US2461939A - Optical inspection apparatus for use in inspecting potentiometer cards - Google Patents

Description

J. I OPTICAL INSPECTION APPARATUS FOR USE IN Feb. 15, 1949. s, s'ru| INSPECTING POTENTIOMETER CARDS 2 Sheets-Sheet 1 Filed June '6, 1945 Feb. 15, 1949. 2,461,939

J. S. STULL OPTICAL INSPECTION APPARATUS FOR USE IN INSPECTING POTENT-IOMETER CARDS Filed June 6, 1945 -2 Sheets-Sheet 2 I ,47' ORA E) Patented Feb. 15, 1949 LJNE'EED STATES PATENT QEFIQE OPTEGAL INSPECTION APPARATUS FOR USE IN INSPECTIN G POTENTIOMETER CARDS John S. Stull, Chicago, 111., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application June 6, 1945, Serial No. 597,768

in a predetermined path to guide successive por tions thereof under a microscope Where the card may be inspected, the card being moved by actuation of the carrier through the manual rotation of a capstan drivingly connected to the carrier by a strand.

The invention will be more fully understood from the following description taken in connection with the attached drawings, in which Fig. 1 is a plan view of the apparatus with parts shown in section;

2 is a detailed sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a vertical cross sectional view taken along the line 3'3 of Fig. 1 with parts broken away;

Fig. 4 is an enlarged front elevational view of a portion of the device showing a potentiometer card mounted on the apparatus;

Fig. 5 is a fragmentary vertical sectional View taken along the line 5--5 of Fig. 4;

Fig. 6 is an enlarged fragmentary plan view of the potentiometer card, and

Fig. 7 is an enlarged fragmentary sectional view of the capstan.

The inspection apparatus is used for inspecting potentiometer cards ID or other elongated articles. The potentiometer cards vary in size and shape and consist of an elongated flat form or card I! of dielectric material and predetermined outline having a straight top edge and upon which a fine wire [2 is closely wound. The convolutions of the wire l2 are spaced apart from each other and the insulating coating surrounding the wire is removed from a portion of the wire at the top edge of the potentiometer card to bare the metallic wire and form a contacting surface for engagement with the usual cooperating contact member, and it is this part of the potentiometer card that is inspected.

The inspection apparatus comprises a frame or carrier l5 in the shape of a quadrant having an arc-shaped rim [1 and converging ribs l8 meeting to form an elongated vertical hub 19. The carrier is mounted for pivotal movement on a shaft or pin which passes through an aperture 2! in the hub l9 and which is secured in apertures 23 and 24, respectively, of a base member-25 and a bracket 28 mounted on the base. A pair of antifriction bearings 28 and 29 are provided inthe hub l9 and cooperate with members 30 and 3|, respectively, to rotatably support the carrier on the shaft 28 A look nut 32 engaging the upper' threaded portion of the shaft 2o cooperates with the member 30 also threadedly engaging the shaft 29 to maintain the member 30 in position. To

retard the rotation of the carrier l5, a pair of brake members 35 and 36, slidably mounted in the bracket 28, are urged against the outer cylindrical surface of the hub I!) by a leaf spring 3! carried by the bracket 26. The rim ll of the carrier is raised to form a card supporting surface 4%, against which the potentiometer card is clampedby a plurality of clamps 4i spaced apart 'bers 47 which engage the threaded apertures 48 in the jaws 42. The members 41 ma be turned to rock the members 42 about the; pins 44 and thereby move the upper ends of thejaws 42 open against the action of bowed leaf springs 49 interposed between the jaws 42 and the arms of the U-shaped brackets 45. Upon movement of the member M in the opposite direction to a' point where the head of the member 4'! is disengaged I from the U-shaped brackets, the jaw 42 will be closed by the action of the spring 49 which will apply a uniform pressure thereto to clamp the card against the surface 40 of the rim H.

To accurately position the potentiometer card I. so that its top edge is in a horizontal plane a gage 'in the form of a fiat member 5!, having an arcuate edge, is mounted on the carrier l5. The gage Si is provided with parallel slots 55, through which pass securing studs 56. The gage member .1 55 is adapted to be moved forward to overlie and project beyond the rim I! in which position the potentiometer card may be moved upward into engagement therewith while the potentiometer card is being applied to the carrier l5 and clamped After the potentiometer card has been clamped in place, the gage member 5! may be moved back to the position shown in Figs, 1 and 3 in which position the top edge of the potentiometer card, which is mounted on said carrier and engageable with the edge of said card for use in axially positioning said card in a predetermined position on the arcuate portion of said carrier and with its edge parallel to the predetermined path of movement of said carrier, a stationary optical inspection device mounted on said base adjacent said predetermined path for inspecting the card on said carrier, a capstan mounted on said base, a strand having its intermediate portion encircling and operatively engaging said capstan, means for connecting the ends of said strand at Widely separated points to said carrier, and resilient means associated with said strand for maintaining said strand taut and in operative engagement with said capstan whereby, upon rotation of said capstan, the strand is moved to rotate the carrier about said axis, thereby to bring successive portions of the card mounted on said carrier into the field of said optical inspection device.

4. An inspection apparatus comprising a base, a carrier having an arcuate surface for supporting a potentiometer card in an arcuate position thereon, a plurality of holding members mounted on said carrier for holding said potentiometer card in said arcuate position on said carrier, a pivot support pivotally mounting said carrier on said base to turn about an axis concentric with saidarcuate surface whereby said arcuate surface is guided through a predetermined path, a movable gage member mounted on said carrier and engageable with an edge of said card for use in axially positioning said card in a predetermined position on the arcuate surface of said carrier and With the edge of the card parallel to the predetermined path of movement of said carrier, an arm pivotally mounted on said carrier adjacent one edge thereof, an optical inspection device mounted on said base adjacent said predetermined path for inspecting the card on said carrier, a capstan mounted on said base, a strand having its intermediate portion encircling and operatively engaging said capstan and having one of its ends attached to said pivoted arm and its other end attached to said carrier adjacent another edge thereof spaced from and opposite said one edge, and spring means urging said arm for rotation in one direction to maintain said cord taut and in operative engagement with said capstan, said capstan being rotatable to move said strand and said carrier and thereby bring successive portions of the edge of the card mounted on the carrier into the field of the optical inspection device.

5. An inspection apparatus comprising a base, a carrier having an arcuate portion for supporting a potentiometer card in arcuate position thereon,

a plurality of clamping members mounted on said carrier for holding said potentiometer card in said arcuate position on said carrier, a pivot support for pivotally mounting said carrier on said base to turn about an axis concentric with said arcuate portion whereby said arcuate portion is guided through a predetermined path, an

optical inspection device mounted on said base.

adjacent to said predetermined path for use in inspecting said card, a member movably mounted on said carrier, a strand connected at one end to said movable member and at its other end to said carrier at a point widely separated from said one end, a capstan mounted on said base and encircled in operative engagement by the intermediate portion of said strand, and spring means tending to move said movable member to maintain said strand taut and in operative engagement with said capstan whereby, upon rotation of said capstan, the strand is moved to advance the carrier and thereby move successive portions of the card mounted on the carrier into the field of the optical inspection device.

6. An inspection apparatus comprising a base, a movable carrier having a card supporting surface thereon, holders on said carrier for holding a potentiometer card in position on said card supporting surface, means mounting said carrier on said base for movement in a predetermined path whereby said card supporting surface is guided in a predetermined path of movement, a stationary optical inspection device mounted on said base adjacent the path of movement of said card supporting surface for use in inspecting a card on said carrier, a capstan mounted on said base, a strand having its intermediate portion encircling and operatively engaging said capstan, means for connecting the ends of said strand at widely separated points to said carrier, and resilient means associated with said strand for maintaining said strand taut and in operative engagement with said capstan whereby, upon rotation of said capstan, the strand is moved to advance the carrier and thereby move successive portions of the card mounted on said carrier into the field of said optical inspection device.

JOHN S. STULL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Baker Oct. 31, 1944

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