US2644356A - Strap joint-forming mechanism - Google Patents

Description

July 7, 1953 w. c. CHILDRESS E'I'AL smp JOINT-FORMING MECHANISM 2 Sheet's-Sheet 1 Filed June 15, 1950 Patented July 7, 1 953 i Ericsson, Chicago, Ill., assignors to Signode Steel Strapping Company, Chicago, 111., a corporation of Delaware Application June 15, 1950, Serial No. 168,196

7 Claims.

. I .-,1 V I 1 Our inventionrelates to strap joint-forming mechanism, or as it is rather generally' termed, sealing mechanism. Themechanism is especially adapted for producing joints between overlapping portions of flat or ribbon like metallic strapping,

which is usually subject to considerable tension,

and a joint-reinforcing sleevelike seal. Such strapping is. employed ina variety of ways in reinforcement of boxes, packages and bundles,

and of aggregates or groups of such objects, containing or consisting of a wide diversity of merchandise. J,

One well knownand extensively used joint for this purpose is produced by shearing, inwardly from their edges, the adjacent or juxtaposed longitudin'al. margins of overlapping strap portions and the sleevelike seal to form pairs of slits that extend a short distance inwardly from the margins and define tongues in both the overlapping portions and the encompassing seal, each tongue, defined by a pair of such slits, being displaced or offset laterally-out, of the normal plane of. strap and seal to cause edges of strapping and seal at opposite sides of slits to lie in planes that interward the thing or things being bound by the to some objection.

.ofother boxes or bundles.

strapping so far beyond the plane of the body, of the joint as to cause such joints to be subject"; For example, the tongues have projected sufliciently'to raise the joint and cause it to interfere with the sliding of boxes or bundles upon or against each other and tocatchl'. obstructions, such as the joints. or the strapping j This may subject joints to sudden strains caused by shock in tran j sit or in handling with liability of rupture. And

the tongues have protruded sufficiently farto indent and mar the underlying surfaces or edges of superposed bundles or the constituents of bun? dles. This last phenomenon is particularly ob; jectionable where the boundbundles are of relativel delicate or easily dented and marred matee,

rial such, for example, as sheets of tin plate and' sect. Thus, adjacent layers of strapping and seal 1 on opposite sides of a slit are caused to abut each other with abrupt opposing edge-to-edge interlocking shoulders which resist relativelongitudinal movement of theoverlappingv portions of.

an effective tension-resiststrapping and create ant joint.

The most feasible if not the necessary pro- I duction of such joints requires mechanism which, upon a single operation and essentially simultaneously will produce both completeor true marginal slits through both the seal and the strap- 1 ping and also the necessary offsetting of l the tongue formed and definedby the slits to insure that adjacent sheared edges of both strapping and sleeve on opposite s'id'esof theslits lie in abutting shoulders. strap portions and both layers of the sleeve are crossing planes so as to form theedge-to edge If both of the overlapping not sheared or cut entirely through the ofisetting will merely bend the metal and only curved rather than edge-to-edge shoulders and.

metal joints will result Heretofore, however, in

orderv to insure that both the seal and strapping are actually out or sheared through, rather than merely bent, and sufficiently offset to provide insheets of thin steel currently used in automobile"' bodies and fenders. The principal object of our invention is to pro-,.: vide a joint forming or sealing mechanism that. will produce joints of the sheared and offset, tongue type which are as strong as those heretofore produced but wherein the tongues do not protrude to such an objectionable extent. Another object is to, provide a simple and ef-f fective tool or machine for producing joints com parable in strength to those heretofore known but wherein the projection of the offset tongue is reduced. I A further'object is to provide amethod for, producingsuch joints. Our invention will, be illustrated and explained as embodied in a hand operated sealing tool al-' though, as will be readily appreciated, the mode of operation and the essential mechanism can be performed by and incorporated in power-op erated machines.

' Other objects and advantages willhereinafter and finally retract or pull back the tongues to;

reduce the amount they protrude from the fin i ished joint, without, however, detracting from the strength and effectiveness of the joint. j:

A typical embodiment of our invention incorporated in a simple hand operated sealing tool offsetting mechanism at the completion or the:

slitting and offsetting operation;

Fig. 6 is a View similar to Fig. 5, showing the relation of the folding jaws and the slitting. and,

oifsetting mechanism at the completion of a joint forming operation, when the tongues of the joint have been retracted;

Fig. 7 is. an enlarged View of merely the tips r,"active portions of the folding. jaws and the slitting and offsetting. mechanism in the three. positions shown, for. the entire tool, in Figs. 4, 5.

and 6; and

'Fig. 8' is a perspective of one edge of. a joint, showinghow the. marginal edges. of the SIEQVQ-r.

like seal and the overlapping strap portions are sheared and the intervening tongue is. offset to insure the necessary crossing edge-to-edge shoulder abutment and then the tongue, is re,- tracted to reduce. its protrusion.

Referring first to Figs. 1,".2. and 3, the specific. hand operable tool illustrated includes a head The inner ll'lfandv a pair of handles i l and I2. en'dfof handle I2 is located'between and assists in'the spacing of a' pair'of headside plates i3 and HI and is rigidly attached thereto by a pair of'bolts l5. Handle between side plates [3 and i l on a pivot bolt Head sideplates l3. and M are further retained in proper. spaced relation by a pair ofjaw pivot pins l1 and apair. of movement-directing and 'stop pins l8. duced diameter where they project into side plates I3 and l iso. as to provide side-platespacing shoulders l9 and 20, as shown most clearly in Fig. 3 and the entire head assembly is clamped together by the bolts i and I6 and their respective nuts 2 I,

Pivotally connected to jaw pivots ll between the side. plates are a pair of complementary seal-folding jaws 25, each of which has three laterally spaced inwardly pointing hooklike tips 26; 2! and 23. The three tips of one jaw confront corresponding tips of the other jaw and each has'an inwardly opening depression or recess 29 which lies opposite a like opening or 'recess. in. the corresponding tip of the other jaw. The connection between each folding jaw 25 and its pivot pin I! is made with a tight. bearing fit so that each jaw may oscillate about its pivot pin without other relative movement between jaw and pin.

The rear ends and confronting inner faces of foldingjaws 25 are provided with a pair of par allel slots. 35 and 36. in which, as will be later eirplained, notching and offsetting blades .39. slid.-

ably andpivotally fit. By means of a toggle pin.

arms rear. of each folding jaw 25 is connected to'one end of a link 42, the. other ends. of the two links being connected to 'a guiding and notching blade actuating pin it. Pin 46 is connected to. handle H by means of a pair of links and a. pin 48. The opposite ends of pin 45 H. is pivotally mounted.

All four of these pins are of re are flattened to form a pair of keys 49, each key fitting into a slot or keyway 5il5l formed in the inner face of side plates l5 and 14, respectively, midway between and perpendicular to a line intersecting the axes of the two pivot pins i1. Thus it will be understood that as handle. H is moved between. a position such as indicated in Fig[ 4 to a positionsuch as indicated in Fig. 6, the toggle connection formed by pin 43, links 41, pin 46, links 42 and pins 4! will swing the folding jaws 25 from open position to closed position and the flattened key ends of. guide pin 4% Will-travel from near the top of guides 5i) 5| toward the bottom thereof; and that thereafter reverse movement of handle II will return the folding jaws from closed to open position.

'Each of the previously mentioned notching and oifsetting blades 39 has a hole 653 through which the corresponding jaw pivot pin i7 loosely passes, and near the rear. upper endv eachblade. is provided with an outwardly opening recess. or. slot.

6| which slidably accommodates a block 'fizjthat has a. bearing fit upon the corresponding pin l lif Also each blade 39 has on .its upper outer edge.

an angular cam surface 53 which bears against and rides along the corresponding guidepin I 8. And further each blade. 39. has. along its inner upper edge a rounded cam surface'65 and along its longitudinal inner edge two merging angui larly related surfaces 66-61., Of these, the sur-. face 55 may be considered as an extension of the cam surface 65. carried with a bearing fit upon centering pin llfi. each roller. lying between and in a plane of two' opposing n'otchingand'oifsetting bladesand in a position to engage cam surfaces. 65.'6-B. -E 1. of:

. both blades.

A chair or' anvil l5 lies betweenthefolding jaws l5 and the'notching and offsetting blades- 39, 'being'slotted to accommodate the notching' blades, and is retained in place by trunnions 16 which project into holes in the side. plates: l3. and I4. w Y

In operation handle I l is. swung to separate. it from handle I2 to open the tool for application to the work. In this condition, as shown in Fig.

4, the tips of both sealing jaws 25 and the tips of the notching and offsetting blades 397 are fully separated and the notching blades are retracted; If the joint between the overlapping strap por tions and 8| is to be reinforced by a sleeve 82 of the flange type, the jaws and the nctching and offsetting blades are now open suiflciently to enable the tool to be appliedwith the chair'or anvil 15 againstthe sleeve back plate 82m) and the. sleeveflangesflflb) flanked by the jaws and notching blades as shown in Fig. 4 with the shear ing edges and offsetting shoulders of each notching blade separated some distance from the lateral outer corners of the reinforcing sleeve 82 as shown in Fig, 4 and as indicated by the full lines. 72 of Fig. '7. Now, with the tool applied to the A pair of. rollers l9, are

' linkage 4l4642 between the handle I! and folding jaws 25 causes the rear ends of jaws 25 to be separated and the hooklike tips 26 to approach, as previously explained; and the movement of rollers between and over the rounded cam surfaces 65 cause the tips H of the notching and offsetting blades'39 to approach each other.

These initial approaching movements of the folding jaws 25 and of the notching and offsetting blades 39 bends the sleeve flanges 82 (b) inwardly and'rearwardly to cause the sleeve to encircle the overlapping strap portions 80-8l and to clamp the strap portions and encircling sleeve tightly back against anvil 15. As soon as the rollers 10 enter upon the straight portions 66 of the cam track, these portions then being parallel, further outward movement of the top ends of the blades is' not forced and in fact is inhibited by the pins [8. The notching and offsetting blades are therefore pushed straight downwardly by the blocks 62 acting in the slots 6| inasmuch as the blocks have V a considerable downward component of movement, they being well beyond the pivot pins I! at this point in their travel. Also the angle made by the slots 6i with the vertical can be such as to give just the desired degree of relative movement between the jaws and blades. At the end of travel of the handles in the closing direction therefore the strapping is tightly wrapped in the seal, the notches are formed, and the tongues are well offset downwardly.

As the handles are pulled apart the 'jaws immediately start their retracting movement by swinging outwardly. During the early portion of the return travel of the handles the notching blades are pulled approximately straight upwardly since rocking movement is prevented by the rollers 10 between the relatively parallel cam surfaces 66. The lower edges of the tongues are therefore caught by the inwardly directed tongue These horns thereforeretracting horns I1. pull the tonguesstraight backwardly until the rollers 10 emerge'from the approximatelypar'allel portions 66 of the cam surfaces of the blades on to the sharply outwardly flaring portions 85,. When the flared'portions 65 of the cam surfaces are reached, the notching and offsetting blades are permitted to pivot inwardly'at the top-and this movement is forced by the block 82 being brought against the ends of the slots 6!. This rocks the retracting horns ll outwardly until they,

clear the edges of the tongues; With slight additional'opening' movement of thehandles the tool can be removed from the joint. I

From the above description of one embodiment of our invention, it will be seen that the seal is automatically tightly wrapped about the strapping, strapping and seal are sheared and offset a considerable distance below the plane of the strapping so as to insure good angularly opposed sheared surfaces, and that thereafter with opening movement of the tool, the tongues are reonly slightly below the rectly because of the danger of insufficient shearing action taking place with this small degree of a pair of tongues on each'side of the oflset. Furthermore, all of this is accomplished by the operator in a natural manner so that an op-'- erator need not be taught any different technique when first introduced to the use of this novel;

sealing tool.

Having described our invention, what we claim" 7 as new and useful and desire to secure by Letters Patent of the United States is:

l. A. tool for producing a'joint between over lapping portions of metallic strapping and an encircling metallic reinforcing sleeve, comprising a pair of spaced side plates, a pair of pivot pins held by and bridging between said side plates, a pair of folding jaws, each jaw being pivotally mounted mom of said pivot pins,said jaws hav-{ ing confronting hooklike tips which approach each other to clamp the strap portions and sleeve when said jaws are oppositely rocked about said pins, a pair of shearing and offsetting blades,-

each blade being loosely mounted on one of said pins by means of an opening therein substantially larger than said oin so that said blade and the.

jaw mounted on said same pin may move longitudinally relative to each other, an operating linkage pivotally connected to said jaws for rock-' ing said jaws about said pivot pins, means inf-J eluding cam surfaces on said blades and a mem-. ber engageabl-e therewith carried on said linkage to rock said blades about said pivot pins, and

means holding said side plates in place.

2. A. tool for producing a joint between'overei lapping portions of metallic strapping and an encircling metallic reinforcing sleeve, comprising a pair of spaced side plates, a pair of pivot pins held by and bridging between said side plates, a; pair of folding jaws, each jaw being pivotally mounted on one of said pivot pins, said jaws being adapted to clamp the strap portions and sleeve when oppositely rocked about said pins, a

pair of notching and offsetting blades, eachblade having an openingtherein substantially larger.

than said pin through which said pin projects to mount the blade thereon and so that said blade and the jaw mounted on said same pin may have nected to said jaws for rocking said jaws about said pivot pins, a blade engaging means on said link-, age and cooperating means on said blades adapted to be engaged by said blade engaging means to rock said blades about said pivot pins to bring "said blades into notching and offsetting position,

and a lost motion connection between said link- ,age and said blades to move said blades longitudinally-relative to said jaws and to rock said blades from notching and offsetting -position,, whereby when said linkage is moved in a first direction said blades and jaws are rocked togeth er to grasp the strap edges encircled by the sleeve, and subsequently said blades are moved primareily longitudinally relative to said jaws while said jaws hold the strap and sleeve to notch the strapand sleeve and to offset portions thereof a predee termined distance, and when said linkage moved in the opposite direction said bladesare retracted primarily longitudinally to return the offset portions apart of the offset distance, and

place.

3. A tool for producing a joint'between overlapping; portions; Qif: metallic and, anv on circling metallic reinforcing sleeve, comprf.,,ing apair of spaced side plates, a pair of pivot pins held,

mounted on one of said pinsby means of an opening therein substantially larger than said pin so that said blade and t e jaw mounted on said same, pin may move longitudinally relative to each other, said blades having confronting booklike tips for grasping the edge of the strap por tions encircled by the sleeve when said blades are rocked toward each other, a movable operating linkage pivotally connected to said jaws for reciring, said jaws about said. pivot pins and connected to said blades for moving said blades longitudinally and about said pivot pins, cam m ans on said blades and a cooperating member on linkage and movable-therewith to reel: blades about said pivot pins, whereby when said linkage is movedin a first direction said blades and jaws areroclied together to grasp the strap edges encircled by the sleeve and subsequently said blades are moved primarily longitudinally relative to said jaws while said jaws hold the strap sleeve to notch the strap and sleeve and to offset portions thereof a predetermined distance, and when said linkage is moved in the opposite direction said blades are retracted primarily longitudinally to return the offset portions a part of the oifset distance, and subsequently said jaws and said blades are rocked away from each other to release the strap and sleeve, and means holding said side plates in place.

l. A tool for producing a joint between overlapping portions of metallic strapping and an encircling metallic reinforcing sleeve, comprising a pair of spaced side plates, a pair of pivot pins held by and bridging between said side plates, a pair of folding jaws, each jaw being pivotally mounted on one of said pivot pins, said jaws being adaptedto clamp the strap portions andsleeve when oppositely rocked about said pins, a pair of notching and offsetting blades, each blade being loosely mounted on one of said pins by means of an opening therein substantially larger than said pin so that said blade and the jaw mounted on said same pin may move longitudinally relative to each other, means held by said side plates for limiting pivotal movement of said blades so that said blades are then constrained for longitudinal movement, said, blades having confronting hcoklike tips for grasping the edge of the strap portions encircled by the sleeve when said blades are rocked toward each other, a movable operating linkage pivctally connected to said jaws for rocking said jaws about said pivot pins and pivotally and slidably connected to said blades for moving said blades longitudinally and about said pivot pins, cam means on said blades and a cooperating member on said linkage and movable therewith to rock said blades about said pivot pins, whereby when said linkage is moved in a first direction said blades and jaws'are rocked together to grasp the strap edges encircled by the sleeve and subsequently said blades are moved primarily longitudinally relative to said jaws while said jaws hold the strap sleeve to notch the strap and sleeve and to offset portions thereof a predetermined distance, and when said linkage is moved in the opposite direction said blades are retracted primarily longitudinally to return the, Ofiset portions, a part of the offset, distance, and subsequently said jaws andsaid blades are rocked away. from. each other to, release the strap and sleeve, and means holding said side,- plates in place.

5., A tool for producing a joint between over lapping portions of metallicstrapping and, an, encircling metallic reinforcing sleeve, comprising a pair of spaced side plates, a pairof, pivot pins,

held by and bridging betweensaid sideplates, a.

tive to each, other, first cam means on said bladesy a pair of pins held by-said side plates and-engageable with said cam means for guiding said blades in pivotal and longitudinal movements, said blades having-confronting hooklileetips for grasping the edge of the strap portions encircled by the sleeve when said blades are rocked toward each, other, a movable operating linkage pivotally connected to said-jaws for rocking said jaws about said pivot pins and'pivotally and slidably connected to said; blades for moving said blades longitudinally and about said, pivot pins, second cam means on said blades and a cooperating member on said linkage andmovable therewith to rock said blades about said pivot pins, whereby when said linkage is moved in a first direction said blades and jaws are rocked together tograsp the strap edges encircled by the sleeve and sub sequently said blades are moved primarily'longitudinally relative to said jaws while said jaws hold the strap sleeve to notch the strap and sleeve and to offset portions thereof a predetermined distance,-and when said linkage is moved in the opposite direction said blades are retracted primarily longitudinally to return the offset portions part of the offset distancaand subsequently said jaWs and said blades are rocked awayfrom each other to release the strap and sleeve, andmeans holding said side, plates in place,

6. In a tool for producing a joint between overlapping portions of metallic strapping, and an encircling metallic reinforcing sleeve, having a pair of spaced side plates, a pair of pivot pins held by and bridging between said side plates,

, a pair of folding jaws, each jawbeing pivotally' mounted on one of said pivot pins, said, jaws having confronting hook-like tips which approach each other to clamp the strap portions and sleeve when said jaws are oppositely rocked about said pins, an operating linkage pivotally connected to said jaws for rocking said jaws about said pivot pins, and means holding said side plates in place, the improvement which comprises a pair of shearing and offsetting blades, each blade being loosely mounted on one of said pins by means of an opening therein substantially larger than said pin so that said blade and said jaw mounted on said same pin may move relative to each other, a blade actuating means on said linkage means, and cam means on said blades adapted to be engaged by saidblade actuating means as said linkage means is operated to pivot said blades to; bring them into shearing and ofisetting position, stop means limiting such pivotal movement of said blades, and means connecting said linkage mechanismto said bladestomovesaid bladeslon:

gitudinally relative to. said jaws to shear and offset the overlapping strapping portion and encircling sleeve.

'7. In a tool for producing a'joint between overlapping portions of metallic strapping and an encircling metallic reinforcing sleeve, having a pair of spaced side plates, a pair ofpivot pins held by and bridging between said side plates, a pair of folding jaws, each jaw being pivotally mounted on one of said pivot'pins, said jaw having confronting hook-like tips which approach each other to clamp the strap portions and sleeve when said jaws are oppositely rocked about said pins, an operating linkage pivotally connected to said jaws for rocking said jaws about said pivot pins, and means holding said side plates in place, the improvement which comprises a pair of shearing and offsetting blades, each blade being loosely mounted on one of said pins by means of an opening therein substantially larger than said pin so that said blade and said jaw mounted on said same pin may move relative to'each other, a blade actuating means on said linkage means, cooperat- References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,793,990 Bayer Feb. 24, 1931 1,893,901 McGregor Jan. 10, 1933 1,924,845 Edwards Aug. 29, 1933 1,974,913 Childress Sept. 25, 1934 2,216,579 Adamso-n Oct. 1, 1940 2,315,596 Childress Apr. 6, 1943

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