US3509757A

US3509757A - Device for bending a workpiece

Info

Publication number: US3509757A
Application number: US403141A
Authority: US
Inventors: Eduard Hanni
Original assignee: Haemmerle AG Maschinenfabrik
Current assignee: Haemmerle AG Maschinenfabrik
Priority date: 1963-10-11
Filing date: 1964-10-12
Publication date: 1970-05-05
Anticipated expiration: 1987-05-05
Also published as: FR1408555A; FR89367E; DE1452682A1; AT258674B; DE1777268B1; CH414508A

Description

May 5, 1970 Y E. HNNI l 3,509,757

i DEVICE FOR BENDING A woRKPIEcE Filed Oct. 12. 1964 5 Sheets-Sheet 1 May 5, 1970 E. HNNI 3,509,757

` DEVICE FOR BENDING A WORKPIECE Filed Oct. 12', 1964 3 Sheets-Sheet 2 III I Illll May 5, 1970 E. HNNI DEVICE FOR BENDING A WORKPIECE 5 Sheets-Sheet 5 Filed Oct. 12. 1964 /n u-ef/ for United States i. Patent ll() U.S. Cl. 72-414 2 Claims ABSTRACT `oir Tirs. DISCLOSURE The present invention concerns a device for bending a workpiece which device is suitable for carrying out bending work according to a pre-determined programme.

Hitherto, in such operations, interchangea'ble bending parts which can be connected with the ram or table of a `press have been used, the parts beingchanged after each step of the operation.

This procedure is both uneconomical and` time-consuming and is particularly disadvantageous in the mass production of sheet metal pieces.

The present invention provides a device for bending work having a movable ram and a work table characterised in that a tool holder is secured on both the ram and work table, at least one of the tool holders having various bending tools which can be moved from a position of readiness into the working position, and whereby for each tool in the tool holder on the ram a complementary tool is provided in the tool holder arranged on the table.

The tool holders may conveniently be constructed as revolving heads and be adapted to pivot from the insertion position into a position for effecting the change of tools.

The invention will be further apparent from the following description and the several gures of the accompanying drawings which show, by way of example two presses embodying the invention.

In the drawings,

FIG. 1A shows a tool set secured to the ram of the first press;

FIG. 1B shows the complementary tool set secured to the working table of the rst press; and

FIG. 2 shows the second press.

Referring now to FIGS. 1 and 2, it will be seen that the ram of the bending device is indicated by the reference numeral 1.

The ram 1 is provided with a centering stop 2 having a centering face 3 against which a corresponding face of.` a tool set is located. The tool set is constructed as a revolving tool holder 4 and is provided with insertable tools.

As shown in the drawing, three

tool inserts

5, 6 and 7 are provided, which have differently shaped profiles that enable a workpiece to be bent at different angles. The tool holder 4 is rotatably mounted on an axle 8i, which is held at each end by a lever arm 9. The lever arms 9 (only one of which is visible in the drawing) are pivotally mounted in the frame of the ram, for example, on an axle 10, the end of each lever arm remote from the axle 8 being in connection with an actuating rod 11. The rod 11 is connected with a piston (not shown) of a cylinder 12 pivotally mounted on an axle 14 in a housing 13 of the ram. In this way, on actuation of the piston in the direction of the arrow P into the cylinder 12, the lever arms 9 are pivoted counter-clockwise so that the tool holder 4 is pivoted from the working position into the tool-changing position shown by dash-dot lines. In this position the tool holder 4 can be so rotated that the

tools rice

5, 6 or 7 can be brought into their working position. The operation of the piston in the cylinder 12 takes place pneumatically.

l An analogous arrangement is present on the table 14 (FIG. 1B) of the device of FIGS. lA and 1B, which again has a centering stop 15 against whose centering face 16 a corresponding face 17 of a tool holder 18 comes to rest. The tool holder 18 is mounted to rotate on an axle 19 and has

tool inserts

20, 21 and 22 which `are intended to co-operate with the

tools

5, 6 and 7.

The axle 19 of the tool holder 18 is held at each side by a two-armed lever 23 (only one such lever 23y being shown in the drawing).

Each lever 23 is pivotally mounted on an axle 24 and is connected at the opposite end with an actuating bar 25 of a piston to reciprocate in a cylinder 26. The cylinder 26 is pivotally mounted on an vaxle 27 in the housing 28. Similarly to the levers 9, the pair of levers 23 can be pivoted so that the tool holder 18 takes up the position shown by dash-dot lines. In this position, the tool holder 18 can be turned so that the

tools

20, 21 or 22 can be i `brought into their working position. When the pair of levers 23 is swung into the working position, an automatic centering of the tool holder 18 take-s place in that the corresponding face 17 will rest against the centering surface 16.

In this way, continuous and very rapid working is achieved whereby after each bending process the tool holders 4 and/or 18 are swung out and the tools changed by rotation of the tool holders. The pivoting of the levers 9 or 23 takes place in opposite directions, i.e. the levers 9 are pivoted counter-clockwise, and the levers 23 clockwise, so that the

tool holders

4 and 18 are laterally off set with respect to one another in the pivoted position. In this way, free space is made available for the change of tools so that on rotation of the tool holders, the

parts

5, 6, 7 cannot collide with the

parts

20, 21, 22.

A further embodiment of the invention is shown in FIG. 3. This is a chamfering press having a bending device for the carrying out of consecutive operations, for example, multiple bends. The bending device has a table 30 with a tool holder 51 which carries a matrix 31. The matrix is provided with two forms ,32 and 33 which cooperate with two press dies 34 and 35. The die 34 is ex changeably mounted on a tool holder 36 of the ram of the bending device by means of a screw bolt 37 and is provided with a die holder 38 which carries the die 35 that is pivotally mounted on an axle 39 of the holder 38 yso that the die 35 can be pivoted out of the solid line position into one shown by dash-dot lines. The position of the die 35 shown in solid lines corresponds to the working position while the dash-dot line position corresponds to the inoperative position of the die 35.

For the operation of the die 35 an air cylinder 40 is provided which is pivotally secured to the tool holder 36 by means of a forleshaped holder 52. The cylinder has a piston which has a piston rod 41 that is connected with an arm 43 by means of a fork shaped holder 42. This arm 43 is connected by a screw bolt 44 with the pivoting die 35.

On operation of the air cylinder 40 which whereby it is pivoted clockwise in the fork shaped holder 52, the die 35 can be brought from the working position into the inoperative position.

In this way it is possible to work selectively with both dies or with only one die.

Adjustable bolts

45 and 46 which are mounted for axial adjustment by means of a threaded spindle 48 in a holder 47 are provided. The

bolts

45 and 46 act as stops for the piece 49 to be worked and conveniently fed through corresponding bores in the matrix 31. The holder 47 is supported in a pedestal 50` of the device.

,.- A f l3 What I claim is: :""I devicor bending" Work," comprising:

(a) a movable ram, (b) a Work table, Y l (c) two toolholders, one of said tool holders being secured to said ram and said work table, respectively, vat least one of said tool holders being mounted to be i movable from a tool-exchanging position into a Working positionand vice versa,

' (11) each of said tool holders being rotatably mounted in a pair of two-armed levers, each of said pairs of levers being responsive to an actuating rod, each of said rods' being attached i to a pneumatically operable piston, andthus causing pivoting ofthe pairso'f levers from said working position to said tool-exchanging posil l tion, and

(d) bending tools held in said tool holders, whereby i Y foreach .bending tool provided in the'tool holder of said ram there is a complementary tool in the tool holder of said work table. f2. A device for bending work, comprising: (a) a movable ram, f (b) a work table, (c) two tool holders, one of said tool holders being secured to said ram and worktable respectively, at least one of said tool holders being mounted to be movable from a tool-exchanging position into a workingposition and vice versa',

(1) each of said tool holders being rotatably mounted in a pair of two-armed levers, each of said pairs of levers being responsive to an actuatingrod?. each of said rods being attached to a pneumatically operable piston, and thus causing pivoting lof the pairs of levers from said working position to said tool-exchanging position, and Y (.2) said levers and said pistons being arranged to pivot said pairs of levers in opposite direction, and (d) bending tools held in said tool holders, whereby for .each bending tool .providedrin the tool holder of said ram there is a complementary tool inthe tool holder ofsaid work table.

References Cited UNITED STATES PATENTS 2,426,446 V8/ 1947 Funk r.. 72-412 2,456,749 12/ 1948 Steibel 'i2-412 2,847,053 .8/ 1958 Hardman 7.2-414 3,029,858 4/ 1962 Harper i -72-412 yCI'IRLES W. LANHAM, Primary Examiner M. J. KEENAN, Assistant Examiner