US2761115A - Binding post - Google Patents

Description

V Aug. 28, 1956 J. v. VISCONTI BINDING POST Filed Feb. 11, 1955 INVENTOR. JOSEPH V. VISCONTI BY W? Wm ATTORNEYS United States Patent BINDING rosr Joseph V. Visconti, Medford, Mass assignor to Lessells and Associates, Inc., Boston, Mass, a corporation of Massachusetts Application February 11, 1955, Serial No. 487,620 1 Claim. (Cl. 339-455 This invention relates to terminal binding posts and comprises a new and improved binding post adapted to be mounted on a chassis and to connect a number of diflerent sizes and types of electrical conductors.

At the present time there is a wide variety of binding posts on the market suitable for use in electrical equipment, the most common of which is the threaded post and cooperating nut type of terminal for electrically connecting two wires. Clip terminals capable of anchoring but a single bare wire are also extensively employed. Those forms of binding posts as well as all of the other forms known to me have at least one of the following undesirable features. They are either difficult to use, ineffective in performing their intended function, or relatively expensive to. manufacture.

To anchor a wire to most varieties of electrical terminals it is necessary to thread the wire through a rather small aperture. Other types require the operator to tighten a threaded cap or nut with one hand while the other hand holds the wire to be connected in place. In the course of being secured to the latter form of terminal, portions of the wire sometimes become eX- posed, creating an obviously unsafe condition. Furthermore, wires clamped to terminals by means of threaded caps or nuts are particularly susceptible to vibrations and thus often shake loose from the post. The more elaborate forms of binding posts designed to overcome the shortcomings alluded to above are too expensive to be employed extensively in the mass production of electronic components.

Another undesirable feature commonly found in most inexpensive forms of terminals is their lack of capacity for interconnecting more than two wires. Those skilled in the art readily appreciate the difficulties created by this limitation.

The primary object of my invention is to make possible the instantaneous connection of a wire to a binding post and at the same time to eliminate the necessity of threading wires and tightening retainers in securing a wire to a terminal.

Another object of my invention is to increase the elfectiveness of terminal binding posts.

Still another object of my invention is to provide an improved post to which a large number of conductors may be connected.

To these ends, my improved binding post includes as an important feature a tapered mounting screw and a cooperating spring-urged sleeve having a similarly tapered wall which mates with the screw.

Another feature of my improved binding post is the provision of a jack formed in the head of the screw for receiving a banana plug.

Another feature of the binding post of my invention is the provision of a transverse relatively large aperture in the tapered portion of the screw. Wires that are too large to be inserted between the mating tapered walls of the screw and the sleeve may be inserted through the 2 aperture and held in position by the clamping; action, of the sleeve.

These and otherobjects and features of my invention along with incident advantages will be. more readily understood and appreciated from the following detailed description of one embodiment thereof, selected for purposes of illustration and shown in cross-section in the single figure in the accompanying drawing.

The various elements, of the terminal areorganized about a post or screw 14 mounted in an aperture 12 of a chassis 10 by a pair of washers and a nut. A head is defined in the upper terminal portion of thejpost: by a downwardly converging conical wall 18. I A solder recess 20 is formed in the lower terminal portion of the post and a solder lug 24. iscarried by a pair of nuts 22 on the threaded portion 16 of .thepost. to. provide alternative means for soldering wires to the terminal below the chassis. A wire 46. connected to the solder lug is illustrated.

A sleeve 30 surrounds the tapered head: of the post or screw and is composed of an inner annular retainer 32 and an outer insulator 36. The inner wall- 34 of the annular retainer is slightly tapered and is adapted to mate with the conical wall 18 of the screw head.

A coil spring 42 surrounds the shank of the screw. and

extends between a surface Washer 40 on the chassis, and a shoulder 39 formed on the intermediate portion of the inner surface of the insulation. The lower portion 38 of the insulation surrounds, the upper-portion of; the spring to insure proper engagement between the shoulder and the spring. The spring urges. the retainer upwardly causing its inner conical tapered surface; to en; gage the tapered wall 18Hof thehead of the post or screw.

From the foregoing description it will; be aPPreci-ated that movement of the sleeve toward thechassis against the bias of the spring creates an annular gap; between the opposed tapered walls of the retainer and the head, A wire inserted downwardly into the gap will be held in position by the clamping action of the retainer on the screw head under the influence of the spring. Optimum results occur when the taper is between 12 and 22 from the axis of the screw, since in that range, when the wire is pulled, the grip tightens. Although the clamp defined by the retainer and screw head may be opened manually by depressing the sleeve, and undercut 35 is provided about the uppper surface of the sleeve to facilitate the use of a small tool for that purpose if desired.

A jack 50 is provided in the screw head to receive a banana plug (not illustrated). The jack increases the versatility of the binding post by allowing an additional connection to be made thereto. A plug mounted in the jack will not interfere with the operation of the clamp.

A relatively large aperture 52 is transversely cut into the head to receive wires that are too large to be insorted into the annular gap between the tapered walls of the screw and the retainer. A wire inserted through the aperture will be held securely in place by the upper edge of the sleeve under the bias of the spring.

The terminal is assembled in the following manner. The sleeve 30 is first inserted over the threaded portion of the post and moved across the shank until the tapered surface 34 of the retainer engages the conical wall 18. Next the spring 42 is passed over the threaded portion and into the skirt 38 of the insulation. The insulating washer 40 bears against the shoulder 41 of the screw to retain the spring in position.

To mount the terminal on the chassis, the stem of the screw is inserted through the aperture 12 and locked in place by the upper nut 22 and the second insulating washer 26. A screw driver seat 48 is formed in the head to aid in the tightening of the screw. To avoid grounding of the-wires connected to the terminal post,

it is necessary to fully insulate the screw from the chassis.

the tapered mating surfaces. The spring may be made of any substance, but if made of metal, Phosphor bronze is particularly desirable because of its low electrolytic action. When a solder lug is used the nuts 22 should be made of a good conducting material such as cadmium plated brass.

From the foregoing description it is clear that the device comprising my invention will serve many useful purposes in all types of electronic equipment. The ease with which bare wire conductors are connected to the post makes it particularly useful. To connect wires to the post, first the sleeve is depressed against the action of the spring; next the wires are inserted downwardly into the gap between the tapered walls of the retainer and the screw head; and last, the sleeve is released. The spring urges the sleeve upwardly, binding the wires be tween the mating surfaces of the retainer and head. One wire 44 mounted in this fashion is shown in the drawing. Obviously, more than one wire may be secured to the terminal in this manner. Particularly heavy wires too large for the gap can be connected to the post through the aperture 52. The head of the mounting screw may also receive a banana plug in the jack 50. A number of wires beneath the chassis may also be connected to the post. The solder lug 24 and the recess 20 are provided for this purpose.

It is apparent that wires of different sizes can be accommodated in the gap at the same time because the spring 42 afiords lateral displacement to the retainer relative to the post. Furthermore, because wires are inserted into the gap from above the head of the screw, it is unnecessary to provide room about the terminal as is required with most forms of connectors which receive wires in transverse apertures. use of a number of my terminals closely spaced on a single panel.

This feature permits the 40 A reading of the foregoing description will obviously suggest numerous minor variations of my invention to those skilled in the art. For example, the spring 42 may be replaced by a rubberized sleeve to actuate the annular retainer. Substitutions of that nature obviously would not be considered a departure from the spirit of my invention. Therefore, it is not intended that the scope of this invention be limited to the specifically illustrated and described embodiment, but that its breadth be determined by the appended claim and its equivalents.

What i claim as new and desire to secure by Letters Patent of the United States is:

A binding post comprising a retaining screw made of conducting material and having a tapered head defined by a downwardly converging conical wall, an annular retainer made of conducting material and having an inner wall converging downwardly to mate with the conical wall of the head, a spring surrounding a portion of the screw and engaging the retainer for urging the inner wall of the retainer to engage the conical wall of the head, the retainer being movable downwardly against the action of the spring to separate the mating walls of the retainer and head for receiving a wire, an aperture transversely positioned in the head of the screw underlying the retainer when the retainer is urged to its raised position, a jack formed in the head coaxially with the screw for receiving a plug, a recess formed in the bottom of the screw for connecting a wire to the bottom of the screw, and a solder lug carried by the screw for connecting another wire to the screw.

References Cited in the file of this patent UNITED STATES PATENTS 1,001,054 Lawrence Aug. 22, 1911 1,487,954 Kleinhesselink Mar. 25, 1.924

2,567,510 Drescher Sept. 11, 1951 2,714,197 Wharton July 26, 1955 FOREIGN PATENTS 93,547 Germany July 10, 1923

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