screen and are connected at spaced intervals by hangers to the top cross members let. The top cross members 14 are preferably reinforced by channel members 26 which are secured to the under sides thereof as shown in Fig. 4, and the hangers for supporting the reinforcing

straps

21 and 25 comprise bolts 27 which engage the cross members let-6 and reinforcing straps 24-25, and have the sleeve 28 clamped therebetwcen-by the nut 29. This construction not only affords a substantial support for the weight imposed upon the center of the screen, but also serves to effectively transmit the vibration, to which the device is subjected, to the center of the screen and results in greater eiliciency.

For vibrating this screen a shaft 30 is mounted midway between the ends of the shaker section and extends transversely thereof as shown in Figs. 2 and 3, the opposite cnds of said shaft being supported in special bearings 31 carried by a frame structure 32 which extends between the upper portions of the side walls 13 and is rigidly secured thereto. This shaft has an eccentric 33 or other suitable means adjacent each end correspondingly arranged on the shaft 30 so as to unbalance the shaft, and tnis shaft has a. pulley 3% at one end connected by the belt 35 with a pulley 36 on the motor 37 whereby the shaft 30 is rapidly rotated. The eccentrics 33 are comparatively small and the shaft 30 operated at a rather high speed with the result that a rapid vibration or tremble is imparted to the shaker section instead of a perceptible shake, and this serves to screen the material more effectively than the usual shaking movement which it has been customary to provide in devices of this character.

For supporting the shaker section in a manner so that it may vibrate in lines substantially perpendicular to the screen 19, each end of the shaker section is supported by a semi-elliptic spring 38 which is contrally secured as at 39 to the corresponding cross frame member 16, while the outer ends of the springs 38 are connected by the shackles or links 40 to suitable brackets 4-1 on the cross members 3 of the inclined frame 2.

In devices of this character, variations in the quantity of material or uneven distribution of the material on the screen in'lposcs considerable distorting strain on the framework of the shaker section so that if ordinary bearings are employed for supporting the shaft 80, the latter frequently binds in the bearings and this binding is particularly undesirable, in view of the rather high rate of speed 'at which the shaft is required to operate. To insure freedom of operation of the shaft 330 without binding under these conditions, we have provided self aligning -ball bearings such as shown in Fig. (3. These bearings comprise a casing 42 containing a ring 43 which is clamped in the housing by a side plate let, the side of the housing 49 and the plate d-l on the pulley side of the shaker section being provided with apertures l5 and .46 respectively, which are somewhat larger than the shaft extending therethrough so as to permit ample clearance. Packing cm. es 1-? are provided in the outer faces of the housing 4-2 and the cover plate l-lshown in Fig. (i in each of wh ch a quantity of packing is held by a cover plate 1.), which packing tits closely around the shaft without interfering with freedom of movement of the latter. The bearing ring 43 is provided with a concave raceway on the inside as shown at :50 which is engaged by two rows of balls 51, and the portion of the shaft within the raceway has a bearing ring 52 clamped thereon and provided with a pair of concave raceways for the balls The ring may be secured on the shaft 30 in any suitable manner, as for example, by a clamping nut [riwhich is threaded on the shaft 30 and provided with a locking plate for holding the nut against turning movement when it is clamped in position against an adjacent shoulder formed by the reduced end of the shaft. in view of the con "ave raceway 50 of the bearing ring 3, these shaft bearings readily adjust them selves to any slight deviations of alignment caused by strains on the shaker section and permit the shaft 30 to rotate freely at all times. The shaft 30, as will be noted from Figs. 9, and 3, does not project through the hearing at the side of the shaker section opposite the pulley 34-, and a plain cover plate 56 is therefore provided instead of the apertured cover plate 44: shown in Fig. 6.

For the purpose of conveniently supporting the motor 37 the upper end of the side member 2, at the side of the machine on which the pulley 34 is located, is provided with a block 57 near the upper end to which the "bracket 58 is pivoted by means of a bolt 59, said bracket comprising an upright plate portion having a laterally extending shelf on which the motor is secured. concentrically arranged around the bolt 59 are a plurality of bolt holes 60 which are adapted to be engaged by the bolt 61 which passes through the side rail 2 forlocking the bracket in various positions of adjustment around the bolt 59 as a center; this arrangement being provided so that the top or shelf portion of the bracket may be adjusted to occupy a horizontal position in the various positions of angular adjustment of the inclined frame 2.

In Fig. 5 we have shown a modified form of shaker section which is adapted particularly for heavy duty, wherein a perforated plate 62 is used instead of. the screen fabric 19, this plate being sufficiently stiff so that it is unnecessary to mount same for lateral stretching as in the case of the wire fabric. The supporting frame for this screen comprises a pair of laterally spaced angle irons 63 which are held in the required spaced relation by cross bars 6% preferably of channel form and have the angle irons 65 secured thereto with one of the flanges thereof extending inwardly over the upright flange of the angle iron 63. The lateral edges or side margins of the perforated plate 62 are secured to these inwardly extending flanges by bolts 66 or other suitable fasteners, and the intermediate portion of the plate is supported by a channel iron 67 which extends from end to end of the shaker section, is set up on edge and has the lower flange secured to the cross members (it .and the upper flange secured to the plate 62. The sides of the shaker section are composed of upright plates 68 which are set up on edge on the top flange of the angle iron 65 and maintained in the upright position by braces 69 which have the opposite ends secured respectively to the side wall 68 and the side flange of the angle iron 65. The shaft 70 of the vibrating mechanism which corresponds to the shaft 30 of the structure previously described is journaled to the underside of the shaker section in bearings 71 and has eccentrics 72.

secured thereon. Cover plates 73 are disdeposit from the perforated plate 62 coming in contact with the eccentrics. This con struction affords a clear space above the perforated plate 62 without any obstructing cross members such as the cross members 1+t of the previous structure, and is more desirable in some cases, particularly for heavy duty, than is the previously described structure.

which varies with the character of the work which they are required to perform, the supporting frame structure shown in Fig. 1

being conveniently adaptable by reason ofits various adjustments to afford any desired inclination and the mounting of the motor bracket 58 permitting the necessary correction ofLthe motor position to correspond with the angularity of the screen section for maintaining the motor in the proper upright posi ion. In cases where the material is delivered to the screen section by a chute which delivers the material at a greater speed than desired, an obstruction such as shown at 74 in Fig. 1 may be provided to intercept the material from the chute 7 5 and cause the material to drop down onto the upper end of the screen.

While we have shown and described our invention in a preferred form, we are aware that various changes and modifications may be made without departing from the principles of our invention, the scope of which is to be determined by the appended claims.

lVe claim as our invention:

1. In a device of the class described, the combination of a shaker section comprising a pair of. elongated laterally spaced side walls having a screen stretched therebetween, a plurality of rigid cross members connecting the side walls'and spaced from the screen, rigid reinforcing means carried by the cross members and extending length wise of the shaker section and secured to the screen intermediate of the side walls, a supporting frame, springs at the end of the shaker section whereby the shaker section is resiliently mounted on the supporting frame, and means for bodily reciprocating the shaker section and screen substantially perpendicular to the screen surface.

2. In a device of the class described. the combination of a shaker section. comprising a pair of elongated laterally spaced side walls having a screen stretched therebetwcen, a plurality of rigid cross members elevated above the screen and spaced at intervals throughout the length of the shaker section and connecting the upper portions of the side walls, rigid reinforcing means extending lengthwise of the shaker section and secured to the screen intermediate of the sidewalls, hangers rigidly connecting the reinforcing means with the cross braces, a main frame, springs at the ends of the shaker section for These screens are set at an inclination connected with the side resiliently supporting the latter on the main frame, and means for bodily reciprocating the shaker section and screen substantially perpendicular to the screen surface.

3. In a device of the class described, the combination of a shaker section comprising a pair of elongated laterally spaced side walls having a screen stretched therebetween, a plurality of relatively closely related rigid overhead cross braces spaced at intervals throughout the length of the shaker section and connecting the upper portions of the side walls, a pair of rigid reinforcing members extending lengthwise of the shaker section midway between the side walls thereof and engaged respectively against the upper and lower surfaces of the screen, threaded means rigidly connecting the reinforcing members with the cross braces and having spacers thereon interposed between the cross members and the upper reinforcing member, a main frame, springs at the ends of the shaker section for supporting the latter in the main frame, and means for bodily reciprocating the shaker section and screen subst antially perpendicular to the screen surface.

41-. In a device of the class described, the con'ibination of a shaker section comprising a pair of laterally spaced elongated side walls, a screen extending between the side walls, a pair of reversely arranged angle irons extending along each lateral edge of the screen and having the edge of the screen clamped between inwardly extending flanges thereof, said angle irons having their other :tiangcs extending respectively upwardly and downwardly from the screen and spaced from the corresponding side wall of the shaker section, threaded means engaging the latter flanges above and below the screen and "alls of the shaker SCCtlOII fOIT stretching the screen therebctween, a half-round shield secured along the inner sides of the side walls adjacent the upper angle irons to prevent accumulation of material between the angle irons and side walls, a supporting frame, means whereby the shaker section is resiliently mounted on the supporting frame, and mechanism on th shaker section for vibrating the latter.

5. In a device of the class described, the combination of a vibratable frame comprising a pair of laterally spaced elongated side walls, a screen interposed between the side walls and having a pair of angle irons secured along each edge with upright flanges respectively above and below the screen and spaced from the correspomling side wall, threaded members above and below the screen and connecting the said flanges with the corresponding side wall for stretching the screen between the side walls, and a shield on the side wall extending inwardly over the upright flange of the upper angle for closing the gap between the angle. irons and the adjoining side wall.

6. In a device of the class described, the con'ibination of a shaker section having a screen bottom, a supporting frame, an angularly adjustable supporting frame, springs at each end of the shaker section for supporting the latter on the supporting frame, a transverse shaft journaled on the shaker section intermediate of the ends and provided with eccentric means thereon for vibrating the shaker section upon rotation of the shaft, a bracket on the supporting frame having a motor mounted thereon, the latter having driving connections with the aforesaid shaft, and means for adjusting the bracket according to the inclination of the supporting frame so as to maintain the motor in an upright position.

T. In vibrating screen, the combination with a support, of a frame having spaced side 'alls,. a screen stretched between said side walls, transverse frame members rigidly connecting said walls, a plurality of cross members rigidly connecting said side walls and spared from the screen, longitudinal reinforcing members embracing the screen media ly of its width, rigid connecting means between the cross members and said longitudinal reinforcing members, transverse springs at the ends of the frame resiliently inounting the same on' the support, and mechanism for bodily vibrating the frame and screen substantially at right angles to the plane of the latter and in unison.

S. In a device of the class described, the combination of a shaker section comprising a. pair of elongated laterally spaced side walls having a screen stretched therebetween, a plurality of rigid cross members elevated above the screen andconnecting said side walls, rigid reinforcing means extending lengthwise of the shaker section in contact with and Secured to the screen intermediate of the side walls, said reinforcing means being braced and connected to the cross members and screen to cause the screen to move bodily and rigidly with the shaker section at all times and at the same number of vibrations, a main frame, means for yieldably supporting the shaker section and screen, and means for imparting a vertically elongated circular motion to the shaker section in a direction substantially at right angles to the plane of the screen.

'9. In a vibrating screen, a main frame, a shaker section having spaced side walls, transverse frame members connecting said side walls at their bottom edges and near their ends, a plurality of rigid cross members connecting the side walls at their upper ei'lgcs, a screen stretched between the side walls, central longitudinal reinforcing members embracing the screen on opposite sides thereof, rigid connections between the ross 10. In a. device of the class described, the

combination of a shaker section comprising a pair of elongated laterally spaced side "walls, a screen stretched therebetween, a plurality of inverted U-shaped rigid cross members connecting the side walls outwardly thereof and spaced from the screen, rigid reinforcing means carried by the cross members and extending lengthwise of the shaker section incontact with and secured to the screen intermediate oi the side walls,

an inclined supporting frame, meansfoc yieldably supporting the shaker section and screen, and means on. the shaker section for bodily vibrating the same and screen rigidly and in unison in a direction substantially perpendicular to the screen.

11. In a device of the class described, the combination out a frame comprising a pair of laterally spaced elongated side walls, a screen interposed between the side walls and having a pair of angle irons secured along each edge with upright flanges respectively above and below the screen and spaced from the corresponding side wall, adjustable conneutions above and below the screen and con necting the said flanges with the corresponding side wall for stretching the screen between the side walls, and a convex shield on the side wall extending inwardly over the upright 'llange ot' the. upper angle for closing the gap between the angle irons and the adjoining side wall.

ALFRED L. ADRIANSON. AXEL L. BENGTSON.