US3127805A - Cutting tool - Google Patents

Description

April 7, 1964 PARSTORFER 3,127,805

CUTTING TOOL Filed Aug. 15, 1960 l6 42 I V 56 i2 flq- ,nmmwl I0 [In 24 4 ATTORNEY United States Patent Office 3,127,805 Patented Apr. 7, 1964 3,127,805 CUTTING TOOL John Parstorfer, Phiiadeiphia, Pa., assignor to Burroughs Corporation, Detroit, Mich, a corporation of Michigan Filed Aug. 15, 1960, Ser. No. 49,633 8 Claims. ((31. 33-456) This invention relates to a cutting tool for parting or severing printed or etched circuit conductors and the like fixed or otherwise impressed on the face of a panel. The invention was specially designed for, but is not limited to, cutting printed circuit conductors on the contact panels disclosed and claimed in a copending application of John Parstorfer and Edgar O. Sprude, Serial No. 15,920, filed March 18, 1960, and assigned to the same assignee as the present invention.

An object of the invention is to provide a cutting tool of the above-described general character which is simple in construction, easy to use and inexpensive to manufacture.

Another object of the invention is to provide a cutting tool for severing printed circuit conductors and the like and which will produce a sharp, uniform cut through the conductor without tearing it or lifting it from its supporting panel.

Another object of the invention is to provide such a tool with means for clamping a printed circuit panel and the like, and with further means for assuring a predetermined clamping force on the panel.

A more specific object of the invention is to provide in such a tool, a clamping member of rigid, one-piece construction to best resist clamping and cutting forces yet so formed as to allow a hinge-like movement of its operable part.

In accordance with the above objects and first briefly considered in its broad aspects, the invention comprises clamping members for holding a printed circuit or the like panel and a movable cutting member operable to sever a conductor on the panel while the panel is in the clamped position. The invention also contemplates the use of means for limiting relative movement between the clamping members to assure that an operator cannot use excessive clamping force on the panel. The-invention also contemplates the use of guiding means for the cutting member to control it accurately throughout the cutting stroke, and gauge means for readily locating a panel in cutting position in the too-l.

The invention will be more clearly understood when the following detailed description of the preferred embodiment thereof is read in conjunction with the accompanying drawings in which:

FIG. 1 shows an isometric view of a cutting tool constructed in accordance with the invention, and a similar View of a fragment of a contact panel disclosed in the above-mentioned Parstorfer-Sprude application having printed circuit conductors on one face thereof, certain of which have been severed by the illustrated tool, and a plurality of equally spaced knife contacts on the opposite face thereof;

FIG. 2 is a front elevation of the tool shown in FIG. 1 and showing the contact panel in phantom view located in the tool preparatory to a cutting or severing operation;

FIG. 3 is a vertical sectional view of the tool shown in FIG. 2 but with the contact panel omitted;

FIG. 4 is an enlarged fragmentary end view of the tool;

FIG. 5 is an enlarged fragmentary illustration showing the cutting action of the cutting member; and

FIG. 6 is an enlarged view of a portion of the contact panel showing a discontinuity cut in one of its printed circuit conductors.

Turning now to the drawings, the illustrated tool comprises a clamping bed or base 10, a clamping bar 12, a

toothed cutting blade 14 and a rock lever 16 movably mounted on the clamping bar 12 for actuating the cutting blade 14.

The base 10 is secured at one end to an end of the clamping bar 12, as by cap screws 18, and has at least one reduced area portion 20, in this embodiment three, formed by one or more cross slots 21, which allows the free end of the base it) to be moved elastically with a spring or hinge-like action, as will be explained. The base 10 is provided with gauging means for locating a panel transversely of the tool which in the present embodiment takes the form of a plurality of elongated slots 24 for locating the particular contact panel 22 by its knife contacts 28. An adjustable stop gauge 26 is provided to locate the panel 22 longitudinally of the tool and is secured in adjusted position to the base 10 by means of a clamping screw 32.

The free end of the clamping bar 12 is formed with an upwardly extending yoke 34 and a depending jaw 36 provided with a slot 33 for freely guiding the lower portion of the cutting blade 14.

The rock lever 16 is provided with a slot 40 in which is press-fitted the upper portion of the cutting blade 14 and is mounted on a pivot pin 42 journalled at its end portions in the yoke 34 and passing through the cutting blade 14, the pivot pin 42 being held in the yoke 34 by retaining rings 43. The cutting blade 14 is secured further to the rock arm 16 by means of a dowel pin 44 passing through the blade and press-fitted in the depending slotted arm 46 of the rock lever 16. A compression spring 48 operating through the rock lever 16 normally maintains the tooth 49 of the cutting blade 14 against the bottom 50 of slot 38 in which position the cutting edge 52 of the blade tooth 49 is adjacent to the lands or faces 54 of jaw 36. The jaw faces 54 are sufficiently wide, pref erably wider than a conductor 30, to prevent lifting or tearing of the conductor during the cutting stroke, as will appear more clearly hereinafter.

The shank 55 of a knurled-head clamping screw 56 passes freely through an aperture 58 in the clamping bar 12 and similarly through a limiting member or spacer 60 and is threaded into the base 10.

To operate the tool for cutting or shaving off a portion of a conductor 30 on the panel 22, the panel is first placed in the tool between the base 10 and jaw 36, as shown in phantom view in FIG. 2, and located transversely of the tool by positioning appropriate ones of its knife contacts 28 in the slots 24, the stop gauge 26 having been previously set to locate the edge 22' of the panel to bring the particular conductor 30 directly beneath the jaw faces 54. Clamping screw 56 is next tightened causing the free portion of the base 16 to bend or spring about the reduced area portions 20 until first the panel 22 is clamped by jaw 36 and base It and then the spacer 60 next gripped between the base 10 and clamping bar 12. In this position the jaw 36 will be exerting a predetermined clamping force on the conductor 39 and panel 22, the force being determined by the particular height of the spacer 66. The actuating arm 62 of the rock lever 16 is then pressed downwardly to rock the cutting blade 14 thereby to sever and shave off a portion of the conductor 30 by cutting a discontinuity 31 therein (FIG. 6) and forming segment conductors 30. Since the cutting blade 14 has a curved cutting stroke it will also shave a slight arcuate portion 62 (FIG. 5) from the panel 22, this portion not being shown in FIG. 6.

The slotted jaw 36 closely guides the cutting blade 14 to assure a clean, sharp and uniform cut while the jaw faces 54 act as hold-downs as well as clamping faces to prevent tearing of the conductor adjacent to the cut or lifting it from the panel.

The spacer 60 may be omitted if desired, however, it is preferable to use it to obtain a uniform clamping force, particularly when the tool is to be used by different operators.

While there has been disclosed a specific structure exemplary of the principles of the invention, it is to be understood that this is but one embodiment thereof and that the invention may be constructed in a variety of shapes, sizes, and modifications without departing from the true spirit and scope thereof. Accordingly, it is to be understood that the invention is not to be limited by the specific tool disclosed but only by the subjoined claims.

What is claimed is:

1. A tool for shaving off a portion of a printed circuit or the like conductor on a face of a panel comprising, a rigid base, an elongated rigid bar rigidly secured at one end to said base with its other free end spaced therefrom, one of said base and bar members having a formation adjacent to its secured end whereby said base and said free end are relatively movable elastically toward each other, a toothed cutting blade movably mounted on the free end of said bar, screw threaded means operable independently of movement of said cutting blade for eifecting relative movement between said base and said free end to clamp a said panel therebetween, and means for moving said cutting blade across a face of said panel while it is so clamped in such manner that a tooth of said cutting blade will shave off a portion of a said conductor thereon.

2. A tool for shaving oif a portion of a printed circuit or the like conductor on a face of a panel comprising, a rigid base, an elongated rigid-bar rigidly secured at one end to said base with its other free end spaced therefrom, one of said base and bar members having a reduced crosssectional area adjacent to its secured end whereby said base and said free end are relatively movable elastically toward each other, a toothed cutting blade movably mounted on the free end of said bar, screw thread means manually operable independently of movement of said cutting blade for effecting relative movement between said base and said free end to clamp a said panel therebetween, means for limiting said movement to limit the clamping force on said panel, and means for moving said cutting blade while said panel is clamped in such manner that a tooth of said cutting blade will shave off a portion of a said conductor thereon.

3. A tool for shaving off a portion of a printed circuit or the like conductor on a face of a panel comprising, a rigid elongated base member, a rigid elongated bar member rigidly secured at one end to an end of said base member and the free ends of said members being spaced apart,

by said bar member for moving said cutting blade while said panel is clamped in such manner that a tooth of said cutting blade will shave off a portion of a said conductor thereon.

4. A tool for shaving off a portion of a printed circuit or the like conductor on a face of a panel comprising, an elongated base member, an elongated bar member rigidly secured at one end to an end of said base member, the free portion of one of said base and bar members being movable elastically relative to the free portion of the other member, the free portion of said bar member being provided with a jaw spaced apart from the free portion of said base member, a lever mounted on said bar member, a toothed cutting blade guided by said jaw and actuated by movement of said lever, and means for effecting relative flexing movement between said jaw and said free portion of the base member to rigidly clamp a said panel therebetween, a tooth of said cutting blade cutting a curved groove in said panel and shaving off a portion of a said conductor thereon when said lever is moved.

5. A parting tool for severing or shaving off a portion of a printed circuit or the like conductor on a face of a panel comprising, an elongated rigid base member, an elongated rigid bar member rigidly secured at one end to an end of said base member, the free portion of one of said members having a formation adjacent to its secured end making it flexibly movable toward the free portion of the other member, a jaw on the free portion of said bar member, a movable cutting blade carried by said bar member and having a tooth with a cutting edge thereon movable longitudinally of said bar member when said blade is moved, means for flexing said movable free portion of said one of said members toward the free portion of the other member to rigidly clamp a said panel between said jaw and said base member and to bring said cutting edge into substantial contact with said panel, and means operable to move said cutting blade to project said cutting edge through a portion of said panel to sever and shave off a portion of a said conductor thereon.

6. A parting tool according to claim 5 characterized further in that said cutting blade is pivotally mounted on said bar member and said jaw is slotted for guiding said cutting blade therein.

7. A parting tool according to claim 5 characterized further by the inclusion of gauge means on at least one of said members for locating said panel in clamping position in at least one of two mutually perpendicular directions, said gauge means including a slotted surface having at least one slot for receiving an associated element connected to said panel and further including an adjustably mounted gauge on a lateral side of said base member and settable in a direction parallel to the direction of said slot.

8. A tool according to claim 3 wherein said one of said members having a reduced cross-sectional area is said base member and said reduced cross-sectional area is formed thereon by at least one cross-slot extending through the major portion of the thickness of said base member.

References Cited in the file of this patent UNITED STATES PATENTS 964,182 Porter July 12, 1910 2,606,613 Junkunc Aug. 12, 1952 2,611,434 Mugler Sept. 23, 1952 2,948,177 Arvidson Aug. 9, 1960

Claims (1)

1. A TOOL FOR SHAVING OFF A PORTION OF A PRINTED CIRCUIT OR THE LIKE CONDUCTOR ON A FACE OF A PANEL COMPRISING, A RIGID BASE, AN ELONGATED RIGID BAR RIGIDLY SECURED AT ONE END TO SAID BASE WITH ITS OTHER FREE END SPACED THEREFROM, ONE OF SAID BASE AND BAR MEMBERS HAVING A FORMATION ADJACENT TO ITS SECURED END WHEREBY SAID BASE AND SAID FREE END ARE RELATIVELY MOVABLE ELASTICALLY TOWARD EACH OTHER, A TOOTHED CUTTING BLADE MOVABLY MOUNTED ON THE FREE END OF SAID BAR, SCREW THREADED MEANS OPERABLE INDEPENDENTLY OF MOVEMENT OF SAID CUTTING BLADE FOR EFFECTING RELATIVE MOVEMENT BETWEEN SAID BASE AND SAID FREE END TO CLAMP A SAID PANEL THEREBETWEEN, AND MEANS FOR MOVING SAID CUTTING BLADE ACROSS A FACE OF SAID PANEL WHILE IT IS SO CLAMPED IN SUCH MANNER THAT A TOOTH OF SAID CUTTING BLADE WILL SHAVE OFF A PORTION OF A SAID CONDUCTOR THEREON.

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