Sheet feeding or delivering – Feeding – Separators
Reexamination Certificate
2001-07-26
2002-11-19
Skaggs, H. Grant (Department: 3653)
Sheet feeding or delivering
Feeding
Separators
C271S105000, C271S901000
Reexamination Certificate
active
06481706
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to magnetic apparatus adapted for inducing magnetic fanning of steel sheets for purposes of efficient manual handling.
BACKGROUND OF THE INVENTION
Sheet steel is commonly stored in a stacked configuration upon a horizontally oriented work table or storage rack. Where, for example, rectangular sheets of one-eighth inch steel are stored in a stacked configuration, such sheets are commonly used in sequence from the top down. Where such sheets are neatly stacked one upon the other, the topmost sheet offers no surface which may be conveniently manually grasped to effectuate removal from the stack. Such stacked sheets of steel are often resistant to sliding, preventing a worker from exposing an edge over a side of the stack for grasping. Also, oil which is commonly disposed between such stacked sheets often results in cohesion creating further resistance to removal of a single sheet from the stack. Such cohesion effectively sticks together the sheets.
Stacks of sheet steel are known to become temporarily magnetized upon exposure to a magnetic field. Where the magnetic lines of flux from a magnetic field cross the striations of a stack of sheet steel, the individual sheets are magnetized in a manner causing their broad faces to form a series of magnetic poles. Where such magnetization occurs, consistent orientation of the magnetic poles causes opposing poles to be in contact with each other, adhering the layers of sheet steel together. Conversely, where lines of magnetic flux are caused to pass horizontally through stacked sheet steel, the induced magnetic poles are located at the edges of the sheets of steel. Consistent orientation of such induced magnetic poles causes like poles to be grouped together at the edges of the stack, resulting in magnetic repulsion. Such magnetic repulsion at the edges of the sheet steel stack upwardly fans the stack, separating adhered sheets from each other, and exposing individual edges for convenient grasping. Magnetic mechanisms adapted for accomplishing such magnetic fanning of stacks of sheet steel are known.
One such known magnetic mechanism incorporates an electromagnet which may be conveniently placed in operating proximity with a stack of sheet steel. The electromagnet may be turned on for magnetic fanning of the sheets, and may be conveniently be turned off when no longer needed. However, the coiled windings of such mechanisms are undesirably bulky, and such mechanisms undesirably require an electrical power supply.
Magnetic fanning mechanisms incorporating permanent magnets are similarly known, such mechanisms overcoming some of the undesirable characteristics of electromagnets. However, permanent magnets may not be switched on and off in the manner of electromagnets. Therefore, where a permanent magnet sheet fanner is utilized, its magnet must be forcefully pulled away from the stack of sheets when not in use. Strong magnetic attraction between a magnetic fanner incorporating permanent magnets and sheet metal typically makes it difficult to pull the fanning mechanism away from sheet metal when not in use.
The instant invention ameliorates or lessens the difficulty of pulling such magnets away from stacked sheet steel by providing structures adapted for rotating or pivoting a permanent magnet assembly away from the stacked sheet steel rather than directly forcing or driving the magnet linearly away from the sheet steel stack. By providing structure for pivoting the magnets toward and away from the stacked sheet steel the inventive sheet fanner incorporates a novel, inventive and useful “on-off” function.
BRIEF SUMMARY OF THE INVENTION
The instant inventive magnetic sheet fanner comprises four core structural elements: a housing or support frame, a permanent magnet assembly, pivotal or rotatable mounting means, and turning means; the housing supporting each of the other three structural elements.
The housing primarily functions as a support frame member. Ideally, the housing forms an occlusive closure, protecting supported structures from dirt and debris. Suitably though less desirably, the housing may be configured as an open frame. Preferably, the housing has a sheet contact side configured as a vertically elongated bearing face. The vertical length of the bearing face typically is equal to or greater than the maximum height of sheet metal stacks to be fanned by the magnetic sheet fanner. For example, where the magnetic sheet fanner is to be utilized for fanning sheet metal stacked ten inches high, the vertical dimension of the bearing face should be at least twelve inches. Suitably, such vertical length may be less than such maximum height where means are provided for alternately upwardly and downwardly positioning the magnetic sheet fanner with respect to stacked sheet steel.
The vertically elongated bearing face of the housing comprises the structure through which magnetic flux emanates for fanning a stack of sheet steel. It is preferable for the bearing face to be composed of non-magnetic steel so that the thickness of the face provides an “air gap” between the sheet stack and the magnet; such gap lessening the force needed to pivot the magnet away from the sheet stack. Where magnetic flux from opposing poles emanates through the bearing face, the non-magnetic character of the bearing face additionally functions to avoid a magnetic armature across the magnetic poles, which may undesirably reduce the strength of the magnetic field available for fanning sheet steel. Where the bearing face comprises magnetic steel, avoidance of such magnetic armature effect may be suitably achieved by configuring such face as vertically oriented strips or plates, which are spaced apart from each other; the space providing an air gap between the strips or plates. Preferably, the outer surface of the vertically elongated bearing face has a plurality of vertically oriented slide ridges for reducing frictional forces between the sheet steel and the magnetic sheet fanner.
The permanent magnet of the instant inventive magnetic sheet fanner is preferably situated within the housing immediately behind the vertically elongated bearing face. Preferably, the poles of the permanent magnet are vertically elongated allowing them to be mounted co-extensively along the inner surface of the bearing face. Where it is desirable to expose the bearing face to magnetic flux from opposing poles, the permanent magnet is preferably configured as a vertically elongated horseshoe magnet. Preferably the axes of magnetization at the poles of such magnet are parallel to each other. Suitably, though less desirably, such axes may be oriented at an angle to each other. A preferred means of constructing such vertically elongated horseshoe magnet incorporates a vertically elongated mild magnetic steel back plate upon which dual rows of block shaped bar magnets are fixedly mounted. The magnets in each row are consistently arranged so that the magnets in one row forwardly expose their south poles, while the magnets in the other row forwardly expose their north poles. Such arrangement allows the mild magnetic steel back plate to serve as an armaturing link between the rearwardly exposed north and south poles of the bar magnets, causing the combination of the bar magnets and the back plate to form the vertically elongated horseshoe magnet.
In a suitable alternate configuration of the permanent magnet, similar block-shaped bar magnets are arranged in a single vertical row along a backing plate, cumulatively forming at least a first vertically elongated bar magnet. The block shaped bar magnets are preferably consistently oriented with their north (or alternately south) poles facing forwardly from the back plate. Where the back plate serves as a mounting surface for a single row of permanent bar magnets, such back plate is preferably composed of a ferrous material such as mild steel to aid in redirecting the rearwardly oriented field toward a stack of sheet steel.
In each permanent magnet configuration described above, the pivotal or rotatable mountin
Gaeddert Tom
Signer Ryan S.
Suderman Donald A.
Davis & Jack, L.L.C.
Jack Kenneth H.
Skaggs H. Grant
LandOfFree
Magnetic sheet fanner does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Magnetic sheet fanner, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic sheet fanner will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2926637