US3429156A - Devices for bottom stroke stop in hydraulic edge presses - Google Patents

Devices for bottom stroke stop in hydraulic edge presses Download PDF

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Publication number
US3429156A
US3429156A US555585A US3429156DA US3429156A US 3429156 A US3429156 A US 3429156A US 555585 A US555585 A US 555585A US 3429156D A US3429156D A US 3429156DA US 3429156 A US3429156 A US 3429156A
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United States
Prior art keywords
press
ram
bed
hydraulic
stroke stop
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Expired - Lifetime
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US555585A
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English (en)
Inventor
Egon Ake Lennart Eriksson
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URSVIKENS MEKANISKA VERKSTADS AB
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URSVIKENS MEKANISKA VERKSTADS AB
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
    • B30B15/16—Control arrangements for fluid-driven presses
    • B30B15/18—Control arrangements for fluid-driven presses controlling the reciprocating motion of the ram

Definitions

  • a bottom stroke stop device for use in hydraulic edge presses or press brakes including a pair of limit switches supported from the bed of a press at opposed ends respectively of the press ram in a selectively adjustable manner, said switches being respectively engageable by respective abutment means at the opposed ends of said press ram, said switches being each operatively coupled to the actuating valves of the respective hydraulic cylinder means for control of such valves to selectively control the location of the lowermost end of the ram stroke and maintain the ram in the desired alignment relative to the press bed.
  • the present invention relates to a bottom stroke stop device in hydraulic edge presses or press brakes with two hydraulic cylinders for the movement of the press ram to and from the press bed, said cylinders being connected to each end of said ram.
  • edge presses of this kind hitherto used it is a wellrecognized difliculty that the deflection of the press frame has a detrimental effect on the accuracy of the bottom stroke stop position and on the parallelism between the ram and the bed.
  • the device utilized in the various structures for determination of the stroke stop mostly is mounted in the upper part of the press adjacent the ram and the hydraulic cylinders thereof and is secured to the frame, unfortunately at a point thereon where the deflection becomes highly observable.
  • For symmetrical loads in such an edge press there will be achieved different press depths dependent on the length of the metal sheet to be treated and on the deflection varying with the non-uniform press force.
  • the limit switch is vertically adjustable from a place at or below the bed through a suitable transmission, but said switch is secured to the frame and therefore the deflection thereof will have quite a considerable influence upon the press 3,429,156 Patented Feb. 25, 1969 result and the desirable parallelism between the ram and the bed cannot be achieved at all.
  • Another structure that gives sufficient parallelism comprises screw jacks between the press ram and the bed, said jacks being disposed at each end of the ram.
  • These jacks involve, however, several difliculties for the work in the press, particularly for the reason that they may hinder a draw-off laterally of the pressed workpiece which occurs rather often in deeply-pressed profiles.
  • said stop means the deflection in the end housings of the press is certainly eliminated, but instead, there must be taken into account a non-negligible deflection of the jacks, often amounting to about 0.2 mm. ⁇ .008 in.).
  • the concept forming the basis of the present invention resides therein that only by relating the bottom stroke stop means as well as the parallel-keeping means to the press bed, the position of which of course is completely independent of any deflections in the frame, it is possible to obtain a really suflicient accuracy in the press work. However, only this step alone will not give the proper result, there must also be provided one set of such' means at each end of the press ram.
  • the main object of the present invention is to provide a bottom stroke stop device that will completely eliminate the detrimental effect of the frame deflections on the accuracy of the press work. Another object is to provide a bottom stroke stop device that secures a better parallelism of the press ram and the press bed during the last portion of the press stroke. A further object of the invention is to provide a bottom stroke stop device that will constitute no obstacle for the work in the press and that is compact, easy adjustable for various work dimensions, reliable in operation and easy and economical in manufacture and maintenance.
  • a device distinguished in that two limit switches for control of the actuating valves of the hydraulic cylinders are mounted one at each end of the press ram but supported from the bed, the vertical position of the limit switches being commonly adjustable by transmission means anchored in the bed and entirely separated from the end housings of the press, and in that the press ram at each end carries an abutment corresponding to the limit switch, said pair of abutments being adapted to act on the respective limit switches in direct dependence of the vertical position of the ram ends so as to provide for an exact press depth and particularly a parallelism between the ram and the bed independent of the deflection of the end housings.
  • the device according to the invention it is thus achieved a greatly improved result in the press works owing to the fact that it is possible to obtain an accuracy of fine as 0.05 mm. (.002 in.), in the parallelism of the press ram and the press bed and also in the bottom stop positioning. It is further to be noted that in the present device the press bar is forced to continue its operative stroke as long as the limit switches in both the *bar ends are not engaged thereby.
  • FIG. 1 is a diagrammatic front elevation and FIG. 2 a side elevation of a press brake with a device according to the invention, while FIG. 3 illustrates a side elevation partly in section and to an enlarged scale, of an embodiment of the very device and its localization on the press.
  • a hydraulic edge press or press brake of a type known per se comprises a press bed 1 and a ram 2 movable thereto and therefrom and operable by a pair of hydraulic cylinders 3 acting on each end of the ram 2 and supported from a press frame with end housings 4.
  • the hydraulic cylinders 3 are fed each from a constant-flow pump (not illustrated) so as to provide for a parallel motion of suflicient accuracy during idling movements.
  • brackets 6, 7 With a support 8 for a limit switch 10.
  • the vertical positions of the respective supports 8 and their limit switches 10 are commonly adjustable at the bed 1, and the supports are entirely separated from the end housings of the press.
  • the transmission means as mentioned comprise an adjustment screw 14 on which moves axially a nut 15 guided in the bracket 7 and carrying in its turn the support -8 for the limit switch 10.
  • the screw 14 is rotated by a linked transmission shaft 16 from a gearing or pair of bevel gears 20.
  • Said gearin'gs disposed at each side of the press are mutually connected by an intermediary shaft 18 extending longitudinally below the bed 1, and one of them is operable by a knob or wheel 17 located below the bed 1.
  • said wheel 17 is provided with an indicia scale 19 and/ or a counter (not illustrated) for counting the number of position adjustment turns.
  • the ram 2 carries an abutment 22 located opposite the limit switches 10, and said pair of abutments are arranged to act on the respective limit switches 10 in direct relation to the vertical position of the ends of the ram, so that exact stroke length and particularly a good parallelism of the ram 2 to the bed 1 is achieved independently of the deflection of the end housings 4.
  • the abutments 22 are adjustable individua l in a direction parallel to the direction of movement or the ram 2 so as to allow an intentional tilting of the ram 2 in cone pressing and other similar operations.
  • the abutment 22 consists of a screw, preferably a micrometer, so that the vertical position of the abutment can be micro-adjusted with greatest accuracy.
  • the screw is mounted on a bracket 23, secured in its turn to the ram 2 for sliding movement in the direction of movement of said ram so as to provide for an easy coarse-adjustment of the position of the abutment 22.
  • the ram In operation and after a suitable pre-setting of the limit switches 10 and the abutments 22 cooperating therewith in regard to the desired press operation, the ram will move towards the bed 1 and it will not stop that movement until it has engaged both the limit switches 10 with both its ends by the abutments 22, thus completely independent of how much the housings 4 have deflected during this operation due to the pressure applied. By this it is secured not only an accurate parallelism between the ram and the bed but also an eflicient and exact determination of the position of the bottom stop for the stroke.
  • This last-mentioned speed reduction can easily be achieved by mounting adjacent to the stop limit switch 10 on the support '8 also a further speed-reducing limit switch 10', adapted to act on particular actuation valves (not shown) of the hydraulic cylinders 3, such as to reduce the stroke speed of the ram 2 in a suitable extent e.g. to 1:, or
  • the last-mentioned limit switch 10' must be mounted so as to be actuated by the abutment 22, preferably through a transferring plate 24, at the desired moment before the first limit switch 10-.
  • the limit switch 10' conceals the switch 10 lying therebehind, said switch also being mounted on the support 8.
  • a bottom stroke stop device in hydraulic edge presses or press brakes comprising at least two hydraulic cylinder means, for the movement of a press ram to and from a press bed, said cylinder means, each including an actuating valve means for starting and stopping the operation of said cylinder means, are respectively connected to said ram, at least two limit switches operatively coupled respectively to said actuating valve means of the respective cylinder means for control of the actuating valve means to selectively stop the operation of said hydraulic cylinder means to selectively control the bottom position of the ram stroke, said switches being mounted one at each end of said ram and supported from the bed, the vertical position of said limit switches being commonly adjustable by transmission means anchored in the bed and entirely separated from the end housings of the press, and said press ram at least at each end carries an abutment corresponding to the limit switch, said pair of abutments being adapted to act on the respective limit switches in direct dependence of the vertical position of the ram ends so as to provide for an exact press depth and particularly a parallelism between the ram and the
  • each of the limit switches is adjustable by the intermediation of an adjustment screw with a nut, said nuts supporting said limiting switches a transmission member operatively coupled at one end to said screw and having a gearing at its opposed end, said gearings being commonly operated by an actuation shaft disposed along the press whereby rotation of said shaft drives each of said transmission members for respective rotation of each of said screws.
  • a device according to claim 1 wherein the abutments are vertically adjustable relatively to the press ram so as to allow a tilting of said ram in cone bending and similar operations.
  • each abutment consists of a screw for fine-adjustment of the vertical position of said abutment, and in that said screw is mounted in a vertically adjustable bracket so as to allow a coarse adjustment, said bracket being mounted to said ram.
  • a device further including at least two reduction switches mounted on said bed adjacent said limit switches respectively said reduction switches being operatively coupled to said actuating valve means, and wherein the abutments are adapted also to actuate said reduction switches respectively at a selected moment before their actuation of said limit switches, said reduction switches being located adjacent said limit switches and arranged to act on said actuation valve means for suitable reduction of the speed of the ram at the end of the stroke thereof.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Bending Of Plates, Rods, And Pipes (AREA)
  • Press Drives And Press Lines (AREA)
  • Control Of Presses (AREA)
US555585A 1965-06-10 1966-06-06 Devices for bottom stroke stop in hydraulic edge presses Expired - Lifetime US3429156A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE7668/65A SE309401B (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1965-06-10 1965-06-10

Publications (1)

Publication Number Publication Date
US3429156A true US3429156A (en) 1969-02-25

Family

ID=20271977

Family Applications (1)

Application Number Title Priority Date Filing Date
US555585A Expired - Lifetime US3429156A (en) 1965-06-10 1966-06-06 Devices for bottom stroke stop in hydraulic edge presses

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US (1) US3429156A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
AT (1) AT263485B (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
BE (1) BE682379A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
CH (1) CH435984A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
DE (1) DE1577192A1 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
ES (1) ES328158A1 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
FR (1) FR1510834A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
GB (1) GB1111013A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
NL (1) NL6608037A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
SE (1) SE309401B (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3841140A (en) * 1972-12-18 1974-10-15 Dreis & Krump Mfg Co Control system for press brakes and the like
JPS541284U (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) * 1977-06-07 1979-01-06
JPS5414479U (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) * 1977-07-01 1979-01-30
US5187969A (en) * 1990-02-13 1993-02-23 Morita And Company Co. Ltd. Leaf spring cambering method and apparatus
US5295381A (en) * 1991-09-05 1994-03-22 Sumitomo Heavy Industries, Ltd. Twist-forming press for crank shaft or the like
CN108620473A (zh) * 2018-07-13 2018-10-09 宜兴市佳信数控科技有限公司 一种用于成型封头的大型深喉式液压机
CN112024694A (zh) * 2020-08-12 2020-12-04 姚小芳 一种液压机重复定位系统

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
PT68274A (en) * 1978-07-11 1978-08-01 A A Ribeiro De Almeida Device applicable to presses and metal bending presses to syncronize the movements of the hydraulic cylinders and control slider cross member
US4366699A (en) * 1980-05-26 1983-01-04 Amada Company, Limited Hydraulic presses
US4608852A (en) * 1983-08-24 1986-09-02 Amada Company, Limited Press machine

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2840135A (en) * 1955-03-04 1958-06-24 Fowler Alexander Control for press brake
US3165140A (en) * 1961-07-19 1965-01-12 Cincinnati Shaper Co Multiple stop device for press brakes and the like

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2840135A (en) * 1955-03-04 1958-06-24 Fowler Alexander Control for press brake
US3165140A (en) * 1961-07-19 1965-01-12 Cincinnati Shaper Co Multiple stop device for press brakes and the like

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3841140A (en) * 1972-12-18 1974-10-15 Dreis & Krump Mfg Co Control system for press brakes and the like
JPS541284U (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) * 1977-06-07 1979-01-06
JPS5414479U (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) * 1977-07-01 1979-01-30
US5187969A (en) * 1990-02-13 1993-02-23 Morita And Company Co. Ltd. Leaf spring cambering method and apparatus
US5295381A (en) * 1991-09-05 1994-03-22 Sumitomo Heavy Industries, Ltd. Twist-forming press for crank shaft or the like
CN108620473A (zh) * 2018-07-13 2018-10-09 宜兴市佳信数控科技有限公司 一种用于成型封头的大型深喉式液压机
CN112024694A (zh) * 2020-08-12 2020-12-04 姚小芳 一种液压机重复定位系统
CN112024694B (zh) * 2020-08-12 2022-09-02 聊城冠县尚敖超硬材料有限公司 一种液压机重复定位系统

Also Published As

Publication number Publication date
AT263485B (de) 1968-07-25
NL6608037A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1966-12-12
BE682379A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1966-11-14
CH435984A (de) 1967-05-15
FR1510834A (fr) 1968-01-26
SE309401B (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1969-03-24
GB1111013A (en) 1968-04-24
DE1577192A1 (de) 1970-02-12
ES328158A1 (es) 1967-04-01

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