Magnetic pick-up tool

Information

  • Patent Grant
  • 6677845
  • Patent Number
    6,677,845
  • Date Filed
    Wednesday, January 19, 2000
    24 years ago
  • Date Issued
    Tuesday, January 13, 2004
    20 years ago
Abstract
A magnetic pick-up tool, which preferably features a magnet retained on its non-exposed sides within a ferrous-containing carrier. The ferrous-containing carrier redirects the magnetic forces issuing from the magnet toward the exposed surface area, significantly increasing a magnet's strength without the need for increasing magnet size. In one embodiment, the pick-up tool features a threaded carrier, mated to a sleeve member in a manner allowing the sleeve member to be adjustably positioned relative to the magnet and carrier by rotation of the sleeve member in the desired direction.
Description




FIELD OF THE INVENTION




This invention relates generally to pick-up tools and, more specifically, to an improved magnetic pick-up tool having increased pick-up strength and flexibility of use.




BACKGROUND OF THE INVENTION




Magnetic pick-up tools are generally known in the art. Typically, these tools feature a cylinder-shaped magnet housed in an aluminum carrier or jacket, with a telescoping shaft being inserted into a rear portion of the magnet (or carrier) to allow the tools to be used in difficult-to-reach areas. The most common use for such tools is in the field of vehicle repair, although many other uses are possible.




U.S. Pat. No. 5,945,901 issued to Coleman illustrates one such tool. The tool of Coleman further features a ferromagnetic sleeve member that is slidably positioned about the magnet (or carrier), with the sleeve member being held in position by magnetic forces emanating from the sides of the magnetic. The Coleman tool further features an arrangement in which the sleeve member extends beyond the exposed surface area of the magnet, to eliminate or reduce the possibility that the exposed magnet surface will unintentionally attract radially positioned objects.




There are several drawbacks with the prior art tools, including the Coleman tool, however. With specific regard to the Coleman tool, it discloses a pick-up tool having a magnet holder (i.e., carrier) comprising a non-ferrous material, such as aluminum, brass, plastic, or non-magnetic stainless steel. Such a holder does not interfere with flux from the magnet, so that the sleeve member car still be retained in position by the magnet despite the presence of the holder/carrier.




However, because the non-ferrous magnet holder/carrier does not interfere with flux from the magnet, it does not redirect flux from the magnet in the direction of the exposed surface area and thus results in a magnet having less than optimal strength. Moreover, some users find the slidable sleeve member to be a nuisance, and want the flexibility of being able to adjust the amount by which the sleeve member extends beyond the surface of the magnet, or to retract the sleeve member so that it does not extend beyond the surface of the magnet at all.




A need therefore existed for a magnetic pick-up tool capable of using magnets of the size typically used in prior art tools, yet having significantly increased pick-up strength. A need further existed for a magnetic pick-up tool having an adjustable sleeve member.




SUMMARY OF THE INVENTION




It is an object of this invention to provide a magnetic pick-up tool capable of using magnets of the size typically used in prior art tools, yet having significantly increased pick-up strength.




It is a further object of this invention to provide a magnetic pick-up tool having an adjustable sleeve member.




BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS




In accordance with one embodiment of the present invention, a magnetic pick-up tool assembly is disclosed. The assembly comprises, in combination: a magnet having an exposed pick-up area, a rear area opposite the exposed pick-up area, and side surface areas disposed between the exposed pick-up area and the rear area; a carrier fixedly coupled to the side surface areas of the magnet; wherein the carrier comprises a ferrous-containing material; and a shaft attached to at least one of the rear area and the carrier.




In accordance with another embodiment of the present invention, a magnetic pick-up tool assembly is disclosed. The assembly comprises, in combination: a magnet having an exposed pick-up area, a rear area opposite the exposed pick-up area, and side surface areas disposed between the exposed pick-up area and the rear area; a carrier fixedly coupled to the side surface areas of the magnet; wherein an exterior surface of the carrier is threaded; a ring adapted to engage the threaded exterior surface of the carrier so that a position of the ring relative to the magnet may be altered by rotating the ring about the carrier; and a shaft attached to at least one of the rear area and the carrier.











The foregoing and other objects, features, and advantages of the invention will be apparent from the following, more particular, description of the preferred embodiments of the invention, as illustrated in the accompanying drawings.




BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a perspective view of an embodiment of the magnetic pick-up tool assembly of the present invention.





FIG. 2

is a side, cross-sectional view of the magnetic pick-up tool assembly of

FIG. 1

, taken along line


2





2


.





FIG. 3

is a side, cross-sectional view of the magnetic pick-up tool assembly of

FIG. 1

, taken along line


2





2


and illustrating the movement of the sleeve member from the position in

FIG. 2

to that shown in FIG.


3


.





FIG. 4

is a cross-sectional view of the magnetic pick-up tool assembly of

FIG. 2

, taken along line


4





4


.





FIG. 5

is a perspective view of another embodiment of the magnetic pick-up tool assembly of the present invention.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS




Referring first to

FIGS. 1-3

, reference number


10


refers generally to one embodiment of the magnetic pick-up tool assembly of the present invention. The pick-up tool assembly


10


generally comprises a magnet


12


which is covered by a carrier


14


. (Preferably, the carrier is dimensioned to cover at least the side areas of the magnet


12


and the non-exposed rear surface of the magnet


12


as well, and is adhered to the magnet


12


using a glue-type adhesive.) As shown in this embodiment, the magnet


12


and carrier


14


are preferably cylindrical in configuration, although other shapes for each are certainly permissible without departing from the spirit or scope of the present invention—provided of course that the carrier


14


appropriately mates with the magnet


12


so as to redirect the side and rear magnetic forces of the magnet


12


to its exposed surface.)




Referring specifically to

FIGS. 2 and 3

, the carrier


14


in one embodiment has threading


16


, which enables the carrier


14


to be coupled to a sleeve member


18


in a manner allowing the sleeve member


18


to be moved in either direction along the carrier


14


by rotating the sleeve member


18


. In this embodiment, the sleeve member


18


has a projection


20


that inserts into the threading


16


, so that upon rotation of the sleeve member


18


, the projection


20


travels along the threading


16


in the desired direction—causing the sleeve member


18


to change position, as desired, relative to the carrier


14


. In this manner, the sleeve member


18


can be positioned to extend beyond the exposed surface of the magnet


12


by the amount desired as shown in

FIG. 2

, or the sleeve member


18


can positioned so as to be flush with the exposed surface of the magnet


12


as shown in FIG.


3


. Also in this embodiment, because the sleeve member


18


is not retained in position by magnetic force from the magnet


12


, the sleeve member


18


can be manufactured from a non-ferrous material.




Referring now to

FIG. 5

, another embodiment of the pick-up tool assembly


10


is shown, referred to as the pick-up tool assembly


100


. Like the pick-up tool assembly


10


described above, the pick-up tool assembly


100


generally comprises a magnet


120


which is covered by a carrier


140


in the manner described above with respect to the magnet


12


and carrier


14


. In this embodiment, there is no equivalent for the sleeve member


18


.




As shown in

FIGS. 2 and 3

, a telescoping shaft


22


is preferably coupled to the carrier


14


at a side opposite the exposed surface of the magnet


12


. The telescoping shaft


22


may be positioned, as desired, taking into account the distance needed to be covered by the pick-up tool assembly


10


. (While the shaft


22


is shown as being of the telescoping variety, a non-telescoping shaft


22


would also be suitable.) As shown in

FIG. 1

, a handle


24


is preferably positioned at the end of the telescoping shaft


22


opposite the carrier


14


. With respect to the pick-up tool assembly


100


, it also preferably features a telescoping shaft, identified in this embodiment by reference number


220


.




Referring to

FIGS. 1-5

, in a preferred embodiment the carrier


14


and carrier


140


is made of a ferrous-containing material, which will have the effect of redirecting side and, if the carrier covers the rear unexposed surface of the magnet


12


(or magnet


120


), rear magnetic forces toward the exposed surface of the magnet


12


(or magnet


120


). The ferrous-containing material is preferably any mild steel and, in the preferred embodiment, is C


12


L


14


low carbon re-sulfurized freemachining steel of the type available from British Steel Alloys. It is believed that any metal having a relatively high content of manganese and/or iron, when formed into the carrier


14


(or carrier


140


), will yield significant benefit over prior art non-ferrous carriers, and the term “ferrous-containing material” as used herein is to be construed broadly to encompass any such material.




Tests of a pick-up tool assembly


10


having a cylindrical magnet


12


with a thickness of 0.375″ and a diameter of 0.5″ and housed in a carrier


140


comprised of C


12


L


14


low carbon resulfurized free machining steel showed a maximum pick-up capacity for the magnet


120


of approximately 14.30 pounds. Using the same size and type of magnet


120


but with a carrier


140


comprised of


2011


TC aluminum—a material typical of that commonly used in carriers of the prior art assemblies—a maximum pick-up capacity of approximately 8.97 pounds resulted. Thus, the change in material in the carrier


140


of the present invention resulted in an increase in pick-up capacity of approximately 62.73%—without any change in the size of the magnet


12


used.




While in the embodiment of

FIG. 5

the carrier


140


comprises a ferrous-containing material, in the embodiment of

FIGS. 1-4

the carrier


14


may be of either the ferrous or non-ferrous variety. While use of a non-ferrous material in the manufacture of the carrier


14


will not result in the increased magnet strength described above, the adjustability of the sleeve member


18


relative to the carrier


14


having threading


16


will still yield substantial benefit over the prior art with respect to the ability to adjust the position of the sleeve member


18


as desired.




While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.



Claims
  • 1. A magnetic pick-up tool assembly comprising, in combination:a magnet having an exposed pick-up area, a rear area opposite said exposed pick-up area, and side surface areas disposed between said exposed pick-up area and said rear area; a carrier fixedly coupled to said side surface-areas of said magnet; wherein said carrier comprises a ferrous-containing material; wherein an exterior surface of said carrier is threaded and wherein said assembly further comprises a ring adapted to engage said threaded exterior surface of said carrier so that a position of said ring relative to said magnet may be altered by rotating said ring about said carrier; and a telescoping shaft attached to at least one of said rear area and said carrier.
  • 2. A magnetic pick-up tool assembly comprising, in combination:a magnet having an exposed pick-up area, a rear area opposite said exposed pick-up area, and side surface areas disposed between said exposed pick-up area and said rear area; a carrier fixedly coupled to said side surface areas of said magnet; wherein an exterior surface of said carrier is threaded; a ring adapted to engage said threaded exterior surface of said carrier so that a position of said ring relative to said magnet may be altered by rotating said ring about said carrier; and a telescoping shaft attached to at least one of said rear area and said carrier.
US Referenced Citations (6)
Number Name Date Kind
2878342 Arthur Mar 1959 A
2947563 Stitt Aug 1960 A
3041697 Budrek Jul 1962 A
4373967 Roper, Jr. et al. Feb 1983 A
5821840 Ricker Oct 1998
5945901 Coleman, Jr. et al. Aug 1999