The present invention relates to a mobile screening device for the screening of soil and other materials having a chassis, which is carried by at least one wheel or a similar member, and a screen frame, which is carried by said chassis and which comprises at least one screen that is supplied with material to be screened.
Screening devices for the separation of, e.g., stones and roots from a soil material are usually stationary, which generally means that unscreened material is transported to the screening assembly, is screened and divided into at least one useful fraction and one useless fraction, which should be deposited on, e.g., a dump. The useful fraction is in many cases used as refilling where the material once was excavated and accordingly has to be transported back to the place of origin. Therefore, there is a need of being able to screen, e.g., soil material on-site to avoid transports and unnecessary material handling.
A principally movable screening device is known from U.S. Pat. No. 5,285,905, but the device is not suited for, e.g., being moved along a pipe trench to refill material as excavation and piping advances. A screening device that is more suitable for a successive screening of material and repetitive movement is known from WO, A1, 9804783. This screening device has a chassis that is carried by caterpillar tracks and that carries an infeed bucket, a crushing device, a storage bin for soil improvement material as well as conveyors, an output conveyor of which for finished soil seems to be fixedly connected with the chassis. Similar screening devices are also known from JP, A, 2003041618 and JP, A, 2003170118 and have output conveyors that are fixedly connected with the chassis.
The caterpillar propulsion of the known screening devices is a disadvantage if the devices are to be transported longer distances, since they have to be transported on trailers. Another disadvantage of the known screening devices is that the infeed bucket and the output conveyor cannot be placed in a labour-saving way, e.g. when screening is to be made during successive movement of the screening device and, e.g., the excavator that excavates material and feeds the screening device. The chassis carried by caterpillar tracks has in such cases to be driven a distance, and then the entire chassis has to be rotated to come into position for a simultaneous excavation and replacement of screened material.
The object of the present invention is to provide a screening device that better meets the needs, e.g. in excavation and replacement of material. Thus, the invention embraces a mobile screening device for the screening of soil and other materials having a chassis, which is carried by at least one wheel or a similar member, and a screen frame, which is carried by said chassis and which comprises at least one screen that is supplied with material to be screened. Said screen frame is pivotable around a primarily vertical turning axis in relation to said chassis.
At least one feeding device may be arranged connected to said at least one screen and said screen frame may carry at least one output conveyor for finished screened material.
At least one locking device may be arranged between the chassis and the screen frame for the fixation of the position of the screen frame in relation to the chassis. The screen frame may be carried by a base, which is mounted to a turntable, which in turn is arranged on the chassis and has two mutually rotatable parts, wherein one part may be connected to the base and the other part may be connected to the chassis.
Said at least one locking device may comprise at least one tooth rim, which is connected with the base, and which further is connected to at least one lock member. At least one of said at least one lock member may be arranged to spring in between teeth on at least one of said at least one tooth rim by means of force from at least one spring, and to spring out when the screen frame is subjected to a horizontal force of a determined size that rotates the screen frame around the turning axis. The force from at least one of said at least one spring may be adjustable by means of at least one adjusting member.
By chassis, here all kinds of underframes with or without wheels or caterpillar tracks, which may be movable by their own engines or by towing by means of a traction vehicle or the like, are intended.
One or more feeding devices are arranged connected to occurring screens, preferably a feed hopper that in a freestanding way projects down into a spring-suspended feed bucket, which is provided with vibrators for the disintegration and feed of the material to the screen, which also is spring-suspended. The feed bucket has an outlet end, which suitably projects inwardly over the screen tray, inside which one or more mutually parallel grating-like screens are arranged. The screen tray also carries vibrators, by means of which the soil material is screened at the same time as separated coarser material is fed rearwardly and out through an opening in the rear end of the screen tray.
It is within the scope of the invention to implement the locking device in several different ways, e.g. in the form of friction blocks that abut against a brake disc that substitutes the chain wheel. It is also within the scope of the invention to rotate the screen frame mechanically, e.g. by means of an electric motor, which also may be remotely controlled from, e.g., the excavator operating at the screening device. This solution may advantageously be combined with different kinds of locking devices for the screen frame, which also may be remote-controlled.
An integrated drive generator is arranged hanging under the front part of the conveyor frame and comprises an internal combustion engine, which drives an electric generator. The belt conveyor and the vibrators are supplied with electric current from the integrated drive generator. To the integrated drive generator, a hydraulic pump may also be connected in the case hydraulic operation is an advantage.
By means of the screening device according to the invention, it is possible to carry out screening during successive movement of the screening device and, e.g., the excavator that excavates material and feeds the screening device. By means of the excavator, it is possible to tow the screening device to a desired location and there rotate the screen frame into a desired angle to the longitudinal direction of the chassis so that the excavator can feed in material into the feed hopper directly from the location where the material is excavated.
The screening device shown in
A screen frame 2 is carried by the chassis 1 and comprises a base 2.1 that is pivotable around a vertical pivot in relation to the chassis 1, and a belt conveyor 2.2 that is arranged in a conveyor frame 2.3 on the base 2.1. The conveyor frame 2.3 may slope 10-20°, preferably 11° to the horizontal plane. In
A feed hopper 3 for the soil material M is arranged on legs 3.1 that are attached to the conveyor frame 2.3 and project down freely into a feed bucket 4 provided with two electrically driven feed vibrators 4.1. The feed bucket is carried by four helical springs 4.2 connected to the conveyor frame 2.3. The feed vibrators 4.1 cause material M filled through the feed hopper 3 to be thrown upwardly and rearwardly against a screen tray 5 as shown schematically in
An integrated drive generator 6 is arranged hanging under the front part of the conveyor frame 2.3 and comprises an internal combustion engine 6.1, which drives an electric generator 6.2. The belt conveyor 2.2 and the vibrators 4.1, 5.3 are supplied with electric current from the integrated drive generator 6.
The base 2.1 of the screen frame 2 is, as shown in
A locking device 8 shown in detail in
Upon a change of the position of the screen frame 2 in relation to the chassis 1, pressure is applied, e.g. by an excavator bucket or the like, against the side of the front part of the screen frame 2, whereby the upper lock arm 8.2 springs out from the tooth rim 8.1 into a new position. For this purpose, the screen frame 2 may be provided with rubber linings 2.4, 2.5 at each side at the front as well as the rear end. For a permanent setting of the position of the screen frame 2, e.g. during road transportation of the screening device, the tooth rim 8.1 can be locked, e.g. by a cotter (not shown) that is brought down into a hole in any one of the teeth of the tooth rim 8.1, down into a corresponding hole in the triangular portion 1.6.
A simple movement of the screening device is provided by pulling or pushing, e.g. by means of an excavator bucket, a member (not shown) projecting from the chassis 1 and arranged on the telescopic towbar 1.2. In longer distance transportation, the towbar 1.2 is coupled to, e.g., a wheel-loader via the tow loop 1.3.
The invention is not limited to the embodiments shown herein, but may be varied within the scope of the subsequent claims.
Number | Date | Country | Kind |
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09015066 | Nov 2009 | SE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/SE2010/051320 | 11/30/2010 | WO | 00 | 5/29/2012 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2011/065915 | 6/3/2011 | WO | A |
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6378686 | Mayer et al. | Apr 2002 | B1 |
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Number | Date | Country |
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2459287 | Oct 2009 | GB |
2003041618 | Feb 2003 | JP |
2003170118 | Jun 2003 | JP |
9804783 | Feb 1998 | WO |
Entry |
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International Search Report, dated Mar. 1, 2011, from corresponding PCT application. |
Number | Date | Country | |
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20120234734 A1 | Sep 2012 | US |