US2937733A - Overload relief assembly for power presses - Google Patents

Overload relief assembly for power presses Download PDF

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Publication number
US2937733A
US2937733A US619456A US61945656A US2937733A US 2937733 A US2937733 A US 2937733A US 619456 A US619456 A US 619456A US 61945656 A US61945656 A US 61945656A US 2937733 A US2937733 A US 2937733A
Authority
US
United States
Prior art keywords
press
valve
cylinder
piston
pressure
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US619456A
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English (en)
Inventor
James C Danly
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Danly Machine Specialties Inc
Original Assignee
Danly Machine Specialties Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Danly Machine Specialties Inc filed Critical Danly Machine Specialties Inc
Priority to US619456A priority Critical patent/US2937733A/en
Priority to DE19571752358 priority patent/DE1752358B1/de
Priority to GB20431/57A priority patent/GB871019A/en
Priority to DED25885A priority patent/DE1300029B/de
Priority to FR1178667D priority patent/FR1178667A/fr
Application granted granted Critical
Publication of US2937733A publication Critical patent/US2937733A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
    • B30B15/28—Arrangements for preventing distortion of, or damage to, presses or parts thereof
    • B30B15/281—Arrangements for preventing distortion of, or damage to, presses or parts thereof overload limiting devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
    • B30B15/28—Arrangements for preventing distortion of, or damage to, presses or parts thereof
    • B30B15/281—Arrangements for preventing distortion of, or damage to, presses or parts thereof overload limiting devices
    • B30B15/284—Arrangements for preventing distortion of, or damage to, presses or parts thereof overload limiting devices releasing fluid from a fluid chamber subjected to overload pressure
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/2496—Self-proportioning or correlating systems
    • Y10T137/2559—Self-controlled branched flow systems
    • Y10T137/2574—Bypass or relief controlled by main line fluid condition
    • Y10T137/2605—Pressure responsive

Definitions

  • pfiA/LY OVERLOAD RELIEF ASSEMBLY FOR POWER PRESSES My invention relates to an overload relief assembly for power presses having-one or more connections to the press working slide and more particularly to an overload relief assembly which relieves an overload occurring on one or more of the corners of the working slide either by relieving the load on the slide connections or by relieving the load on the press tie rods.
  • fluid under pressure is fed to press tie rod cylinders carried by the press frame. This fluid acts on pistons carried by the tie rods to place the rods under the proper predetermined tension; When an overload occurs on a particular rod, the piston is displaced to relieve the tension on this rod and to stop the ress.
  • an overload relief assembly which may be applied either to the press inner slide driving connections orto the press blank holder driving connections. In either case this sys tem operates to relieve an overload imposed on the slide to which the system has been applied.
  • overloading of any one of the driving connections of a slide results in relieving the load on the remaining slide connections in the event an unsymmetrical loading occurs.
  • Still another object of my invention is to provide an improved overload relief assembly for power presses which stops the press operation in response to an unsymmetrical overload.
  • the second embodiment of my invention contemplates the provision of an overload relief assembly for a multiple point suspension power press including a respective hydraulic cylinder and piston coupling each of the slide.
  • Figure 1 is a perspective view of a power press provided with my overload relief assembly with parts of the press broken away.
  • Figure 2 is a schematic view of the first form of my overload relief assembly for power presses.
  • Figure 3 is a sectional view of one of the tie rod. cylinder supply valve assemblies of my overload relief assembly for power presses.
  • Figure 4 is a fragmentary sectional view of the second embodiment of my overload relief assembly for power presses.
  • T-fitting 88 connects the supply pipes 68 leading to the respective valve assemblies 36 and 38 to a pipe 90.
  • a fitting 92 connects pipe and the pipes 68 leading to the respective valve assemblies 32 and 34 to the main supply pipe 94.
  • My hydraulic system includes a pump 96, the shaft 98 of which is driven by a motor 100.
  • a pipe 102 connects the inlet of pump 96 to a source (not shown) of fluid such as oil.
  • a check valve 104 connects the outlet side of pump 96 to a relief valve 106 connected to the main supply pipe 94.
  • Check valve 104 permits fluid to be pumped into the system but prevents oil from returning to the pump.
  • Relief valve 106 permits fluid to flow out of the system through a pipe 108 if the fluid pressure exceeds a predetermined value.
  • a valve 110 connected to line 94 may be actuated to permit fluid to enter a pressure meter 112.
  • a plug 176 screwed into a bore in the wall of body 40 slidably supports a switch actuating pin 180.
  • a spring 182 bears between plug 176 and a head 184 formed on pin 180.
  • piston 48 moves to the right as viewed in Figure 3, its head 52 cams pin 180 outwardly of bore 42 against the action of spring 182.
  • the resulting movement of pin 180 is employed to actuate a suitable control (not shown) of a type known to the art to stop the press by unclutching the press drive from the flywheel. It is to be understood that I provide a switch actuating pin 180 for each of the valve assemblies 32, 34, 36, and 38.
  • Slide 184 carries a pair of cylinders 210 and 212 which house respective pistons 214 and 216. Respective passages 218 and 220 are adapted to admit fluid under pressure to the interior of cylinders 210 and 212 to force pistons 214 and 216 upwardly as viewed in Figure 4 against stop rings 222' and 224 carried by the cylinders.
  • Bolts 226 secure respective housings 228 and 230 disposed over nuts 206 and 208 to the pistons 214 and 216.
  • the motor drives pump 96 to supply oil to the system.
  • Motor 132 is driven to supply air to'cylinder 114 under piston to exert a predetermined pressure on the oil in the system.
  • the oil transmits this pressure to the respective pistons 24 carried by the press tie rods.
  • the tie rods are thus placed under a predetermined tension.
  • any one of the rods is overloaded, its piston 24 displaces fluid out of the cylinder 30 and into the bore 42 of the associated valve assembly 32, 34, 36, or 38. As a result of this action, the piston 48 moves to.
  • piston 48 so that the valve formed by the engagement of the piston wall with the part of the bore between enlargements 60 and 74 opens slightly before head 52 is unseated to. permit the system pressure to be relieved slightly be fore the pressure on the overloaded rod is relieved.
  • valve assemblies 32, 34, 36, or 38 When any one of the valve assemblies 32, 34, 36, or 38 is actuated', pressure throughout the system is relieved. Owing to the normal tension on the remaining tie rods of the system, these rods force fluid out of their associated cylin ders 30 against the relieved pressure in the supply system to actuate their respective valve assemblies.
  • piston head 52 moves a slight distance to the right as viewed in Figure 3 to permit fluid. from the cylinder 210 to flow out through relief pipe 64' press tie. rods. in response to an overload imposedon any one of the rods.
  • My system preventsdamage to the press. parts owing to an unsymmetrical overload applied to the press as. when. a sheet or material of irregular thickness is. fed. to the press.
  • My system operates in response to an overload onany one of. the presstie rods. It may be applied to, press: slides suspensions as well as; to the. tie rods;
  • a power press having a pair of elements subjected to stress and amcmber to which said elements are connected, respective piston and cylinder units for connecting said elements to said member, said units being adaptedv to transmit stress between the respective elements and said member when fluid under pressure is present in the cylinders, a common fluid systemfor supplying fiuid to said units, and respective valve assemblies providing communication between said cylinders and said system, each of said assemblies comprising a valve responsive to a predetermined pressure difierence between the associated cylinder pressure and the common. system pressure resulting. froman increase in cylinder pressure for relieving the common, system pressure.
  • a. power press having. a pair of elements subjectedto stress and a member to which said elements are connected, respective piston and. cylinder units for connecting said elements to said member, said units being adapted to transmit. stress between the respective elements and said member when fluid under pressure is present in the cylinders, 21 common fiuid system for supplying fluid to said units, and. respective valve. assemblies providing communication between said cylinders and said system,
  • each of said valve assemblies comprising a first normally closed valve adapted to relieve the pressure in its corresponding cylinder and a. second normally closed valve.
  • each of. said first and second valves being responsiveto a predetermined increase in pressure in the corresponding cylinder to relieve the system and cylinder pressure.
  • each of said assemblies. includes a check valve for connecting said system to the corresponding cylinder.
  • first and second valves comprise a valve cylinder formed with a pair of respective valveseats, a piston disposed within said valve cylinder having a pair. of valve heads for cooperation with the respective seats, a relief opening formed in said valve cylinder between said seats, means normally urging said piston to seat said heads, said piston urging means being responsive to a. predetermined pressure to permit said piston to move to unseatsaid heads.
  • first and second valves comprise avalve cylinder for-med with a pair of respective spaced valve seats, ahollow piston disposed within said valve cylinder and having a pair of valve heads for cooperation. with the. respective seats, means.
  • saidvalve cylinder means providing communica tionbetween. theother end; of: the valve cylinder and the. corresponding; unit cylinder, means. forming a relief opening in said valveicyli'nd'er between said valve seats, and means for urging said piston to seat said. heads on said seats to.prevent communication-between said system and said relief opening and. between said corresponding unit cylinder and said relief opening, said: piston urging means being responsiveto a predetermined increase in pressure in. said corresponding-unit cylinder to permit said piston to be displaced torelieve-the pressure in said unit cylinder and in said system.
  • said common fluid system comprises an accumulator having a first cylinder and a second cylinder, said first cylinder having a small diameter relative to the diameter of the second cylinder, respective'first and second pistons disposed in said cylinders, means connectingsaid first and second cylinders for movement as a unit, means for supplying air under pressure to said second cylinder and means responsive to. movement of said pistons for regulating said air supplying means.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Presses (AREA)
  • Press Drives And Press Lines (AREA)
US619456A 1956-10-31 1956-10-31 Overload relief assembly for power presses Expired - Lifetime US2937733A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US619456A US2937733A (en) 1956-10-31 1956-10-31 Overload relief assembly for power presses
DE19571752358 DE1752358B1 (de) 1956-10-31 1957-06-28 UEberlastsicherung an Pressen
GB20431/57A GB871019A (en) 1956-10-31 1957-06-28 Overload relief device for power presses
DED25885A DE1300029B (de) 1956-10-31 1957-06-28 Hydraulische UEberlastsicherung an Pressen
FR1178667D FR1178667A (fr) 1956-10-31 1957-07-05 Dispositif de protection contre les surcharges pour presses mécaniques

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US619456A US2937733A (en) 1956-10-31 1956-10-31 Overload relief assembly for power presses

Publications (1)

Publication Number Publication Date
US2937733A true US2937733A (en) 1960-05-24

Family

ID=24482011

Family Applications (1)

Application Number Title Priority Date Filing Date
US619456A Expired - Lifetime US2937733A (en) 1956-10-31 1956-10-31 Overload relief assembly for power presses

Country Status (4)

Country Link
US (1) US2937733A (de)
DE (2) DE1752358B1 (de)
FR (1) FR1178667A (de)
GB (1) GB871019A (de)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3160089A (en) * 1964-04-09 1964-12-08 Niagara Machine & Tool Works Overload relief system for power presses
US3190141A (en) * 1961-06-13 1965-06-22 Massey Schlatter A G Hydraulic overload safety device
US3208219A (en) * 1964-03-25 1965-09-28 Floyd M Williamson Hydraulic system for dies
US3407913A (en) * 1965-08-26 1968-10-29 Aida Iron Works & Co Ltd Safety device in press machine and control device therefor
US3426873A (en) * 1965-08-26 1969-02-11 Aida Iron Works & Co Ltd Hydraulic overload release and control for a press machine
US4015620A (en) * 1974-10-11 1977-04-05 Gulf & Western Manufacturing Company High response unloading valve
US4030336A (en) * 1976-07-09 1977-06-21 Anatoly Sergeevich Grigorenko Hydraulic protection device for presses
US5078003A (en) * 1989-05-09 1992-01-07 Aida Engineering, Ltd. Overload protector for press machine
US5638748A (en) * 1996-01-25 1997-06-17 The Minster Machine Company Hydraulic overload proportional valving system for a mechanical press

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2471275A1 (fr) * 1979-12-14 1981-06-19 Ew Bliss Co Paris Procede et dispositif de protection d'une presse a bati assemble
CN114749949B (zh) * 2022-05-18 2023-03-28 无锡贝斯特精机股份有限公司 一种保持夹紧力的液压夹具锁紧机构

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB189261A (en) * 1921-09-06 1922-11-30 Massey Ltd B & S Improvements in power presses
US1844250A (en) * 1930-02-01 1932-02-09 Mccord Radiator & Mfg Company Draw press
US1971937A (en) * 1929-01-16 1934-08-28 Firm L Schuler Ag Power press
US2270549A (en) * 1940-01-20 1942-01-20 Gen Tire & Rubber Co Control valve for fluid operated devices
US2270943A (en) * 1939-03-07 1942-01-27 Messerschmitt Boelkow Blohm Hydraulic system
US2286798A (en) * 1940-05-16 1942-06-16 Hydraulic Dev Corp Inc Hydraulic circuit for press brakes
US2367682A (en) * 1943-04-09 1945-01-23 Adel Prec Products Corp Landing gear by-pass valve
US2491279A (en) * 1947-06-25 1949-12-13 Dayton Rogers Mfg Co Safety overload pitman for power presses
US2616543A (en) * 1949-03-19 1952-11-04 Danly Mach Specialties Inc Safety assembly for power presses
US2732851A (en) * 1956-01-31 ashley etal
US2770342A (en) * 1954-02-01 1956-11-13 Us Industries Inc Overload release assembly for power presses
US2790305A (en) * 1953-01-20 1957-04-30 Electraulic Presses Ltd Control valves for hydraulic presses

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE581753C (de) * 1930-09-13 1933-08-02 Schuler L Ag Pressengestell fuer Pressen mit zusammengesetztem Koerper und Fuehrungswerkzeugen
DE614154C (de) * 1933-06-13 1935-06-03 Schuler L Ag Kurbelpresse mit in mehreren Punkten gemeinsam angetriebenem, hydraulisch abgestuetztem Stoessel
DE657540C (de) * 1935-11-20 1938-03-07 Weingarten Vorm Hch Schatz A G Kurbelpresse mit einem gegen mehrere Antriebspunkte durch Fluessigkeitspolster abgestuetzten Stoessel
DE872733C (de) * 1951-11-16 1953-04-02 Karl Keck Presse mit in mehreren Punkten angetriebenem Stoessel

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2732851A (en) * 1956-01-31 ashley etal
GB189261A (en) * 1921-09-06 1922-11-30 Massey Ltd B & S Improvements in power presses
US1971937A (en) * 1929-01-16 1934-08-28 Firm L Schuler Ag Power press
US1844250A (en) * 1930-02-01 1932-02-09 Mccord Radiator & Mfg Company Draw press
US2270943A (en) * 1939-03-07 1942-01-27 Messerschmitt Boelkow Blohm Hydraulic system
US2270549A (en) * 1940-01-20 1942-01-20 Gen Tire & Rubber Co Control valve for fluid operated devices
US2286798A (en) * 1940-05-16 1942-06-16 Hydraulic Dev Corp Inc Hydraulic circuit for press brakes
US2367682A (en) * 1943-04-09 1945-01-23 Adel Prec Products Corp Landing gear by-pass valve
US2491279A (en) * 1947-06-25 1949-12-13 Dayton Rogers Mfg Co Safety overload pitman for power presses
US2616543A (en) * 1949-03-19 1952-11-04 Danly Mach Specialties Inc Safety assembly for power presses
US2790305A (en) * 1953-01-20 1957-04-30 Electraulic Presses Ltd Control valves for hydraulic presses
US2770342A (en) * 1954-02-01 1956-11-13 Us Industries Inc Overload release assembly for power presses

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3190141A (en) * 1961-06-13 1965-06-22 Massey Schlatter A G Hydraulic overload safety device
US3208219A (en) * 1964-03-25 1965-09-28 Floyd M Williamson Hydraulic system for dies
US3160089A (en) * 1964-04-09 1964-12-08 Niagara Machine & Tool Works Overload relief system for power presses
US3407913A (en) * 1965-08-26 1968-10-29 Aida Iron Works & Co Ltd Safety device in press machine and control device therefor
US3426873A (en) * 1965-08-26 1969-02-11 Aida Iron Works & Co Ltd Hydraulic overload release and control for a press machine
US4015620A (en) * 1974-10-11 1977-04-05 Gulf & Western Manufacturing Company High response unloading valve
US4030336A (en) * 1976-07-09 1977-06-21 Anatoly Sergeevich Grigorenko Hydraulic protection device for presses
US5078003A (en) * 1989-05-09 1992-01-07 Aida Engineering, Ltd. Overload protector for press machine
US5638748A (en) * 1996-01-25 1997-06-17 The Minster Machine Company Hydraulic overload proportional valving system for a mechanical press

Also Published As

Publication number Publication date
FR1178667A (fr) 1959-05-13
GB871019A (en) 1961-06-21
DE1300029B (de) 1969-07-24
DE1752358B1 (de) 1970-08-27

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