US3645376A

US3645376A - Billet handling system including magnetic pickoff means

Info

Publication number: US3645376A
Application number: US851809A
Authority: US
Inventors: Richard S Gewartowski
Original assignee: Magnaflux Corp
Current assignee: Magnaflux Corp
Priority date: 1969-08-21
Filing date: 1969-08-21
Publication date: 1972-02-29
Anticipated expiration: 1989-02-28

Abstract

Billet-handling system in which a plurality of spaced arms pivotal on a common horizontal axis carry electromagnets having faces engageable with longitudinally spaced portions of a vertical face of a billet on an edge portion of a horizontal support table, the arms being rotatable to move the billet sidewise to a position over receiving rollers which move the billet lengthwise. The magnets are supported on the arms through a pivotal connection which is preferably loose and the arms are independently operated through fluid-operating means, with the magnets being independently movable into firm engagement with the billet even though the billet is twisted or cambered. Each arm is preferably provided with a surface which underlies the billet during the pickoff and transfer operation.

Description

United States Patent Gewartowski 1 Feb. 29, 1972 [54] BILLET HANDLING SYSTEM INCLUDING MAGNETIC PICKOFF Primary Examiner-Richard E. Aegerter Attorney-Hill, Sherman, Meroni, Gross & Simpson [57] ABSTRACT Billet-handling system in which a plurality of spaced arms pivotal on a common horizontal axis carry electromagnets having faces engageable with longitudinally spaced portions of a vertical face of a billet on an edge portion of a horizontal support table, the arms being rotatable to move the billet sidewise to a position over receiving rollers which move the billet lengthwise. The magnets are supported on the arms through a pivotal connection which is preferably loose andthe arms are independently operated through fluid-operating means, with the magnets being independently movable into firm engagement with the billet even though the billet is twisted or cambered. Each arm is preferably provided with a surface which underlies the billet during the pickoff and transfer operation.

11 Claims, 6 Drawing Figures PATENTEDFEBZS I972 3,645,378

SHEET 1 OF 3 DRIVE TRANS BILLET HANDLING SYSTEM INCLUDING MAGNETIC PICKOFF MEANS This invention relates to a billet-handling system and more particularly to a billet-handling system having magnetic pickoff means operative to pickoff and transfer billets seriatim in a highly reliable fashion even when the billets have relatively severe twists or eambers.

The system of this invention was designed for the handling of large steel billets or square cross-sectional shape but it will be understood that the principles of the invention can be applied to the handling of other types of objects having round or other cross-sectional shapes. Prior billet handling systems have generally used strictly mechanical arrangements which have often failed to pickoff a single billet, resulting in jamming of the handling apparatus with consequent losses of time and in some cases great expense because of the shutdown of equipment.

It has been found that the problems with prior art systems arise to a substantial extent because of the fact that billets are subject to twists or cambers or bends, in some cases quite severe. It has also been found, however, that even with fairly straight billets, they may not be delivered exactly parallel to the pickoff mechanism, resulting in extreme skewing or cobbling.

This invention was evolved from the observation of the difficulties encountered with prior systems and with the general object of overcoming such difiiculties and of providing a highly reliable billet handling system.

According to this invention, transfer means are provided which support and move magnet means transversely from generally horizontally aligned pickoff positions to generally horizontally aligned release positions, faces of the magnet means in the pickoff positions thereof being disposed adjacent longitudinally spaced portions of one side of a billet to attract and hold the billet thereto. With this comparatively simple arrangement, a pulling force, rather than a mechanical lifting or sliding force, is exerted and the pulling force is exerted only on one billet whether it be twisted and/or cambered and irrespective of any out-of-parallel orientation on a supply or load table.

According to an important specific feature of the invention, the magnet means are so supported as to allow limited freedom of movement thereof independently in directions generally normal to the side of the billet so as to facilitate the magnetic attraction even with severe carnbers in the billet.

Another important specific feature relates to the provision of pivotal support means to allow limited freedom of pivotal movement independently about axes parallel to the billet, so as to further facilitate the magnetic attraction even with severe twists in the billet.

In accordance with another feature of the invention, the faces of the magnet means are preferably in a generally vertical plane to engage longitudinally spaced portions of a generally vertical side of a billet. Preferably, surface means are provided adjacent the magnet means and positioned under the underside of a billet engaged with the faces of the magnet means.

A further feature of the invention relates to the provision of delivery means for delivering billets seriatim to a generally horizontal position in which they are picked off and transferred, the delivery means preferably comprising a generally horizontal table for receiving billets in side-by-side relation with means for sliding the billets sidewise.

Still another feature of the invention relates to the support of the magnet means on a plurality of spaced arms pivotal on a common horizontal axis. Preferably, the arms are independently actuatable by fluid-operated means facilitating the above-mentioned freedom of movement.

This invention contemplates other objects, features and advantages which will become more fully apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate a preferred embodiment and in which:

FIG. 1 is a top plan view of a billet-handling system constructed according to the invention;

FIG. 2 is a sectional view, on an enlarged scale, taken substantially along line II-ll of FIG. I and showing a magnetic pickoff ann assembly;

FIG. 3 is a sectional view, on a further enlarged scale, taken substantially along line IIIllI of FIG. 2 and showing the construction of an electromagnet and its connection to an actuating arm;

FIG. 4 is a sectional view, on an enlarged scale the same as FIG. 3, taken substantially along line IV-IV of FIG. 2;

FIG. 5 is a sectional view taken substantially along line V- V of FIG. 3; and

FIG. 6 is a schematic diagram of a hydraulic system and electrical control circuitry.

Reference numeral 10 generally designates a billet-handling system constructed in accordance with the principles of this invention. In the system 10, billets are placed by means of a crane or the like on a load table generally designated by reference numeral 11 which in the illustrated arrangement comprises five spaced parallel skid rails 12-16 having upper surfaces in a common horizontal plane. To catch scale and to provide a place to walk,

horizontal plates

17, 18, 19 and 20 may be supported, respectively, between the

rails

12 and 13, 13 and 14, 14 and 15, and 15 and 16, with the upper surfaces of the plates preferably being 4 to 6 inches below the upper surfaces of the skid rails.

A group of the billets are placed on the table 11 in roughly parallel relation and a plurality of aligned feed lugs, four lugs 21-24 being illustrated, are moved transversely across the table 11 to engage one of the billets of the group and to slide the group of billets transversely across the table toward one edge thereof. Three

billets

25, 26 and 27 are shown, with billet 27 being positioned at the edge of the table, i.e., at the ends of the skid rails 12-16. It will be understood that a much larger number of billets may be moved as a group.

To operate the feed lugs 21-24, they are secured to links of endless sprocket chains 29-32, entrained about sprocket wheels on parallel axes. One set of the sprocket wheels are affixed and keyed to a common shaft 33, one of such sprocket wheels 34 being shown in FIG. 2, meshed with the chain 30. It will be understood that similar sprocket wheels on the shaft 33 are meshed with

chains

29, 31 and 32 while an additional set of four sprocket wheels are supported at the opposite side of the table. As diagrammatically illustrated, the shaft 33 is driven from an electric motor 36 through a drive transmission 37 which may comprise a gear reduction unit having an input shaft coupled to the motor 36 and having an output shaft coupled through a multiple chain sprocket drive to the shaft 33.

When each billet reaches a position at the edge of the table 11, i.e., the position occupied by billet 27 as illustrated, the drive of the feed lugs 21-24 is stopped and the billet is transferred by means of magnetic pickoff arm assemblies 39-42 to be placed on a series of aligned rollers 43-49, formed with generally V-shaped grooves and journaled on spaced parallel axes. The rollers 43-49 are coupled through coupling units 51-57, which preferably include gear reductions, to electric motors 59-65 which are simultaneously energized to move the billet in a lengthwise direction. In the illustrated system, the billet is moved to the left as viewed in FIG. 1 into testing and/or processing apparatus, and additional rollers may be provided to receive the billet, one additional roller 66 being shown which is driven through a coupling unit 67 from an electric motor 68.

Although not forming part of the invention, it is noted that if the billet placed on the rollers 43-49 is defective it may be rejected by means of reject arms 70-72 operated by suitable hydraulic cylinders and functioning to lift the billet from the rollers 43-49 to allow it to slide down inclined rails 73-77 having stop bumpers 78-82 at the lower ends thereof.

As shown in FIG. 2, the magnetic pickofi arm assembly 39 comprises an arm 84 in the form of a plate which is welded or otherwise secured at its lower end to a block 85 which is bolted to a second block 86 to clamp a shaft 87 therebetween, a key 88 being provided to lock the arm 84 against rotation relative to the shaft 87. Shaft 87 is journaled by means including a bearing block 89 on a member 90 forming part of a frame structure of the system. An arm 91 is also keyed to the shaft 87 and the end of the arm 91 is pivotally connected by means including a pin 92 to one end of a rod 93, the other end of rod 93 being connected to a piston movable in a cylinder 94. Cylinder 94 is pivotally supported by means including a pin 95 and a support bracket 96 on a plate 97 fonning part of the frame structure. The cylinder 94 is double acting to allow positive control of movement of the arm 84 in either direction.

An electromagnet 100 is carried from the upper end of the arm 84 and has a generally vertical face 101 for magnetically attracting, engaging and holding the side surface of the billet 27, i.e., the end billet supported on the table 11. Electrical power is supplied by means of a cable 102 coupled at one end of the electromagnet 100 and at its opposite end to a junction box 103 on the arm 84, which is connected through suitable supply lines and a control circuit to a DC source. Electromagnet 100 is energized with the arm 84 in a position as shown in FIG. 2 and while maintaining energization of the electromagnet 100, the arm 84 is pivoted in a clockwise direction to remove the billet 27 from the table 11.

With continued rotation of the arm 84 (and the arms of the other pickoff arm assemblies) the billet is placed on the rollers 43-49. The final position of the arm 84 and electromagnet 100 may be as indicated by broken lines in FIG. 2 and the electromagnet 100 is preferably deenergized before the time that the billet initially engages the rollers 43-49. To permit flexibility in the timing of the deenergization of the electromagnet 100 and to insure against dropping of the billet, the arm 84 is preferably formed with a surface 104 disposed in underlying relation to the underside of the billet 27. With this feature, the electromagnet 100 may be deenergized when the arm reaches an intermediate position, whereupon the billet 27 is cradled between the face 101 of the electromagnet and the surface 104. With continued rotation of the arm 84, the billet is then smoothly placed on the rollers 43-49.

An important feature of the invention is in the support of the electromagnet 100 from the arm 84 in a manner to allow limited freedom of movement thereof in a horizontal direction, generally normal to the vertical side of the billet engaged by the face 101 and limited freedom of pivotal movement about an axis parallel to the longitudinal axis of the billet, so as to allow flush engagement of the face 101 with the billet surface, regardless of twists and cambers in the billet. In the illustrated arrangement, a plate 106 is welded to a backplate 107 of the electromagnet 100 and extends between upper end portions of a pair of

plates

109 and 110 having lower end portions secured on opposite sides of the arm 84. A cross pin 111 is secured to and extends between the upper ends of the

plates

109 and 110 through an opening 112 in the plate 106. Opening 112 is preferably enlarged in a horizontal direction so as to have a dimension substantially greater than the diameter of the pin 111 and so as to permit movement of the electromagnet 100 in a horizontal direction as well as permitting pivotal movement.

Preferably, the thickness of the plate 106 is substantially less than the distance between plates 109 and 1 and with the enlargement of the opening 112, the electromagnet 100 may also pivot about an axis which is generally vertical in the position of the arm 84 shown in FIG. 2. To limit such pivotal movement, a pair of

stops

113 and 114 are provided on the inner sides of forward end portions of a pair of

plates

115 and 116 having rearward end portions secured through

plates

117 and 118 to the

plates

109 and 110.

Stops

113 and 114 are engaged by

side plates

119 and 120 which together withthe back plate 107 and lower and

upper plates

121 and 122 form an outer casing or housing of the electromagnet 100. Plates 107 and 119-122 are of a magnetic material such as soft iron and the forward end surfaces of the plates 119-122 are used to form an outer magnetic pole portion of the face 101. An inner pole is formed by the forward end surface of a central block 123 having a rearward end secured to the plate 107, block 123 also being of a magnetic material such as soft iron. An energizing coil 124 is wound around the block 123 and is surrounded by insulating material 125, preferably formed by a potting compound.

It is noted that the downward pivotal movement of the electromagnet is limited by means of an adjustment screw 126 threaded into the arm 84, the head of the screw 126 being engageable with the lower plate 121 of the electromagnet 100. A nut 127 is threaded on the screw 126 for frictionally locking the screw 126 in a desired position.

The pickoff arm assemblies 40 and 41 are preferably substantially identical to the assembly 29, each including its own actuating cylinder. The arm of the assembly 42, which is provided for the purpose of accommodating billets longer than those illustrated, is connected to a shaft 128, common to the assembly 41, so that both assemblies 41 and 42 are operated by a common cylinder. Thus with billets within a certain range of length, at least three magnets engage the billet at three points spaced along its length, each having its own actuating mechanism.

FIG. 6 is a schematic diagram of a hydraulic actuating system and electrical control arrangement. The roller drive motors 59-65 and 68, and additional roller drive motors, not shown, are connected through a controller 130 to lines 131-133 which may be connected to a suitable supply of three phase power, controller 130 being controlled by start and stop

switches

134 and 135. After energization of the roller drive motors for a time suflicient to clear a billet from the rollers 43-49, the magnetic pickoff arm assemblies may be operated, controlled by a controller 136 which is connected to

lines

132 and 133 and to a solenoid control 137 for a valve 138 which connects the cylinder 94 of the mechanism 39 and

cylinders

139 and 140 for the mechanisms 40 and 41 to a pump 141 and reservoir 142. Controller 136 is additionally connected to the electromagnet 100 and to electromagnets 143, 144 and 145 for the assemblies 40, 41 and 42, and also to limit switches 146 and 147 which may be mechanically coupled to the piston rod 93 of the assembly 39. Controller 136 is controlled by start and stop push button switches 149 and 150.

Upon depression of start switch 149, a signal is applied to solenoid control 137 to move the valve 138 to a position such as to supply fluid to the

cylinders

94, 139 and 140 in a direction to move the arm 84 of assembly 39 and like arms of the assemblies 40-42 from positions as illustrated in broken lines in FIG. 2 to positions as illustrated in full lines thereof. Upon reaching the full line position, or prior thereto, the controller operates to supply rectified AC or DC power to the electromagnets 100 and 143-145 so as to magnetically hold the electromagnets to the billet. Limit switch 146 is then closed to cause the controller 136 to reverse the signal to the solenoid control 137 and to move the valve 138 to a reverse position, fluid being then supplied in a direction to cause the arms to be moved back to positions as illustrated in broken lines in FIG. 2. The limit switch 147 is then closed to cause the controller 136 to apply a signal to the solenoid control 137 to move the valve 138 to an intermediate position and to stop movement.

At an intermediate point in the transfer movement of the arms, the electromagnets 100 and 143-145 are preferably deenergized, as discussed above. It is noted that stop switch 150 may be operated at any time to discontinue operation, should it appear necessary to the operator.

It is noted that when moving to positions as represented in full lines in FIG. 2, pressure on the

cylinders

94, 139 and 140 is equalized to insure that the face of each of the electromagnets is engaged with the surface portion of the billet with the same force and with the support of the magnets as described above, proper magnetic attraction and holding engagement is obtained, regardless of twists and cambers in the billet.

When a billet is transferred by the pickoff arm assemblies, a limit switch 152, which senses any billet at the position of the billet 27 as illustrated, is closed to cause the supply of electrical power to motor 36, from lines 131-133 through a controller 153. The motor 36 then drives the sprocket chains 29-32 and the lugs 21-24 until the next billet (billet 26 as illustrated) is at the position of billet 27 whereupon the switch 152 is opened and motor 36 is deenergized. Motor 36 may be stopped at any time by means of a stop switch 154 and the operation may be resumed by means of a start switch 155.

If desired, the operation may be made more fully automatic by providing sensing means to sense the removal of the billet from the rollers 43-49 to automatically initiate operation of the magnetic pickoff arm assemblies.

It will be understood that modifications and variations may be effected without departing from the spirit and scope of the novel concepts of this invention.

I claim as my invention:

1. In a system for handling of elongated steel billets or the like, delivery means for delivering billets seriatim to a generally horizontal position, a plurality of spaced transfer arms pivotal about a common generally horizontal axis parallel to said horizontal position, a magnet supported on an end portion of each of said transfer arms and each having a face for attraction of a billet thereto, and actuating means for simultaneously pivoting said transfer arms about said axis between receiving and release positions, said magnet faces in said receiving position of said transfer arms being disposed in close proximity to longitudinally spaced portions of one side of a billet in said generally horizontal position to magnetically attract and hold the billet to said faces, each of said magnets being an electromagnet, means for electrically energizing said magnets when said transfer arms are in said receiving position and for maintaining energization of said magnets through at least a portion of the movement of said transfer arms to said release position, and roller means for receiving and supporting a billet released from said magnets in said release position of said transfer arms and for conveying the billet in a longitudinal direction.

2. In a system as defined in claim I, support surface means on said transfer arms disposed in a common plane generally at right angles to said magnet faces and in supporting relation to a second side of a billet disposed in generally horizontal position.

3. In a system as defined in claim 1 and including at least three transfer arms, said actuating means being arranged to allow displacement of each transfer arm relative to the others for accommodating cambers in a billet.

4. In a system as defined in claim 3, said actuating means comprising an individual fluid-actuated device for each of said transfer arms, a common source of fluid under pressure and means for coupling said fluid-actuated devices to said common source for movement of said arms between said receiving and release positions.

5. In a system as defined in claim 1, connecting means between said magnets and said transfer arms arranged to allow limited freedom of movement of said magnem independently about an axis generally parallel to the longitudinal axis of the billet to accommodate twists in the billet.

6. In a system as defined in claim 5, said connecting means being additionally arranged to allow limited freedom of movement of said magnets independently in directions generally normal to said one side of the billet to accommodate cambers in the billet.

7. In a system as defined in claim 6, said connecting means comprising for each magnet a pivot pin generally parallel to the billet in said generally horizontal position and a member having an opening receiving said pivot pin and elongated in a direction generally normal to said one side of the billet.

8. In a system as defined in claim 1, said delivery means comprising a generally horizontal table for receiving billets in side-by-side relation, and means for sliding said billets sidewise to be delivered seriatim to said generally horizontal position.

9. In a system as defined in claim 8, said magnet faces being in a generally vertical plane in said receiving position of said transfer arms to engage longitudinally spaced portions of a generally vertical side of a billet in said generally horizontal position.

10. In a system as defined in claim 1, said magnet faces being in a generally vertical plane in said receiving position of said transfer arms, support surface means on said transfer arms disposed in a generally horizontal plane to underlie the underside of the billet in said generally horizontal position.

11. In a system as defined in claim 10, said support surface means being spaced above said common horizontal plane in said receiving position of said transfer arms, the planes of said support surface means and said magnet faces being inclined in opposite directions from a vertical plane in said release position of said transfer arms.

Claims

2. In a system as defined in claim 1, support surface means on said transfer arms disposed in a common plane generally at right angles to said magnet faces and in supporting relation to a second side of a billet disposed in generally horizontal position.

5. In a system as defined in claim 1, connecting means between said magnets and said transfer arms arranged to allow limited freedom of movement of said magnets independently about an axis generally parallel to the longitudinal axis of the billet to accommodate twists in the billet.