Tramp metal removing device

A tramp metal removing device has a primary housing to define a product flow path for being passed by a stream of raw materials and a moving path. A secondary housing is connected to the primary housing. A plurality of drawer units are sequentially stacked on the primary housing and secondary housing. Each drawer unit has a frame, a plurality of magnetic members and a scraping assembly. The frame is coupled with the primary and secondary housings in a movable way. Each of magnetic members is secured on the frame and has a magnetic section and a non-magnetic section. The scraping assembly is coupled with the frame in a way that it is only moveable in the secondary housing for removing tramp metals of a stream of raw materials in a two-stage manner.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to devices for removing tramp metals from a stream of raw materials, and more particularly to a tramp metal removing device that can scrape off tramp metals in a two-stage manner.

2. Description of the Related Art

A conventional device for removing tramp metals from a stream of raw materials is disclosed in U.S. Pat. No. 4,867,869. The device includes a duct, a frame removably housed within the duct and a plurality of non-magnetic tubes supported by the frame and extending across an opening in the frame. Each of the tubes removably houses a magnet. The magnets can be pulled out of the tubes in order to remove tramp metals from the exterior of the tubes. A disadvantage of this device is that tramp metals in a stream of raw materials are not directly attached to the magnets thereof, so the tramp metals cannot be effectively removed from the stream of raw materials. And another disadvantage of this device is that the tramp metals attached on the exterior of the tubes are separated from the exterior of the tubes only in an automatic way, so there is still a small amount of the tramp metals remained on the exterior of the tubes.

Another conventional device for removing tramp metals from a stream of raw materials is disclosed in U.S. Pat. No. 6,902,066. The device named a removal unit for metal alien removal apparatus includes a body and a removal unit coupled to the body in a way that it can be inserted into or pulled out the body. The removal unit includes a plurality of magnet members and a removal member arranged to be slidable along the magnet members while being in contact with the outer peripheral surfaces of the magnet members. Each of the magnet members includes a cylindrical stainless steel rod, a magnet received in one end of the cylindrical stainless steel rod and a non-magnetic piece received respectively in the other end of the cylindrical stainless steel rod. A disadvantage of this device is that, as shown inFIGS.5B and5Cof the patent, as the removal member is used to wipe the metallic alien materials attached to the outer peripheral surface of each stainless steel rod, it must slide from one end of the stainless steel rod toward the other end of the stainless steel rod in which the non-magnetic piece is received. In other words, when the removal member is to wipe the metallic alien materials attached to the outer peripheral surface of each stainless steel rod, the sliding distance of the removal member is almost equal to the whole length of stainless steel rod. Such an operation is not only laborious but also time-consuming.

Thus, it is need to configure a tramp metal removing device to overcome the disadvantages mentioned above.

SUMMARY OF THE INVENTION

Disclosed herein is a tramp metal removing device comprising a primary housing, a secondary housing and a plurality of drawer units. The primary housing includes an upper inlet, a bottom outlet opposite the upper inlet and a first internal space disposed between the upper inlet and the bottom outlet to define a product flow path through which a stream of raw materials may pass. The first internal space also defines a moving path and has a first length in the direction of the moving path. The secondary housing is connected to the first housing and includes a second internal space adjacent to the first internal space. The second internal space has a second length shorter than the first length in the direction of the moving path. The drawer units are sequentially stacked on the primary housing and the secondary housing. Each of the drawer units comprises a frame, a plurality of magnetic members and a scraping assembly. The frame is coupled with the primary housing and the secondary housing in a way that it is moveable in the moving path between a retracted, passaged and extended positions. Each of the magnetic members has a magnetic section, a non-magnetic section and a third length shorter than the first length but longer than the second length and is secured on the frame in a way that when the frame is in the retracted position, each of the magnetic members is received in the first internal space and adapted to be in contact with a stream of raw materials, when the frame is moved from the retracted position to the passaged position, the magnetic members are moved a first distance to be in a state that a portion of each of the magnetic members is positioned outside the first internal space and the other portion thereof is received within the first internal space, and when the frame is moved from the passaged position to the extended position, the magnetic members are moved a second distance to be in a state that a portion of each of the magnetic members is positioned outside the second internal space and the other portion thereof including the non-magnetic section is received within the second internal space. The scraping assembly is coupled with each of magnetic members and the frame in a way that when the frame is located on the retracted position, the scraping assembly is received and located in one side of the second internal space, when the frame is moved from the retracted position to the passaged position, the scraping assembly is moved synchronously with the frame to be located in the other side of the second internal space for removing tramp metals from the portion of each of the magnetic members positioned outside the second internal space to the other portion of each of the magnetic members received within the second internal space as the frame is continuously moved in the moving path, and when the frame is moved from the passaged position to the extended position, the scraping assembly is still located in the other side of the second internal space for removing tramp metals from the magnetic section of each of the magnetic members to the non-magnetic section of each of the magnetic members to discharge tramp metals as the scraping assembly is moved relative to each of magnetic members in a direction opposite to the moving path.

In this way, the tramp metal removing device disclosed provides the advantage of the sliding distance of the scraping assembly for removing tramp metals attached to the magnetic members being shorten and thereby resulting in not only labor-saving but also time-saving.

The frame of the tramp metal separation device may include a front plate, a rear plate opposite the front plate, a face plate opposite the front plate, a pair of guiding rods, and at least a connecting rod. Each of the guiding rods has a fourth length in the direction of the moving path and longer than the third length and is coupled between the face and rear plates in a way that one of the guiding rods is coupled at a first end thereof to one side of the face plate and at a second end thereof to one side of the rear plate, and the other one of the guiding rods is coupled at a first end thereof to the other side of the face plate and at a second end thereof to the other side of the rear plate. The at least connecting rod is coupled between the front and face plates in a way that a front end thereof is coupled to the front plate and a rear end thereof is coupled to the face plate.

Each of the magnetic members may include a non-magnetic rod, a magnetic set and a non-magnetic element. The non-magnetic rod has a proximal end coupled to the front plate and a distal end coupled to the rear plate. The magnetic set is received within the non-magnetic rod and extends from the proximal end of the non-magnetic rod to at least a middle portion of non-magnetic rod for forming the magnetic section. The non-magnetic element is received within the distal end of the non-magnetic rod and extends from the distal end to abut to the magnetic set for forming the non-magnetic section.

The scraping assembly may comprise a base plate and a first scraper. The base plate is coupled with the guiding rods and includes a window. The first scraper is made of a first material with a predetermined hardness, secured on one side of the base plate, and having a plurality of first apertures arranged in an area thereof corresponding the window for being passed through by each of the magnetic members respectively wherein the inner peripheral surface of each of the first apertures is in close contact with the outer peripheral surface of an associated one of the magnetic members.

The scraping assembly may further comprise a second scraper made of a second material with a hardness less than that of the first material, secured on the other side of the base plate, and having a plurality of second apertures arranged in an area corresponding the window for being passed through by each of the magnetic members respectively wherein each of the second apertures has an inner diameter smaller than the outer diameter of the non-magnetic rod to form an interference fit therebetween.

The primary housing may further comprise a first entrance from which each of the drawer units is pushed into or pulled out the first internal space of the primary housing, two first support plates respectively disposed on each side of the first entrance through which the guiding rods of each of the frames pass so that each of the frames can be moved independently along the moving path between the retracted, passaged position and extended positions.

The secondary housing may further comprise two side walls defining the second internal space with a second entrance so that a portion of each of the drawer units can be pushed into or pulled out the second internal space from the second entrance, and two second support plates respectively disposed on each side of the second entrance through which the guiding rods of each of the frames pass.

Each of the side walls of the secondary housing may comprise a plurality of guiding slots spaced apart from each other and having a predetermined length in the direction of the moving path to define the second distance, and the scraping assembly may further comprise a pair of guiding bars extending outwardly from each of the guiding slots to which each of the guiding bars corresponds so that the scraping assembly can be moved along the guiding slots.

The tramp metal removing device may also comprise at least a mechanical latch for selectively locking the drawer unit in a closed position with respect to the secondary housing.

DETAILED DESCRIPTION OF THE INVENTION

Referring firstly toFIG.1, it shows a tramp metal removing device100configured according to a first preferred embodiment of the present invention. The tramp metal removing device100comprises a primary housing10, a secondary housing30connected to the primary housing10, a collector50disposed under secondary housing30, and three drawer units60respectively arranged within the primary housing10and secondary housing30in a sequentially stacked manner.

The primary housing10includes a pair of first side walls102and104, a pair of first supporting plates106and108and a stopping plate110. The first side walls102and104are combined to define an upper inlet14, a bottom outlet16opposite the upper inlet14and a first internal space12between the upper inlet14and the bottom outlet16. The first internal space12defines a product flow path through which a stream of raw materials may pass, a moving path P perpendicular to the product flow path, a first length L1in the direction of the moving path P and a first entrance18. The stopping plate110is disposed on the first entrance18. Each of the first supporting plates106and108is respectively secured on the left and right sides of the stopping plate110.

The secondary housing30includes a pair of second side walls302and304, a pair of second supporting plates306and308and an upper plate307. The second side walls302,304and the upper plate307are combined to define a second internal space32with a second length L2in the direction of the moving path P, a collecting opening34located above the collector50and a second entrance36. The second internal space32is adjacent to the first internal space12in the direction of the moving path P. The second length L2is shorter than the first length L1of the first internal space32. The secondary housing30further includes two cross bars38fixed to the second supporting plates306and308respectively in a way that the second entrance36is divided into three exits361,362and363so that each of the drawer units60can be pushed into or pulled out the second internal space32independently. The upper plate307has a top opening313so that the operator can view into the second internal space32therefrom.

Next, referring toFIG.2, each of the drawer unit60comprises a frame61, six magnetic members70and a scraping assembly90.

The frame61includes a front plate62, a rear plate64, a face plate66and a pair of guiding rods80. The front plate62has a first width W1defining a first range for fixing one end of each of the magnetic members70. The rear plate64has a second width W2that is longer than the first width W1for fixing the other end of each of the magnetic members70in a second range opposite to the first range and reserving two edges thereof for fixing one end of each guiding rods80respectively. The front and rear plates62and64are spaced apart from each other by a desired distance. The magnetic members70are coupled between the front and rear plates62and64in a way that each of them is spaced apart and horizontally side by side with one end thereof fixed to the front plate62and the other end fixed to the rear plate64.

Each of the magnetic members70, as shown inFIGS.2-5, includes a non-magnetic rod701, a magnetic set720and a non-magnetic element742. The non-magnetic rod701has a third length L3in the direction of the moving path P, a proximal end702coupled to the front plate62and a distal end704coupled to the rear plate64. In this embodiment, the non-magnetic rod701has a drop-shaped cross section for reducing the accumulation of raw materials. The magnetic set720includes a plurality of magnets722and a plurality of spacers724respectively disposed between the two adjacent magnets722. The magnetic set720is received in the non-magnetic rod701and extends from the proximal end702of the non-magnetic rod701to at least a middle portion of the non-magnetic rod701for forming a magnetic section72. The non-magnetic element742is received in the distal end704of the non-magnetic rod701and extends from the distal end704to abut to the magnetic set720for forming a non-magnetic section74. Preferably, the third length L3of the non-magnetic rod701is shorter than the first length L1of the first internal space12but longer than the second length L2of the second internal space32.

Each of the guiding rods80, as shown inFIG.2, has a fourth length L4longer than the third length L3of the non-magnetic rod701and coupled between the face and rear plates66and64in a way that one of the guiding rods80is coupled at a first end802thereof to one side of the face plate66and at a second end804thereof to one side of the rear plate64, and the other one of the guiding rods80is coupled at a first end802thereof to the other side of the face plate66and at a second end804thereof to the other side of the rear plate64.

In this embodiment, for enabling the magnetic members70to be moved stably, the frame61further includes a pair of connecting rods82having a fifth length L5approximately equal to the second length L2of the secondary housing and coupled between the front and face plates62and66respectively in a way that a front end822of each of the connecting rods82is coupled to the face plate66and a rear end824of each of the connecting rods82is coupled to the front plate62.

The scraping assembly90is disposed in the second internal space32of the secondary housing30and arranged to be slidable along the longitudinal direction of the non-magnetic rods701while being in contact with the outer peripheral surface of each of the non-magnetic rods701. In this embodiment, as shown inFIG.6, the scraping assembly is specially designed as described below.

The scraping assembly90comprises a base plate92, a first scraper94, a second scraper96and an emplacing plate98. The base plate92includes a window920and two through holes922respectively located on each end thereof for being passed through by the guiding rods80. The first scraper94is made of a first material with a predetermined hardness, such as Mono Cast Nylon, and secured on one side of the base plate92. The first scraper94has a plurality of first apertures942arranged in an area thereof corresponding the window920for being passed through by the magnetic members70respectively wherein the inner peripheral surface of each first aperture942is in close contact with the outer peripheral surface of an associated one of the magnetic members70. The second scraper96is made of a second material with a hardness less than that of the first material, such as silicone rubber and secured on the other side of the base plate92. The second scraper96also has a plurality of second apertures962also arranged in an area corresponding the window920for being passed through by the magnetic members70respectively. In this embodiment, each second aperture962has an inner diameter smaller than the outer diameter of the non-magnetic rod701, resulting in an interference fit therebetween that will further aid in totally and reliably scraping tramp metals. The emplacing plate98has a plurality of third apertures982opposite to the second apertures962, and is secured on the base plate92in a manner that the second scraper96is emplaced between the base plate92and the emplacing plate98for being passed through by the non-magnetic rods70stably and tightly.

In combination, as shown inFIGS.1,7and8, each of the drawer units60is combined with the primary and secondary housings10and30in the same way. Accordingly, each of the drawer units60will be described herein with reference to the upper drawer unit60. In this embodiment, each of the guiding rods80of the frame61passes through a first guiding bore113and115disposed on each of the first supporting plates106,108and a second guiding bore309and311disposed on each of the second supporting plates306,308so that the frame61is supported thereby and movable along the moving path P. For enabling each guiding rod80to slide smoothly on each of the guiding bores, a self-lubricating bearing can be respectively installed therein. Furthermore, each of the two side walls302and304of the secondary housing30comprises three guiding slots310that are spaced apart from each other and have a sixth length L6approximately equal to the second length L2in the direction of moving path P. The scraping assembly90further comprises a pair of guiding bars924disposed on each side of the base plate92and extending outwardly from each of the guiding slots310so that the scraping assembly90is movable in a first distance defined by the sixth length L6of the guiding slots310. The face plate66includes a pair of handlebars660for the operator to hold when moving the drawer unit60.

When the frame61is combined with the primary housing10, the rear plate64is received in the first internal space12and the stopping plate110has a plurality of guiding bores112so that when the frame61is pulled out to be located in the extended position, the rear plate64is stopped by the stopping plate110to limit the frame61in that position and allow the magnetic members70passing through the guiding bores112to enter the second internal space32. And when the frame61is pulled out to be located in the extended position, the scraping assembly90is moved synchronously to lean against the front ends of the guiding slots310by the guiding bars924thereof. In such a state, as shown inFIG.8, for the fourth length L3of the magnetic member70is longer than the second length L2of the secondary housing30, a front part707of the magnetic member70is located outside the secondary housing30and a rear part708of the magnetic member70including the non-magnetic section74is located inside the secondary housing30. Preferably, the length of the front part707is longer than that of the rear part708.

Moreover, in this embodiment, as shown inFIG.7, the first length L1of the first internal space12is longer than the fourth length L3of the magnetic member70and the front plate62is disposed outside the first internal space12so that when being pushed into until the front plate62is stopped by the stopping plate110, the frame61is located in the retracted position, all the magnetic members70are received in the first internal space12for contacting with the stream of raw materials, and the face plate66is lean against the second supporting plates306,308of the secondary housing30. At the same time, the scraping assembly90is moved synchronously to lean against the rear ends of the guiding slots310by the guiding bars924. In addition, the secondary housing30may further comprise a plurality of mechanical latches39disposed on the second side walls302and304of the secondary housing30respectively for selectively locking the drawer units60in a closed position with respect to the secondary housing30.

Hereinafter described is the operation of the tramp metal removing device100and, thereby, the advantages of it will be more clearly understood. As shown inFIGS.7and9, all the drawer units60are firstly positioned in the retracted position. In this state, the magnetic members70are received in the first internal space12for contacting with the stream of raw materials introduced into the first inter space12from the upper inlet14, and allowed to pass through the first inter space12. As the stream of raw materials passes through the primary housing10, tramp metals contained therein are attached to the outer peripheral surface of the magnetic section72of each magnetic member70. And at this time, all the drawer units60are locked in this position by the mechanical latches39. As tramp metals attached to the magnetic members70reach a predetermined amount, as shown inFIG.7, the operator firstly unlocks the mechanical latches39and then holds the handlebars660to pull the upper frame61outwardly along the moving path P in a first distance approximately equal to the second length L2. At the same time, the scraping assembly90is moved synchronously in the first distance to lean against the front ends of the guiding slots310by the guiding bars924, as shown inFIG.9. In this state, the frame61and the scraping assembly90are both located at the passaged position. And when the frame61is pulled out continuously along the moving path P in a second distance to be located in the extended position, as shown inFIG.10, tramp metals attached to the front part707of the magnetic member70are removed by the scraping assembly90and gathered on the rear part708of the magnetic member70received in the secondary housing30for performing the first stage of scraping. Then, the operator re-locks the mechanical latches39and holds the guiding bars924to move the scraping assembly90in a direction opposite to the moving path P until the guiding bars924lean against the rear ends of the guiding slots310, as shown inFIGS.11and12, such that tramp metals attached to the rear part708of the magnetic members70are removed by the scraping assembly90toward the non-magnetic section74and automatically separated therefrom for performing the second stage of scraping action. The design mentioned above, by pulling out the frame61while performing the first stage of the scraping action, can shorten the distance of the second stage of scraping action. Therefore, compared with the prior art, the present invention is not only labor-saving but also time-saving.

Besides, referring toFIG.13, it shows a tramp metal removing device200configured according to a second preferred embodiment of the present invention. The tramp metal removing device200may include two drawer units202and204, two first linear actuators206and208, and two second linear actuators214and216. The first linear actuators206and208are coupled with the face plates210and212of the drawer units202and204respectively. The second linear actuators214and216are coupled with the scraping assembly218and220of the drawer units202and204respectively. When operating, the first linear actuators206and the second linear actuator214are driven synchronously to move the upper drawer unit202from a retracted position along the moving path P to an extended position. And then, only the second linear actuator214is driven to move the scraping assembly218in a direction opposite to the moving path P to remove tramp metals attached to the magnetic members of the upper drawer unit202.