US3297352A

US3297352A - Magnetic pickup device

Info

Publication number: US3297352A
Application number: US483548A
Authority: US
Inventors: John E Larrison; Bob G Bender
Original assignee: Hughes Aircraft Co
Current assignee: Raytheon Co
Priority date: 1965-08-30
Filing date: 1965-08-30
Publication date: 1967-01-10
Anticipated expiration: 1984-01-10

Description

1967 J. E. LARRISON ETAL 3,297,352

MAGNETIC PICKUP DEVICE Filed Aug. 50. 1965 Fig. t 38 John E. Lurrison,

Bob G. Bender,

INVENTORS.

(Juli fi- ATTORNEY.

United States Patent Company, Culver City, Calif., a corporation of Delaware Filed Aug. 30, 1965, Ser. No. 483,548 3 Claims. (Cl. 294-655) This invention relates to a magnetic pickup device and more particularly to a magnetic pickup device for positioning small semiconductor elements in holes in a circuit board;

The increased use of subminiature and micro-electronic circuits has introduced to the electronic industry the problem of handling extremely small electronic components such as semiconductor diodes. Typically, such components have a diameter of .062 inch and a thickness of .038 inch, and because of this miniature size have been handled with tweezers. While such handling has proven satisfactory for some operations, it has been found'difi'icult to pick up with a pair of tweezers such small items and position them in small holes in circuit boards.

Therefore, it is an object of the present invention to provide an improved magnetic pickup device for picking up extremely small objects.

A further object of the improved magnetic pickup device is to provide a device for picking up small semiconductor elements having metallic edges and positioning them in holes in circuit boards.

A still further object is to provide an improved magnetic pickup device for small semiconductor elements which is simple to operate and can be used to efiiciently assemble such elements at increased assembly rates.

Other advantages of the invention will hereinafter become more fully apparent from the following description of the drawings which illustrate a preferred embodiment thereof and in which:

FIGURE 1 is a front elevational view of the improved magnetic pickup device illustrating the configuration of the device to facilitate the gripping of it by the operators hand;

FIG. 2 is an enlarged view of a portion of the improved pickup device of the present invention shown in cross section illustrating the tapered point, the magnetic element and the resilient pad; and

FIG. 3 is a perspective view of a portion of a circuit board and the end of the magnetic pickup device of the present invention showing a semiconductor element positioned in a hole therein having its electrode caps in contact with conductors on the circuit board.

Briefly, the magnetic pickup device of the present invention comprises an elongated cylindrical body configured for gripping between the fingers of the hand in a pencil-like fashion. A tapered point having a blunt end is aflixed to one end of the body and extending inwardly from the blunt end is a chamber which has a chamfered edge. A magnetic element is positioned in the chamber and is retained therein by a resilient plug. The plug has a slightly larger diameter than the chamber so that it can be wedged or forced into the chamber into engagement with the magnetic element and is positioned in the chamber sufficiently inward from the blunt end to define along with the chamfered edge a dished recess or detent.

Referring now to FIGS. 1 and 2, the magnetic pickup device of the present invention comprises an elongated generally cylindrical body which may be made of a plastic material. The body includes a plurality of grooves 12 near a tapered end 14. These grooves 12 are generally shaped and spaced in a manner to facilitate the 3,297,352 Patented Jan. 10, 1967 gripping of the body 10 by the fingers of the hand in a pencil-like fashion. A tapered point 16 of a metallic non-magnetic material such as stainless steel is ailixed to the body 10 by press fitting a protruding portion 18 thereof into a bore 20 in the end of the body. The point has 7 a blunt tip 22 which defines one end of a chamber 24 extending coaxially into the point 16 and including a chamfered edge 26.

A magnetic element 28 such as a permanent magnet having an elongated cylindrical shape such as an Alnioo magnet li inch in diameter and inch long manufactured by General Electric Company is inserted into the chamber 24. Because of the elongated shape of the magnetic element, the magnetic lines of force are caused t concentrate immediately adjacent to the blunt tip 22 of the point 16.

To retain the magnetic element 28 in the chamber 24 tween the pickup device and the object to be picked up, a resilient plug 30 of a mate-rial such as rubber having a diameter slightly greater than that of the chamber is inserted into and held by the wall of the chamber 24. The plug 30 is positioned in the chamber sufficiently inward from the blunt tip 22 so that along with the charnfered edge 26 of the chamber 24 it defines a slight recess or detent 32 in the blunt tip 22.

Referring to FIG. 3, the magnetic device of the present invention is adapted in a preferred embodiment to the picking up and positioning of a semiconductor element 34 having a generally cylindrical shape and a pair of metallic electrode cap elements 36. In the preferred embodiment of the device, the detent 32 has a diameter sufficient to permit the semiconductor element 34 to be inserted in the detent 32 into contact with the rubber pad 30 and held therein by the magnetic force of the magnetic element 28. In this fashion, the pickup device may be positioned over the semiconductor element in a specific orientation since the metal electrodes 36 will both be held in contact with the rubber pad 30 by the magnetic force. Such orientation permits the semiconductor element to be positioned in a hole 37 in a circuit board 38 with the electrodes 36 in contact with the ends of conductors 40 forming a portion of the periphery of the hole 37. When the semi-conductor element is so inserted, the friction force between the engaging metal portions is enough to retain the element in the hole and to permit the pickup device to be pulled away from engagement therewith, thus disengaging the element from in contact with the blunt tip 16.

While one embodiment of this invention has been herein illustrated, it should be appreciated by those skilled in the art that variations of the disclosed arrangement both as to its details and the operation of such details may be made without departing from the skill and scope thereof. Accordingly, it is intended that the fore-going disclosure and the showings made in the drawings may be considered as illustrative of this invention and not construed in a limited sense.

What is claimed is:

1. A magnetic pickup device comprising:

an elongated cylindrical body shaped for gripping between the fingers of the hand in a pencil-like fashion;

a tapered point afiixed to one end of the body and including a blunt tip defining the end of a chamber having a chamfered edge;

an elongated magnetic element retained in said cham ber and having an exposed end positioned inwardly from said blunt tip; and

a resilient plug of slightly larger diameter than said chamber wedged into said chamber into engagement with said magnetic element, said plug being inserted v 3 4 into said chamber sufficiently to define with said References Cited by the Examiner chamfered edge a detent. 2. A magnetic pickup device according to claim 1 UNITED STATES PATENTS adapted for manual operation wherein the cylindrical 2,993,723 7/1961 Twachtman 5 body includes a portion configured for gripping between '5 3 169 791 2/1965 Twachtman the fingers of the hand.

3. A magnetic pickup device according to claim 1 wherein said detent is of a configuration to engage a GERALD FORLENZA, P Timmy Exammer cylindrical semiconductor having metallic portions With G F ABRAHAM Assistant Examiner said portions engaging said resilient plug. 10

Claims

1. A MAGNETIC PICKUP DEVICE COMPRISING: AN ELONGATED CYLINDRICAL BODY SHAPED FOR GRIPPING BETWEEN THE FINGERS OF THE HAND IN A PENCIL-LIKE FASHION; A TAPERED POINT AFFIXED TO ONE END OF THE BODY AND INCLUDING A BLUNT TIP DEFINING THE END OF A CHAMBER HAVING A CHAMFERED EDGE; AN ELONGATED MAGNETIC ELEMENT RETAINED IN SAID CHAMBER AND HAVING AN EXPOSED END POSITIONED INWARDLY FROM SAID BLUNT TIP; AND A RESILIENT PLUG OF SLIGHTLY LARGER DIAMETER THAN SAID CHAMBER WEDGED INTO SAID CHAMBER INTO ENGAGEMENT WITH SAID MAGNETIC ELEMENT, SAID PLUG BEING INSERTED INTO SAID CHAMBER SUFFICIENTLY TO DEFINE WITH SAID CHAMFERED EDGE A DETENT.