US3613981A - Safety device for machine tools - Google Patents

Safety device for machine tools Download PDF

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Publication number
US3613981A
US3613981A US884122A US3613981DA US3613981A US 3613981 A US3613981 A US 3613981A US 884122 A US884122 A US 884122A US 3613981D A US3613981D A US 3613981DA US 3613981 A US3613981 A US 3613981A
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US
United States
Prior art keywords
tool
operating
tool holder
electrical switch
receiving member
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
US884122A
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English (en)
Inventor
Paul Ramseier
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.)
Braecker AG
Original Assignee
Braecker AG
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 Braecker AG filed Critical Braecker AG
Application granted granted Critical
Publication of US3613981A publication Critical patent/US3613981A/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
    • B30B15/285—Arrangements for preventing distortion of, or damage to, presses or parts thereof preventing a full press stroke if there is an obstruction in the working area
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D55/00—Safety devices protecting the machine or the operator, specially adapted for apparatus or machines dealt with in this subclass
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16P—SAFETY DEVICES IN GENERAL; SAFETY DEVICES FOR PRESSES
    • F16P3/00—Safety devices acting in conjunction with the control or operation of a machine; Control arrangements requiring the simultaneous use of two or more parts of the body
    • F16P3/02—Screens or other safety members moving in synchronism with members which move to and fro
    • F16P3/04—Screens or other safety members moving in synchronism with members which move to and fro for machines with parts which approach one another during operation, e.g. for stamping presses
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16P—SAFETY DEVICES IN GENERAL; SAFETY DEVICES FOR PRESSES
    • F16P7/00—Emergency devices preventing damage to a machine or apparatus
    • F16P7/02—Emergency devices preventing damage to a machine or apparatus by causing the machine to stop on the occurrence of dangerous conditions therein

Definitions

  • a primary switching or control means is provided for the purpose of interrupting the tool operating motion of the tool holder during a portion of its operating stroke if there is exerted on the tool member a pressure opposing the operating motion.
  • secondary switching or control means bridge the primary switching or control means or prevent such from moving into a breaking position as soon as the portion of the operating stroke of the tool has exceeded a predetermined value.
  • the present invention relates to a new and improved safety device for machine tools with a member that performs a tool operating motion in operation, and means for the interruption of the tool operating motion in the presence of anomalous conditions.
  • This invention is designed to provide an effective safety device which is comparatively simple in design and does not make operation of the machine tool difficult or cumbersome.
  • This invention is characterized by the presence of primary switching or control members which cause an interruption of the feeding member during a portion of the operating stroke thereof if a pressure counteracting the operating motion is exerted, while secondary switching or control members are provided which bridge the first switching or control members or prevent them from passing into disconnecting position as soon as the portion of the operating stroke of a tool holder has exceeded a predetermined value.
  • FIG. 1 is a section of a spindle with a riveting anvil or set in'nonoperative position
  • FIG. 2 is a section analogous to that shown in FIG. 2 with the anvil in operative position
  • MG. 3 shows a detail with :the anvil and a rivet
  • FIG. 4 is a sectional view illustrating a further modified embodiment of the invention.
  • a tool holder in the present case in the form of a spindle 2, so as to be axially displaceable.
  • a tool receiving bushing 3 which is also movable in the axial direction.
  • a spring d urges this tool receiving bushing 3 into an outer extreme position where it rests against a shoulder 5 of the spindle 2.
  • a tool viz a riveting anvil or set 6, is inserted and held in position inside by a permanent magnet 7.
  • This switch 9, 15 is connected, via an electrical circuit 23, with a further electrical switch 10.
  • the second switch 10 is arranged outside the spindle 2 and held on the machine housing by means of a screw 16. Loosening of this screw 16 enables the height of the switch 10 to be adjusted, possibly with the aid of a setscrew (not shown).
  • An actuating roller 12 rests against the surface of the spindle2 which is provided with an exterior annular shoulder 13. When this tool holder or spindle 2 moves in thedownward direction, theswitch 10. is closed by roller 12 contacting shoulder 13.
  • the annular shoulder.13 may also be replaced by other actuating means which cause a switching motion whenthe spindlet2tperformsan axial movement.
  • the two switches 9, 15 and '10 are-electrically connected in parallel and, via the-electrical circuit 23, to acontrol device 11 of the machine.
  • the actuating roller 12 is arranged in such a manner relative to the annular shoulder 13 that the spindle 2 starting from the inoperative position shown in FIG. 1, first performs a portion of its operating stroke before the switch It) is closed. 0n the other hand, the spindle 2 may move further in the operating direction or direction of tool advance after this switching operation without influencing the switch 10, in its closed position.
  • the switch 10 in .the machine housing can be adjusted in height or the annular shoulder 13 can be adjusted along the spindle axis.
  • This safety device is preferredly used in conjunction with a riveting machine as described in the Swiss Pat. specification No. 450,l18 where the riveting set or anvil and, respectively, its holder performs not only an axial motion but, in addition, a nonconcentric motion in order to deform the rivet head.
  • the tool receiving bushing 3 and, along with it, the tool can thus be moved relative to the spindle 2 either only in the axial direction or, additionally, concentrically .or nonconcentrically, or perform a wobbling motion with .or without simultaneous rotation about its own axis.
  • the mode of operation of this safety device is as follows: The deviceis designed to ensure that the operating motion of the spindle accommodating the tool is interrupted in the presence of anomalous operating conditions, i.e. if, by way of example, a finger is placed under the riveting anvil 6, a rivet is not properly inserted or the object to be riveted is not in the proper position.
  • the ball 9 being thrust upwards opens the first switch 15 which causes, in the control device 11, either immediate stoppage of the further spindle feed or an opposite movement of spindle 2 since the second switch 10 is still open,
  • the switching position defined by the height of the space 14 is so selected that the space 14 is as small as possible, at all events less than the thickness of a finger, so as to provide the best possible protection against injuries to the hand.
  • this safetydevice may also be employed in other machine tools, by way of example in production lines equipped with .rotating tools or machines with turntables.
  • the switch 9, 15 could also be arranged outside the spindle 2 on a member motionally connected therewith, transmission of the movement of the tool receiving bushing 3 being effected by mechanical links.
  • the embodiment of the switch 9, 15 shown in the drawing could also be replaced by a commercial microswitch.
  • the electrical switching means could also be replaced by switching or control means that operate mechanically, pneumatically or hydraulically and produce a similar effect.
  • FIG. 4 Such a modified form of the invention has been depicted in FIG. 4 wherein the same or analogous elements have been substantially designated by the same reference characters.
  • the spindle 2 carries the pivotably mounted bellcrank lever 30 which acts upon the switch mechanism 10 through the agency of a pivotably mounted arm member 32 pivotably supported at the machine frame at location 34.
  • the switch mechanism 10 possesses a normally closed switch contact 10a corresponding to the condition of the switch arrangement 9, 15 shown and discussed in connection with the embodiment illustrated in FIGS. 1 and 2.
  • the spindle 2 defining the tool holder likewise possesses a tool receiving bushing 3 for the riveting anvil or set 6.
  • a spring 41 corresponding to the spring 4 of the embodiment of FIGS 1 and 2, which serves to urge the tool receiving bushing 3 into an outer extreme position where it rests against a shoulder 5 of the spindle 2.
  • the bellcrank lever 30 is capable of transmitting displacements of the anvil 6 and the tool receiving bushing 3 relative to the tool holder or spindle 2 to the pivotably mounted arm member 32. Pivoting of the arm member 32 in counterclockwise direction under the action of the bellcrank lever 30 will open switch contact 10a of the switch mechanism 10 and thereby interrupt downward movement, that is the operating movement of the tool holder.
  • a safety device for machine tools comprising a tool holder for a tool and which performs a tool operating motion during operation of the machine tool, said tool holder moving towards a workpiece through a portion of its operating stroke, means for the interruption of said tool operating motion when anomalous operating conditions prevail at the machine tool, said interruption means comprising primary switching means for initiating interruption of the operating motion of said tool holder during said portion of its operating stroke if a pressure counteracting the tool operating motion of said tool holder is exerted against the tool, and secondary switching means operably coupled with said primary switching means for preventing interruption of said tool operating motion as soon as said portion of the operating stroke of said tool holder has exceeded a predetermined value.
  • a safety device for machine tools as defined in claim 4 further including a stationary machine part, said secondary electrical switch being secured to said stationary machine part, an actuating member for said secondary electrical switch, said actuating member cooperating with said movable tool holder.
  • said spindle includes a hollow portion, a tool receiving member defining a bushing located within said hollow portion of said spindle, said bushing being provided with bore means for interchangeably accommodating a riveting anvil defining said tool, said bushing being displaceable in said hollow portion of said spindle, and means for limiting the stroke of said bushing.
  • a safety device for machine tools comprising a tool holder for a tool and which performs a tool operating motion during operation of the machine tool, said tool holder moving towards a workpiece through a portion of its operating stroke, means for the interruption of said tool operating motion when anomalous operating conditions prevail at the machine tool, said interruption means comprising switching means for initiating interruption of the operating motion of said tool holder during said portion of its operating stroke if a pressure counteracting the tool operating motion of said tool holder is exerted against the tool, and means operatively associated with said switching means for selectively operating said switching means and for preventing interruption of said tool operating motion as soon as said portion of the operating stroke of said tool holder has exceeded a predetermined value, said last-mentioned means incorporating bellcrank lever means mounted at said tool holder which when said tool holder is located throughout a portion of its operating stroke is in operable association with said switching means whereas when said tool holder has moved completely through said portion of its operating stroke said bellcrank lever means is located in a position where it no longer can
US884122A 1968-12-13 1969-12-11 Safety device for machine tools Expired - Lifetime US3613981A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH1857768A CH500043A (de) 1968-12-13 1968-12-13 Sicherheitseinrichtung für Werkzeugmaschinen

Publications (1)

Publication Number Publication Date
US3613981A true US3613981A (en) 1971-10-19

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ID=4433922

Family Applications (1)

Application Number Title Priority Date Filing Date
US884122A Expired - Lifetime US3613981A (en) 1968-12-13 1969-12-11 Safety device for machine tools

Country Status (7)

Country Link
US (1) US3613981A (de)
JP (1) JPS50309B1 (de)
CH (1) CH500043A (de)
CS (1) CS151537B2 (de)
DE (1) DE1962293A1 (de)
FR (1) FR2026071A1 (de)
GB (1) GB1293559A (de)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3917507A1 (de) * 1989-05-30 1991-02-14 Fraunhofer Ges Forschung Einrichtung zum automatischen wechseln von werkzeugen zum herstellen von blindnietverbindungen
EP0465945A1 (de) * 1990-07-02 1992-01-15 Yoshikawa Iron Works Ltd., Maschine zum Formen von Nietköpfen
FR2724856A1 (fr) * 1994-09-26 1996-03-29 Otalu Sa Soc Dispositif de controle pour le sertissage des ecrous noyes
US6763568B1 (en) * 1999-06-14 2004-07-20 Technische Universitaet Dresden Method, device and rivet for effecting a mechanical joining
EP1724101A1 (de) 2005-05-18 2006-11-22 Werner Dinkel Schutzeinrichtung für Presswerkzeuge
EP1852228A3 (de) * 2006-04-24 2008-10-29 Ricca Andrea & C. S.n.c. Holzschneide- und Baumstammspaltmaschine
US20110100811A1 (en) * 2008-05-15 2011-05-05 Msa Auer Gmbh Electrochemical Sensor with Diffusion Labyrinth
US8207697B1 (en) * 2008-09-18 2012-06-26 Daniel Reed Positioning work stop
WO2016030430A1 (de) * 2014-08-29 2016-03-03 Ribe Anlagentechnik Gmbh Sicherheitseinrichtung zur erfassung eines objekts in einem arbeitsbereich eines bearbeitungswerkzeugs
US9857780B1 (en) 2013-03-15 2018-01-02 Daniel Reed Positioning work stop
US9956658B1 (en) 2015-03-20 2018-05-01 Daniel Reed Positioning work stop

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2299589A1 (fr) * 1975-01-31 1976-08-27 Prepac Sarl Dispositif de securite pour plateau de presse
DE2906922C2 (de) * 1979-02-22 1982-07-08 Bernhard Steinel Werkzeugmaschinenfabrik GmbH u. Co, 7730 Villingen-Schwenningen Sicherheitseinrichtung für Rollnietmaschinen
GB2158175B (en) * 1984-05-03 1988-04-20 Hartridge Ltd Leslie A press
DE3418108A1 (de) * 1984-05-16 1985-11-21 Rainer Dipl.-Ing. 7000 Stuttgart Brockmann Werkzeugmaschine mit sicherheitsvorrichtung

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US546416A (en) * 1895-09-17 Safety attachment for drivi nq-mach
US945670A (en) * 1909-05-17 1910-01-04 Oscar A Anderson Riveting-machine.
US2199286A (en) * 1939-06-20 1940-04-30 Minco Products Corp Safety control mechanism for a wire stitching machine
US2758303A (en) * 1955-05-04 1956-08-14 United Shoe Machinery Corp Anvil construction
US3489327A (en) * 1966-05-13 1970-01-13 Lucas Industries Ltd Riveting machines

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US546416A (en) * 1895-09-17 Safety attachment for drivi nq-mach
US945670A (en) * 1909-05-17 1910-01-04 Oscar A Anderson Riveting-machine.
US2199286A (en) * 1939-06-20 1940-04-30 Minco Products Corp Safety control mechanism for a wire stitching machine
US2758303A (en) * 1955-05-04 1956-08-14 United Shoe Machinery Corp Anvil construction
US3489327A (en) * 1966-05-13 1970-01-13 Lucas Industries Ltd Riveting machines

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3917507A1 (de) * 1989-05-30 1991-02-14 Fraunhofer Ges Forschung Einrichtung zum automatischen wechseln von werkzeugen zum herstellen von blindnietverbindungen
EP0465945A1 (de) * 1990-07-02 1992-01-15 Yoshikawa Iron Works Ltd., Maschine zum Formen von Nietköpfen
FR2724856A1 (fr) * 1994-09-26 1996-03-29 Otalu Sa Soc Dispositif de controle pour le sertissage des ecrous noyes
US6763568B1 (en) * 1999-06-14 2004-07-20 Technische Universitaet Dresden Method, device and rivet for effecting a mechanical joining
EP1724101A1 (de) 2005-05-18 2006-11-22 Werner Dinkel Schutzeinrichtung für Presswerkzeuge
EP1852228A3 (de) * 2006-04-24 2008-10-29 Ricca Andrea & C. S.n.c. Holzschneide- und Baumstammspaltmaschine
US20110100811A1 (en) * 2008-05-15 2011-05-05 Msa Auer Gmbh Electrochemical Sensor with Diffusion Labyrinth
US8632665B2 (en) 2008-05-15 2014-01-21 Msa Auer Gmbh Electrochemical sensor with diffusion labyrinth
US8207697B1 (en) * 2008-09-18 2012-06-26 Daniel Reed Positioning work stop
US9857780B1 (en) 2013-03-15 2018-01-02 Daniel Reed Positioning work stop
WO2016030430A1 (de) * 2014-08-29 2016-03-03 Ribe Anlagentechnik Gmbh Sicherheitseinrichtung zur erfassung eines objekts in einem arbeitsbereich eines bearbeitungswerkzeugs
US9956658B1 (en) 2015-03-20 2018-05-01 Daniel Reed Positioning work stop

Also Published As

Publication number Publication date
CH500043A (de) 1970-12-15
CS151537B2 (de) 1973-10-19
DE1962293A1 (de) 1970-07-09
JPS50309B1 (de) 1975-01-08
GB1293559A (en) 1972-10-18
FR2026071A1 (de) 1970-09-11

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