US2693979A - Magnetic device - Google Patents

Description

G. L. RUSSELL MAGNETIC DEVICE Nov. 9, 1954 Filed Aug. 5, 1950 4 Sheets-Sheet l INVENTOR. 6801?? X. FusseZZ.

Nov. 9, 1954 G. L. RUSSELL 2,693,979

' MAGNETIC DEVICE Filed Aug. 5, 1950 4 Sheets-Sheet 2 8 Fla-58x1 E v m,%;4,y/5M

WTTA/V/YEVS.

G. L. RUSSELL MAGNETIC DEVICE Nov. 9, 1954 4 Sheets-Sheet 4 Filed Aug. 3, 1950 Way/7:222

7L2 Z M M 5 1 WM 0/ M M M M bw M 1 WM 4 1 M M( M/ M. m M; n l qov\ l H M fi 4/ /w/ 0 m 4/ M w I N V EN TOR. yea/3 1. FasseZZ B Y United States Patent Ofitice 2,693,979 Patented Nov. 9, 1954 MAGNETIC DEVICE George L. Russell, Fair Haven, Mich.

Application August 3, 1950, Serial No. 177,541

18 Claims. (Cl. 294-655) This invention relates generally to magnetically energized devices and more particularly to such devices which utilize a permanent magnet as the source of flux.

An object of this invention is to provide a more efficient and more economically manufactured permanent magnet device for collecting magnetic material.

Another object is to provide a device of the character described which may be easily used.

Another object is to provide such a device in which the material collected by the device may be easily removed therefrom when desired.

Another object is to provide such a device in which the magnet is movable relative to the material attracted thereby for discharging such attracted material.

Another object is to provide such a device in which a permanent magnet is contained within a shell, a portion of which is made of nonmagnetic material and a portion of which is made of magnetic material, the magnet being movable relative to the shell into the nonmagnetic material portion for picking up magnetic material and then into the magnetic portion whereby the material is released.

Another object of this invention is to provide a device having a nonmagnetic shell enclosing a magnet movable relative thereto and providing a magnetic material tip which may be energized or deenergized by the magnet for attracting magnetic material.

Another object of this invention is to provide a device for collecting magnetic material in which the means for moving the magnet may be disconnected therefrom to provide an extension for lowering the magnetic device into otherwise inaccessible locations for attracting magnetic material.

Another object is to provide such a magnet in which the magnet moving means comprises a rodlike member of magnetic material which may be inserted into spaces too small to receive the magnetic device.

Another object is to provide such a tool which may be used to remove small pieces or chips of magnetic material from a much larger piece of magnetic material.

Another object is to provide such a tool in which the permanent magnet used to energize the tool is prevented from contacting the large piece of magnetic material by a nonmagnetic material spacer.

Another object is to provide such a tool which can be readily used to remove iron or steel chips from drilled or other holes in a steel or iron member.

Another object is to provide such a tool which can readily be used to remove nails, tacks, screws, or other small parts from bins or other containers.

Other objects of this invention will be apparent from the specification, the appended claims, and the drawings, in which drawings,

Figure 1 is a view in central, vertical section of a magnetic tool embodying the invention;

. Fig. 1A is a view in reduced size of the tool of Fig. 1 in its carrying case;

Fig. 2 is a view taken substantially along the line 22 of Fig. 1;

Fig. 3 is a modified form of a portion of the tool shown in Fig. 1 within the dash-dot circle 3;

Fig. 4 is a view in central, vertical section of another form of magnetic device embodying the invention;

Fig. 5 is a view taken substantially along the line 5-5 of Fig. 4;

Fig. 6 is a view taken substantially along the line 6-6 of Fig. 4;

Fig. 7 is a view taken substantially along the line 7-7 of Fig. 4;

Fig. 8 is a view in central, vertical section of a still further modified form of magnetic tool embodying the invention;

Fig. 9 is a view taken substantially along the line 9-9 of Fig. 8;

Fig. 10 is a further modified form of magnetic tool embodying the invention;

Fig. 11 is a view taken substantially along the line 11--11 of Fig. 10;

Fig. 12 is a view in central, vertical section of another form of magnetic tool embodying the invention;

Fig. 13 is a view in vertical section of a still further modified form of magnetic tool embodying the invention;

Fig. 14 is a view in central, vertical section of another form of the magnetic tool embodying the invention;

Figs. 15 and 16 are partial views in vertical, central section showing modified forms of tips for the magnetic tools;

Fig. 17 is a view in central, vertical section of a modified form of the invention;

Fig. 18 is a view in central, vertical section of a further modified form of the invention;

Fig. 19 is a view in vertical section of a still further modified form of magnetic tool embodying the invention;

Fig. 20 is a view taken substantially along the line 2020 of Fig. 19;

Fig. 21 is a view taken substantially along the line 21-21 of Fig. 19; and,

Figs. 22, 23 and 24 are similar to Figs. 19, 20 and 21 respectively but showing a modified form of the invention.

As used in the specification and claims and unless otherwise set forth, magnetic material is any material such as iron which responds to or is attracted by a permanent magnet whether or not it retains any magnetism when removed from the influence of the magnet and nonmagnetic material is any material which does not respond to or is not attracted by a magnet to any substantial extent.

Referring to the drawings by characters of reference and to Fig. 1 in particular, the numeral 1 indicates generally a permanent magnet energized tool which may be used for collecting and/or separating magnetic material. The tool 1 comprises a thin-walled elongated tubular member 2 of nonmagnetic material and closed at one end by a magnetic material pole piece 4. Such pole piece 4 as well as the pole pieces 4a, 34, 34 and 34" are preferably of soft iron or like material which will retain no substantial magnetism when removed from the influence of a magnetic field. The other end of the tube 2 is closed by means of a flexible closure 6 which may be of neoprene or other suitable deformable material and which has a central aperture 8 extending therethrough. A small diameter rod 10 of magnetic material, preferably soft iron, extends through the central aperture 8 and is provided on its outer end with a flattened screw driver edge-like portion 12 and provided on its inner end with an armature 14 of magnetic material which is attracted to the adjacent end of a permanent magnet 16 whereby the magnet may be moved longitudinally of the tube 2 by the rod 10. The armature 14 is preferably cup-shaped having a central aperture extending through its end wall which receives the inner end of the rod 10 held therein by means of the deformed portions 18 located on either side of the end wall of the armature 14. The cup-shaped armature 14 opens toward the magnet 16 and its peripheral edge engages the adjacent end face of the magnet 16. Preferably a thin sheet of nonmagnetic material 20 is provided between the end of the magnet 16 and the pole piece 4 to reduce the attraction of the magnet for the pole piece 4 to less than the attraction to the armature 14 so that upon outward movement of the rod 10 the magnet will move w1th the armature 14 rather than remaining against the pole piece 4. The nonmagnetic material 20 may be, and preferably is, of resilient material such as neoprene or rubber and will absorb shocks occurring upon inward movement of the magnet 16 toward the pole piece 4. The central aperture of the armature 14 is preferably somewhat larger than that of the rod and the spacing between the deformed portions 18 is greater than the thickness of the armature end wall to provide a loose joint between the rod 10 and armature 14 to eliminate binding.

The tool of Fig. 1 is particularly adapted for removing magnetic material from deep holes and, when in the position shown in Fig. 1, it is inserted with the pole piece leading into the hole by grasping the exterior surface of the tube 2. The flux set up by the magnet 16 travels down through the pole piece 4 and attracts the magnetic material within the hole in which the tool 1 has been lowered. There may, of course, be some attraction of magnetic material to the outer surface of the tube 2 surrounding the magnet 16. However, the majority of the magnetic material will be attracted to the pole piece 4. After the desired magnetic material has been collected by the tool 1, it is removed from the hole, grasped with the hand encircling the tool 1 substantially at the location of the line 22 thereof. The other hand grasps the outer end of the rod 10 which is then pulled outwardly drawing the magnet 16 along the longitudinal axis of the tube and past the first hand so that the accumulation of the magnetic material, held against longitudinal movement along the tube 2 by the first hand, is sufliciently out of the flux field of the magnet and so falls away.

If it is desired to use the tool 1 in a hole which is deeper than the length of the tool 1 in the condition in which it is shown in Fig. 1, the rod 10 is pulled out of the tube 2 and the tube given a quick shake to dislodge the magnet 16 from the armature 14. The magnet 16 will then move against the material 20 and energize the pole piece 4. The rod 10 may then be used to lower the tool into the deep hole for collecting the loose magnetic material therein. After the magnetic material in the hole has been collected by the tool 1, substantially as described above, the tool 1 is withdrawn from the hole, the rod 10 pushed inwardly to bring the armature 14 into engagement with the magnet 16. The picked-up magnetic material may then be released as described above.

Another useful feature of this form of the invention is that the rod may be pulled outwardly of, or extended from the tube 2 as in the case of unloading and inserted within the holes too small to permit insertion of the tube 2. The rod 10 being of magnetic material will act as a pole piece and conduct magnetic flux and will collect magnetic material. The flattened screwdriver-like end portion 12 of the rod 10 provides a greater area to pickup chips, and permits of insertion into a crack or crevice which would otherwise be inaccessible and into a stack of accumulated chips.

The tool 1 is adapted to be of a size suitable to be carried in a persons pocket or in a machinists tool box. When so carried it is contemplated that it will be placed within a magnetic material keeper 3, preferably of soft iron as shown in Fig. 1A. The keeper 3 comprises a tube closed at one lower end as by a rubber or neoprene member and having an open upper end open for insertion and withdrawal of the tool 1. The tool 1 will be held within the keeper 3 by the magnetic flux of the magnet 16 and the keeper will shunt a large proportion of the flux so that the magnet 16 will not magnetize adjacent objects, such as a persons watch or other tools in the machinists tool box. The keeper or carrier 3 is also provided adjacent its open upper end with a pocket clip.

In Fig. 3 there is shown a modified form of the tool of Fig. 1 in that the lower end surface of the pole piece 4a is positioned slightly inwardly of the end of the non-. magnetic tube 2. This construction prevents direct contact of the tool 1a with ferrous surfaces and since the pole piece 4a is spaced therefrom, the tendency of the tool to adhere to the ferrous material against which the tool 1 may be placed is reduced.

In the form of the invention of Fig. 4, the tool 31 comprises a thin-walled nonmagnetic tubing 32 closed at one end by a soft iron pole piece 34 and at its other end by a closure member 36 having a central aperture 38 extending therethrough and in which a rod 40 is reciprocally guided and positioned by screws 57. The. outer end of the rod 40 is formed into a handle portion 42 and its inner end portion screw-threadedly engages a connecting member 44 which is permanently secured to one end of a permanent magnet 46, as by welding 48. The magnet 46 is reciprocally movable within the tube 32 by the rod 40 and in its inward position it is preferably spaced from the pole piece 34 by means of a thin layer of pliable or resilient nonmagnetic material 50. A helical coil spring 52, arranged concentrically with the rod 40 within the tube 32 and having its opposite ends abutting the connecting member 44 and closure member 36, urges the magnet 46 toward the pole piece 34.

As shown more clearly in Figs. 6 and 7, the closure member 36 comprises a dislike portion which is slotted intermediate its parallel end surfaces to provide an aperture 54 which receives a sealing member such as a felt washer 56. The aperture 38 is of slightly larger diameter than that of the rod 40 While the normal unflexed aperture through the felt washer 56 is slightly less than the diameter of the rod 40 and tightly engages the rod to prevent entry of foreign material into the interior of the tool 31.

The tool 31 is also provided with a nonmagnetic radially extending peripheral wall 58 which may be frictionally supported by the tube 32 for movement therealong or which may be secured in fixed position thereon. The wall 58 is preferably located longitudinally of the tube 32 such that the magnet 46 is movable from a position adjacent the pole piece 34 in which it is on one side of the wall 58 to a second or unloading position in which the magnet 46 is on the other side of the wall 58. The wall 58 preferably extends a suflicient radial distance to prevent any magnetic material from following the upward movement of the magnet 46 therebeyond so that with the magnet in its up position such material will be sufficiently out of the flux field of the magnet to permit such material to fall away from the tool 31.

The pole piece 34 has a cylindrical portion 60 which fits Within the end of the tube 32 and a portion 62 of converging truncated conelike formation which extends outwardly from the tube 32. The outer end of the pole piece portion has an inwardly extending aperture 64 which receives a nonmagnetic pin 66. As shown in Fig. 4, the pin projects slightly beyond the furthest extensions of the pole piece 34, and acts to preventengagement of the pole piece with magnetic material members from which loose material is being removed. The tapered surface of the pole piece 34 with the pin 66 extending from its apex permits the tool 31 to be used in corners without contact of the pole piece 34 with the magnetic material surfaces. The pole piece 34 is suitably held within the tube 32 as by means of a diametrically extending pin 68. A similar diametrically extending pin 70 may be provided through the connecting member 44 and the screw-threaded portion of the rod 40 to prevent removal of the rod.

The tool 31, like the tool 1, is adapted to pick up magnetic material by its pole piece 34 and the portion of the tube 32 surrounding the magnet 46. This tool 31 is adapted to remove magnetic material from bores in castings or other bored pieces in which the bored piece is itself of magnetic material in which case the lower end portion is insertable into the hole and the loose magnetic material is attracted by the magnet 46 to the pole piece 34 and in some instances to the wall of the tube 32 surrounding the magnet 46. The magnetic material pole piece 34 is held from direct contact with the walls of the bore by the pin 66 so that the tool 31 will not tightly adhere to the magnetic workpiece and may be easily removed from the hole. To further protect the tool 31 from adhering to the side walls of the bore, a narrow thin ring 74 of nonmagnetic material which preferably is a pliable material such as neoprene or rubber may be located along the lower portion of the tube 32 which surrounds the magnet 46. This ring 74 insures a slight air gap between the tube 32 and the adjacent walls of the bore but is of insufiicient radial thickness to prevent upward movement of loose material upon upward movement of the magnet or to prevent the magnet from attracting loose material at this location. This ring 74 may be secured in fixed position along the tube 32, however, it has been found more desirable to have it frictionally held against the tool so that it is adjustable'therealong as conditions may require.

The unloading of the tool 31 is accomplished in a manner similar to that of the tool 1. When it is desired to .release the collected loose magnetic material, the tool 31 is held over a suitable container and the rod 40 is pulled outwardly moving the magnet along the tube 32 past the wall 58. Since the wall 58 extends a sufiicient radial distance outwardly of the tube 32 it prevents the magnetic material from following the magnet 46 past the wall 58 permitting the magnet 46 to be moved past the wall 58 away from such loose collected material so that such loose material falls away from the tool 31 into the container. The tools 31, 31b, 31c and 31d are also adapted to collect loose material from storage bins such as nails from kegs and in such use the tapered pole pislce 34 aids in inserting the tool into the loose materi The tool 31a of Fig. 8 is quite similar to the tool 31 of Fig. 4 .in that it has a tube 32, a pole piece 34, an end closure 36, a spring 52 and a magnet 46. In this form, however, the rod 40 is shown connected to the connecting member 44 by means of a universal joint connection so that any slight .irregularities in connection between the rod 40 and magnet 46 will not interefer with the reciprocation of the magnet 46 within the tube 32 by the rod 40. More specifically, the inner end of the rod loosely extends into an oversized aperture and is provided with an oversized aperture in its inserted end which loosely receives a diametrically extending pin 45 carried by the connecting member 44.

The tool 31a is provided with a pliable flexible radially extending peripheral wall 74a which perferably resiliently engages the tube 32 and is adjustably positioned therealong. The wall 74a being flexible will permit its .insertion in bores or holes which are of lesser diameter. Furthermore the distortable ring permits a much closer movement of the tool 31a to the walls of the bore even when used in large diameter bores. The wall 74a preferably does not extend as great a radial distance from the tube 32 as does the wall 58 but does extend a suificient distance so that it prevents small loose material from following the magnet 46. may be supported by the operators hand wrapped around the tube 32 immediately upwardly of the wall 74a. The hand also serves to prevent any magnetic material which might pass the wall 74a from following the magnet 46 when it is being pulled upwardly by the rod 40.

In Fig. there is shown another form of tool 31b which is quite similar to the tools 31 and 31a. In this instance, however, the outwardly extending portion of the rod 40b is enclosed within a nonmagnetic material tubular member 33b which has a telescoping sliding fit with the upper end of the tube 32. .A spring 52 is located in the upper end of the telescoping tubular member 3311 and exerts an expanding force between the closure member or wall 36 and aclosure wall 37 to urge the magnet 46 to its upper or unloading position. The closure 37 closes the upper end of member 33b and is secured thereto as by means of pin 71. Breather holes 39 are provided to permit any air flow caused by the telescoping movement of the members 32 and 33b.

When the tool is used .for collecting magnetic material, the member 33b is telescoped inwardly with respect to the tube v32 to 'bring the magnet 46 adjacent the pole piece 34. .It may be locked in this position by a suitable releasable means, shown herein as comprising a pin and slot connection. A radial pin 76 is carried at the upper end of the tube 32 and extends therethrough into the closure member 36. The projecting end of the pin 76 extends into a longitudinally extending slot 78 in the tubular member 33b. At its upper end, the slot 78 is provided with a circumferentially extending portion 80 for receiving the pin 76 to lock the member 33b in its telescoped position. Such relative movement is facilitated by a pin 81 extending radially outwardly of the tube '32 adjacent the wall 58b.

As shown, the magnet is provided with a resilient nonmagnetic material layer or spacer 50 to maintain it slightly spaced from the pole piece 34 to facilitate movement of the magnet 46 away from the pole piece 34. The spacer 50 is of small dimension so that it does not materially interfere with the ability of the magnet 46 to cl'iarge .the pole piece 34 for picking up magnetic mater'ia The tool 31b normally will be in the unloading position with the magnet 46 above the wall 58b. In use the operator normally will grasp the member 3371 and di- In operation the wall 74a rect the tool toward the magnetic material to be picked up. For example, such material may be loose particles lying on a supporting piece or nails, tacks or the like in a container. The tool 311) is pushed into or toward such material. The movement of the pole piece 34 will be restricted by such material or such supporting piece and continued pushing on the member 33b will cause it to telescope downwardly along the member 32 until the pin 76 passes along the slot 78 into alignment with the portion 80.. The operator will then rotate the member 32 relative to the member 33b, as for example by pressing his thumb against pin 81 to bring the pin 76 and slot portion into registration to lock the tool .31 in its active or pickup position. With the magnet 46 in its position adjacent the pole piece 34, magnetic material will be attracted to the pole piece 34 and the lower wall portion of the member 32 below the wall 58b whereby such material may be moved with the tool 311) as desired.

To unload such picked-up material, the operator holds the tool 31b over a suitable container or the like and pushes the pin 81, as for example with his thumb, to align the slot 78 and pin 76. The spring 52 then will push the member 32 outwardly drawing the magnet 46 away from the pole piece 34 and past the wall 58b to the position shown in Fig. 8. The picked-11p material is prevented from following the magnet 46 by the Wall 58b and falls away from the tool 31b into the container since the gap between the picked-up material and the magnet 46 will at this time be .such that not enough of .its flux .lines will pass through such material to .hold it.

It will be apparent from the foregoing that the length selected by the designer for the above air gap will depend upon the strength of the flux field of the magnet and the permissible amount of flux below the wall 58b. This air gap should be large enough in relation to the above flux factors, to limit the flux below the wall 58b to an amount insuflicient to hold even very small particles of magnetic material.

The tool 310 (Fig. 12) is like the tool 31b of Fig. F10 except that the member 320 comprises a lower thin walled nonmagnetic tubular portion 32' and an upper thicker walled magnetic material tubular portion 32 which acts as a flux-shunter or magnetic keeper. Portion 32" has enough flux carrying capacity to shunt enough of the flux of the magnet 46, when the magnet 46 is in the upper or unloading position, to release even very fine pick-up material, without, however, reducing the potential lifting power of the unit. The upper end wall .370 is also of slightly different construction and the rod 400 is secured to the wall 37c by nuts threaded thereon and positioned to clamp against opposite sides of the end wall.

The operation of this tool 310 is similar to that described in connection with tool 31b in so far as the telescoping of the members 32c and 330 and consequent movement of the magnet 46 between pick-up and unloading positions are concerned. The unloading of the pick-up material, however, is accomplished primarily by the aforesaid flux-shunting action rather than by providing a gap between the pickup material and the magnet. More particularly, as aforesaid, portion 32" is proportioned to shunt enough of the flux of the magnet so that the flux which flows outside of the portion .32" is insufficient to hold magnetic particles. Consequently, movement of the magnet from portion 32 into portion 32" releases material picked up by the tool 31c.

The tool 31d of Fig. 13 embodies the flux shunting feature for unloading found in tool 31c of Fig. 12 but differs therefrom in certain details .of construction. It comprises a tubular member 32d having a thin nonmagnetic material portion 32d and a relative heavier wall magnetic portion 32d". The lower end of the portion 3211 is closed by means of a thin-walled nonmagnetic material plate or wall 32d and the upper end wall is closed by means of a closure 36d. The closure 36d is provided with a central aperture 38d in which is adjustably positioned a bearing sleeve 82 supporting the rod 40d for reciprocal movement therein. The lower end portion of the rod 400. is screw threaded and extends through a central aperture in a cup-shaped nonmagnetic material member 84. A pair of nuts acts to secure the member 84 to the rod 40d. The member 84 is suitably secured to a tubular magnet 86 as by cement. a press fit, .or otherwise. A helical coil spring 88 surrounds the sleeve 82 and rod 40d with its lower end between the upper nut on the rod 40d and the cup-shaped member 84. The upper end of the spring 88 extends up through an aperture in the closure 36d and has a hooklike portion seating against the outer surface of the closure 36d. The spring 88 exerts a contracting force tending to maintain the magnet 86 within the housing portion 32d". 9

The tubular sleeve 82 is provided with a laterally extending hand gripping bar or member 90 which has an aperture aligned with the central aperture of the sleeve 82 and through which the rod 40d extends.- A hand gripping ring or handle 92 is carried by the rod 40d above the member 90 through which an operators thumb or finger may be inserted. Other of the operators fingers may clasp the member 90 so that the rod 40d may be moved inwardly to move the magnet 86 against the end wall 32d by the operator. When the magnet 86 is in the portion 32d, as will be understood from the description of the foregoing figures, it will attract magnetic material thereto. When it is desired to unload the collected magnetic material from the tool 31d, the tool is held over a suitable container and the ring 92 and rod 40d are permitted to move upwardly under force of the spring 88 or with added force if necessary, to move the magnet 86 up into the magnetic material housing portion 32d", which shunts enough of the magnetic flux of the magnet to release the picked-up material.

The tubular sleeve or member 82 is preferably of sufficient length to form a substantial guiding surface for the rod 40d so that the magnet 86 is easily movable longitudinally of the tubular member 32d and is adjustably positioned relative to the closure 36a such that when the magnet 86 is at the extreme lower limit of its travel (adjacent the Wall 32d) the handle 92 will engage the upper surface of the bar 90. In this way the thin will 32d is protected against rupture by an operator applying excess pressure in moving the magnet 86. The member 82 may be adjusted upwardly from the position shown to limit the downward movement of the magnet 86 to a position spaced above the wall 32d' to control the pick up capacity of the tool 31d. The greater the spacing of the lower limit from the wall 32d' the less the capacity of the magnet. This is desirable when the tool is used to dispense nails, etc. The tubular member 82 is held in its adjusted position as by means of set screw 94.

The form of tool 31a, as shown in Fig. 14, is quite similar to the tool 31d of Fig. 13 except that it is provided at its lower end portion with a magnetic material pole piece 34 having a non-magnetic pin 66 and the spring 88 is an expanding spring and acts to maintain the magnet 86 in its downward position adjacent the pole piece 34 and against the nonmagnetic material resilient spacer 50. A substantially L-shaped handle 96 is secured to the upper portion of the tube 32e. The upper end of the rod 40d is provided with a cross bar 98 so that the operator may apply a lifting force to the rod 40d by merely closing his hand thereby lifting the magnet 86 for releasing the attracted magnetic materail. The end closure 36e may be simply a disk having a central aperture therethrough or may be of the same type as the closure 36, shown in other of the figures.

Figs. 15 and 16 illustrate modified forms of pole pieces 34' and 34", which may be used in lieu of the previously described pole pieces. In the form shown in Fig. 15, the pole piece 34 comprises a magnetic material slug similar to the pole piece 4a which is spaced inwardly from the end surface of the nonmagnetic material portion or sleeve 32' to hold the magnetic material slug 34 from engaging a planar surface of magnetic material such as a work bed to prevent excessive attraction between the tool and the work bed. In the form shown in Fig. 16, the slug 34" is aligned with the lower end wall of nonmagnetic sleeve portion 32 and a nonmagnetic material pin 66" is provided to space the slug or pole piece 34" from a'magnetic material work bed or workpiece. 1

The form of tool 31 shown in Fig. 17 is substantially identical with that shown in Fig. 12 with the exception that a wall 74 is added thereto whichgis like the wall 74a. The wall 74 is flexible to permit insertion of the tool 31 into holes of lesser diameter than the wall 74) and upon upward movement of the magnet prevents picked up material from moving 'therebeyond.

. spasms It also acts as a nonmagnetic spacer and provides a gap which prevents small particles of picked-up magnetic material from being held to the portion 32 by any leakage flux which may be present. With this construction, other design factors remaining the same, the flux carrying capacity of the keeper 32 may be reduced somewhat, or the magnet strength may be increased, since, in view of this gap, a greater total amount of leakage flux may be tolerated, and still cause even very small picked-up particles to unload.

Fig. 18 shows a tool 31g comprising a nonmagnetic shell 32 closed at one end by a pole piece provided with a nonmagnetic pin 66. A permanent magnet 46 is positioned within the tubing'or shell 32 and abuts the inner end of the pole piece 34 and is held thereto-by a nonmagnetic spacer 47 which is interposed between the magnet 46 and an end closure 36g which may be a wooden block. In order to resiliently hold the spacer 47 against the magnet 46, a resilient disk 47g is placed between the closure 36g and spacer 47. The disk 47g is shown as being of natural or synthetic rubber but could be of any material which will exert a resilient force similarly thereto including a spring.

The tool 31g is adapted to perform most of the functions of the tools 31, 31a, 31b, etc., but is not unloaded in the same manner. To unload or remove the picked up material from tool 31g the hand with the fingers wrapped about the shell 32 is slid therealong in either longitudinal direction. If moved in the direction toward the pole piece 34, the hand and fingers encricle the shell 32 suificiently far from the magnet 46 toward closure 36g to include all of the material which is to be un; loaded or discharged and the picked up material is slid along the shell 32 and along the pole piece 34 and finally wiped therefrom along the outer surface of the pin 66. If the movement is in the other direction, the hand and fingers encircle the tool 31g adjacent the pin 66 and slid along the pole piece 34 and shell 32 toward the wall or closure 36g until the material to be unloaded is slid sufiiciently far from the magnet 46 that it is no longer held to the shell 32 thereby and will fall away.

In Fig. 19 there is shown a still further form of tool 101 which comprises a downwardly facing cup-shaped thick-walled nonmagnetic material housing 102 having a peripheral side wall 104 and an end wall 106. The wall 104 terminates at its lower end portion in a pcripheral edge 108 against which is secured a peripheral flange 110 of an upwardly facing nonmagnetic material dished member 112. The member 112 has a peripheral side wall 114 and an end wall 116. The cross-sectional contour of the members 102 and 112 is preferably rectangular as shown in Fig. 21. A permanent bar magnet 118 is substantially in the form of a rectangular parallelepiped with however the two lower longitudinal and lateral edges rounded off. The magnet 118 is normally positioned within the cup-shaped member 112 and against the wall 116. In such position, magnetic material will be attracted to the outer surface of the member 112.

An operating rod 120 is suitably secured at its lower end portion to the magnet 118 and extends upwardly through an aperture 122 extending through a boss in the wall 106. A resilient sealing cap 123 may be pro vided over the boss to seal the aperture 122 against passage of foreign material. A transversely extending handle 124 is suitably secured as by the split clamping connection 126 to the upper end portion of the rod 120. The housing 102 is provided with spaced upwardly extending side members 128 havinga connecting handle 130. The operators hand surrounds the handles 124 and 130 so that as he clenches his fist the rod 120 will be moved upwardly moving the magnet 118 out of the member 112 into the housing 102. The picked-up material cannot follow the magnet, due to the shelf afforded by the flange 110.

The housing 102 is provided with a magnetic material downwardly facing flux shunter or keeper 132. The keeper 132 has an upper end wall and downwardly depending integral side walls forming a pocket to receive the magnet 118. When the magnet 118 is drawn upwardly into the keeper 132, a substantial gap is left between the magnet and the picked-up material. As before the flux carrying capacity of the keeper should be such, in relation to the other design factors involved (strength of magnet, length of gap, etc.), that it shunts 9 enough of the flux to cause even very small particles to unload, without reducing the potential lifting power of the unit.

In tools of this kind the amount of relative movement of the handles 124 and 130 and the amount of movement which can be imparted to the magnet 118 and yet retain its simplicity and the ease by which it can be operated is limited to a distance that can be spanned by a persons hand. In the absence of a keeper, the strength of the magnet, which can be used in such structures, is limited. By providing a keeper to shunt some or all of the flux, muchv stronger magnets may be used and the picked-up material can still be released.

The handle 124 is adjustably clamped to the rod 120 to control the distance the magnet is moved into the member 112. If the magnet 118 moves clear in, as shown, a maximum of material is picked up thereby. If less pick-up of material is desired, the connection 126 is adjusted to limit such movement into the member 112, and thereby limit the flux available to pick up material. This limitation is in part imposed by the gap between the magnet and wall 116 and in part by the proximity of the keeper 132. I

The above adjustment may also be used in connection with the type of material to be picked up. With heavy material, the adjustment is. made to permit. the magnet to engage the wall 116 and the material will be released by a partial movement of the magnet into the keeper housing 132. When thin, light pieces or particles are to be picked up, the handle 12.4 is adjusted downwardly on the rod 120 so that its engagement with the cap 123 holds the magnet 118 from touching the wall 116. In this position, the magnet still passes sufiicient flux through the wall 116 to collect a desired quantity of such thin, light pieces. When the handle 124 is moved upwardly, the magnet 118 is moved away into the keeper housing 132 against the top wall, in which position the keeper has its greatest shunting efiect, and releases such thin, light particles.

When the magnet 118 is within. the keeper housing 132 it will tend to stay in that-position due to the low reluctance of its flux'pa-th afforded by the keeper housing 132. A tapered spring 134 is provided on the rod.

120 between the housing 132 and magnet 118 and'is compressible upon movement of the magnet 118 into the housing 132. When so compressed it exerts .a force to urge the mag-net 11S sufliciently out of the influence of the housing 132 sothat gravity will return it the remainder of the way to the position shown in Fig. 19 upon release of the handle 124. Since, as above noted, gravity will tendto move the magnet 118 toward and hold it against the member 112 after an initial outward movement of the magnet 118, the spring 134 need only move the magnet part way toward the wall 116 andis therefore made of a less dimension than that between the upper surface of the magnet 118 and the lower surface of the housing 132 when the magnet 118 is in its lower position.

Figs. 22, 23 and 24 illustrate a modified form of the tool 101:? in which the downwardly cup-shaped thickv/alled housing 102a is fabricated of magnetic material which may be, for example, soft iron. The fact that the housing 102a is of itself made of magnetic material eliminates the necessity of the separate keeper 132 used with the nonmagnetic housing 102 of the tool 101. The member 112a is made much deeper than the member 112 so that when the magnet 118 is in its operative position, as shown. the poles of the magnet are spaced sufficiently from the housing 102a so that it does not bypass any substantial portion of the flux. The member 112a has its outturned peripheral flange or edge 1080 forming a nonmagnetic shelf which prevents any material picked up by the magnet from engaging the ]ower peripheral edge of the magnet material housing 102a. In this form because of the much smaller gap between shoulder 108a and the up position of the magnet 118. a larger portion of the flux of the magnet must be shunted in order to release the picked-up material and therefore the thickness of the walls of the housing 102:! must be greater than that of the keeper housing 132. It will e noted however, that some gap is provided by flange 108a and even if there is a small amount of leakage flux escaping outwardly from the lower peripheral edge of the housing 1020, the flange 108a acting as a nonmagnetic spacer will space picked-up particles from this 10 leakage flux to permit the particles to release and fall away from the tool 101a. Thus the shelf as in Fig. 17 permits of a reduction of the weight of magnetic material needed for the magnet shunt. This reduction in weight may in many situations be desirable.

Although only a few difierent embodiments of the invention have been described in detail, it will be appreciated that various further modifications may be made in the form, number, and arrangement of the parts without departing from the spirit and scope of the invention, as defined in the appended claims.

What is. claimed and is desired to be secured by United States Letters Patent is as follows:

1. In a magnetic tool, a housing having a first portion thereof fabricated from nonmagnetic material, a permanent magnet within said housing, means for positioning said magnet within said housing and operable to move said magnet into a first position in said first portion whereby magnetic material will be attracted by said magnet and operable to move said magnet into a second position in which one part of said first portion is substantially out of the path of the flux of said magnet, said housing being provided with a second portion of magnetic material on the side of said one part opposite to said magnet when said magnet is in said second position, said housing having a nonmagnetic portion projecting relative to said second portion to hold said second portion out of engagement with planar surfaces.

2. In a magnetic tool, a housing having a first portion thereof fabricated from nonmagnetic material and having a second portion thereof fabricated from magnetic material, a permanent magnet within said housing, means for positioning said magnet within said hous- .ing and operable to move said magnet into said first 3'5' portion whereby magnetic material will be attracted by said magnet and operable to move said magnet into a second position within said second housing portion so that the flux of said magnet will be directed primarily through said second housing portion, said housing being provided with a third portion of magnetic material on the side of said first portion opposite to said second portion, said housing having a nonmagnetic portion projecting relative to said third portion to hold said third portion out of engagement with planar surfaces.

3. In a magnetic tool, a housing having a portion thereof fabricated from nonmagnetic material, a permanent magnet within said housing, means for moving said magnet into said housing portion through one end thereof and out of said housing portion through said one end,

and a magnetic pole piece carried by said housing portion and spaced from said one end, said housing being provided with a nonmagnetic portion projecting so as to space said pole piece from engaging planar surfaces.

4. In a magnetic tool, a hollow shell of nonmagnetic 'material and having an end, a permanent magnet, means for supporting said magnet for movement within said shell toward and away from said end, a hollow shell of magnetic material in fixed contiguous relation with said nonmagnetic shell and spaced from said end, a magnetic material pole piece carried by said shell one end, said magnet supporting means being operable to move said magnet into a position adjacent said pole piece whereby said pole piece is energized for attracting magnetic particles thereto and operable to move said magnet into said magnetic material shell whereby said magnetic material shell acts to concentrate the flux of said magnet whereby said magnetic particles are released.

5. The combination of claim 4 in which said pole piece is provided with a tip of nonmagnetic material which extends outwardly thereto to space said pole piece from surfaces.

6. In a magnetic tool, a hollow shell of nonmagnetic material and having an end, a permanent magnet, means for supporting said magnet for movement within said shell toward and away from said end, a pole piece of magnetic material carried by said shell at said end, said piece externally of said shell being of generally converging shape, and a nonmagnetic member projecting from the outer end of said pole piece.

7. The combination of claim 6 in which said shell is provided with an outwardly extending shoulder spaced away from said one end, said magnet supporting means being operable to move said magnet past said shoulder away from said end.

8. In a permanent magnet energized article of the char- 1 1 acter described, a hollow casing comprising a pair of casing sections, one of said sections being of magnetic material, the other of said sections being of nonmagnetic material, an encircling member of pliable material carried by said casing, and a permanent magnet within said casing and movable relative to said casing from said other casing section to said one casing section, said one casing section acting to form a low reluctance flux path for the flux of said magnet whereby at least a portion of the magnetic material which may be attracted to the walls of said other section while said magnet is positioned in said other section will be released, said encircling member being positioned relative to the path of movement of said magnet whereby at least a portion of said magnet will pass through said encircling member during movement of said magnet from said one casing section to said other casing section.

9. In a permanent magnet energized article of the character described, a hollow casing, a permanent magnet within and movable relative to said casing between desired limits, a member encircling said casing and forming a radial wall extending therefrom, said encircling member being adjustably located longitudinally of the path of movement of said magnet such that at least a portion of said magnet passes through said encircling member during said relative movement between said limits, the encircling member being frictionally supported by said casing for adjustable sliding movement thereon.

10. In a magnetic tool, a thin walled tube of nonmagnetic material, a magnetic material pole piece closing one end of said tube and having a convergingly tapered end portion projecting therefrom, a nonmagnetic material pin carried by said pole piece and extending outwardly beyond said pole piece end portion, a bar type magnet longitudinally polarized and having one end portion seating against said pole piece, a closure member for the other end of said tube, a holding member of nonmagnetic material within said tube between said magnet and said closure member for immovably holding said magnet against said pole piece.

11. In a tool of the character described, an elongated tubular housing having opposite end walls, 'a permanent magnet within said housing and movable longitudinally therein toward and away from said walls, one of said walls having an aperture therethrough, an elongated member extending through said aperture and having one end portion secured to said magnet, a tubular member having an inner dimension slightly greater than the external dimension of the portion of said housing adjacent said one wall, said tubular member being arranged to telescope over said housing portion, and means securing a second portion of said elongated member to said tubular member whereby said magnet is moved within said housing upon relative movement of said tubular member and said housing.

12. The combination of claim 11 in which said tubular member is provided with an L-shaped slot and said tubular housing is provided with a radially extending pin received within said slot.

13. The combination of claim 11 in which said one wall comprises a disk member having spaced end walls and a peripheral wall, said disk member having a slot therein between said end walls and opening through said peripheral wall, a deformable member within said slot and having an aperture therethrough aligned with said one wall aperture, said deformable member aperture being of less diameter than said one wall aperture.

14. In a magnetic tool, a housing having an end portion, a pole piece of magnetic material carried by said housing end portion, a nonmagnetic material extending beyond said pole piece whereby said pole piece is prevented from contacting planar surfaces when said end portion is placed in engagement therewith, a flux producing element carried by said housing and having a magnetic pole closely adjacent said pole piece whereby flux is induced in said pole piece to cause magnetic material on such surface to be picked up by such tool.

15. The combination of claim 14 in which said housing end portion is of nonmagnetic material and said extending material is an extending portion of said housing.

16. The combination of claim 14 in which said extending material is a piece of nonmagnetic material carried by the outward face of said pole piece.

17. The combination of claim 14 in which said pole piece is located wholly within said housing end portion and the end wall of said housing end portion extends outwardly at least as far as the outer end surface of said pole F piece.

18. In a magnetic tool, a housing having an end portion, a pole piece of magnetic material carried by said housing end portion, a flux producing element carried by said housing and having a magnetic pole closely adjacent said pole piece whereby flux is induced in said pole piece to cause magnetic material on such surface to be picked up by such tool, and a spacing member disposed between said pole piece and said magnet pole, said spacing member clomprising a relatively thin layer of nonmagnetic materia References Cited in the file of this patent UNITED STATESPATENTS Number Name Date 512,381 Keyes Jan. 9, 1894 1,487,811 Savage Mar. 25, 1924 2,179,625 Groden Nov. 14, 1939 2,285,440 Kaiser June 9, 1942 2,417,762 Koller Mar. 18, 1947 2,517,325 Lamb Aug. 1, 1950 2,529,440 Willis Nov. 7, 1950 FOREIGN PATENTS Number Country Date 122,983 Australia Dec. 3, 1946- 336,282 Germany Apr. 29, 1921

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