US2357480A - Apparatus for applying metal straps - Google Patents

Description

Sept. 5, 1944. re F. M MAHAN 2,357,480

APPARATUS FOR APPLYING METAL STRAPS Original Filed Oct. 15,1938 4 Sheets-Sheet 1 A 9 v '10 D A 9 1 ,Afimm p U '1:

A A fi V A A D A A p A A g .2 3b 2 9 VV V VV V V VVV lNVENTO R Y RoY F. MCMAHAN TTORNEY Sept. 5, 1944. R. F. McMAHAN 2,357,480

APPARATUS FOR APPLYING METAL STRAPS Original Filed Oct. 15, 1938 4 Sheets-Sheet 2 AEA a 2 an 162- 4- F 1 79 a I {6/ 762 6/2 {0 8 8d 2 poy Fig. /0 2%,xm T T ATTORNEY Sept. 5, 1944.

MQMAHAN 2,357,480

APPARATUS FOR APPLYING METAL STRAPS Original Filed Oct. 15, 1938 4 Sheets-Sheet I5 Fiy. /3

INVENTOR ROY F. MQMAHAN ATTORNEY Patented Sept. 5, 1944 UNITED STATES PATENT QFFICE 2,357,480 a i APPARATUS FOR APPLYING METAL STRAPS Roy F. McMahan, Avondale, near Louisville, Ky; Original application October 15, 1938, SerialNo.

235,129. Divided and this applicationtApril: 1, 1942, Serial No. 437,301

7 Claims application, Serial Number 235,129, filed October 15,1938, and entitled Metal bound box.

In the aforesaid applicatiomthere is discloseda' wood box having a metal binding-strap engaging one face of each of the respective box seefit Figure '5 is an end view of the binding-strap showing the corner protecting members 8/ and By before thesame are secured tothe corresponding side and end ofthe'box;

Figure 6 is a partialsectional-view of the binding-strap showing the construction and relation of the short teeth lllthat are pressed through'the relatively thin side'members of the box, and long tions. The strap is provided with a plurality of teeth 9 that .are pressed through the relatively teeth, struck therefrom and integral therewith, 10 thick end members of the box; I I

and each tooth has a flat shank extending through Figure 7 is a partial sectional view taken along its respective box section. The free-end portion lines l'! of F gu e 2 showing the shape o the of each tooth is folded against the opposite face corner protecting member 81 after same is seof the respective box section, and arched longitucure to its corresponding box member;

dinally throughout the length thereof so that "the igure 8 is' a partial vertical sectional-view end edge of the tooth is curled into the respecshowing the preferred construction of the aptive box section; reenforcing means is formed in 'paratus employed to apply the metal bindingthe arched free-end portion of each tooth for sestrap to a box, and illustrating the teeth ID of curing the same in its folded position against the the strap pressed through box members I and opposite face of the respective box section. There- Figure 9 is a so a partial vertical sectionalfore, it is the object of this invention to provide view ill t g the r pying apparatus a simple and effective apparatus for applying such "su stantia y beginning h e s p of bending a metal binding-strap to the respective sections th te th I d ner p t ng m s a of a box. into approximately arch-shape;

Another object of this invention is to provide F ure 10 is likewise ap Vertical Sectionala simple tool that is mounted upon a conventional -V i lu rat t ppp y apparatus power-driven punch-press, much in the same ubstantially completing the a f g p manner as a conventional forming die, for applytion-required to curl the free-end edges of each ing the said strap to the respective sections of a et nd the f ee nd edge of each end-p wood box. tect-ing member into their respective box sections, Also, it is a further object of this invention to and substantially beginning the forming of the provide apparatus for applying a metal-binding r nforc a 90 e a e ee-end p strap to articles other than the wood box illust o of e ch tOOthtrated in my aforesaid application. Figure 11 is an enlarged partial elevational These and other objects will be apparent to view of one of the tooth forming tools as viewed those skilled in the art as the following descrip- I ng n s o ure 1 tion is read in connection with the accompany- F r l is an ed d View Of O e o fing drawings, in which: the tooth forming tools;

Figure 1 is a perspective view of a box having 40 Figure 13 is a partial sectional view showing a: metal binding-strap applied by the apparatus the final shape of a tooth in secured relation with disclosed in this invention; its corresponding box member;

Figure 2 is an enlarged partial view of the Figure 14 isapartial sectional view taken along corner of the box illustrating teeth Sand l0 lines I 4| 4 of Figure 13 showing the reenforcpressed through their respective box sections, and .45 d 90 formed in the arched free-end of each also showing the relation of the corner-protectt d ing members 8 and 89 before the free-ends of Figure 15 is a partial vertical sectional view ilsame are secured to the corresponding box secl st ti e tr p pp in ppa us n no tions; condition, that is, the relation of the various Figure 3 is a partial view showing the outer p rts te t e Press is loaded and before the press faceof the binding-strap that lies along side 2 is op at d. Figure 15 also shows guide p ns P of th box; and limit stops S holding the pressure plate l4 Figure 4 is a partial View showing the outer in functional relationship with its associated face of th binding-strap that li along end 4 parts, and the manner in which the die H is assoof the box; V ciated with the head or ram of a:power press.

In the foregoing drawings, only vertical sectional-views of the forming tools are presented, as it is believed that these are the essential views required to gain a thorough understanding of the invention. As illustrated in Fig. 15, it is to be understood that the tool holder II is provided with a suitable mounting means so that the same is fixedly secured to the reciprocating slide of a conventional power-driven punch-press, for vertically reciprocating the same relative to a stationary table T that is fixedly secured to the stationary bolster plate of a conventional power press. Therefore, it is to be understood that the metal binding-strap 8 rests upon the table T while the reciprocating forming tool consisting of pressure plate 14 and forming tools l2, etc., is moved downwardly into engagement with the respective box members and the teeth of the binding-strap.

The specific apparatus illustrated in the drawings, is primarilyemployed to secure a sheetmetal binding-strap to the respective sections of a wood box. However, it will be apparent that the teachings of this invention may be utilized to secure metal binding-straps. to various kinds of articles. Accordingly, it is important to observe the relation existing between the inner faces of the arched ends of the forming tools l2 and the outer faces of the teeth that are engaged by the respective forming tools.

For the specific relation between the various parts of the forming tool, reference is directed to the drawings.

Thus, in specifically describing the particular embodiment of my strap-applying tool, I do not desire to be limited other than by the scope of the appended claims. Therefore, although the forming tool includes depending arms IGI and arched contours [8 for securing the end-protecting members 8g to their respective box members, it is to be understood that these may be altered or omitted, without affecting the operation of the pressure plate I 4 and forming tools I2. Thus, for a more complete understanding of the parts utilized in securing the end-protecting members 8g, reference is made to my earlier United States Patent Number 2,253,639Qissued August 26, 1941, and entitled Bending die; also for a more complete understanding of the method utilized in securing these end-protecting members to their respective box sections reference is made to my earlier United States Patent Number 2,201,193, issued May 21, 1940, and entitled Hanger and method of attaching same.

In Figure l of the drawings, a box is shown having metal binding-straps 8 secured to the respective sections of the box by means of the strap-applying tools forming the primary object of this invention. It will be observed that the box is preferably constructed from five pieces of relatively thin timber, or similar material, to form the side members I and 2, end members 4 and 5-, and bottom member 3. It will also be observed that all of these box members are rigidly and permanently secured together by two metal binding straps 8 of specially constructed anglesection. V

Each face of these angled binding-straps has a series of teeth struck therefrom, which teeth are adapted to be pressed into and through juxtapositioned faces of the box members, for rigidly and permanently securing the same together without the use of nails, screws, battens, or other similar securing means. With particular reference to Figures 1 to 7 inclusive, it will be observed that the teeth along each face of the binding-strap have a triangula shape and project substantially at right angles from the corresponding face thereof in substantially a fiat plane. In this respect, particular emphasis is made of the fact that the plane of each tooth is made to register with the grain of the timber forming the side, end and bottom members of the box. Thisconstruction and arrangement is clearly shown in Figure 1. The object of this arrangement is not only to facilitate assemblage, but to provide the least possible fracturing of the fibres of the timbers so as to afford the greatest mechanical strength. This arrangement further minimizes rejects because of split timbers that would otherwise be encountered by not having the plane of the teeth substantially parallel with the grain of the timbers. This arrangement further enables the teeth to be pressed into and through the box members with the least possible disturbance to their free projecting positions, thus assuring proper alignment of the teethwith their corresponding forming or clinching tools, hereinafter described.

In arranging the box members prior to being assembled into the box illustrated in Figure 1, two specially constructed angled binding-straps of the required length and gage are provided, each strap having a series of teeth struck from each of its faces and substantially uniformly spaced throughout its length. The particular relation of each tooth, one to the other and to the grain of the timber, isclearly shown in Figure 1.

In assembling the binding-straps with the box timbers, the two straps are laid parallel on a stationary table T of a conventional power press, and the sides I, 2 and bottom 3 laid fiat-wise upon the upstanding free-ends of the teeth projecting from the corresponding faces of the straps, which relationship is shown in Fig. 15. The power press is then operated, and the reciprocating forming tool consisting of tool holder II and pressure plate l4 moves downwardly towards the box timbers. The pressure plate l4 engages the timbers and presses the same downwardlyso that the upstanding teeth ID are pressed into and through the box timbers, observe Figures 1, 2, 8, 9, 10, 13 and 14. Each side membe I and 2, and the bottom member 3 are spaced, and the upright face of each strap is formed with a V gap or mitre adjacent each junction of a side and bottom member so that the box members can be subsequently folded to assume the position illustrated in Figure 1. Y

Referring now to Figures 8 to 12, and 15, it will be observed that the tool for pressing the teeth l0 intoand through the box timbers, and for subsequently clinching same, comprises aseries of forming tools l2 carried by a die block I l, and a pressure plate l4 normally biased away from the die block H by suitable springs l2s disposed between the die bloclc ll and pressure plate M.

Thus, it will be apparent that the pressure plate I4 shown in Figures 8, 9', 10 and 15, first contacts the box members I, 2 and 3, and presses the teeth l0 into and through same by force from the power press transmitted to the saidplate through the springs l2s, which springs are sufficiently strong to effect penetration. As illustrated in Figure 8, each forming tool 12 engages its corresponding tooth l0 after the box member is pressed against therespective inner face of the binding-strap. l

I 2 has a concaved arcuate contour I21), and an arcuate beading rib I20 located'centrally of the lower face of the forming tool l2. Note Figures 11 and 12.

Thus, each arcuate beading-rib I20 engages the free-end of a tooth ID in its downward movei ment; and progressively rotates, or curls, the free-end in the manner illustrated in Figures 8, 9 and 10, until the final position illustrated in Figures 13 and 14 is reached. Just prior to each tooth reaching itsfinal position, the resistance of the compressed box member increases, and exerts: sufficient pressure to permit the beading-rib l2c of each tool to form a reenforcing bead in the curled end of each corresponding tooth, as illus- "trated-i-nFigures 13and 1'4. 7 I

It is important to note that my strap-applying apparatus provides a slight shearing of the fibres of the box timbers adjacent the inner faces of the box members, so that each tooth is independently and simultaneously curled to a position below the inner face of the box members. This arrangement eliminates objectionable metallic projections within the box that may otherwise injure the hands of those required to handle the box.

Thus, with a single stroke of a conventional power press, the side and bottom members of the box are secured to the corresponding faces of the binding-straps. In Figures 1, 2,5 and '7 to 10,.inclusive, it will be observed that each end of the binding-strap 8 is provided with corner protecting and end securing members 8 and 8g, These members are each curled around the edge of the corresponding box timbers, and their free-ends driven into the corresponding member. particularly illustrates the member 8 curled into the respective box section 4.

With reference to Figures 8 to 10 inclusive, it will be observed that I have provided arcuate faces l8, guides I62 and projections IQ for arching the members 89/, or 8], in accordance with the teachings of my aforesaid earlier Patents Numbers 2,253,639 and 2,201,193. It will also be observed that the face I9a between the arched contours I8 is depressed, not only to provide the required projections I9 for penetrating the surface of the box member to provide the final securing operation for the members 80, but sufficient to provide a recess into which the pressure plate i4 moves during the operation of the tools I2 upon the free-ends of the teeth I0.

As illustrated in Figure 12, the pressure plate I4 is provided with a series of round apertures through which the respective forming tools I2 operate. It will also be noted that each tool l2 has a fiat portion l2a, and it is to be understood that each tool [2 is secured to the die block II by set screws l5, as illustrated in Figure 11,

It is also to be understood that the pressure plate I4 is provided with guide pins P and limit stops S so that the same is normally held in a position relative to the forming tools l2 as shown in Fig. 15. Obviously, such expedients are well known to those skilled in the art, and it is not regarded necessary to elaborate upon their construction and relation. It is to be understood that the construction and arrangement of the guide pins and limit stops for the pressure plate 14 may take various forms without departing -cua te contours l 8, projections 19 and arms: I61,

Note Figure '7 which- -tice the same from the spirit of this invention, since the essential novelty of this invention resides in the construction of the forming tools l2, the relation of these tools'relative tovthe teeth [0, and the use of the tools l2 in combination with the arcuate contours l8. Accordingly, it .is believed that Figs. 8 to 12 and- 15; sufiiciently illustrate the invention so that those skilled in the art may prac- Therefore, while I have described and. illustrated the construction and relation of the tools required to secure the binding-strap 8 to the sides and bottom of the box, it is believed that it will-be apparent to those skilled in the art, the

required arrangement of the tools to secure the straps B to the respective ends of the box.

Thus, after the strap is secured to the side members! and 2, the side members are bentupright at' the-initre joints asillustrated -in Figure l. The end members 4 and 5 are-then placed within the partially constructed box, either separately or together, and subjected to the action of suitable tools, made in accordance with the teachings of those described for the side and bottom members, for curling the teeth 9 into the respective ends of the box and forming the reinforcing means in the arched ends thereof, as shown in Figures 13 and 14. In this respect, it is to be understoodthat the tools for the ends of the box are also provided-with the required arfor curling the end protecting-members 8] as shown in Figure 7.

While Ihave shown and described 'what I con.- sider to be the most practical embodiment of my invention, it is to be understood that various changes in construction may be made under the scope of the appended claims.

Having thus described my invention, I claim:

1. In apparatus for applying a metal bindingstrap having a plurality of fastening projections formed integrally therewith to a Wooden member; a plurality of forming tools, one for each fastening projection, each tool having on its forming end a semi-circular concave-face; a pressure plate operatively associated with the said forming tools; means fo moving the pressure plate against the said member to press simultaneously the said fastening projections into and through the same; means for longitudinally moving each forming tool against its respective fastening projection, to curl it into substantially arch shape and to force the free end thereof into the opposite face of the said member; and means operatively associated with each forming tool for longitudinally denting the curled portion of each corresponding projection so as to re-enforce the said fastening projection in its curled condition.

2. In apparatus for applying a metal bindingstrap having a plurality of fastening projections formed integrally therewith to a wooden member; a plurality of forming tools, one for each fastening projection, each tool having on its forming end a semi-circular concave face having the plane of the extremity of its concave face substantially parallel with the plane of the extremity of the corresponding fastening projection, each tool also having a convex rib extending circumferentially of its concave face; means for longitudinally moving each tool against its respective fastening projection, to curl it into substantially arch shape and to form a concave reenforcing bead longitudinally therein.

3. In apparatus for applying a metal bindingstrap having a fastening projection formed integrally therewith to a wooden member; means for longitudinally moving a forming tool having on its forming end a semi-circular concave face, a convex rib extending circumferentially of said face and an end edge of the concave face positioned just outside the projecting end of the said projection; and means for guiding the forming tool against the said projection to curl it into an approximately arch-shaped clinched-end, force the free-end thereof into the wooden member, and to form a concave re-enforcing bead longitudinally of said clinched end.

4. In apparatus for applying a metal binding strap having a fastening projection formed integrally therewith to a wooden member, means for longitudinally moving a forming tool having on its acting end a semi-circular concave face and a. convex rib extending circumferentially of said face, and means for guiding said forming tool against said projection to curl it into substantially arch-shape and to form a concave reenforcing bead longitudinally therein.

5. In apparatus for applying a meta1 binding strap having a plurality of fastening projections formed integrally therewith to a wooden member; a plurality of forming tools, one for each fastening projection, each tool having on its forming end a semi-circular concave-face, a convex rib extending circumferentially of the concave face and an end edge of the concave face positioned above and just outside of the projecting end of the corresponding fastening projection; a pressure plate operatively associated with the said forming tools; means for moving the pressure,

plate against the member to press simultaneously the said fastening projections into and through the same; means for longitudinally moving each forming tool; and means for guiding each forming tool against its corresponding fastening projection to curl it into substantially arch-shape, force the free-end thereof into the opposite face of the wooden member, and to from a concave re-enforcing bead longitudinally of the arched end.

6. In apparatus for applying a metal binding strap having a fastening projection formed integrally therewith to a wooden member; a forming tool having on its forming end a semi-circular concave-face and a convex rib extending circumferentially of the said face; a pressure plate operatively associated with the said forming tool; means for moving the pressure plate against the member to press simultaneously the said fastening projection into and through the same; means for longitudinally moving the forming tool; and means for guiding the forming tool against the said projection to curl it into substantially archshape and to form a concave re-enforcing bead longitudinally therein.

'7. In apparatus for applying a metal binding strap having a fastening projection formed integrally therewith to a wooden member; a forming tool having on its forming end an arched concave face for curling the projection longitudinally into substantially arch-shape, and means for bending the arched projection laterally to reenforce the same in its arched condition; means for longitudinally moving the forming tool and means for guiding the forming tool against the free end of the said projection to curl the projection into substantially arch-shape and to bend the arched projection laterally to re-enforce the same in its arched condition.

ROY F. MCMAHAN.

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