US2371138A - Forming die - Google Patents

Description

March 13 1945.

R. R. HARRISON ETAL FORMING DIE Filed Nov. 28, 1941 2 Sheets-Sheet 1 FIG.

INVENTOR ROBERT R BARRISON FIG.

VBY v a LESLIE .SCORE A ORNEY March 13, 1945.

R. R. HARRISON ET AL FORMING DIE Filed Nov. 28, 1941 2 Sheets-Sheet 2 FIG. 4

FIG. 5 B v INVENTOR ROBERT R. HARRISON Patented Mar. 13, 1945 UNITED STATES FORMING DIE Robert R. Harrison and A Iieslie 11. :Score, .North Hollywood, Qalifi, assignors, by :mesne assignments, to Ben'dixAviation Corporation, it South Bend,"lnd,,' alcorporationo'f Delaware iApplication 'November 28, I941, SeridfNos420L-784 A'Claima- (01. 153-33) This invention relates -to forming dies and more pa'i'ticulaily to :a "-fotniing idle "for forming tube I clamps from -metal" strip material.

Tube clamps are metal *loopsihaving'holesat each end, designed to -be placed around a'tube and secured to' a support bypassing "a screw or bolt thr-oughboth holes in the ends of the-loops. harge numbers of such clamps :are usedinthe aircra'ft industry 'to secure hydraulic {and elec- 'trical conduits to a 'frame :member. The clamps are=also useful in: anyapplica'tion requiring a conduit of any 1? type to be se'curedto a support.

It-is an object o'f th'e invention to provide a forming die which will mompletely form a'itube cl'amp from metalstrip-stoc It l -isanother object "to provide a die which holtlsm strip (ifStOCkybY punching a hole J'therein,

holding the :strip "until a forming operation isz-completed aa'ndhaving means to'thencut off th-e strip to release: it'from thepunchingl-mechanism. Still another 'objectzis "to provide 1 a die which formsstripimaterialz-into loopscby'forcing aaman- :drelrbetweenrtworsupportslupon which a strip of stockrrests. i

lflnotherrcobjectis ;to :provide ca .die which room- :pletes the iforming 'of s=a=Jstrip about set-mandrel :by having a':pivoted"cross-=;arm' member 'strike a mrctruding :endrof LthB "strip :and bending it rover :upomthe mandrel. Y

.Ajflllth'BI' :object isuto provide a die wherein off :means are tprovided c-which 'force the tube :clamps ofi Offin"'ODEn'BndIOf :the :mandrel.

;:In"thei drawings formingxa :part; of this specifiication: i t

.Figure l-is-aside view inzelevationkand partly-Lin section "of ia .die made in accordance with the invention showingtthe I, die in :an open position to permit insertion of :metahstrip stock therein;

Figure 2lis a-zside view in elevation L and partly in section of the dieshowingthe die in .thelower most portion .of .itsjtorming .s'troke;

.Figure 3 is a'topview in section-of the lower bed oftthe die,".the *sectionlbeing taken along the "linej3- 3 ofFigure 1;

Fligurei is asectional' view of the 'die alone the lined-4 oiFieurefl; and 1 v fFigurefad's' an isometric View of -a"tu'be clamp 'ma'de b the die of thisinvention.

'Referring to *Fi'gure "1, the die "comprises "a' bottom bed plate In having upright guide posts 12 secured it'hereto. Guided on post -12 is 'an upper bed plate 1 4 which is free *to reciprocate 'with'relation' to thetbottom bed plate *1 ll. Secured and spaced'therefrompn-theleft is"a pivotblock "1'8.

*Pivotedto' block -l-8is'a shaft 2|] having agear "2 2 "secured thereto, and having an arm '24 also 5 "secured thereto. At the *outerend -'ofarm '24 is *secureda 'rod 26 which isa-xially parallel to the 'shaiftzll. Also-pivdta'lly secured 'to block 18 is a toothed quadrant 2B pivoted at 30 engaging the -teeth of'gear 22. When quadrantZBrotates about 0 itsaids it causes gear 22 to rotate also=which'in turn "causes the arm 24 to-pivot on the shaft '20. One-end of quadrant 28 is secured to i a member 32 having a lostmotion connection with a-socket member-34, the-movement beinglimited' by a pin 36 in member 3-2 sliding ir'r-a =slot= 38 in socket member 34. Socket member 34 is in turnpivotally connected to the upper'bedplate l4.

secured 'to the upper bed plate M with a lost motion connection is a mandrel support 40 "havingrigidly secured thereto a mandrel-'44. 'When the' upper bed plate 14 moves downwardly to- WardS -bedplate Hi the mandrel-support moves withity-forcing the mandrel in opening 11 between the blocks l fi and 18.

" 5 Rigidly secured to-upper'be'd plate r4 is-a block on which are mounted-a punch member 52, a punchmemberSLand a cutter'56. *Punch52 is guided at its lower'end by block 58 yieldingly secured toblock :50 by pin '60 and compression "3o springEZ. Punch 54 is similarly guided byblock itube clamps rare lformedaon :.=a mandrel and take- $4 secured =t0'block 50 bypinGB and-spring'GB.

The punch block l 6 contains punch holes for the punches 52 and :Mand-the cutter '56. Punch hole 510'- receives' the I punch '52, punch 'hole 12 're- 35 'eei-ves pun'ch 54,-and punch hole 14 receives cut- :ter156. rA 'tube 'clamp -whichis'formed by the die of this invention isshownin Figure 5. "The clamp comrprises aistrip of metal formed into a loop with- :one end of the strip tangent -to the loop, and

with the'other end'ofatheloop benteat right angles :toithe loopshapetobe parallel with the first end. -A'.holes82 is: formed'at'each'end of the loopflman'd rhoth are axially =aligned in the 'ifinished loop.

- 45 The clamps 80 are made .from long strips of rmaterialxwhich may=betof any suitable metal such aaluminum. Referringto Figurel, a strip M is inserted' in the :die, and rests on pun-ch "block -'I 6 zandzpivotsblock l8. The'exterit-to which the strip 0 3:41 is inserted in thediemay be limited by :automatic feedingmechanisms (not'shown) which are available on the market, or maybe limited 'by a stop 80 secured to the pivot-block I 8.

After the'strip fl'd' is inser-ted inthedieasshown to bedlplate lfi isaazpunch blockil fi onxone side, '55 .in Figure 1, the -upper "bed plate 14 'is *forced downwardly toward the lower plate In, the guide blocks 58 and 64 striking the strip 84 first. These guide blocks hold the strip tightly, and further movement of the upper plate l4 causes punch 54 to pierce the strip 84 and pass therethrough into punch hole I2. Shortly thereafter during further movement, the punch 52 also pierces the strip 84 forming a second hole therein.

Immediately after the punch 54 has passed through strip 84 and into its hole 12 the mandrel 44 descends upon the strip 84 and pulls the strip downwardly between the two blocks I6 and [8. Since the right end of the strip is held by punch 54, the left end is the free end and consequently must slide into the hole I! between the two blocks as the mandrel pulls it downwardly. At the lower limit of the movement of the mandrel 44, the strip 84 will be formed as shown in Figure 2, with the free or left end sticking upwardly as shown in dotted lines in Figure 2.

During the stroke of the die when plate 14 is moving toward plate In, the quadrant member 28 is also actuated. Member 32 slides upwardly into its socket member 34 until the two abut. Thereafter these two members cause the quadrant 28 to be rotated about its pivot 38, and this in turn rotates gear 22. The consequent rotation of shaft 28 causes arm 24 to rotate also, until the resultant position at the end of the stroke of the die is that shown in Figure 2. While passing to the extreme position shown in Figure 2, the arm 24 and its rod 26 engage the upper right end of strip 84 (as shown in dotted lines in Figure 2) and forces it down upon the mandrel 44. This action completes the tube clamp as shown in Figure 2.

Near the end of the stroke of plate l4 toward plate [8, and after the tube clamp is substantially completed the cutter 56 reaches the strip 84 and passes therethrough into its punch hole 14, cutting the left end of the strip completely off from the main body of the strip 84. This action, however, occurs only after the mandrel 44 has securely gripped the strip against the punch block l6, and this succession of operations is made possible by the lost motion connection of mandrel support 48 to the upper bed plate l4.

After the plates I4 and ill have reached the position shown in Figure 2 they are thereafter separated by any suitable mechanism, and this return stroke causes quadrant 28 ,to rotate to its original position as shown in Figure 1 rotating the arm 24 counter-clockwise and causing the rod 26 to rest in the hole 21 in the pivot block 18. The cutter 56 is also withdrawn. The guide blocks 64 and 58 remain pressed against the strip 84 by their springs 68 and 62 respectively, until The forming die ispreferably a multiple die as shown in Figure 3. There it will be seen that there are four strips 84 inserted into the die at one time. The punches 52 and 54 are also four in number as well as the cutter 56. The mandrel 44 is made long enough to act on all four strips 84, and the pivoted rod 26 is made of similar proportions.

The details of the mandrel and its push-off mechanism are shown in Figure 4. The support member 48 is L shaped with the mandrel 44 rigidly secured to the vertical arm of the L. Since the mandrel 44 would not be rigid when acting as a cantilever arm, a pivoted support member 42 is provided on the left end of mandrel support 46, and engages the upper surface of mandrel 44. A leaf spring 43 urges the pivoted support member 42 to a vertical position. The push-off mechanism .comprises a crescent shape member 46 shown most clearly in Figure 1. Crescent shape member 46 is secured to a rod 48 having a head 41, the assembly being urged toward the right by a compression spring 48 resting upon one leg of the mandrel support 48.

When it is desired to remove the finished tube clamps from the mandrel 44 the rod 48 is moved inwardly by manual or power means, and the crescent shape member 46 moves along the lower half of the'mandrel 44 shoving finished clamps off of the left end of the mandrel 44. When the clamps strikepivoted support member 42 when moving to the left, this member freely rotates clockwise to provide a clearance, since there is no load on the mandrel at the same time.

In operation, strip metal 84 is moved into the open die as shown in Figure 1. As the die is closed the guide blocks 64 and 68 touch the strip 84 first, and punches 54 and 52 pass through the strip, anchoringit as well as punching it. At the same time the mandrel 44 descends on the strip pulling the left end thereof into the opening ll between blocks l6 and I8, causing the free end the punches 54 and 52 are withdrawn out of the holes formed in strip 84. In the final opened position, the parts have the relative positions shown in Figure 1 except that finished tube clamps are secured around the mandrel 44. The finished tube clamps are removed from the mandrel 44 by a push-off device 46 which will be more completely described later.

The pivot block I8 is adjustably movable on the bottom bed plate II). By moving the block l8 .to the right or left (Figures 1 and 2) the opening I! may be made larger or smaller. opening ll thus accommodates larger or smaller size clips 88 when themandrel 44 is made correspondingly larger or smaller. For example one die made in accordance with the invention can make clips varying from three quarters of an inch in diameter to two and a half inches in diameter.

This variable of the strip to assume an upright position as shown by the dotted lines in Figure 2. Simultaneously the quadrant 28 is rotated by its actuating mechanism causing the arm 24 to rotate allowing rod 26 to strike the upright end of the strip 84 and bend it fiat upon the mandrel 44 as shown in Figure 2. Near the end of the closing stroke of the die, the cutter 56 cuts off the left end of the strip, severing the completed tube clamp (Figure 5) from the body of the strip 84. The arrangement of parts in the die is such that the hole punched by the punch 52 forms the hole on the right end or bottom end of the next finished tube clamp as it is completed on the mandrel 44. The hole punched by the punch 54 is the hole forthe left end or upper end of the next succeeding finished tube clamp.

When the die is opened the finished tub clamps will be pressed around the mandrel 44. The push-off mechanism (shown most clearly in Figure 4) is then operated either manually or by power mechanism. The rod 48 is moved to the left moving the crescent shaped member 46 along the mandrel 44, pushing the finished clamps off of the left end of the mandrel. During this operation the pivotedsupport leg 42 pivots clock- -wise to provide clearance for the finished tube clamps.

Although this invention has been described with reference to a particular embodiment thereof it is not limited to this embodiment nor other- Wise except by terms of the following claims.

A We claim:

1. A tube clamp die for forming a strip of metal into a loop having generally tangential ends, comprising two spaced supports upon which the metal strip rests when in the fiat form, movable means adapted to close on said strip to lock it to one of said supports, the portion of the strip on the other support being free, a movable mandrel adapted to move between said supports and contact said strip to form it in a generally semicircular form, the secured end being formed radially to said semicircular portion, and pivoted means to strike the unsecured end of said strip and bend it about the mandrel until the end is in a position generally parallel to the secured end, to form the completed metal article, the die being characterized in that said two spaced supports define a recess therebetween of greater depth than said mandrel when the latter is moved between said supports, whereby the strip is unsupported between said two supports and is shaped against said mandrel solely by tension.

2. A tube clamp die for forming a strip of metal intoa loop having generally tangential ends, comprising upper and lower bed plates relatively movable toward each other, two separated blocks secured to one of said plates against which the metal strip is adapted to rest, a locking block upon the other plate, adapted to contact the strip on one block to lock it thereto, the other end of the metal strip being free, a mandrel of generally round cross section secured to said other plate and adapted to be moved between said blocks to form the strip in a semicircular shape, the secured end being bent generally radially to the semicircular shape, and arm means pivoted to one of said bed plates and adapted to strike the free end of said strip and bend it about the mandrel until that end is generally parallel to the locked end, said die being characterized in that said two spaced supports define a recess therebetween of greater depth than said mandrel whenthe latter is moved between said supports, whereby the strip is unsupported between said two supports and is shaped against said mandrel solely by tension.

3. A tube clamp die for forming a strip of metal into a loop having generally tangential ends, comprising two spaced supports upon which the metal stri rests when in fiat form, movable means adapted to close on said strip to lock it to one of said supports, the portion of the strip on the other support being free, a mandrel adapted to move between said supp rts and contact said strip to form it in a generally semicircular shape, the secured end being formed radially to said semicircle, pivoted means to strike the unsecured end of said strip to bend it about the mandrel until the end is in a position generally parallel to the secured end, to form the completed metal tube clamp, said mandrel being a cantilever structure, a pivoted leg normally supporting the free end of the cantilever, and means adapted to move along said mandrel to push off of the same the completed tube clamps, said pivoted leg being pushed aside during this step.

4. A forming mechanism for bending a strip into a substantially closed curve comprising: a mandrel and cyclically operable means cooperating therewith for wrapping a work strip about said mandrel, said means exerting lateral force against said'mandrel during only a portion of each cycle; supporting means for said mandrel for resisting lateral force including a rigid support connected to said mandrel at one end thereof, and a pivoted leg normally supporting the other end of said mandrel against said lateral force; and means adapted to move along said mandrel to push off of it strips that have been bent there around, during a. portion of said cycle when said means is not exerting lateral force on said mandrel, said pivoted leg being pushed aside by the bent strips to permit their discharge off the end of the mandrel.

ROBERT R. HARRISON. LESLIE H. SCORE.

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