US3168635A - Assembly of elements for making intermittent electrical contact - Google Patents

Description

Feb. 2, 1965 J. P. GEBHART 3,168,635

ASSEMBLY OF ELEMENTS FOR MAKING INTERMITTENT ELECTRICAL CONTACT Filed Dec. 31, 1962 Er .10 11 -.5

i I JII I I i 3 r r. 1 ZIIIIIIHI MIL 9 mnoi I/ (Q INVENTOR. i time 196554427 Irraevss tact'siare involved in the United States Patent Filed Dec. 31,1962, Ser. No. 243,791

7 Claims. 01. 200-166 This invention relates to electrical contacts and particularly to intermittent electrical contact elements which provide substantially one hundred percent reliability.

lIn.U.S. patent application, Serial. No. 57,832, filed September 22, 1960, entitled Tape Program Apparatus,

now Patent No. 3,071,317, issued January 1, 1963, and

assigned to. the sameassignee as the present application, a readout system is disclosed and claimed. This system utilizes two groups of a plurality of electrical contacts, one group of which is movable simultaneously toward the other grou Contact being made between opposite ele ments onlywhen a perforation appears in a film or tape positioned therebetween. Although the contact element's shown. in the patented system have good reliability, greater reliability is desired, especially whenmanyelectrical con aiid complex circuitry. 3 4 I l i e,

The present invention, therefore, ,is directed .to an electrical contact arrangement which may be used in the apparatusshown in I the ab'ov'e mentioned patent with substantially one hundred percent reliability. This reliability is provided by using a plurality of knife edges arranged in a circle which are adapted to beficontacted by the sloping sides of almovabl tapered element. e

Reliability is obtainable eventhough there isa certain amount of eccentricity between the axisof the tapered element and the axis of the knife edges. Furthermore, the use ofknife edges provides the minimum of jarea exposable to dirt and dust, and even though dirt and dust may collect on the. tapered surfaces, the knife edges can readily penetrate through the dirt and dust to insure a good contact.

A combination of contact elements for use with continuously moving perforated film or tape and having a high degree of reliability is also described hereinafter.

The principal object of the invention, therefore, is to provide the optimum of reliability in the making of intermittent electrical contacts.

testing of complicated systems Another object of the invention is to provide an improved contact construction between two electrical conducting elements. N

A further object ofthe invention is to provide an improved rolling electrical contact construction.

A still further object of the invention is to provide an improved intermittent electrical contact construction which provides substantially one hundred percent reliability.

A better understanding of this invention may be had from the following detailed description when read in conjunction with the accompanying drawings, in which:

FIG. 1 is a side view, partly in cross-section, of a pair of electrical contact elements embodying the invention;

FIG. 2 is an enlarged cross-sectional view showing two contact elements in contact;

FIG. 2a is a cross-sectional view taken along the line 2a2a of FIG. 2;

FIG. 3 is a perspective view, partly incross-section, showing the movable contact element;

FIG. 4 is a perspective view, showing the fixed contact element;

FIG. 5 is a perspective view, partly in cross-section, showing a rolling contact element for continuously moving tape or film;

. 6 is aperspective view, partly in cross-section, of

the contactor for the element shown in FIG. 5; and

FIG. 7 is a cross-sectional view taken with the rolling contact shown in FIG. 5 and the contactor of FIG. 6 in engagement. 1 6

Referring, now, to the drawings in which the, same numerals identify the same elements, a-fixed block 5 of these elements can be mounted as described in the above-mentioned patent.

A mounting block 14 adapted to be oscillated in the direction of the arrow 15 mounts a pair of contact elements shown generally at 16 and17, movement of the block 14 bringing the contact elements 16 and 17 in contact with the fixed contact elements 6and 7. The elements 16 and 17 may. be insulated from the block 14 by, e

21, or the block maybe of insulatinsulations 20 and ing material.

Shown passing between the contact elements 6-7 and 16-17 is a filmortape 23 which has been. perforated in a prearranged order to permit certain of opposing con-. tact elements to contact each other when a perforation appears between them. If no perforation is present, thenthetips of the contacts film or .tape and; no contactis made.1 e

a The details of the fixed contact elements are shown. in FIGS. 2, 2a,.and {1, the fixed contactors such as 6 and 7 having a cross-notched plate 25 attached to a-cylindr icalbody seetion 26,;having an end cavity 27 in which the end .ofan electrical conductor may be soldered. By cross-notching plate 25, four centrally arranged parallel knife edges30 are provided, a practicalfplate having a thickness of 5/ of an inch, a notch widthof 9 of an inch, while the diameter. of thebody 26 is of aninch. i I it Each o f the movable contact elements such as shown -at 16 and 17 and in detail in FIG. 3 has a hollow cylindrical body 32 of of an inch diameter. Near the end of the body is a flange 33 of a thickness of of an inch and through which passes a cylindrical element 34 having a tapered conical tip surface 35 and a flat tip surface 36. The inner section of the cylinder 34 has a flange 39, while the end of the cylinder has mounted thereon a compression spring 40, the other end of the spring 40 abutting an electrical connecting element 41. Thus, the cylinder 34 is biased outwardly by the spring 40. The dimensions of a typical contact element such as shown in FIG. 3 are those in which the cylinder 34 is of an inch in diameter, the diameter of the surface of the tip 36 is of an inch, while the angle of the tapered surface 35 with respect to the surface of the cylinder 34 is 45 degrees. I

As shown in FIGS. 2 and 2a,-when a perforation appears in the tape 23, the tapered surface 35 is brought into contact with one or more of the knife edges 30 of the plate 25 when the block 14 is moved toward the block 5. As shown in FIG. 2a, the axis of the tapered portion 35 is concentric with the circle of the knife edges 30. However, if a certain eccentricity should exist, the surface 35 may only contact one ortwo of the knife edges but this contact is sufiicient to provide the desired electrical connection. Since the cylinder 34 is under the compression of the spring 40, no damage is done to the contacting surface if some eccentricity exists.

As mentioned above, since the knife edges have prac-' tically no appreciable surface on which dust or dirt can collect, and if any dust or dirt should exist on the tapered surface 35, it will be easily pierced by the sharp knife edges 30.

Patented Feb. 2, 1965 16 and,17 rest against the 'In FIG. 5, the construction of one element of a rolling type of contact system for continuouly moving film or tape is shown. This element includes a roller 50 mounted on a shaft 51 in a yoke 52 which has a pin 54 therethrough, the ends of the pin being in slots 55"and 56 in a cylindrical body 60. The roller 60 is under tension of a spring 61 having one end against the yoke 52 and the other end against an electrical connecting element 62 fastened to the body 60. Thus, the roller 50 may roll along on the film until a perforation is reached, at which time the-contact roller 50 may connect the special contacting element shown in FIGS. 6 and 7. The element shown in FIGS. 6 and 7 has'a cylindrical body 43 and an electrical connecting element 44 which is threaded to the body 43 in order to vary the tension of-a spring 45, one end of which abuts the contact element 46. The end of body 43 has a flange 63, the central opening for the element 46 being chamfered as shown at 64. The normal position of the tapered end of element 46 is such that its tip surface is in the outer plane of flange 63, a flange 66 on element 46 abutting a shoulder of body 43 to hold the element 46 in position. Now, the spring 61 of the roller element shown in FIG. is stronger than the spring 45 of the element shown in FIG. 6 so that when the roller 50 encounters a perfora tion, it first makes contact with the flat tip of element 46 and then depresses element 46 to make contact with the chamfered surface 64, as shown at 50". This action pro- ,vides double insurance of a goodcontact being made.

Iclaim: I 1. An electrical contact assembly comprising a fixed element'and a movable element adapted to be intermittently brought into contact with said fixed element, one

i of said elements having at least one knifeedge contacting surface and the other of said elements having a tapered surface for contacting said knife edge surface, said fixed element being a plate havingv cross notches therein to form a plurality of parallel knife edge surfaces concentrically positioned.

4 surface for contacting said knife edge surface, said movable element being a cylinder having a tapered conical surface at the end thereof, the axis of said cylinder being substantially concentric with the axis of said concentrically positioned knife edge surfaces.

3. A pair of electrical contact elements adapted, to make contact intermittently comprising one'fixed element and one movable element, one of said elements having a contactor plate with crossed notches over the surface thereof to provide a plurality of parallel knife edge surfaces and the other of said elements having a tapered conical surface with respect to the surface of said firstmentioned element, said tapered surface and said knife edge surfaces being brought into contact upon movement of said movable element.

4. A pair of electrical contact elements in accordance with claim 3 in which means are provided for resiliently biasing one of said contact elements toward the other of said contact elements. I

5. A pair of electrical contact elements in accordance with claim 3 in which said movable contact element includes a hollow cylindrical body and a cylinder passing through one end of said body, the end of said cylinder having its outer surfacetapering toward the axis of said cylinder. 7 g

6. A pair of electrical contact elements in accordance with claim 5 in which said cylinder is resiliently biased toward said fixed element.

7. A pair of electrical contact elements in accordance withclaim 6 in which said parallel knifeedge surfaces are concentrically positioned. I

References Cited by the Examiner v UNITED STATES PATENTS 2,339,996

1/44 Kight 20019' 2,753,432 7/56 Long et a1. 200l66 2,931,874 4/60 Leaman 200 6l.08 X 2,934,628 4/ Massar etal ZOO-1 17 X 3,002,061 9/ 61 Perkins 20046 3,032,620 5/62 Siiberg 200l66 3,047,682 7/62 Hults 200l66 BERNARD A. GILHEANY, Primary Examiner.

Claims (1)

1. AN ELECTRICAL CONTACT ASSEMBLY COMPRISING A FIXED ELEMENT AND A MOVABLE ELEMENT ADAPTED TO BE INTERMITTENTLY BROUGHT INTO CONTACT WITH SAID FIXED ELEMENT, ONE OF SAID ELEMENTS HAVING AT LEAST ONE KNIFE EDGE CONTACTING SURFACE AND THE OTHER OF SAID ELEMENTS HAVING A TAPERED SURFACE FOR CONTACTING SAID KNIFE EDGE SURFACE, SAID FIXED ELEMENT BEING A PLATE HAVING CROSS NOTCHES THEREIN TO FORM A PLURALITY OF PARALLEL KNIFE EDGE SURFACES CONCENTRICALLY POSITIONED.

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