Патент USA US3077231код для вставки
Feb- 12, 1963 G. E. FRANCK ETAL 3,077,221 Filed Aug. 28, 1961 20 t' @eofgeEj-’v'œnc/Q 3 Charleâljlïäowe, 3,077,2Zl Patented Feb. l2, i963 2 FIG. 4 is a fragmentary elevation similar to that of FIG. 3 but with the shoe positioned as upon completion of a 180° bend in the tube; and 3,077,221 ' TUBE BENDER George E. Franck, Morton Grove, and Charles L. Rowe, FIG. 5 is a fragmentary enlarged section taken sub stantially along the line 5_5 of FIG. 3. In the exemplary embodiment of the invention as dis closed in the drawing, a tube bender generally designated . Lake Forest, Ill., assignors to Imperial-Eastman Cor poration, a corporation of Illinois Filed Aug. 28, 1961, Ser. No. 134,402 9 Claims. (Cl. 153-46) 10 is shown to comprise a mandrel 11 and a shoe 12 movably associated wtih the mandrel by means of a 10 connector 13. Herein, the connector is integrally asso ' In one well-known construction of manually operable ciated with the shoe; the connector, however, may com tube bending tools, a mandrel is provided with a tube prise a separate element tixedly secured to the shoe by bending peripheral groove generated about an axis. The suitable means. This invention relates to tube working tools and in particular to manually operable tube bending tools. groove is arranged to receive the tube during the bending operation, the tube being pressed into the groove by The mandrel 11 is provided with a peripheral segment ally annular groove 14 generated about an axis 15 of the mandrel and arranged to receive the tube T during the tube bending operation. As best seen in FIGS. l and means of a bending shoe provided with a tube pressing surface. Conventionally, the bending shoe is moved along the groove with the tube pressing surface thereof 5, the mandrel comprises a generally cylindrical member having a chordal surface 16 at opposite ends of the groove 14. A conventional tube holding hook 17 may be secured confronting the groove. To maintain the shoe in the desired confronting relationship juxtaposed to the man drel groove, the shoe conventionally is connected to the mandrel by a suitable connector. The present invention comprehends such a tube bender having a new and im» to the mandrel at surface 16 by suitable means such as screw 18. A handle 19 may be secured to the mandrel 11 and a handle 20 may be secured to the shoe 12 for proved connecting means which positively retains the shoe manipulation of the shoe 12 to eifect the desired bend in the desired arcuate path adjacently along the mandrel 25 in the tube T. groove while permitting a desired spacing of the shoe from _ As best seen in FIG. 5, connector 13 comprises a ñat the mandrel periphery at a ’single preselected portion of ‘ _element pivotally juxtaposed to one surface 21 of the the groove to permit facilitated installation and removal mandrel 11 by means of a stepped cylindrical post 22 of the Átube in and from the space between the mandrel projecting coaxially from the mandrel and provided at groove and pressing surface of the shoe. 30 its opposite ends with enlarged heads 23 and 24 retaining Thus, a principal object of the present invention is the connector 13 and handle 19 respectively in associ to provide a new and improved tube bender structure. ation with the mandrel. The post includes a- ilatted Another object of the invention is to provide such a cylindrical mid>portion 25 retained against rotation about tube bender structure comprising new and improved axis 15 in a corresponding ilatted cylindrical hole 26 ex means for connecting the shoe and mandrel element-s 35 tending axially through the mandrel 11. Adjacent en thereof. larged head 24, the post is provided with a portion 27 A further object of the invention is to provide such extending through the handle 19 for fixing the handle a tube bender structure having new and improved means 19 against rotation about the axis of the post. Between for permitting spacing of the shoe from the mandrel mid-portion 25 and enlarged head 23, the post is provided groove at a single preselected portion of the groove and 40 with a portion 28 having a wedge-shaped cross section arranged to retain the shoe in juxtaposed confronting re and extending through a slot 29 in the connector 13. lationship to the groove at all other portions thereof. Referring now more speciiically to FIG. 1, slot 29 " Still another object of the invention is to provide comprises a keyhole-shaped slot having a circular portion such a tube bender structure wherein the connecting 30 and a generally trapezoidal portion 31 extending radi means comprises a post on the mandrel projecting axially ally from the circular portion. The cross section of post therefrom and having a wedge-shaped cross section com portion 28 comprises a portion of a circle deñned by al prising a portion of a circle defined by allochiral converg lochiral converging chords 32, a short arc 33, and a long ing chords and 4diametrically opposed long and short arcs, arc 3d. As shown in FIG. 1, the arcuate length of arc and a connector having a first portion fixed to the shoe 34 is greater than the corresponding arcuate distance be and4 a second portion provided with a slot for exten 50 `tween the side surfaces 35 of the trapezoidal portion 31 siontherethrough of the post, said slot having a cross of the slot 29 at the juncture thereof with the circular section comprising a circular portion having a diam portion Sil. As best seen in FIG. 2, the arcuate length eter substantially equal to the diameter of the post defined of the short are 33 is shorter than the corresponding by the arcs and a trapezoidal portion extending radially arcuate distance between the side surfaces 35 at the junc~ from the circular portion and having radially outwardly 55 ture thereof with the circular portion 3d. As may be converging side surfaces corresponding to the chords, seen in FIG. 1, the radial length of the trapezoidal por~ whereby the connector may be disposed with the post tion 31 is substantially less than the diameter of the post extending selectively through the circular portion or 22 defined by the arcs 33 and 3K3. The radially outer end through the trapezoidal portion of the slot. of the trapezoidal portion 31 may be arcuate generally Other features and advantages of the invention will be 60 similar to the arcuate portion 33 of the post so that, as apparent from the following description, taken in con nection with the accompanying drawing wherein: FIG. 1 is a fragmentary elevation of a tube bender provided with connecting means embodying the invention, with a tube portion associated therewith as at the initia shown in FIG. 1, the post effectively bottoms thereon when received fully in the trapezoidal portion of the slot, The side surfaces 32 of the post and the side sur faces 35 of the slot are arranged to converge at similar 65 angles. Thus, when the post is so disposed in slot por tion 31, the side surfaces 32 of the post facially engage the side surfaces 35 of the slot portion 31. Herein, the side surfaces 32 and the side surfaces 35 respectively con~ tube bending position; verge at the included angle of approximately 8°. FIG. 3 is a fragmentary elevation similar to that of 70 The invention further comprehends the arrangement FIG. 2 but with the shoe positioned as subsequent to the of the trapezoidal portion 31 of slot 29' so as to receive completion of a 90° bend in the tube; the post portion 28 only when the shoe is arranged with tion of a tube bending operation; FIG. 2 is a fragmentary elevation similar to that of FIG. 1 but with the shoe juxtaposed to the mandrel in a serveer 3 ea its tubefpressing surface 37 disposed at a preselected start ing portion 33 of groove 1li. in the illustrate-d embodi ment, the diameter of slot portion 3d bisecting the trape Zoidal portion 3l extends through the bend starting por~ tion 33 and, thus, is perpendicular to the pressing surface 37 when the pressing surface is disposed at -bend starting of many modifications. Changes, therefore, in construeF tion and arrangement may be made without departing from the spirit and scope of the invention as defined in the appended claims. ' portion 33. To facilitate the desired bending of tube T, the mandrel li may be provided with conventional peripheral angle markings 39 and the connector i3 may be provided with a sight hole 40 through which the markings 39 may be viewed. Thus, as shown in FIG. 2, when the shoe is at the bend starting position, the zero degree marking is observable through the opening di). Other angles of dis position of the sho-e relative to the bend starting position may similarly be determined by observation of the mark ings 39 through the opening ‘itl in the various positions of the shoe. The use of tube bender 1t) is seen by consecutive con sideration of FIGS. 1-4. Thus, in FIG. l, the tube bender is arranged so that the shoe 12» is spaced from the mandrel sufficiently to allow lready insertion of the tube T between the shoe surface 37 and the mandrel groove 14. To per mit this spacing, the connector 13 is arranged so as -to We claim: l. in a tube bender having a mandrel provided with a tube-bending peripheral groove generated about an axis, and a bending shoe provided with a tube-pressing surface for urging a tube portion into the mandrel groove for conformation therewith, means for selectively retaining the shoe for movement along the tube-bending groove with the tube-pressing surface closely adjacent thereto and for spacing the shoe substantially from the tube-bending groove at a single preselected portion of the groove comprising: a post on the mandrel projecting axially therefrom, said post having a wedge-shaped cross .section comprising a portion of a circle defined by allochiral converging chords and diametrically opposed long and short arcs; and a connector having a first por tion fixed to the shoe, and a second portion provided with a slot for extension therethrough of said post, said slot having a cross section comprising a circular portion having a diameter substantially equal to the di ameter of the post defined by said arcs, and a trapezoidal receive the post portion 23 within the trapezoidal portion 25 portion extending radially from the circular portion and having radially outwardly converging side surfaces cor» 31 of the slot 29 with the arcuate portion 33 of the post bottoming on the radially outer surface 36 of the slot. To dispose the shoe 12 in position for the beginning of responding to said chords, whereby said connector may be disposed with said post extending selectively through said circular portion or through said trapezoidal portion. the bend, the shoe is then moved toward the mandrel 2. The tube bender means of claim 1 wherein said until the connector 13 is redisposed so as to have post por 30 tion 28 disposed fully within the circular portion 30 of post includes enlarged end portions retaining the post against substantial axial movement in said mandrel. the slot. Suitable manipulation of handle 20 may then 3. The tube bender means of claim l wherein said be effected to move the shoe circumferentially along the long are is longer than the corresponding arcuate distance peripheral groove 14 from the position of FIG. 2 to the between said side surfaces of the trapezoidal portion of position of FIG. 3. During this movement, the arcuate the slot at the juncture thereof with said circular portion surfaces 33 and 34 of the post have sliding facial engage ment with the cylindrical surface 30 of the slot 29 posi of the slot. tively retaining the shoe surface 37 juxtaposed t-o the 4. The tube bender means of claim 1 wherein the radial length of said trapezoidal portion is substantialiy mandrel periphery for proper bending of the tube T into 40 less than the diameter of the post defined by .said arcs. the groove 14. Referring now to FlG. 4, the manipulation of shoe 12 5. The tube bender means of claim 1 wherein the trapezoidal portion of the slot includes a radially outer may be continued, if desired, until the shoe is redisposed approximately 180° from the bend starting position arcuate end surface substantially similar to the portion 'whereby the tube Tis bent int-o a U-shaped configuration. of the post defined by said short arc whereby the post .As the arcuate surface 34t- of the post now confronts the may be bottomed on said end surface with the portion -trapezoidal portion 3i of the slot, and as the length of the of the post defined by said chords facially engaging said :arcuate surface 34 is substantially greater than the cor side surfaces of the slot. :responding arcuate spacing between the slot surfaces 35 6. The tube bender means of claim l wherein said 'at the juncture thereof with the circular portion 30, the -glâords converge at an included angle of approximately post is positively prevented from entering the trapezoidal -portion 3l. Thus, the post is effectively precluded from 7. in a tube bender having a, mandrel provided with 4catching or hanging up and a simple foolproof manipula a tube-bending peripheral groove generated about an :tion of the tube bender is assured. axis, and a bending shoe provided with a tube-pressing To release the bent tube, the handle 253` is manipulated surface for urging a tube portion into the mandrel groove ‘to return the shoe l2 back to the starting position of 55 for conformation therewith, means for selectively re FIG. 2 whereupon the post is once again aligned with taining the shoe for movement along the tube-bending ,the trapezo-idal portion 31 of the slot so as to permit the groove with the tube-pressing surface closely adjacent >ready movement of the shoe outwardly from the position thereto and for spacing the shoe substantially from the lof FIG. 2 to the position of lG. l. A_s the shoe is then tube~bending groove at a preselected bendstart portion substantially spaced from the mandrel, the bent tube may 60 of the groove comprising: a cylindrical post on the be removed from the mandrel groove as desired. Tube mandrel projecting axially therefrom, said post having a bender l@ is then ready for a subsequent bending opera~ wedge-shaped cross section comprising a portion or" a ’tion similarly as discussed above. circle defined by allochiral converging chords and di As a substantial surface enagement occurs between the ametrically opposed long and short arcs, the center of post and the circular portion of the mandrel slot at all said arcs being disposed on a diameter of said axis ex’ times during the bending operation, improved trouble tending through the bend-start portion of the mandrel free life of the bending tool is obtained. Further, the groove; and a connector having a first portion fixed to connection between the mandrel and the shoe is extremely the shoe, and a second portion provided with a slot rugged so as to assure maintained alignment of the shoe for extension therethrough of said post, said slot having surface 37 relative to the groove lo at all times. Further, 70 a cross section comprising a circular portion having a the simple structure of the connecting means effectively minimizes the cost of the bending tool while effectively maximizing etiiciency and facility of operation. While we have shown and described one embodiment ,of our invention, it is >to be understood that it is capable diameter substantially equal to the diameter of the post defined by said arcs, and a trapezoidal portion extending radial-ly from the circular portion and away from said circular portion and having converging side surfaces corresponding to said chords, whereby said connector 5 3,077,221 may be disposed selectively with `said post extending selectively through said circular portion or through said trapezoidal portion. 6 ular to a diameter of said circular portion of the slot bisecting said trapezoidal portion thereof. 9. The tube bender means of claim 7 wherein the 3. The tube bender means of claim 7 wherein said radial length of said trapezoidal portion of the slot is first portion of the connector is fixed to the shoe to have 5 greater than the diameter of the tube to be bent. said tube~pressing surface extend substantially perpendic No references cited.