US3520218A - Transistor cap remover - Google Patents

Description

July 14, 1970 FIG.

R. A. TOLKMITT TRANSISTOR CAP REMOVER Filed April 10, 1968 I 1\-' VEN TOR. RICHARD A. TOLKMITT V. C. MULLER ROY MILLER ATTORNEYS,

United States Patent O 3,520,218 TRANSISTOR CAP REMOVER Richard A. Tolkmitt, China Lake, Califi, assignor to the United States of America as represented by the Secretary of the Navy Filed Apr. 10, 1968, Ser. No. 720,135 Int. Cl. B23]: 3/04, 5/14 U.S. C]. 82-92 1 Claim ABSTRACT OF THE DISCLOSURE Method and apparatus for severing the side wall of a transistor can to expose its contained electronic com ponent, such as a se-miconductor chip, without producing cuttings from the can wall which could contaminate or otherwise injure the component.

BACKGROUND OF THE INVENTION In the repair of malfunctioning circuits, employing semiconductor chips which are enclosed in cans, it has been the practice to cut the can sidewall to expose the chip for inspection. If the chip is reuseable it has been found economical to remove it and repackage it for use in a circuit. In one method of cutting the can wall the can was rotated in a lathe and the wall severed with a parting tool. This, however, produced metal cuttings which could injure the chip or the chip could otherwise be injured when the severed part, to which the chip is aflixed, dropped from the lathe chuck.

Another method of opening the can was to sever it with a chisel or like tool which could also injure the chip if impacted by the tool.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an isometric view of the invention, and FIG. 2 is an enlarged longitudinal cross section of a workpiece.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 2, transistor can is formed with a cylindrical metallic wall 12 and an integral end wall 14, the opposite end being closed by a cup shaped closure 16, having a flange 18, and an end wall 20 to which is affixed chip 22. The purpose of the invention is to sever wall 12 at a desired plane P without producing chips from wall 12.

Referring to FIG. 1, the apparatus for performing the method aforesaid comprises a C shaped frame 24 to which is journaled a knurled drive roller 26 and a plain roller 28, the knurled roller being afiixed to a shaft 30 having a hand crank 32 on the end of same. Each roller is provided with a groove 34, into which flange 18 of cup shaped closure 16 may project when wall 12 is lying on the rollers.

A cutter wheel head 36 is supported by the frame for rectilinear movement, and is fed toward the rollers by a conventional screw (not shown) contained within rotatable feed knob 38, the cutter head having a circular knife shaped cutter 39 journaled to same. Frame 24 is preferably aflixed to a rigid support 40 which may be affixed to a bench or the like.

In the operation of the apparatus can 10 is placed on the rollers with flange 18 disposed in grooves 34 and the cutter wheel moved into contact with the can with sufficient pressure to cause the teeth on the knurled roller to slightly indent the can wall and provide a positive drive to the can wall as it is rotated by the crank. A slight increase in the feed of the cutting wheel, as the crank is rotated severs the can wall without the production of chips.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the sco of the appended claims the invention may be practiced otherwise than as specifically described.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

.1. Apparatus for severing the side wall of a cylindrical transistor container comprising:

(a) an easily portable base member having an upstanding support member thereon,

(b) an open C-shaped frame member aflixed to said support member,

(c) first and second rotative work support rolls parallelly mounted at one extremity of said C-shaped frame,

(d) an infinitely manually adjustable feed circular knife cutter being freely rotatably mounted at another extremity of said C-shaped member with the axis of the said knife being aligned and parallel to the axes of the said rolls,

(e) each of said rolls having transversely aligned grooves that are offset from the plane of cut of the said circular knife cutter in order to receive any appendicies of a transistor container, and

(f) one of said rolls being knurled and utilizing as its rotative support shaft one arm of a hand crank directly attached thereto,

(g) the construction and arrangement being such that the one of said rolls along with the said hand crank thereon provides rotative impetus to the apparatus as well as support for a transistor container in association with the other of said rolls and wherein the open C-shaped frame provides a clear field of vision during operation of the said apparatus.

References Cited UNITED STATES PATENTS 1,042,998 10/1912 Blackmore 82-91 X 1,256,556 2/1918 Hedges 82-4 X 1,304,770 5/1919 Hestand 30-102 1,468,935 9/1923 Vosper 82-101 X 2,065,138 12/1936 Lang 30-102 2,582,078 l/ 1952 Solum et al. 82-92 2,753,739 7/1956 Dreier 77-73 X 2,753,744 7/1956 Therien 30-97 X 3,125,915 3/1964 Ahearn 82-101 X HARRISON L. HINSON, Primary Examiner U.S. Cl. X.R. 30-102

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