US3393437A

US3393437A - Tool useful for bending conductive strips around terminals

Info

Publication number: US3393437A
Application number: US530209A
Authority: US
Inventors: Walter F Hutchinson; Gerald G Koss; Leland E Wickstrum
Original assignee: Bunker Ramo Corp
Current assignee: Bunker Ramo Corp; Eaton Corp
Priority date: 1966-02-25
Filing date: 1966-02-25
Publication date: 1968-07-23
Anticipated expiration: 1985-07-23

Description

w. F. HUTCHINSON ET AL 3,393,437

July 23, 1968 TOOL USEFUL FOR BENDING CONDUCTIVE STRIPS AROUND TERMINALS Filed Feb. 25, 1966 LLAND E. W/c/(sT/euM BY United States Patent 3,393,437 TOQL USEFUL FOR BENDING CONDUCTIVE STRIPS AROUND TERMINALS Walter F. Hutchinson, Thousand Oaks, Gerald G. Koss, Simi, and Leland E. Wickstrum, Santa Susana, Calif., assignors to The Bunker-Ramo Corporation, Stamford, Conn., a corporation of Delaware Filed Feb. 25, 1966, Ser. No. 530,209 4 Claims. (Cl. 29-203) ABSTRACT OF THE DISCLOSURE A tool useful for bending fiat conductive strips around terminals. The tool is comprised of a head including first and second spaced rollers connected by a hub so as to define an annular groove therebetween. In use the head is intended to straddle a row of terminals with the spaced rollers engaging side portions of the conductive strips and with the terminals projecting beyond the side portions into the annular groove. The head is rotatably mounted on a handle which permits it to be rolled along the strips so as to bend the side portions thereof around the terminals.

The present invention relates to electrical component crimping tools and more particularly to an improved crimping tool for rapidly and accurately folding or bending electrical component leads or components themselves over terminals located on a terminal board so that a sufficient mechanical connection ensues.

In the manufacturing and assemblig of electronic circuit boards, it has been a conventional practice to employ a base or strip of electrically insulating material having apertures in which electrically conductive terminals are held and on which electronic components and circuitry or assemblies are mounted. A conventional form of terminal comprises a member generally stamped from sheet metal and consisting of an elongated pin portion provided at one end with a U-shaped lug. The circuit boards generally provide for the pin side of the terminals to project from one side of the circuit board so that various wiring and external circuit conductors may be Wire Wrapped to the pin side of the terminal. It is customary to project the opposite end or lug end of the terminal from the other side of the circuit board for accommodating the connection of various circuit components.

In some electrical circuits, it is required that many terminals be connected to one another by a common strip or line for purposes of grounding, thermal conductivity, common power supply, etc. Such strips are known in the art as bus strips or bars. One such bus strip currently in use is a strip which is provided with a plurality of elongated apertures through which the lugs of adjacent terminals may be received so that the length of the strip may seat snugly and firmly in contact with both sides of the component attachment side of the terminal when the bus strip has been properly installed. Such a novel bus strip is disclosed in copending application for US. Letters Patent, Ser. No. 408,888, entitled Electrical Bus Strip. To install such a bus strip on the U-shaped component attachment portion of a terminal, the bus strip segment is manually bent over the terminal lugs into clamping engagement with the terminal per se.

Although employing manual pressure has been found to satisfactorily retain a length of bus strip to a group of terminals, the installation necessitates the manual forcing or urging of the strip over the relatively sharp pointed terminal lugs which may cause injury to the fingers of an assembler installing the bus strip. Furthermore, as many as twenty-five individual bus strips may be required to be bent or crimped upon a row of terminals situated on a single terminal strip. The manual installation of the bus strip requires the assembler to physically bend each of the twenty-five bus strips arranged in a row individually and successively which represents a time consuming assembly process. It has been customary for an assembler to crimp the electrical bus strip by individual segment bending or incremental bending of long segments. The irregular surface presented by the ends of the numerous adjacet terminal lugs normally interferes with movement of slidable devices and thus, has heretofore required a step-by-step procedure as the bus strips are positioned for installation.

The device of the present invention obviates the above difficulties by providing a novel component crimping tool for rapidly applying electrical bus strips or the like by bending the bus strip along the longitudinal central axis thereof so that side portions of the strip grip the opposite sides of the terminal lugs through permanent deformation of the bus strip material. The device of the present invention comprises a roller having an annular groove provided in its circumferential periphery which is of sufiicient depth to accommodate the insertion of the lug portion of a conventional electrical terminal that projects above the surface of its mounting base and which is of sufficient width to accommodate the width of such a terminal including the thickness of the strip side portions so that the edge marginal region on opposite sides of the groove engage with the electrical component and force the component to be bent about its longitudinal axis against opposite sides of the terminal lug. The rotary fanning feature of the present invention obviates the problems associated with the irregular surface presented by the numerous adjacent terminal lugs and facilitates rapid and smooth installation of a plurality of components such as bus strips rather than the individual stepby-step component procedure as is currently practiced.

Therefore, it is a primary object of the present invention to provide a novel electrical component crimping tool which may be employed to readily install a plurality of electrical components by an assembler without causing discomfort or injury to the fingers and hands of the assembler during the installation procedure.

Another object of the present invention is to provide a novel electrical component crimping device which can be employed to readily mount a plurality of electrical components, such as bus strips, on the component connection portion of a plurality of terminals so that such compoents are retained thereon by adequate mechanical connection.

Still a further object of the present invention is to provide a novel electrical component crimping device which suitably folds or bends electrical components over the component side of a plurality of terminals so that the components are urged into gripping relationship therewith.

It is still a further object of the present invention to provide a novel assemblers tool having a grooved rotary element capable of rapidly installing electrical bus strip segments either as individually placed on the lug portion of a plurality of terminals or as consecutively placed in a multiple array whereby the segments are permanently deformed into gripping relationship with the terminal.

The features of the present invention Which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings, in which,

FIGURE 1 is a sectional view of the novel crimping tool incorporating the present invention; and

FIGURE 2 is a perspective view of the crimping tool shown in FIGURE 1 illustrating the use of the tool in connection with installing electrical strips onto a row of adjacent terminals.

Referring to FIGURE 1, one form of crimping tool in accordance with the present invention is indicated in the general direction of arrow which includes a preformed handle including an elongated section 11 having a loop 12 formed on one end thereof and having its midsection 13 bent at a right angle and bent again at a right angle to form a section 14. The opposite end of the handle from its end formed with loop 12 is provided with a section bent at a right angle with respect to section 14 in the same vertical plane as section 13 and which terminates at a point slightly beyond the central axis of the handle section 11. The free end of section 15, which may be said to be cantilevered from the section 14, operates as an axle on which a roller 16 is rotatably mounted. The roller 16 is retained on the axle section 15 by any suitable means but as illustrated, a pair of washers 17, that are press fitted on the axle, are employed to capture and retain the roller on the axle section 15.

The outer annular periphery of the roller 16 includes

roller faces

18 and 20 which are connected by a hub portion and which define an annular groove 21 therebetween. The annular groove 21 is suificiently deep to accommodate a substantial portion of the length of a conventional terminal which projects above the surface of a terminal board. In any case, the groove depth should not be less than the width of the edge portion of the bus strip plus the height of the terminal lug legs as will be clearly seen hereinafter. It is to be particularly noted that the groove 21 is disposed in the same vertical plane as the handle section 11 and that the rotation of the roller may be said to be in parallel with the handle section 14.

Preferably, the roller is composed of plastic material such as nylon, for example, and is preferably one inch in diameter. It has been found that the width of faces 18 and 21) may be in the order of .150 inch and the width of the groove 21 may be .067 inch with the depth of groove in the order of /2 inch.

Referring now to FIGURE 2, a typical application of the present invention is shown for afiixing eletrical components such as bus strips to a row of terminal lugs.

A bus strip, as more clearly described in the above referenced patent application, is indicated in the general direction of arrow 22 which comprises a thin sheet of metal, preferably soft copper, which is hot tin dipped to provide a thin coating of tin approximately .0005 to .002 inch thick. The strip includes a body portion 23 and an edge portion 24 which is of lesser width than the body portion. Connecting the body portion with the edge portion are a plurality of connecting strips 25 so that the body portion, edge portion and connecting strips define an elongated openings or aperture 26. The bus strip 22 is illustrated in the position prior to installation on a terminal board. It is to be noted that the bus strip is installed on the component side 27 of a terminal base 28 carried on a circuit board 29 and that it is disposed so that each connecting strip 25 of the bus line will engage the space or shoulder area of a terminal lug 30 between the

legs

31 and 32 thereof. Other segments of bus strip, such as indicated by

numerals

33 and 34, are shown having been installed on a plurality of terminals by means of each connecting strip 25 resting between a pair of lug legs so that the bus strip straddles the plurality of terminals with the body portion 23 continuous on one side and the edge portion 24 continuously disposed on the opposite terminal side.

In actual use, the bus strip 22 is positioned over a plurality of terminals 31 arranged in a line on the terminal strip 28 mounted on the circuit board 29. The bus strip is lowered over the component attaching lugs of the terminal on the component side 27 of the circuit board such that each connecting strip 25 of the bus strip is received into the area or space separating adjacent legs of each terminal. The connecting strips seat on the terminals and the aperture 26 of each strip receive adjacent legs of terminal lugs so that the entire strip straddles the plurality of terminals to be interconnected. The handle section 11 and loop 12 of the crimping tool 10 are held in the hand of an assembler and the tops of the terminals are received into the groove 21 of the roller 16. Roller faces 18 and 20 engage the top of the strip 28 and are intended to roll on the surface of the strip throughout its length. The depth of groove 21 is such that the entire length of the terminal projecting above the strip 28 is received therein. The assembler now rolls the roller 16 over the surface of strip 28 so that the adjacent edges of

faces

18 and 20 which define the groove 21 engage the body portion and edge portion respectively of each strip as the roller approaches each strip one after the other. Engagement of the roller with the strip causes the strip to deform by bending about the connecting strips 25 so that the body portion and edge portion engages the opposite sides of the terminals as the roller passes thereover. Bus strip 35 is illustrated as being partially deformed as the roller passes over the terminal lugs. The width of the groove 21 is such as to accommodate the Width of a terminal with the body portion and edge portion bent thereover whereby the body portion and edge portion are mechanically secured to the terminal lugs over which the connecting strips straddle. The bus strip is bent along its center line so that the body portion 23 lies in contact with one side of the plurality of terminals and the edge portion 24 lies in contact with the opposite side of the terminal. The deformed bus strip is folded beyond its elastic limit and takes a permanent set so that the entire length of the bus strip remains fixed in mechanical connection with the plurality of terminals.

It is to be particularly noted that in the preferred form of the invention the pressure of the roller is against the terminal strip 28 as it is rotated in either a clockwise or counterclockwise direction and not against the terminals per se. The roller may be pushed from one end of the strip 28 to its opposite end and then reversed to rotate over the strip again to insure that all of the bus strips have been properly deformed and seated.

The bus strips or segments illustrated represent only one type of electrical component which may be installed by the use of the present invention. It is contemplated that the invention may also be employed for mounting or installing other components such as those components having wire leads are intended to be mechanically coupled to terminals.

Although certain specific embodiments have been shown and described, it is obvious that many modifications thereof are possible without departing from the true scope and spirit of the invention.

What is claimed is:

1. A tool useful for bending a conductive substantially flat strip comprised of first and second spaced side portions and at least one connecting portion therebetween around a substantially flat terminal projecting between and extending substantially perpendicular to said side portions, and having a shoulder abutting said connecting portion, said tool comprising:

a head including first and second spaced rollers mounted for rotation about a common axis and defining a groove therebetween, said head adapted to straddle said terminal with said first and second rollers respectively engaging said strip side portions and with said terminal extending into said groove, said groove having a depth greater than the distance said terminal projects beyond said side portions; and

handle means coupled to said head for moving said head along said tsrip side portions and for applying a force to said head to cause said rollers to bend said side portions around said shoulder and into essentially parallel relationship with respect to said terminal.

2. The tool of claim 1 wherein said rollers are substantially cylindrically shaped and secured to a common hub extending therebetween.

3. The tool of claim 1 wherein said handle means includes a portion extending substantially perpendicular to said axis and essentially coplanar with said groove.

4. The tool of claim 1 wherein said rollers are cylindrically shaped and are formed integral with a hub extending therebetween.

References Cited UNITED STATES PATENTS 1,936,185 11/1933 Brenizer 29-628 2,248,147 7/1941 Wilson 140-113 3,278,880 10/1966 Lewis et al. 336-l92 THOMAS H. EAGER, Primary Examiner.