Retractible Magnet Holder

Abstract

A retractible magnet holder including a barrel member with an elongated cap member extended outwardly from one end, and a sleeve member fixed in the barrel member adjacent such one end. The barrel member and end cap are composed of a non-magnetic material, and the sleeve member is formed of a magnetic material. A non-magnetic shaft member and an attached magnet are reciprocally movable within the barrel member to a first metal pick-up position wherein the magnet is within the cap member and to a second metal release position wherein the magnet is within the sleeve member. A latch means stops and releasably holds the shaft member and magnet in the second position therefor.

Description

SUMMARY OF THE INVENTION

The retractible magnet holder is of a simple and economical construction and quickly and easily manipulated to pick up small metal particles that are either exposed or located in generally inaccessible places such as cavities or drilled holes and to completely release such particles for disposal. The holder is compact and of a pencil shape for convenient carrying in a shirt pocket or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the retractible magnet holder with the magnet in an operative or metal pick-up position;

FIG. 2 is an enlarged longitudinal sectional view on the line 2--2 in FIG. 1;

FIG. 3 is an enlarged detail sectional view of the magnet end of the holder showing the magnet releasably held in the inoperative or metal release position therefor; and

FIG. 4 is a fragmentary sectional view showing the magnet holding means in a released position.

DETAILED DESCRIPTION OF THE INVENTION

The retractible magnet holder is shown in full size in FIG. 1. As shown in FIG. 2 the holder includes a tubular cylindrical barrel member 10 having an axial bore with an upper section 11, a lower section 12 and an intermediate section 13 of a reduced bore relative to the upper section 11 but of an enlarged bore relative to the lower section 12. A cylindrical sleeve member 14 of a length less than the axial length of the lower bore section 12, and having an outer diameter slightly smaller than the diameter of the bore section 12, is inserted within the bore section 12 to a position defined by the engagement of its inner end 16 with a shoulder 17 formed at the junction of the bore sections 12 and 13.

An elongated cylindrical cap member 18 has an open end 19 of a size to snugly fit within the terminal bottom end 21 of the lower bore section 12 to a position limited by the abutting engagement thereof with the outer end 22 of the sleeve member. The bottom end 21 of barrel member 10 has a side wall of a reduced thickness which is secured, as by crimping, about the cap member open end 19. It is seen, therefore, that the sleeve member 14 is held against movement axially of the barrel member 10 by the engagement of its inner and outer ends 16 and 22, respectively, with the shoulder 17 and cap member end 19, also respectively.

Referring to FIGS. 2 and 3, it is further noted that the diameter of the upper bore section 11 is substantially equal to the inner diameters of the sleeve member 14 and cap member 18, which constitutes a closed lower extension of the barrel member 10. The sleeve member inner end 16 is tapered to form a cam surface 23 extended between and joining the wall surface of the intermediate bore section 13 with the inner peripheral surface of the sleeve member 18, for a purpose to appear later.

Reciprocally movable within the upper bore section 11 and sleeve member 18 is a round rod or shaft 24 having an end section 26 projected outwardly from the upper end of the barrel member 10 (FIGS. 1 and 2). The opposite or inner end section 27 of the shaft 24 (FIGS. 2 and 3) is formed with an axial bore 28 to receive, in a press fit, a cylindrical magnet 29, that has a diameter of a length slightly less than the inner diameters of the sleeve member 14 and cap member 18. In response to a manual actuation of the rod 24, the magnet 29 is movable to a metal pick-up or operative position within the cap member 18, and to a metal release or inoperative position within the axial confines of the sleeve member 14. The operative position is defined by engagement of the magnet 29 with the closed end of the cap member 18, and its inoperative position by a spring pressed latch pin 31.

The pin 31 includes a body or piston portion 32 slidably movable within a transversely extended hole 33 formed in the shaft 24 and having a bottom wall 34. A coil spring 36 is arranged in compression between such bottom wall 34 and the piston portion 32 to continuously urge a stem or follower portion 37 of the pin into slidable bearing engagement with the continuous surface formed by the wall surface of the intermediate bore section 13, the cam surface 23 and the inner peripheral surface of the sleeve member 14.

In the construction of the retractible magnet holder of this invention the barrel member 10, cap member 18, shaft 24 and latch pin 31 are composed of a non-magnetic material such as aluminum. The sleeve member 14 is composed of a magnetic ferrous material such as steel, while the magnet 29 is of a well-known type commonly referred to as an alnico magnet.

As shown in FIG. 2, the magnet 29 is in its metal pickup or operative position located within the cap member 18 and partially extended within the sleeve member 14. The nonmagnetic properties and low relative permeability of the cap member 18 do not appreciably diminish the magnetic field intensity of the magnet 29 which is able to exert its magnetic force or field intensity to pick up ferrous particles indicated as 38 in FIG. 2. In this operative position of the magnet 29 the pin 31 is in bearing engagement with the sleeve member 14 and retracted within the transverse confines of the rod 24.

In FIG. 3, the magnet 29 is shown in a metal release or inoperative position. In this position the magnet 29 acts to induce within the sleeve member 14 a magnetic field of opposite polarity to that of the magnet 29. The field of the magnet 29 is thus confined within the sleeve member 14 so that the magnetic force thereof is substantially neutralized. Stated otherwise, the density of the magnetic field outside of the sleeve member 14 is negligible whereby the ferrous particles 38 are released.

On manipulation of the shaft 24 to move the magnet 29 from the metal pick-up position of FIG. 2 to the metal release position of FIG. 3, the pin follower portion 37 is successively moved into bearing engagement with the sleeve member 14, the cam surface 23 and wall surface of the intermediate bore section 13. During this movement, the pin 31 is progressively extended radially outwardly from the shaft 24 to provide for the stop engagement of the follower portion 37 with the shoulder 39 at the junction of the bore sections 11 and 13. With the pin yieldably extended within the bore section 11 at a position between the shoulder 39 and cam surface 23 the magnet 29 is releasably held in its inoperative or metal release position.

In moving the magnet 29 from the position therefor in FIG. 3 to its operative or metal pick-up position in FIG. 2, the latch pin 31 is movable along the cam surface 23 for progressive retraction within the shaft hole 33 as illustrated in FIG. 4. To facilitate movement of the shaft 24 its upper projected end 26 is formed with a finger grip 41 for one hand, and the upper end of the barrel member 10 is formed with a knurled finger hold 42 for the other hand. A clip member 43 may be provided for carrying the holder in a shirt pocket or the like.

Although the invention has been described with respect to a preferred embodiment thereof, it is to be understood that it is not to be so limited since changes and modifications can be made therein which are within the full intended scope of this invention as defined by the appended claims.

Claims

I claim:

1. A retractible magnet device comprising:

a. a non-magnetic tubular barrel member having an axial bore closed at one end thereof,

b. a cylindrical sleeve member of a ferrous material located within said bore at a position spaced inwardly from the closed end thereof,

c. a manually actuated non-magnetic shaft member reciprocally movable within said bore having one end projected outwardly from the other end of said bore,

d. a magnet means attached to the opposite end of said shaft member for movement therewith from an operative position, located within the bore of said barrel member at the closed end thereof, to an inoperative position located within said sleeve member, said magnet means in the inoperative position therefor having one end adjacent the closed end of the bore and the other end located intermediate the ends of said sleeve member,

e. a latch means movably mounted on said shaft member, and

f. a stop portion on said barrel member engageable with said latch means to releasably lock the magnet means in said inoperative position therefor.

2. The retractible magnet device according to claim 1, wherein:

a. said latch means includes a stop pin movable transversely of and within said shaft member, with one end thereof extendible outwardly from said shaft member, and

b. the axial bore of said barrel member has the wall surface thereof formed with an annular groove located between said sleeve member and the other end of said bore, said groove having the side surface thereof adjacent the sleeve member tapered in a direction inwardly of the barrel member and toward the sleeve member and the opposite side surface thereof located in a plane extended transversely of the barrel member, and

c. means for yieldably urging said one end of the pin into bearing engagement with the wall surface of said bore,

d. said one end of the pin member, when said magnet means is in the inoperative position therefor, being within said groove in abutting engagement with the opposite side surface of said annular groove which opposite side surface constitutes said stop portion.