US2515734A - Stretch-bending machine with work clamps mounted on pivoted arms - Google Patents

Description

Jul 18, 1950 Filed Dec. 2, 1944 E. A. RAT STRETCH-BENDING MACH HGEN 2,515,734

INE WITH WORK CLAMPS MOUNTED ON PIVOTED ARMS 5 Sheets-Sheet l INVENTOR EWALT A RATHGEN BY FM ATTORNEY July 18, 1950 CLAMPS MOUNTED ON PIVOTED ARMS 5 Sheets-Shget 2 Filed Dec. 2, 1944 IIIIIII N UFW INVENTOR A TTORNE Y N E a w A A m m July 18, 1950 Filed Dec. 2, 1944 FIG? ' E. A. RATHGEN STRETCH-BENDING MACHINE WITH WORK CLAMPS MOUNTED ON PIVOTED ARMS 5 Sheets-Sheet 3 iOi iNl ENTOR I I EWALT A. RATHGEN ATTORNEY E. A. RATHGEN STRETCH-BENDING MACHINE WITH WORK CLAMPS MOUNTED ON PIVOTED ARMS July 18, 1950 5 Sheets-Sheet 4 Filed Dec. 2, 1944 FIG. 12

INVENTOR ATTORNEY July 18, 1950 E. A. RATHGEN 2,515,734

STRETCH-BENDING MACHINE WITH WORK CLAMPS MOUNTED 0N PIVOTED ARMS Filed Dec. 2, 1944 s Sheets-Sheet 5 FIGJO INVENTOR EWALT A. RATHGEN A TTORNE Y provided in the top plate 44 of the arm 31. The rod 54 of the piston 55 in the cylinder has its outer end secured to a bracket 56 which is slidably guided by the top plate 44. Attached to the bracket 56 by universal joint connecting means 51 is a vise 58 adapted for holding one end of a workpiece 59.

Secured to the base 20 between the inner ends of the arms 31 is a support 60 for a table 6|. The table has a raised margin 62 which in combination with the top surface of the table serves for holding a forming die 63. The die has one of its margins shaped in accordance with the form and the cross section of the workpiece 59, which in the embodiment is shown as an angle section.

Pressure medium may be admitted to the cylinders 29 and 5| by means of valves 64 and 65 and pipe lines 66, 61 and 68, 69. The pressure medium is supplied by a source (not shown) which feeds into the pipes 10, 1| leading to the valves 94, 65. 1| are the exhaust or return pipes for the pressure medium.

The control means 50, 64, 65 are for the sake of simple diagrammatic illustration shown near the respective appertaining motors and cylinders but they will be arranged in reality, as a matter of course, together in one or. two groups at a location or locations most suitable for the person or persons handling the production.

The operation of the machine will be evident to those skilled in the art from the foregoing description of the elements of the machine, so that a brief description of the operation will suflice.

After the die 63 has been placed on top of the table BI and the cylinders 5| have been secured in place on the arms 31 at the distance from each other corresponding to the length of the workpiece, the latter is firmly secured in the Vises 58. Hereafter pressure medium is admitted to the inner ends of the cylinders 5| by means of the valves 65 and pipes 68 so that the workpiece 59 is subjected to stretching. While the workpiece is in the stretched condition, the arms 31 are swung about their pivots 34 by means of the motors 45, the gears 41, the pinions 48 and the gear sectors 39, so that the workpiece is wrapped around the working edge of the die 53. During the movement of the arms. pressure in the cylinders 5| is maintained and, if need be, ressure medium admitted or partly released so as to maintain the desired stretching force which will cause the workpiece to assume permanently the exact form of the die surface yet without being stretched beyond its breaking point.

For other forms of the die different positions of the journals 3 for the arms are required. such different positions can be easily attained by moving the brackets 30 along their ibs on the plate 2A after loosening the bolts 4| as described hereinbefore.

If the form of the die is not symmetric relato be moved vertically relative to the die and its support. This vertical movement is achieved by moving the plate 24 with the arms 31 and all other accessories, such as the Vises 58, the cylinders 5|, the motors 46, the gears 41 and the gear segments 39, vertically on the plate 22 by admitting pressure medium to the lower part of the cylinder 29 while the arms are simultaneously swung about their pivots by means of the motors 45.

. The embodiment illustrated in Figures 7 to 14 differs from the first embodiment mainly in the means for swinging the arms about their pivots and in the means for moving the die and the Vises relative to each other in vertical direction. This second embodiment shows certain details which maybe incorporated also in the first embodiment, such as means for conveniently adjusting the position of the pivots for the arms, and such as a different type of universal joint connection between each vise and its piston rod.

The machine illustrated in Figures 7 to 14 has a large foundation plate carrying at one end a cross member 8|, at the other end a supporting structure 82 and near its middle a pedestal or bracket 83.

The structure 82 has a base plate 84, the inner end of which carries a columnar structure 85. Supported at a distance above the plate 84 by means of the columnar structure 85 is a horizontal beam structure composed of a lower plate 86 and an upper plate 81, vertical plates 88, 89, 90 and intervening horizontal plates 9|, 92. The columnar structure is reinforced by an inclined member 93 extending between the plate 81 and. the outer end of the plate 84. The entire structure 92 is composed, as will be evident from the drawing, of closed box sectional beams which give great strength and rigidity.

Gibs 94'are secured to the inner faces of the plates 89 and 90 and form with the latter a horizontal guide and support for a pair of brackets 95. A nut 95 secured to the bracket 95 is in engagement with a screw threaded shaft 91 rotatably but axially immovably supported in the structure 82 between the walls 9|, 92. One nut 96 and one shaft 91 are provided on either side of the middle line (coincidingwith section line Iii-I0 in Figure 8) of the machine for each of the brackets 95. One end of each shaft 91 projects beyond the outer end of the structure 82 andchas a head 99 adapted for turning the shaft by means of a wrench, crank or the like.

Pivoted to each bracket 95 by means of a vertical pin I90 is the innerend of an arm IOI. A gear segment I02 is secured by flanges and bolts or rivets I03 to the arm IOI near the lower edge thereof. The gear segment I02 has its periphery concentric to the respective pivot I00. The teeth ofthe gear segment I02 are engaged by a straight gear rack-I04. The segment I02 and the rack I04 are held in engagement by a shoe I05 which has flanges I06 engaging a pathway concentric to the outer periphery of and provided on the segment I02. Each rack I04 is hitched by a coupling I01 to the rod I08 of a piston I09. The piston I09 is movable in a long cylinder II 0 which has its outer end journalled at I II to the cross beam 8|. There is, of course, one cylinder, piston, piston rod, rack and gear segment for each of the two arms IOI as is shown in Figure 7.

Pressure medium can be admitted to or released from the interior of the cylinders II0 on either side of the piston I09 by the valves I I2 and pipe lines H3, H4. Here again as in the first embodiment, the source of pressure medium is I.) not shown but only the supply and exhaust or re- 5. turn lines H5, H. It should be noted that the movement of each arm is'independently controllable by its valve I I2.

The construction of the outer ends of the arms and of their top side is substantially the same as in the first embodiment; this goes also for the cylinders II6 for moving the Vises Ill and the valves (not shown) for controlling the admittance of pressure medium to the cylinder independently from each other.

The universal joint connection between the piston rods I I 8 and the Vises II I is slightly different from the first embodiment. A bracket I I9 -is slidably guided on the top of each arm I 0|;

this bracket carries by means of a ring I20 and intersecting vertical and horizontal pivots I2I, I22 the inner end of the vise III.

Secured to the central portion of the structure 82 between the brackets 95 is a member I23 which has formed therein an undercut vertical groove I24. Slidably guided in this groove I24 by a correspondingly shaped extension I 25 is a member or structure I26. The opposite vertical edge I2'I of this member is guided in a groove I20 provided on the previously mentioned bracket 83.

The structure I 26 is in the form of a frame, the upper side of which is adapted for the attachment of a die or of a supporting table I29 by means of bolts extending'into screw threaded holes I30. The table and its support are held in appropriate alignment by a ridge formed on the underside of the table entering a correspondingly shaped groove I29 on the top of the structure I26.

Secured to the underside of the top member and arranged within the opening surrounded by the four sides of the structure I26 is a hydraulic cylinder I33. The rod I 34 of the piston in the cylinder I33 extends through an aperture in the bottom member of structure I26 and has its end secured to the foundation plate 80. Pressure medium may be admitted to the cylinder by means of the valve I35 from the pressure medium supply line I36 through the pipe line I31, I38; I39 is the return or exhaust pipe.

The operation of the machine shown in Figures 7 to 14 is substantially the same as that of the machine shown in Figures 1 to 6. After proper adjustment of the pivots I00 by moving the brackets 95 along the cross head of the structure 62, the adjustment of the cylinders I I 6 along their arms NH and after having secured a die, such as indicated at I40, on the table I29, a workpiece indicated at MI is secured in the vises II I. Hereafter pressure medium is admitted to the inner ends of the cylinders H6 and to the inner ends of the cylinders I I9 with the efiect that the workpiece is stretched and simultaneously the arms I'EII with the workpiece are swung about their pivots I00. If the workpiece is curved in more than one plane, the die is moved relative to the vises holding the ends of the workpiece and relative to the machine as a whole in vertical direction by admitting pressure medium to the cylinder I33 so that the structure I26 with the table I 29 and the die I49 is moved in vertical direction.

It will be understood that the invention is not restricted to the details of the two embodiments illustrated in the drawing and describedhere- 6 inbefore but that the invention is subject to such modifications and adaptations which are covered by the spirit and the language of the attached claims.

What is claimed is:

1. A stretch-"bender comprising a base, a structure slidably guided on said base and provided with means for moving the structure back and forth, a pair of brackets supported by said structure slidably in a direction transversely to the direction of movement of said structure, said brackets each carrying an arm swingably about an axis which is about parallel to the axis of rotation of the other arm and about parallel to the direction of movement of said structure, means on said arms for gripping spaced portions of a workpiece and for stretching the latter between them, a forming die supported on said base, and power operated means for swinging said arms about their respective axes into relative positions in which a workpiece supported in stretched condition between them is brought against said forming die.

2. A stretch-bender comprising a base, a structure guided on said base for back and forth movement in one direction and means for imparting such movement to the structure, a pair of brackets supported by said structure slidably in a direction transversely to the direction of movement of the structure itself, said brackets each carrying an arm swingably about an axis which is about parallel to the direction of movement of said structure, means on said arms for gripping spaced portions of the workpiece and for stretching the latter between them, a forming die supported in stationary condition on said base in a position intersecting the line joining said gripping devices as said arms are swung about their respective axes.

EWALT A. RATHGEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 537,550 Schacht Apr. 16, 1895 818,932 Baxter Apr. 24, 1906 957,200 Gail May 10, 1910 1,066,247 Brown July 1, 1913 1,264,248 Yoder Apr. 30, 1918 1,379,858 Gail May 31, 1921 1,462,315 Akey et a1 July 17, 1923 1,710,261 Kellogg Apr. 23, 1929 1,968,010 Bailey July 31, 1934 2,155,160 Bruno Apr. 18, 1939 2,190,423 Henricson Feb. 13, 1940 2,292,731 Amiot Aug. 11, 1942 2,305,850 Drysdale Dec, 22, 1942 2,357,027 Seifried Aug. 29,1944 2,370,329 Seifried Feb. 27, 1945 2,431,173 Hawkes Nov. 18, 1947 2,446,089 Hochreiter July 27, 1948 FOREIGN PATENTS Number Country Date 482,769 Great Britain Apr. 5, 1938

Images