CH348260A - Method for bending plastic sheets with thermoplastic properties and device for carrying out this method - Google Patents

Method for bending plastic sheets with thermoplastic properties and device for carrying out this method

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Publication number
CH348260A
CH348260A CH348260DA CH348260A CH 348260 A CH348260 A CH 348260A CH 348260D A CH348260D A CH 348260DA CH 348260 A CH348260 A CH 348260A
Authority
CH
Switzerland
Prior art keywords
plate
bending
groove
shaped
frame
Prior art date
Application number
Other languages
German (de)
Original Assignee
Esta Ag Fuer Lichttechnik Und
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 Esta Ag Fuer Lichttechnik Und filed Critical Esta Ag Fuer Lichttechnik Und
Publication of CH348260A publication Critical patent/CH348260A/en

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C53/00Shaping by bending, folding, twisting, straightening or flattening; Apparatus therefor
    • B29C53/02Bending or folding
    • B29C53/04Bending or folding of plates or sheets
    • B29C53/06Forming folding lines by pressing or scoring
    • B29C53/063Forming folding lines by pressing or scoring combined with folding
    • B29C53/066Forming folding lines by pressing or scoring combined with folding and joining the sides of the folding line, e.g. "Abkantschweissen"
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B31MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31BMAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B50/00Making rigid or semi-rigid containers, e.g. boxes or cartons
    • B31B50/26Folding sheets, blanks or webs
    • B31B50/44Folding sheets, blanks or webs by plungers moving through folding dies
    • B31B50/46Folding sheets, blanks or webs by plungers moving through folding dies and interconnecting side walls
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B26HAND CUTTING TOOLS; CUTTING; SEVERING
    • B26DCUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
    • B26D1/00Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29BPREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B13/00Conditioning or physical treatment of the material to be shaped
    • B29B13/02Conditioning or physical treatment of the material to be shaped by heating
    • B29B13/023Half-products, e.g. films, plates
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/02Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
    • B29C65/14Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation
    • B29C65/1429Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation characterised by the way of heating the interface
    • B29C65/1432Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation characterised by the way of heating the interface direct heating of the surfaces to be joined
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/02Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
    • B29C65/14Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation
    • B29C65/1429Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation characterised by the way of heating the interface
    • B29C65/1464Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation characterised by the way of heating the interface making use of several radiators
    • B29C65/1467Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation characterised by the way of heating the interface making use of several radiators at the same time, i.e. simultaneous welding
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00General aspects of processes or apparatus for joining preformed parts
    • B29C66/01General aspects dealing with the joint area or with the area to be joined
    • B29C66/05Particular design of joint configurations
    • B29C66/10Particular design of joint configurations particular design of the joint cross-sections
    • B29C66/11Joint cross-sections comprising a single joint-segment, i.e. one of the parts to be joined comprising a single joint-segment in the joint cross-section
    • B29C66/112Single lapped joints
    • B29C66/1122Single lap to lap joints, i.e. overlap joints
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00General aspects of processes or apparatus for joining preformed parts
    • B29C66/40General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/41Joining substantially flat articles ; Making flat seams in tubular or hollow articles
    • B29C66/43Joining a relatively small portion of the surface of said articles
    • B29C66/431Joining the articles to themselves
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00General aspects of processes or apparatus for joining preformed parts
    • B29C66/40General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/41Joining substantially flat articles ; Making flat seams in tubular or hollow articles
    • B29C66/43Joining a relatively small portion of the surface of said articles
    • B29C66/432Joining a relatively small portion of the surface of said articles for making tubular articles or closed loops, e.g. by joining several sheets ; for making hollow articles or hollow preforms
    • B29C66/4326Joining a relatively small portion of the surface of said articles for making tubular articles or closed loops, e.g. by joining several sheets ; for making hollow articles or hollow preforms for making hollow articles or hollow-preforms, e.g. half-shells
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00General aspects of processes or apparatus for joining preformed parts
    • B29C66/70General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material
    • B29C66/73General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the intensive physical properties of the material of the parts to be joined, by the optical properties of the material of the parts to be joined, by the extensive physical properties of the parts to be joined, by the state of the material of the parts to be joined or by the material of the parts to be joined being a thermoplastic or a thermoset
    • B29C66/739General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the intensive physical properties of the material of the parts to be joined, by the optical properties of the material of the parts to be joined, by the extensive physical properties of the parts to be joined, by the state of the material of the parts to be joined or by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of the parts to be joined being a thermoplastic or a thermoset
    • B29C66/7392General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the intensive physical properties of the material of the parts to be joined, by the optical properties of the material of the parts to be joined, by the extensive physical properties of the parts to be joined, by the state of the material of the parts to be joined or by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of at least one of the parts being a thermoplastic
    • B29C66/73921General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the intensive physical properties of the material of the parts to be joined, by the optical properties of the material of the parts to be joined, by the extensive physical properties of the parts to be joined, by the state of the material of the parts to be joined or by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of at least one of the parts being a thermoplastic characterised by the materials of both parts being thermoplastics
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C35/00Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
    • B29C35/02Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould
    • B29C2035/0211Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould resistance heating
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00General aspects of processes or apparatus for joining preformed parts
    • B29C66/01General aspects dealing with the joint area or with the area to be joined
    • B29C66/02Preparation of the material, in the area to be joined, prior to joining or welding
    • B29C66/022Mechanical pre-treatments, e.g. reshaping
    • B29C66/0224Mechanical pre-treatments, e.g. reshaping with removal of material
    • B29C66/02245Abrading, e.g. grinding, sanding, sandblasting or scraping
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B31MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31BMAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B50/00Making rigid or semi-rigid containers, e.g. boxes or cartons
    • B31B50/60Uniting opposed surfaces or edges; Taping

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Electromagnetism (AREA)
  • Toxicology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Forests & Forestry (AREA)
  • Thermal Sciences (AREA)
  • Shaping Of Tube Ends By Bending Or Straightening (AREA)

Description

       

  
 



  Verfahren zum Abbiegen von Kunststoffplatten mit thermoplastischen Eigenschaften und Einrichtung zur Ausübung dieses Verfahrens
Das vorliegende Patent betrifft ein zum Abbiegen von Kunststoffplatten mit thermoplastischen Eigenschaften bestimmtes Verfahren, das sich dadurch kennzeichnet, dass man längs der Abbiegestelle der Platte auf einer Seite derselben eine V-förmige Nut erzeugt, die Platte an der so genuteten Abbiegestelle zwecks Materialerweichung mittels eines sich über die ganze Länge der Nut erstreckenden, stromführenden, draht- oder stabförmigen Elementes elektrisch heizt und sie unmittelbar darauf im Sinne der Schliessung der V-Nut abbiegt.



   Das Patent betrifft auch eine zur Ausübung dieses Verfahrens dienende Einrichtung, die sich dadurch kennzeichnet, dass sie einen aus Isoliermaterial bestehenden Aufsetzrahmen aufweist, dessen Öffnung den   Hauptabmessungen    der abzubiegenden Platte entspricht und in welchem in einer der V-Nut in der Platte entsprechenden Anordnung das draht- bzw. stabförmige Heizelement vorgesehen ist, das in den beiden entsprechenden, einander gegenüberliegenden Rahmenwänden gehalten und ausserhalb dieser letzteren mit Stromanschlussmitteln versehen ist.



   Der Hauptvorteil des Verfahrens liegt darin, dass sich die Kunststoffplatte auf diese Weise mit einer möglichst kleinen Abrundung auf der äussern Plattenseite abbiegen lässt, was speziell bei aus solchen Kunststoffplatten hergestellten, trogförmigen Abschirmkörpern für elektrische Leuchten einerseits aus ästhetischen und anderseits aus lichttechnischen Gründen von besonderem Vorteil ist.



   Im folgenden ist die Herstellungsweise eines solchen Abschirmkörpers anhand der Zeichnung beispielsweise näher erläutert.



   Fig. 1 zeigt, in perspektivischer Ansicht, eine zugeschnittene und genutete Kunststoffplatte aus thermoplastischem Material, wie z. B. Acrylharz.



   Fig. 2 ist ein Schnitt nach der Linie   II-II    in Fig. 1.



   Fig. 3 zeigt, auch wieder in perspektivischer Ansicht, einen zu einer Einrichtung zum Abbiegen der Platte gemäss Fig. 1 gehörenden Aufsetzrahmen mit zwischen den Wänden desselben eingespannten Heizdrähten.



   Fig. 4 ist ein senkrechter Schnitt durch eine mit einem rechteckigen Umfassungsrahmen versehene Umbiegeform, und
Fig. 5 ist ein senkrechter Schnitt durch einen trogförmigen Abschirmkörper für eine elektrische Leuchte.



   In Fig. 1 ist ein kreuzförmiges Plattengebilde a gezeigt, das aus einer rechteckigen, z. B. aus Acrylharz bestehenden Platte auf diese Form zugeschnitten wurde. Durch Abbiegen der vorstehenden Plattenteile soll nun der genannte trogförmige Abschirmkörper angefertigt werden. Zu diesem Zwecke werden in das   Plättengebilde    an den in Fig. 1 mittels gestrichelten Linien angedeuteten Abbiegestellen der vorstehenden Plattenteile V-förmige Nuten   at    eingefräst, deren Querschnitt in Fig. 2 ersichtlich ist. Entsprechend dem Abbiegewinkel der Plattenteile, der   90o    betragen soll, weisen auch die Nuten   at    einen Einfräswinkel von   90o    auf.



   Nun handelt es sich darum, das Plattengebilde an den genuteten Abbiegestellen zu erhitzen, und zwar so, dass längs dieser Abbiegestellen eine möglichst rasche und gleichmässige Materialerweichung erfolgt.



  Zu diesem Zwecke werden gemäss Fig. 3 Heizdrähte b verwendet, die kreuzweise und federnd zwischen den Wänden eines aus Holz oder einem andern Isoliermaterial bestehenden Aufsetzrahmens c verspannt sind. Die Innenmasse dieses Rahmens c entsprechen  den Hauptabmessungen, das heisst der Gesamtlänge und der Gesamtbreite, des Plattengebildes a, über das der Rahmen c somit passend aufgesetzt werden kann.



  Die kreuzweise Anordnung der Heizdrähte b ist anderseits so gewählt, dass diese letzteren im aufgesetzten Zustand des Rahmens c die Nuten   at    auf ihrer ganzen Länge überdecken. Die Drähte b sind untereinander elektrisch verbunden und ausserhalb des Rahmens c mittels Leitern an eine geeignete Stromquelle angeschlossen, wie in Fig. 3 schematisch angedeutet ist. Zum Erhitzen der durch die Nuten   at    vorgezeichneten Abbiegestellen des Plattengebildes a wird der Rahmen c ordnungsgemäss über dasselbe gesetzt und der Strom eingeschaltet. Die Abbiegestellen werden von den unter Spannung stehenden Heizdrähten b über die ganze Länge aller Nuten bis zum Erweichungspunkt erhitzt.

   Der Rahmen wird alsdann vom Plattengebilde entfernt und das letztere schliesslich unter möglichst wenig Zeitverlust auf einen Umfassungsrahmen   dl    einer in zweckentsprechender Weise angefertigten, in Fig. 4 gezeigten Form d aufgelegt, deren Innenmasse den Aussenabmessungen des Abschirmkörpers entsprechen. Das Plattengebilde wird daraufhin mit einem rechteckigen Mittelteil in die Form eingepresst, wodurch die seitlich vorstehenden Seitenteile des Plattengebildes a im Sinne der Schliessung der V-Nuten nach oben umgelegt werden, wie in Fig. 5 gezeigt ist. Nachdem die umgelegten Seitenteile des Plattengebildes schliesslich noch in den von ihnen gebildeten Eckteilen miteinander verleimt worden sind, wird das fertige Produkt in Gestalt eines Abschirmkörpers aus der Form d herausgenommen.

   Da die unbearbeitete, glatte Plattenseite beim Abbiegen nach aussen zu stehen kommt, erübrigt sich ein Nachbearbeiten bzw. Nachpolieren der Biegekanten. Ein weiterer Vorteil des oben beschriebenen Verfahrens liegt darin, dass durch die V-Nuten ein absolut genaues Abbiegen gewährleistet ist, da die Platte jeweils von selbst an der dünnsten Stelle, das heisst im Scheitelteil der Nut gebogen wird und so auch absolut gerade Biegekanten mit einem minimalen Krümmungsradius entstehen.



   Zur Erhitzung der genuteten Abbiegestellen der Platte könnten im Rahmen c anstatt normalstromgespiesener Heizdrähte b auch mit Hochfrequenz gespiesene Elektroden, z. B. in Form von Stäben, vorgesehen sein.   



  
 



  Method for bending plastic sheets with thermoplastic properties and device for carrying out this method
The present patent relates to a process intended for bending plastic plates with thermoplastic properties, which is characterized in that a V-shaped groove is created along the bending point of the plate on one side thereof, the plate at the so-grooved bending point for the purpose of material softening by means of a The current-carrying, wire or rod-shaped element that extends over the entire length of the groove is electrically heated and immediately afterwards it bends in the sense of closing the V-groove.



   The patent also relates to a device for carrying out this method, which is characterized in that it has a mounting frame made of insulating material, the opening of which corresponds to the main dimensions of the plate to be bent and in which the wire is arranged in an arrangement corresponding to the V-groove in the plate - or rod-shaped heating element is provided, which is held in the two corresponding, opposing frame walls and is provided with power connection means outside the latter.



   The main advantage of the process is that the plastic plate can be bent in this way with the smallest possible rounding on the outer side of the plate, which is particularly advantageous in trough-shaped shielding bodies for electrical lights made from such plastic plates, on the one hand for aesthetic reasons and on the other for lighting reasons is.



   In the following, the production method of such a shielding body is explained in more detail with reference to the drawing.



   Fig. 1 shows, in perspective view, a cut and grooved plastic plate made of thermoplastic material, such as. B. acrylic resin.



   FIG. 2 is a section along the line II-II in FIG. 1.



   FIG. 3 shows, again in a perspective view, a mounting frame belonging to a device for bending the plate according to FIG. 1 with heating wires clamped between the walls of the same.



   4 is a vertical section through a bending mold provided with a rectangular surrounding frame, and FIG
Fig. 5 is a vertical section through a trough-shaped shielding body for an electric lamp.



   In Fig. 1, a cross-shaped plate structure a is shown, which consists of a rectangular, z. B. made of acrylic resin plate was cut to this shape. The aforementioned trough-shaped shielding body is now to be produced by bending the protruding plate parts. For this purpose, V-shaped grooves are milled into the plate structure at the bending points of the protruding plate parts indicated by dashed lines in FIG. 1, the cross section of which can be seen in FIG. Corresponding to the bending angle of the plate parts, which should be 90o, the grooves at also have a milling angle of 90o.



   The task now is to heat the plate structure at the grooved turning points, in fact in such a way that the material softens as quickly and evenly as possible along these turning points.



  For this purpose, heating wires b are used according to FIG. 3, which are clamped crosswise and resiliently between the walls of a mounting frame c made of wood or some other insulating material. The internal dimensions of this frame c correspond to the main dimensions, that is to say the total length and the total width, of the plate structure a, over which the frame c can thus be placed appropriately.



  The crosswise arrangement of the heating wires b is, on the other hand, selected so that the latter cover the grooves at over their entire length when the frame c is in place. The wires b are electrically connected to one another and connected to a suitable power source outside the frame c by means of conductors, as is indicated schematically in FIG. 3. To heat the bending points of the plate structure a marked out by the grooves at, the frame c is properly placed over the same and the current is switched on. The bending points are heated by the heating wires b under tension over the entire length of all grooves up to the softening point.

   The frame is then removed from the plate structure and the latter is finally placed with as little loss of time as possible on a surrounding frame dl of an appropriately made shape d shown in FIG. 4, the internal dimensions of which correspond to the external dimensions of the shielding body. The plate structure is then pressed into the mold with a rectangular middle part, as a result of which the laterally protruding side parts of the plate structure a are folded upwards in the sense of closing the V-grooves, as shown in FIG. After the folded side parts of the plate structure have finally been glued together in the corner parts formed by them, the finished product in the form of a shielding body is removed from the mold d.

   Since the unprocessed, smooth side of the plate comes outward when it is turned, there is no need to rework or polish the bending edges. Another advantage of the method described above is that the V-grooves ensure absolutely precise bending, since the plate is bent by itself at the thinnest point, that is, in the apex of the groove and so also absolutely straight bending edges with a minimum radius of curvature.



   To heat the grooved bending points of the plate, electrodes fed with high frequency, e.g. B. in the form of rods may be provided.


    

Claims (1)

PATENTANSPRÜCHE I. Verfahren zum Abbiegen von Kunststoffplatten mit thermoplastischen Eigenschaften, dadurch gekennzeichnet, dass man längs der Abbiegestelle der Platte auf einer Seite derselben eine V-förmige Nut erzeugt, die Platte an der so genuteten Abbiegestelle zwecks Materialerweichung mittels eines sich über die ganze Länge der Nut erstreckenden, stromführenden, drahtoder stabförmigen Elementes elektrisch heizt und sie unmittelbar darauf im Sinne der Schliessung der V-Nut abbiegt. PATENT CLAIMS I. A method for bending plastic plates with thermoplastic properties, characterized in that a V-shaped groove is created along the bending point of the plate on one side thereof, the plate at the so-grooved bending point for the purpose of material softening by means of a spread over the entire length of the groove extending, current-carrying, wire or rod-shaped element electrically heats and immediately afterwards it bends in the sense of closing the V-groove. II. Einrichtung zur Ausübung des Verfahrens nach Patentanspruch I, dadurch gekennzeichnet, dass sie einen aus Isoliermaterial bestehenden Aufsetzrahmen aufweist, dessen Öffnung den Hauptabmessungen der abzubiegenden Platte entspricht, und in welchem in einer der V-Nut in der Platte entsprechenden Anordnung das draht- bzw. stabförmige Heizelement vorgesehen ist, das in den beiden entsprechenden, einander gegenüberliegenden Rahmenwänden gehalten und ausserhalb dieser letzteren mit Stromanschlussmitteln versehen ist. II. Device for performing the method according to claim I, characterized in that it has a mounting frame made of insulating material, the opening of which corresponds to the main dimensions of the plate to be bent, and in which in an arrangement corresponding to the V-groove in the plate the wire or . Rod-shaped heating element is provided, which is held in the two corresponding, opposing frame walls and is provided with power connection means outside the latter. UNTERANSPRiiCHE 1. Verfahren nach Patentanspruch I, dadurch gekennzeichnet, dass man an der Abbiegestelle der Platte eine V-förmige Nut einfräst, deren Querschnitt einen Winkel aufweist, der im wesentlichen gleich gross ist wie der Abbiegewinkel. SUBCLAIMS 1. The method according to claim I, characterized in that a V-shaped groove is milled in at the turning point of the plate, the cross section of which has an angle which is essentially the same as the turning angle. 2. Einrichtung nach Patentanspruch II, zum gleichzeitigen Umbiegen von vier Abschnitten einer Kunststoffplatte zwecks Herstellung eines Troges, gekennzeichnet durch einen Umbiegerahmen mit Pressstempel, um nach dem Erhitzen der Abbiegestellen mittels der Heizelemente des Aufsetzrahmens durch Einpressen des mittleren Teils der Platte mittels des Stempels die betreffenden Abschnitte umzubiegen. 2. Device according to claim II, for the simultaneous bending of four sections of a plastic plate for the purpose of producing a trough, characterized by a bending frame with press ram to after heating the bending points by means of the heating elements of the mounting frame by pressing in the middle part of the plate by means of the stamp Bend sections.
CH348260D 1960-01-16 1960-01-16 Method for bending plastic sheets with thermoplastic properties and device for carrying out this method CH348260A (en)

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3479424A (en) * 1965-02-15 1969-11-18 Phillips Petroleum Co Producing a hollow molding by folding and sealing a thermoplastic sheet
FR2426555A1 (en) * 1977-01-20 1979-12-21 Gault Robert METHOD OF MANUFACTURING THREE-DIMENSIONAL OBJECTS IN THERMOPLASTIC SHEET MATERIAL
EP0330228A2 (en) * 1988-02-25 1989-08-30 Mitsubishi Plastics Industries Limited Method for folding a plastic sheet
DE4024504A1 (en) * 1990-08-02 1992-02-06 Friedhelm Veutgen High gloss panel with radiused edge prodn. - by cutting V=section notch along line on acrylic] sheet, heating other side across notch width and bending sheet
DE20022113U1 (en) 2000-06-30 2001-03-22 Huber & Grimme Bearbeitungssysteme GmbH, 86879 Wiedergeltingen Milling tool for milling soft materials, in particular for a device for producing predetermined tear lines in decorative epidermis layers in motor vehicles
GR1004136B (en) * 2001-12-13 2003-02-04 ��������� ���.. Mechanism for the production of reflectors
CN111836690A (en) * 2018-03-16 2020-10-27 伊诺瓦默公司 Method for producing profiled bars with improved connecting device

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Publication number Priority date Publication date Assignee Title
JPS502182B1 (en) * 1970-10-24 1975-01-24
JPS5215633B1 (en) * 1974-12-24 1977-05-02
FR2541932A1 (en) * 1983-03-04 1984-09-07 Rambaud Jean Michel Method for folding a sheet of rigid plastic and for coating a panel by means of such a sheet, and decorative panels obtained thereby
GB2198392B (en) * 1986-12-09 1990-05-30 C R Clarke & Co Heating apparatus
NO900059L (en) * 1990-01-05 1991-07-08 Norsk Hydro As EQUIPMENT FOR FOLDING AND SUMMARY OF BOXES MADE BY FLAT OR MAIN FLAT CASE TOPICS.
FR2809657B1 (en) * 2000-06-06 2003-03-21 Mehl Patrick METHOD FOR MANUFACTURING FURNITURE ELEMENT
EP2090710A1 (en) * 2008-02-13 2009-08-19 Lyngsoe Carpot A/S Integrally formed wall panel
DE102008012098A1 (en) * 2008-02-29 2009-09-10 Rittal Gmbh & Co. Kg Rectangular flat part for use as e.g. planking part, of switching cabinet in automotive engineering, has section folded along opening line by permanent flat plate, and groove attached in region of opening line

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Publication number Priority date Publication date Assignee Title
US2659934A (en) * 1947-04-07 1953-11-24 Plax Corp Method and apparatus for making articles from biaxially oriented thermoplastic sheet material
US2500338A (en) * 1947-08-04 1950-03-14 Bergstein Samuel Manufacture of transparent knockdown containers
DE831314C (en) * 1948-10-02 1952-02-11 Peter Hoppe Dipl Ing Process for the production of profiled bodies

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3479424A (en) * 1965-02-15 1969-11-18 Phillips Petroleum Co Producing a hollow molding by folding and sealing a thermoplastic sheet
FR2426555A1 (en) * 1977-01-20 1979-12-21 Gault Robert METHOD OF MANUFACTURING THREE-DIMENSIONAL OBJECTS IN THERMOPLASTIC SHEET MATERIAL
EP0330228A2 (en) * 1988-02-25 1989-08-30 Mitsubishi Plastics Industries Limited Method for folding a plastic sheet
EP0330228A3 (en) * 1988-02-25 1990-09-12 Mitsubishi Plastics Industries Limited Method for folding a plastic sheet
DE4024504A1 (en) * 1990-08-02 1992-02-06 Friedhelm Veutgen High gloss panel with radiused edge prodn. - by cutting V=section notch along line on acrylic] sheet, heating other side across notch width and bending sheet
DE20022113U1 (en) 2000-06-30 2001-03-22 Huber & Grimme Bearbeitungssysteme GmbH, 86879 Wiedergeltingen Milling tool for milling soft materials, in particular for a device for producing predetermined tear lines in decorative epidermis layers in motor vehicles
GR1004136B (en) * 2001-12-13 2003-02-04 ��������� ���.. Mechanism for the production of reflectors
CN111836690A (en) * 2018-03-16 2020-10-27 伊诺瓦默公司 Method for producing profiled bars with improved connecting device

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