US 3188706 A
Description (OCR text may contain errors)
June 15, 1965 D. E. PARTRIDGE 3,188,706
FASTENERLESS SPLICE AND METHOD OF FORMING SAME Filed June 29, 1962 111111,', r11/111111' .SM1/ ""ll/IIL lll/ W17 Ill.:
United States Patent O 3,188,706 FASTENERLESS SPLICE AND METHOD F FORMING SAME Donald E. Partridge, Los Angeles, Calif., assigner to Universal Steel strapping, Inc., Los Angeles, Calif., a corporation of California Filed June 29, 1962, Ser. No. 206,424 4 Claims. (Cl. 24-20) This invention relates to fastenerless joints or splices and to methods of making the same and more particularly to a splice of this type characterized by its permanently interlocked nature, its high strength, its compactness and its simplicity.
The invention has application to the formation of permanently interlocked splices in stiff sheet material generally and is particularly useful in permanently splicing the overlapped ends of banding and strapping materials of the type commonly employed in Wrapping packaged goods for shipment and handling. In such applications the banding material is wrapped about the packaging and tensioned to a suitable degree prior to splicing its overlapped ends. Heretofore resort has been had to various expe-dients to provide a splice without reliance on supplemental asteners, keys, seals or other expedients usually employed inv connection with upsetting, interlocking or shearing the strapping itself. These various techniques, however, leave much to be desired, both as respects the series of steps and time required to complete the splice, the strength olf the resulting splice and the weakening of the available band strength as an incident of the splicing operation.
By the present invention there is provided an improved and superior splice of the type requiring no auxiliary pieces or fasteners of any kind and yet one which provides a permanently interlocked high strength splice between the overlapped ends of tensioned banding. The banding is slightly overtensioned initially, then slit and simultaneously deformed, then relaxed to a very slight degree to permit the characteristic very limited relative movement of the overlapped ends required to interlock the parts, following which the spliced parts are further deformed in a manner to permanently hold the parts positively interlocked without at the same time weakening the bland assembly as a whole.
, Accordingly it is a primary object of the present invention to provide an improved high-strength fastenerless splice for use in holding the overlapped ends or edges of stiff sheet material locked together.
Another object of the invention is the provision of an improved high efciency splice for mechanically locking two thin sheet parts together without auxiliary devices of any kind.
Another object of the invention is the provision of an improved method of splicing the overlapped ends of thin strip material together.
These and other more specific objec-ts will appear upon reading the following specification and claims and upon considering in connection therewith the attached drawings to which they relate.
Referring now to the drawings in which preferred embodiments of the invention are illustrated.
FIGURE 1 is a perspective view of a pair of strips locked .permanently spliced together in accordance with the present invention;
iFIGURE 2 is a top plan View of the splice at the end of the slitting operation;
FIGURE 3 is a longitudinal sectional view taken along line 3--3 on FIGURE 2;
FGURE 4 is a view similar to FIGURE Z but showing the finished splice; and
j anais Patented .lune 15, 1965 ICC FIGURE 5 is a longitudinal sectional view taken along line 5-5 on FIGURE 4.
The completed joint or splice embodying an exemplary arrangement of a fastenerless positively and permanently interlocked splice, designated generally 1li, is illustrated in FIGURES 1 to 5. As therein shown by Wray of example, splice 10 is made between the overlapped ends of steel banding used to strap goods being shipped. In accordance with well known practice employed in band wrapping such goods, the free end 11 of continuous met-al banding is fed from a supply coil clockwise from the right of FGURE l and wrapped counterclockwise about the package to be banded, the free end 11 being tucked below the main body of supply strip 12 coming from the supply coil. Reference character 12 will therefore be understood as designating the band encircling the package whereas 11 and 13 represent the overlapped portions desired to be spliced together in a permanent manner.
Any suitable stretching and splicing means may be used toA tension the band proper about the package and thereafter to splice the ends together. However, the clombination tensioning and splicing machine shown in my copending applica-tion for United States Letters Patent Serial No. 206,457, tiled concurrently herewith, entitled Splicing Machine, is particularly suitable. However, it will be understood that strapping jacks and splicing machines of other constructions well known to the art :may be employed for tensioning the main body of the stra-p and for splicing the overlapped ends and that h-andheld punches or other suitable means may be employed to lock the splice permanently in assembled condition in accordance with the present invention principles.
Assuming that the opposite ends 11 and 13 are suitably held in a manner to place the main body of the strapping under tension about the package, the next step is to form stepped slits through and lengthwise of t ese ends. `llt will be understood that the slits may be off various coniigurations with one pair of adjacent ends closer together than the other and so arranged that a wider portion of the intervening material between the slits may be interlocked behind another portion of the intervening material, the object being to interlock the wider portion of one end of the slitted band behind a portion of the narrower material in the other end as will be more fully understood from following portions of this specifica-tion. Slits 14 and 15 are stepped intermediate their opposite ends and in a direction opposite to one another with the result that the intervening material is of generally T-conguration. Slits 14 and 15 are formed simultaneously through strip ends 11 and 13 and are therefore in exact registry With one another. For purposes of clarity, the portions of the slits in the exterior end 13 are designated by plain numerals whereas the corresponding parts of the slits in the lower end 11 are designated by the same numerals distinguished by the addition of a prime.
Note that the opposite ends of each of slits 14 and 15 are parallel to one another but offset laterally sufficiently to form narrow shoulders 16 and 17 in end 13 and corresponding shoulders 16', 17 in underlying end 11.
Slits 14 and 15 are formed by bulging the mid portions of a short length of the overlapped ends upwardly While bulging the material to either side of this area downwardly to form the slits by shearing action.
The opposite bulging or displacement of the strip material in the manner just described is suicient that the remote surfaces of the overlapped ends are pressed slightly beyond one another in the manner best illustrated in FIGURE 3. It follows from the foregoing that relaxation of the tension on the main body of the strapping, or bodily anser/oey 'movement of the overlapped ends relativeto one another,
permits shoulders 16', 17 of theunderlying end 11to slide over and overlap with the underlying surfaces Vof. shoulders 16, 17 of upper strip end 13.1 Relative lengthwise movement suliicient to overlap the shouldersby a, distance equal to at least the thicknessof the material bej provide a very high- Y.
ing spliced is found adequate to strength positive splice.
Desirably, two sets or pairs of slits 14 and 15 are arranged in closely spaced relation lengthwise ofthe strip to safeguard against the possibility of the splice-being weakened by relative rotary movement of the spliced ends occurring in the plane of the splice. Such rotary movementris strongly resisted by even a single set 'of slits 14,' by the fact that the edges of super-imposedvones'of the slits lie in the same plane and interengage with'one another owing to the opposite bulging of the material to either side of the slits. Y Y
After theshoulders of the two ends have been interlocked, the spliced ends are permanently'locked against reverse or unlocking movement by simultaneous v,and nested deformation of the endsY in an areacloselyadjacent at least one pair ofslits 14, 15. VThis unique locking deformation, designated 20, comprises, by way of example, deeply nested dimples 21, 22. vThe shape'and size of dimples 21, 22 is not particularly V.important and the dimension of these mayrvary widely. However, itis generally advantageousto keep the dimples small to avoid unnecessarily weakening the strength of the main body of the stripping. Y Y f 1 Y The locking deformations are preferably formed simultaneously by a semi-punching operation performed in a,
manner to avoid shearing of the stripfmaterial but assur- Ying'that the deformed portions will nest sharply against.
one another without: any objectionable tendenc'yrofpthe nested surfaces to cam strip ends 11,13 away from one another. f' On tl1e.contrary,-t he deep indentations 21, 22 serve to lock the ends against relative lengthwise movement of the ends and particularly in a direction to Vdisengage the overlappedshoulders 17, 17 and'16, 16.V
Y tightly compacted overlappedportions of a pair of members of stiff sheetmaterial, said joint comprising a plurality [of associated pairs of ystepped slits in spaced apart relasaid joint, said stepped slits permitting deformation of tion generally parallel toy load forces tending to separate the material adjacent Vsaid slits suiciently `for stepped portions of slits in one sheet to underlieand interlock with As herein shown, locking deformationz is shownV positionedV generally midway between two pairs ofinterlocked slits. However, it will be understood that the locking indentation maybe disposed ink other locations and that morethan one set of nested kdeformationsjmay .be employed. Y
Although the described"Y splice has been illustrated and described as between the overlapped ends of narrow strippingjit will be understood that this type of'splice and the principles of the invention may be employed in wide l variety of ysheet metal constructions to hold ther parts spliced together with the interlockedV pairs of slitsidisposed in side-by-side relation across the Vwidth of theV splice. Y Y Y While the particular fastenerless splice and method of forming same herein shown and'disclosed in detail is fully capable of attaining the objects and providing the, advan- 'ste'pped' portions. of the `slits in the second sheet, and
means for locking said'stepped portions permanently and positively interlocked comprising internested'Y dimples formed Vin overlappedr portions of said sheets in an area closely adjacent and between'said interlocked slits, :said interlocked slits being effective to holdtheoverlapped area of said sheets in intimate contact and said dimples rmly seatedV in compact internested relation Yto one another.
3. A permanently interlocked joint as defined in claim 2 characterized in that said stepped slits are arranged iny Y* pairs closely spaced to one another laterally of the direction of load and with the steps in one slit of each pair n facingin theyopposite'direction from the steps in the other slit, said stepsy beingrelatively narrow and extending crosswise of the'direction ofV load Vonthe joint, the
Vportions of saidsteps extendingin opposite directions crosswise of the length of said slitsy being displaced in a direction vnormal Vto Vthe plane of said vsheets and being interlocked one behind they other to hold said sheets rigidly pressed together, andthe longer portions of the slits in the two sheets being in edge-to-edge abutment and effective Ain cooperation with said internested dimples to resist relative rotary movement Vof said sheets'in the-.plane of said joint. v
4'. A permanently interlocked joint between the overl 'lapped ends ofa metallic band tie, said joint including similar T-'shaped depressions formed in superimposed areas of each band and including oppositely stepped elongated slits so kas to form, laterally extending shoulders,
tages hereinbefore stated, it is to be understood thatit is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intendedv to the details of construction or design herein shown other than as defined in the appended claims.
1. A permanently interlocked joint for use between the overlapped ends ofay band Vtie ofy the ytype made from high-strength stiff deformable'material, said Yjoint comprising aV plurality of pairs of slits located between the lateral edges ofV said.V overlapped ends and shaped to interlock with one another with a portion of one band said T-shaped portions being displaced slightly from one lanother lengthwise of said bandendswith the shoulder portions lof one. pair of slits. in one band end underlying and interlockingfwith the opposed shoulder portions of the pair of slits in therdother Vband end,`andY means for positivelyinterlocking said .band ends against withdrawal from the said interlockedfportion thereof, comprising complementally shaped nested deformations of said overlapped bandV ends'- located between'said interlocked stepped slits.
o` RefereneesQCit'ed bythe Examiner UNITEDV STATES PATENTS 1191844 1o/71f Hamlin 24-20 1so,910,.- s/76` o1msted -m-; 24-20 1393,791- 10/21 mmba11eta1. r s p 24 23 Y VFoREIGN PATENTS A 223,044 7/09V Australia. 719,021. V11/54 Y Great Britain. Y'
Y ooNLEY lI. sToCKING, Primary Femmina..
ABRAHAM STONE, Examiner. Y i