US2406489A - Magnetic control - Google Patents

Description

Au .z7;1946. I. L. CASE 0 4 MAGNETIC CONTROL Filed Sep a. so, 1942 2 Sheets-Sheet 1 Aug. 27, 1946. I. L. CASE MAGNETIC CONTROL 2 Sheets-Sheet 2 Filed Sept. 30, 1942 [EU/IV 4. Gas:

Patented Aug. 27, 1946 MAGNETIC CONTROL Irvin L. CaseaSteubenville, Ohio, assignor toNational Steel Corporation, a corporation. of Delaware Applicatiomseptcmber 30, 19.42, Serial rim-460,321;

1J0 Claims. 1.

This invention relates to a. magnetic control device and. has particular reference; to.- a device for controlling piling of relatively thin flat products of a magnetic. character without scratching or marring their surfaces.

Although the present invention is. adapted to us with any magnetic sheet material. it. is: especially adapted for handling .tinv plate which, has a. highly polished surface, marrin-g of which depreciates. its marketability- Normally in piling tin plate, the tinned sheet comes out of thebranner onto a conveyor which delivers the sheets We point where. they are piled onto skids in even stacks and then removed. When a. pile is. being started, the bottom of the. pile is in the neighbor hood of the floor and as each sheet is fed onto the pile, the drop from the conveyor belt to the bottomv of the pile. is so great that the. resulting, velocity of the sheet cftenmarsthe surface of: the. sheet as it contacts the preceding piled. sheet.

.They present invention contemplates a pilerrhaw ing a lift mechanism so controlled as. to keep the top of the. stack. adjacent the exit side of theconveyor belt whereby the sheets. drop. a. relatively short distance. The present invention fur-- ther contemplates th provision of means to air tomatically control; the operation of. the lift mesh.- 31115111.

Thus, the principal object of the present i:nvention is to provide a mechanism for controlling movement of. a magnetic object.

A. further object of the present. invention. is. tocontrol the piling of magnetic. sheets.

A further object is to provide a, lift mechanism that, can be lowered step by step by the deposit of metal sheets thereon.

A still further object of the invention is to pro-- vide novel means for automatically controlling the lowering of. the lift mechanism.

Other objects of the invention will become apparent to those. skilled. in the; art from the following detailed description of the-accompanying drawings which disclose. a preferred embodiment of the. invention.

In the drawings:

Figure 1' is an end elevational view of. a piling apparatus embodyingthe present invention Figure 2 is. a. side elevational. view thereof- Figure 3.; is. an end view taken partly. section of the. lift controlv means.

Figure. 4 is aside view thereof.

As, best shown in Figures 1 and.2, the reference.

numeral lfldesignates. generally the floor and. H- the pit for housing theli-ft: mechanismand; operating means therefor. The. lift. mechanism: may

21 comprise any suitably operated. lift. and is shown in. the, present case; as: comprising a, motor operated lift designated by numeral. IZ. As. seen. in Figure 1, the operating means: comprises-- motor [3,. bra-kc Ht andv limit switch: l5.

A conveyor table It having a conveyor belt-H. suitably mounted thereon is supported on. the floor adjacent the pit,l.l.. A frame It; support.- ing a. piler box. l9 straddles the. pit II and ,is

suitably supported by the table. I6, and floor H1.

The piler box. l'9' comprises adjustable wallsiil acting as abutment members for Stacking, the sheetsZl as they are fed intothe piler box from. the conveyor belt.. The upper end'of lift IZ' comprises a dished, plate member. 22 having. conveyor. rollers 23' suitably mounted therein. A skid member 241 is supported. on rollers.23 andreceives the stack of plates as they are dropped into the piler box.. In. the specific. embodiment. herein.d'escribed an. automatic piler control in. the form of. a. relay is shown at. 25, mounted on a. wall of the pil'er box. for. automatically controlling, the operation. of the. lift mechanism.

The piler control. comprises the important part of the present. invention. and. the specific embodiment thereof sh-own will be described in. detail as follows: Referring. to Figures. 3. and, 4. in detail, there. is shown a housing 26. suitably secured. to a wall. of the. pil'er box and having.mounted.thereina tilting mercury switch 21 connected by suit. able wiresto motor H to operate. the motor which. in turnoperates.theliftmechanism- The switch 2]. is-carried in aholder 28. supported. on atilting, arm 29 pivotally secured to a. wall. of the. housing by means of. a pivot. pin 31L A counterweight 3 l is secured to tilting. arm 29. through the medium of an arm 32. A lever arm 33" is pivotally secured to a. wall of' housing, 7.6 by means. of a pivot pin. 34 and ha one end, connected to'an' end of the tilting. arm is. through a link 35'. The. opposite. end of lever arm! Siliseonnected to a travel. arm. 35. through. link member. 37. An. adjustable stop. 38 is provided to limit. the tilting, movement. of. tilting arm 29;- Securedto the other. end" of travel; arm 36 is. a relay armature. generally designated" by numeral 40 whichmakes engagement along. its length withthe edges of. the. sheets in the stack through. an opening. in. the. wall 211..

The. relay armature. 36i comprises. a pair. of per.

manent. magnets. M. having. ofiset openings. 42zformed therein to receive. a. clampingrod 4.3-. Themagnet 4t are: arranged with. the.- opening 4.2=reversed with. respect tothe. poles so that there is.- a. magnetic circuit between their ends. The.

clamping; rod. 43: secureduto a pivot; Ht

'. ratus is as follows: At the beginning of the operation, the lift mechanism is broughtup to a position adjacent the exit side of the conveyor belt and slightly below the lower magnet of the armature by means of motor 13 which has separate control (not shown) for raisingthe lift.

Due to the position of pivot 45 with regard to the center of gravity of armature 40, the lower end of armature! will swing to the right. into inoperative position due to gravity and the magnetic circuit through the ends of the magnets will be through the air. In this position of the armature, the switch Z'Iwill be in its downward position or opposite to the position shown in Figure 4. With the switch in its downward position, the circuit i broken and the lift mechanism remains stationary. As the sheets of tin plate or steel drop into the plier boxon plate 24 and piles up to a point adjacent the upper magnetas shown in Figure 4, the presence of this pile of magnetic material furnishes a short path for the magnetic circuit, and due to the tendency of themagnetic lines to contract, the lower magnet is pulled in toward the stack of sheets into operative position. This causes tilting of. the mercury switch 21 into its upward position shown in Figure 4, closing the circuit and starting the motor to opcrate the lift mechanism in 'a down direction, When the top of the pile has dropped to a point adjacent the lower magnet, the magnetic cir-,

cuit will again be through the air and the force of gravity will cause the armature to again swing to the right. Thisoperates mercury switch 21 to again break the motor circuit and the brake l4 slows down the lift mechanism at the desired rate to bring the top of the pile to about the height of the bottom of the lower magnet. This procedure is repeated until the piler lift hasreached its extreme down position as determined by limit switch I5, in which position the stack of sheets may be slid off rollers 23 onto roller conveyor 41.

Stop 38 defines the two extreme positions of the armature by contact with tilting arm 29 in each extreme position. The armature may or may not, as desired, make engagement with the stack'in operative position.

Although the present invention has been specifically described as applied to controlling the stack while piling, it will be apparent that where desired upward movement of the stack it'- self by the lift may be controlled. Thus when part of the entire stack i removed the lo werrand remaining part may be raised up to the proper height for continued piling of additional sheets.

In. such case the armatureacts to reverse motor I3 when the stack has passed the proper height? and motor l3 then position the stack properly.

It is to, be noted that due to the relative positions and, movements of the stack and the arma position until the stack has reached a position in the neighborhood of the lower magnet. On

7 the other hand, once having moved into inoperative position and thus further spaced from the effective path of the stack, the upward path of the stack defined by its increasing height intercepts fewer lines of force and doe not present a short path'sufiicient to pull the armature into operative position until the height of the stack is in the neighborhood of the upper magnet. It is on this phenomenon that the present invention is based. J I

I claim;

1. A piling apparatus for sheets of magnetic material comprising sheet feeding means, sheet stacking means positioned to receive sheets from the sheet feeding means, a support for the sheets associated with the stacking means and positioned below the sheet feeding means, a lift mechanism for changing the height of the support, operating means for the lift mechanism} and magnetic means in magnetic relation withtioned below the feeding means, a lift mechanism for changing the height of the support, operating meansfor the lift mechanism, -and magnetic means in magnetic relation coacting with the stack for actuating the operating means to lower the support when the top of the stack reaches a predetermined point. I

' 3. A piling apparatus for sheets of material comprising sheet feeding means, sheet stacking means positioned to receive sheets from the sheet feeding means, a support for the sheets associated with the stacking means and posi-. tioned below' the sheet feeding means/a lift mechanism for changing the height of the support; operating means for the lift mechanism, and magnetic means in magnetic relation with the stack for actuating the operating means to lower the support a predetermined distance when the top of the stack reaches a predetermined material comprising sheet feeding means, sheet stacking means positioned to receive sheets from the sheet feeding means, a support for the sheets associated with the stacking means and positioned below the sheet feeding means, a lift mechanism for changing the height of the support, operating means for the lift mechanism, means for supplying a magnetic circuit including a path through air so positioned that. sheets being stacked on the support enter the air path, means associated with the last named means to.cause movement of the same toward the stack when a predetermined amount of sheets have entered the air path, and control means actuated bysaid movement to cause theoperating meansto lower the support. j

v 5. A piling apparatus for sheets of :magnetic material comprising sheet, feeding means, sheet stacking means positioned to receive sheets from the sheet feeding means, a support for the sheets associated with the stacking 'means and positioned below the sheet feeding means, a lift mechanism for changing the height of the support, operating means for the lift mechanism; means I for supplying a magnetic'circuit including a path magnetic through air so positioned that sheets being stacked on the support enter the air path, means associated with the last named means to cause movement of the same toward the stack when a predetermined amount of sheets have entered the air path, control means actuated by said movement to cause the operating means to lower the support, means for reversing said movement when a predetermined portion of the stack has moved out of the air path, and control means actuated by the reversal of movement to cause the operating means to stop the support.

6. A piling apparatus for sheets of magnetic material comprising sheet feeding means, sheet stacking means positioned to receive sheets from the sheet feeding means, a support for the sheets associated with the stacking means and positioned below the sheet feeding means, a lift mechanism for changing the height of the support, operating means for the lift mechanism, an armature movable between inoperative and operative position and normally urged into inoperative position, the armature in operative position being adjacent the top of the stack of sheets, means for maintaining amagnetic circuit carried by the armature, the magnetic circuit acting on the armature to move the same into operative position when the top of the stack of sheets reaches a predetermined point, and control means actuated by the armature in operative position to cause the operating means to lower the support.

'7. A piling apparatus for sheets of magnetic material comprising sheet feeding means, sheet sition, the armature in operative position being adjacent the top of the stack of sheets, means for maintaining a magnetic circuit carried by the armature, the magnetic circuit acting on the armature to move the same into operative position when the top of the stack of sheets reaches a predetermined point, control means actuated by the armature in operative position to cause the operating means to lower the support, means causing movement of the armature to inoperative position when the stack has been lowered a predetermined distance, and control means actuated by the armature in inoperative position to cause the operating means to stop the support.

8. A piling apparatus for sheets of magnetic material comprising sheet feeding means, sheet stacking means positioned to receive sheets from the sheet feeding means, a support for the sheets associated with the stacking means and positioned below the sheet feeding means, a lift mechanism for changing the height of .the support, operating means for the lift mechanism, an armature associated with the stacking means and positioned in the neighborhood of the desired height of the stack, the armature including a pair of aligned unlike magnetic poles, vertically spaced and arranged to face in the direction of the stack and be adjacent thereto in operative position, a

pivotal support on the armature so located that the lower pole is urged by gravit away from the stack into inoperative position, and control means operative in response to movement of the armature to actuate the lift operating means when the armature is in operative position and deactuate the same when the armature is in inoperative position.

9. A magnetic control comprising an armature including a pair of aligned unlike magnetic poles spaced along a line and presenting a magnetic field, the armature being movable between an operative and an inoperative position, a magnetic object arranged to move along a path, the line and the path being parallel when the armature is in operative position, the line forming an angle with the path when the armature is in inoperative po sition, supporting means so constructed and arranged as to hold the armature in operative position when more than a predetermined amount of the field is intercepted by the magnetic object and so constructed and arranged as to hold the armature in inoperative position when less than said predetermined amount of field is intercepted by the magnetic object, operating means for moving the magnetic object along the path in a direction to reduce the amount of field intercepted, and control means associated with the armature and the operating means to actuate the operating means when the armature is in operative position and ,deactuate the operating means when the armature is in inoperative position, the distance between the line and the path when the armature is in inoperative position increasing in the direction of the movement of the magnetic object by the operating means.

10. A magnetic control in accordance with claim 9 in which the magnetic object is a stack of sheets of magnetic material and the operating means is a lift mechanism for changing the height of the top of the stack.

IRVIN' L. CASE.

Disclaimer MAGNETIC CONTROL. Patent dated 2,406,489.-Iro'in L. Case, Steubenville, Ohio.

12, 1948, by the assignee, National Aug. 27, 1946. Disclaimer filed Nov. Steel Corporation.

Hereby enters this disclaimer to 01 [Oflio'ial Gazette December 14, 1948.]

aims 1 to 7 inclusive.

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