US 3072880 A
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Description (OCR text may contain errors)
Jan. 8, 1963 B. E OLSSON SNAP-IN TERMINAL FOR PANEL Filed Aug. 5, 1959 JNVENTOR BILLY E. OLSSON United dtates stern asrasss Patented slat; 8, 19d
SLJA EN Chicago,
The present invention relates to electrical terminals, and in particular to electrical terminals that are adapted to be snap-mounted to a support or the like.
it is an object of the present invention to provide a new and improved terminal of the snap-in type.
t is another object of the present invention to provide a snap-tip terminal that is snap-mounted to a support or the like by inserting the tip of the terminal through an opening defined in the support.
It is a further object in accordance with the previous object to provide in a terminal a tip structure that is adapted to be inserted through a range of different sized support openings.
It is yet a further object of the present invention to provide a new and improved terminal which provided with a plurality of barbs to penetrate a baseboard or the like during insertion through an opening defined in the baseboard.
It is still a further object of the present invention to provide in a new and improved terminal a tip embodying a plurality of barbs for penetrating a support during mounting of the terminal and for restraining the terminal against axial movement thereafter.
It is another object of the present invention to pro vide a new and improved snap-tip terminal that is adapted to be manufactured by automatic machinery and can be easily handled, shipped and stored.
The above and other objects are achieved in accord ance with the present invention by providing a new and improved terminal of the snap-in type. The terminal is readily attached to a support or the like, for examplea printed circuit baseboard, incident to its insertion through an opening defined in the baseboard. To this end, the tip of the terminal includes a plurality of barb means that readily penetrate the baseboard during mounting of the terminal yet restrain the tip against axial withdrawal movement after its mounting. The terminal is so constructed that it can be used with a range of differentsized openings within commercially acceptable tolerances. In addition, once the terminal is mounted to the baseboard, it is locked in situ by the coaetion of the barb means and suitably spaced stop means, and can be removed from the baseboard only upon the application of a large force that causes the barbs to rupture the support during its Withdrawal from the baseboard opening.
The invention, both as to its organization and method of operation, taken with further objects and advantages thereof, will best be understood by reference to the following description taken in connection with the accompanying drawing, in which:
FIG. 1 is an elevational view of a plurality of terminals embodying the features of the present invention, illustrated in chain form after fabrication by automatic machinery;
FIG. 2 is a greatly enlarged side elevational view of the terminal of FIG. 1, shown electrically connected to a conductor and mounted on a support, baseboard, or the like;
FIG. 3 is a front elevational view of the terminal of PEG. 2;
FIG. 4 is a top plan view of the terminal of PEG. 2;
FIG. 5 is a fragmentary side elevational view, shown partially in section, of the terminal of FIG. 2, illustrating the terminal immediately prior to mounting on the baseboard;
FIG. 6 is a fragmentary side elevatisnal view, shown partially in son, of the terminal of FllG. 2 during mounting on a baseboard or the like; and
FIG. 7 is a sectional View taken along line 7-7 of PEG. 6.
Referring now to the drawing and in particular to FIG. 1, a plurality of termin ls "odying the features of the present invention are illus'ti d and are individually identified by reference numeral The terminals it) are manufactured in chain form s itable automatic machinery, i.e., are stamped from a strip of stock metallic material by a suitable punch and then are deformed by successive deforming steps into generally tubular terminals. As shown, thetips of the terminals it? are re spectively connected by tabs lid to the longitudinal edge of thin strip 12 of metallic l ater so as to extend perpendicularly to and cop nar with the strip 12. By this chain construction, tne strip and attached terminals can be readily rolled in spiral fashion to facilitate handling, s ipment, and sto age. The terminals in chain form are fed into suit e dispensing equip ment which severs the tip or the terminals from the tabs M of the strip 12 and subsequently crimps the terminals if to suitable electrical leads, for example conductors, ends of electrical components, and the like.
After each ter' i i is severed from the strip 12 and crirnped to a lead, for example conductor 153, it is snap mounted to a support, for example a printed circuit baseboard or the Since the tip of the terminal 1% is to be inserted through a suitable opening 13 l circuit basebowd do, the terminal ill once, as a snap-tip terminal. 5y vii of the un' ue tip construction of th the tip easily passes through the opening terminal and when the tip is in its mounting position it prevents the s tip terminal from being withdrawn through the o ening 13. Hence, in the absence of a large withdrawal force, downward movement of the terminal ltl, as seen in 2, and disasseinbly of the terminal ill and the baseboard o, is prevented. Fu thermore, as best 3. 2, ter the terminal is mounted l6, the tip structu'e loosely seats on ectricall conductive inlie. 19 embedded in the upper cult baseboard l6.
The elecltnown, is used in liver 0L e and serves to electrically :rconn-ect spaced apart points in the baseboard For iple, the material may ext between two open- 5 so that two terminals disposed in the openings 50 it? may be electrically interconnected.
Considering now briefly the general construction of the of the printed err su face I l 13, as best shown in Pr.) 1 2, the terminal "nprises a generally tubular con ruction having a rrel-"lid tip for pass through the baseboard opening and for penetra ng the baseboard structure djacent ie opening during rnot of the terminal end of the term "al fit; remote from the tip provided a or. rig portion 2% for accc-r d end of the conductor 35, the Ill in drical in construction as shown in to; crimping of the conductor and The tip and the crimping portion apart by an intermediate poi ion 22 that is located 'tvithin the baseboard opening when the terminal is ounted on the baseboard 1d.
Conside in; new 2 and 3 in greater detail, the crimping section comprises the lower portion of the l and includes a air of longitudinally extending flanges 2d 23 that y e crimped about the stripped end 25 of the conductor l5, the flanges 2s and 28 being so constructed that their edges 26!: and 28a face and cact with one another throughout substantially their entire lengths to form a substantially continuous cylindrical wall. In order to lock the stripped end 25 of the conductor 15 to the crimping portion 24, the left (forward) and right (rearward) central portions of the crimping section 24, as viewed in FIG. 2, are offset to the left, as indicated at 29. it will be appreciated that, in addition to the crimping action afforded by the flanges 26 and '28, the offset construction prevents movement of the stripped end 25 relative to the flanges 26 and 28 so that a good mechanical and electrical connection is obtained between the terminal and the conductor 15. With such a rigid connection, the crimping section 24 of the terminal 10 remains immediately adjacent to the insulation 27 of the conductor 15. Although the offset, crimping section 24 provides both a mechanical and electrical connection be tween the terminal 19 and the conductor 15, the crimping section 24 and the stripped end 25 of the conductor are soldered together as described hereinafter at the same time as the terminal 19 is soldered to the electrically conductive material 19 embedded in the baseboard 16.
As shown clearly in FIGS. 2 and 3, the upper ends 26b and 28b of the flanges 26 and 28 terminate in generally forwardly extending stops that define a pair of spaced apart stop means or horizontal ledges 3t} and 32 for coacting with the under surface of the printed circuit. board 16. The flange ends 26b and 23b diverge upwardly and are somewhat curled, as best seen in FIG. 3, so that the edges 26a and 28a at their extreme upper ends define a forwardly extending V. By this construction, as described in detail below, the terminal 10 is unable to be moved upwardly out of assembly with the printed circuit board 16. Thus, the ledges 3t and 32 of the crimping section 24 coact with the baseboard 16 to maintain the terminal Ill and the baseboard 15 in assembled relation.
Considering now the tip of the terminal 19, the generally barrel-shaped tip 20 specifically comprises a hollow, generally conical configuration having a continuous wall terminating in a pair of slightly spaced apart edges 40 and 42, the upper end 34 of the wall being generally flat and comprising the extreme upper end of the terminal 10. Actually, the rear part of the tip 29 is substantially cylindrical thereby forming a portion of a some what straight back identified as 43 and extending throughout the length of the terminal 10, while the forward part of the tip 29 is substantially conical to facilitate disposition of the terminal 10 into the baseboard opening 18. As best shown in FIG. 2, the edges 40 and 42 are inclined relative to the axis of the terminal 10 and, as best shown in FIG. 3, the edges diverge slightly relative to one another as viewed from the top toward the bottom of the terminal it The diverging edges 4% and 42 do not perform any particular function other than incidentally guiding the tip 20 into the baseboard opening 18 as a part of the generally conical forward section of the tip 2%). As described below in greater detail, it the back 43 of the tip 29 engages the wall of the opening 18 during mounting of the terminal 11), the edges 40 and 42 do not engage or coact in any way with the lowermost part of the baseboard opening 18.
In accordance with an aspect of the present invention, at the lower ends of the edges 40 and 42 there is provided generally converging and forwardly extending locking barbs 44- and 4&5, respectively. Although barbs 44 and 46 generally converge, their forward edges, in contrast to the diverging edges and 4-2, are generally parallel as viewed in FIG. 3 and parts of the forward edges penetrate the baseboard 16 during snap-mounting of the terminal 16. The lower ends of the barbs 4 and 46 also define generally horizontal, converging ledges 48 and Sil (see E6. 3) which coact with the conductive material 19 embedded in the upper surface of the printed circuit baseboard 16 and prevent the downward movement of the terminal relative to the base 16 once the terminal 10 is snap-mounted on the baseboard 16. More specifically, the barbs 44 and ts; as best shown in FIG. 2 each comrise an axially extending, trapezoidal structure integrally related to the wall of the tip 20. The barbs 44 and 45, as viewed from the top of the terminal 10 (see FIG. 4), converge in the same general way as the wall of the tip 29, while the forward edges of the barbs 44 and 46, as viewed from the front of the terminal 16 (see FIG. 3) are at all points equally spaced apart. As clearly shown in FIG. 2, the forward edges include downwardly and forwardly inclined cutting edges 44a and 46a which respectively interconnect the diverging edges 4t and 42 with vertically extending portions 44b and 46b of the forward edges. The cutting edges 44a and 46a actually comprise the upper parts of the barbs 44- and 46 and are substantially razor sharp so as to cut paths for the bodies of the barbs through the baseboard structure 16 during snap-mounting of the terminal 10. With the terminal 10 in mounting position on the baseboard 16, the ledges 43 and 5t} overlie spaced areas of the electrically conductive material 11 as suggested by FIG. 7. As clearly shown in FIG. 2, the ledges 48 and 50 extend rearwardly of the barbs 4d and 46 a substantial distance, but only those portions of the ledges 48 and 5t} adjacent to the forward edges of the barbs 44 and 46 coact with the electrically conductive material 19. The intermediate portion 22 of the terminal 1! specifically comprises that portion of the terminal 10 between the lower ledges 30 and 32 and the upper ledges 48 and 50. As best shown in FIG. 2, the ledges 30, 32 and 48, 59 extend rearwardly in a generally horizontal manner, and then curve forwardly to respectively define upper and lower cutaway portions 51 and 53 which extend back approximately half the width of the terminal 10. The cutaway portions 51 and 53 specifically define a pair of flanges 52 and 54 which extend forwardly in a generally converging manner. Particularly, the flanges 52 and 54 comprise a part of the forwardly extending cylindrical wall of the terminal 1t and are generally trapezoidal in construction. They terminate in axially extending edges 52a and 54!: which are more spaced apart from one another than the edges 40 and 42 of the tip 20. It will be appreciated that the cutaway portion 51 lends resiliency to the barbs 44 and 46 and to the forward portion of the Wall of the tip 20, whereby slight rearward movement of the barbs 44 and 46 is permitted during snap mounting of the terminal 10 as described below. In any event, the flanges 52 and S4 perform no useful function other than to restrict the amount of sideward movement of the terminal 10 when it is located in the opening 18 prior to a soldering operation. Consequently, it will be understood that the diameter of the intermediate section 22 is somewhat less than the diameter of the baseboard opening 18 and that for various installations the diameter of the intermediate section 22 can be varied by varying the configuration of the flanges 52 and 54 to obtain the desired amount of ply between the terminal 10 and the base board 16.
In accordance with the present invention, the terminal 1t} is quickly and easily snapped into mounting position on the base board 16. As indicated above, the baseboard 16 includes a plurality of openings 18 that are interconnected by electrically conductive material 19 embedded on the upper surface of the base board 16. Specifically, the terminal 10 is mounted on the printed circuit baseboard 16 by first aligning the terminal 10 with a selected one of the openings 18. Once proper alignment is obtained, the terminal 14} and base board 16 are moved relative to one another, whereby the terminal 16 is mounted to the baseboard 16 in one continuous operation. In conventional practice, the terminal 10 is moved toward the printed circuit baseboard 16 and the generally conical tip 20 guides the terminal 10 into the opening 18. If it be assumed that the back of the terminal is disposed immediately adjacent to one side of the opening 13, then, as the tip 24} passes through the opening 18, the edges 40 and 42 move closer to the opposite side of the opening 18, as clearly seen by reference to PEG. 5, but do not engage the undersurface of the baseboard. Although the terminal it? may be used with a range of different-sized openings, the terminal it) is preferably used with an opening having a diameter somewhat less than the effective diameter at the upper ends of the cutting edges 44a and 46a but somewhat greater than the effective diameter at the lower ends of the cutting edges 4 4a and 46a. In any event, assuming that the opening has a diameter as shown in FIG. 5, the tip 29 of the terminal 16 is inserted easily through the opening 18 until the cutting edges 44a and 46a coact with the under surface of the baseboard 16 immediately adjacent to the opening 18, as shown in FIG. 5. Continued upward movement of the terminal in causes the cutting edges 44a and 46a to penetrate or cut into the base board 16. Specifically, as the tip 20, including the barbs 44 and d6 move upwardly, the edges 44a and 46a define a pair of vertically extending grooves dd and 66, seen in FIGS. 6 and 7. FIG. 6 illustrates the barb 46 cutting the groove 66 during its upward movement through the baseboard 16, while FIG. 7 illustrates the relative position and size of the grooves 64 and 66 in a somewhat exaggerated form.
Inasmuch as the inclined cutting edges 44a and 46a of the locking barbs $4 and 46 cut or penetrate the baseboard 16 during snap mounting of the terminal it), a rearwardly directed force component is applied to the barbs 44 and as, with the result that the barbs 44 and 46 move rearward slightly to cause the wall of the tip to bulge or bow outwardly slightly, as seen in solid lines in FIG. 7, the original configuration being indicated in dotted lines. Consequently, as the tip 20 passes upwardly through the baseboard 16, the tip 2% remains somewhat bowed so that when the tip 29 leaves the opening 13 and the barbs 44.- and 46 move above the conductive material 19, the tip 25) unbows and assumes its original position shown in dotted lines in FIG. 7, with the result that the barbs 44 and 46 move forward slightly. By this construction, the barbs 44 and 46 and, thus, the ledges :8 and d overlie more of the conductive material than is cut by the grooves 64 and 66. Accordingly, the barbs and 46 are unable to register and reenter the grooves 64 and 66. In any event, once the barbs d4 and 46 move upwardly above the conductive material 19, the mounting force applied to the terminal it) is removed, whereby the terminal it) moves downwardly under gravity until the forward parts of the ledges 4S and 50 seat against the conductive material 19 immediately surrounding the opening 18.
With the terminal it? in mounting position, the ledges 3t), 32 and 43, 5d coact respectively with the lower and upper surfaces of the baseboard is to limit axial movement of the terminal it} relative to the printed circuit baseboard 16 and, hence, prevent disassembly of the terminal 19 and baseboard l6 irrespective of the position of the baseboard id. Particularly, the forward parts of the ledges 3d and 32 abut against the under surface of the baseboard .16, when the terminal It} is elevated, to limit the upward axial movement of the terminal 19 to a fraction of an inch, while the forward parts of the ledges 48 and 5t} seat against the conductive material 19 and prevent any downward axial movement of the terminal when the baseboard l6 and terminal in are in their normally assembled position shown in FIGS. 2 and 3. It will be appreciated that the terminal it; is not fixedly secured to the baseboard 16 but is maintained in loose assembled relation with the baseboard by the ledges 30, 32 and 48, 56). As best seen in FIG. 2, the terminal in is permitted to move axially a distance equal to the difference of the distance between the ledges 30, 32 and 48, 5t) and the thickness of the baseboard 16, and, further, is permitted to move laterally a distance equal to the difference of the diameter of the intermediate section 22 and the 6, diameter of the opening 18. Thus, there is both axial and lateral play between the terminal it) and the baseboard 16-but, irrespective of this play, the terminal 10 is unable to fall out of the baseboard 16 during subsequent handling operations.
It should be understood, however, that the terminal it may be forcibly disassembled from the baseboard 16 by applying a large downward axial force to either the tip 20 or the crimping portion 24 of the terminal it}. With the application of a relatively large force, the ledges 48 and 5d are forced through both the conductive material 19 and the baseboard 16. However, in contrast to the cutting action of the edges 44a and 46a, the ledges 48 and 5t) rupture or puncture the conductive material 19 and the baseboard material. Since the ledges 48 and 5d are relatively flat in contrast to the sharp, cutting edges 44a and 46a, a substantially larger force is required to cause the ledges 48 and 50 to penetrate the baseboard 16 than is required to cause the edges 44:: and 46a to penetrate the baseboard 16. In addition, it is highly probable that the ledges 48 and 50 will not pass downwardly through the previously cut grooves 64 and as, but will pass downwardly through new grooves (not shown).
After the required number of terminals in are mounted on the printed circuit baseboard is, all of the mounted terminals it} are soldered to the baseboard 16 in a single dip-soldering operation. Particularly, the baseboard 16 and terminals it are inverted with the result that the terminals it) move downwardly until the ledges 3t? and 32 engage the under surface of the baseboard 16. As a result of the inversion of the baseboard ie, the tips 2d are spaced from and extend downwardly from the baseboard l6. Thereafter, the baseboard 16 is lowered in a generally horizontal fashion until the tips 2% are immersed in a solder bath. The solder readily enters the open end 34 of the barrel-like tips 29, as well as the cutaway portions 51 of the tip 20, and flows upwardly by capillary action through the tip it? and the intermediate section 22 into the crimping section 24. Hence, as a result of the single solder operation, the stripped end 25 of the conductor 15 is soldered to the crimping section 24 and the tip 29 is soldered to the electrically conductive material 19 on the upper surface of the baseboard 16. By this operation, a good electrical connection is obtained between the conductive material 19 and the terminal lid and, further, between the terminal it} and the conductor 15.
While the embodiment described herein is at present considered to be preferred, it is understood that various modifications and improvements may be made therein, and it is intended to cover in the appended claims all such modifications and improvements as fall within the true spirit and scope of the invention.
What is desired to be claimed and secured by Letters Patent of the United States is:
l. A terminal of the snap-in type adapted to be inserted through an opening of a support, said terminal comprising a substantially rigid generally frusto-conical, hollow tip embodying adjacent spaced apart and generally parallel barb means located at one side of the terminal and extending in the same general direction, each of said means including cutting means extending outwardly and rearwardly to penetrate said support during mounting of the terminal and, further, stop means integral with but spaced axially of said cutting means to restrain said tip against axial movement after mounting of the terminal, and means axially spaced from said spaced apart means for re-.
straining said tip against axial movement in a direction opposite to the above referred to axial movement, said stop and axially spaced means coacting to lock said tip to said support.
2. A terminal of the snap-in type adapted to be inserted through an opening of a support, said terminal comprising a wall having generally converging, spaced apart edges for engaging the support adjacent said opening, said edges including at their lower ends adjacent 7 8" spaced apart barb means that extend outwardly and rear- References Cited in the file of this patent vvardly to cut through said support during passage of said UNITED STATES PATENTS up through said openlng, generally flat ledge means mtegral with an spaced axially of said barb means, said 2,551,970 samlfson May 1951 ledge means being adapted to pass through said support 5 2,892,178 Hams June 231 1959 after said barb means and to coact with a first surface 310011171 Schultz Sept- 19, 1961 of said su ort to restrain said ti from movement in a first directi n, stop means spaced irom said ledge means FOREIGN PATENTS for coacting with a second surface of said support to re- 1,179,246 France Dec. 22, 1958 strain said tip from movement in a second direction, said 19 567,798 Great Britain Mar. 5, 1945 ledge and stop means being spaced apart to accommodate one of a plurality of supports having a variety of cliiferent widths.
UNITED STATES PATENT OFFICE QER'HHQAE l QQ RECTION Patent No $072,880 January 8 i963 Billy Ea Olsson It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.
l'olumn 4, line 1 for base read baseboard line 27 "The intermediate" will start a new paragraph; column 4, line 58, 0; "ply" read play column 7, line 4, for "an" read an ""m Signed and sealed this 10th day of September 1963',
ERNEST W. SWIDER L. LADD Attesting Officer Commis sioner of Patents