DE102021109062A1 - Tension electric heater - Google Patents

Abstract

Electric heating device (100, 200, 300, 400) with an axial opening for receiving an object to be heated, with an electric heating element (110, 210, 310, 410) and with a clamping jacket (120, 220, 320, 420) for generating an adjustable force acting radially in the direction of an axis (A) of the axial opening, at least the clamping jacket (120, 220, 320, 420) of the electrical heating device (100, 200, 300, 400) at least in sections through at least one recess (121, 221, 321, 421) is penetrated, the width (b) of which can be changed by means of at least one clamping slide (130, 140, 230, 330, 340, 430) which overlaps the recess (121, 221, 321, 421) , wherein the clamping slide (130, 140, 230, 330, 340, 430) at least partially encompasses more than half the circumference of the clamping jacket (120, 220, 320, 420) of the electrical heating device (100, 200, 300, 400).

Description

The invention relates to an electrical heating device with the features of the preamble of claim 1.

Known from the prior art are heating devices with an electrical heating element, which are pushed onto a body to be heated and fastened there by clamping. For example, such heating devices are used in injection molding machines or in hot runner and distributor systems as nozzle heating for heating nozzle bodies.

It is already known from the prior art available on the market to provide a one-piece clamping jacket in direct contact with the heating element or, for example, if this is embedded between an inner and an outer metal jacket, in indirect contact around the heating element Has mutually overlapping portions viewed in direction, between which a wedge mechanism operated with a screw is arranged. If the screw is turned in one direction, the wedge mechanism is moved so that its height changes, which brings about an increase in the distance between the overlapping sections of the clamping jacket, which, because of the substantially constant length of the clamping jacket, leads to a clamping of the heating device on the heating body leads. Turning the screw in the other direction makes it possible to loosen the clamping sleeve again.

The problem with this heating device with clamping jacket is the increased space required by the clamping mechanism in the radial direction due to the wedge mechanism, because in many cases, especially with hot runner nozzles, the individual nozzles to be heated are arranged in blocks and there is only a relatively narrow one between the nozzle and the block , tubular channel available into which the heater must fit.

In particular for applications in which such an increased space requirement can not be satisfied, heating devices with clamping devices have been developed, such as those in FIG DE 10 2013 111 303 A1 or the DE 20 2011 003 451 U1 are disclosed. These heating devices have a slot penetrating them in the axial direction. Furthermore, clamping slides bridging the slot are provided, which interact with the outer jacket of the heating device in such a way that their displacement in the axial direction changes the width of the slot in the circumferential direction, thereby achieving clamping on the body to be heated. In practice, however, it has been shown that on the one hand these clamping slides can be lost and, on the other hand, cannot always apply the desired clamping forces.

The object of the invention is thus to provide a tensionable heating device in which the tensioning device is less easily lost. This object is achieved by a heating device with the features of claim 1. Advantageous further developments of the invention are the subject matter of the subclaims.

The electrical heating device according to the invention has an axial opening for receiving an object to be heated, the outer contour of which can typically be cylindrical at least in sections, an electrical heating element which preferably surrounds the axial opening at least in sections and a clamping jacket which is preferably in the form of a cylinder jacket or a truncated cone jacket for generating an adjustable, force acting radially in the direction of an axis of the axial opening.

• Die Geometrie einer solchen Heizvorrichtung kann insbesondere vorzugsweise unter Rückgriff auf Begriffe aus der Geometrie des Zylinders bzw. des verallgemeinerten Zylinders und Zylinderkoordinaten beschrieben werden. Die Richtung der Zylinderachse ist durch die Achse, die die axiale Öffnung der Heizvorrichtung, in welche der zu beheizende Gegenstand in der Regel eingeschoben wird, definiert, vorgegeben und wird nachfolgend als axiale Richtung bezeichnet.

The following explanations should contribute to an even clearer understanding of this terminology, which is in itself clear:

• The geometry of such a heating device can in particular preferably be described with recourse to terms from the geometry of the cylinder or the generalized cylinder and cylinder coordinates. The direction of the cylinder axis is predetermined by the axis that defines the axial opening of the heating device, into which the object to be heated is usually inserted, and is referred to below as the axial direction.

A force acts radially in the direction of this axis when it acts on a connecting line perpendicular to this axis between a point on the cylinder jacket and a point on the axis in the direction of the axis and is therefore particularly suitable for connecting the electrical heating device to a to press the object to be heated arranged in its axial opening.

The course of an electrical heating element in space can be described in particular in these cylindrical coordinates, i.e. by the position on the axis of the axial opening, the distance in the radial direction from the axis of the axial opening and a polar angle between 0 ° and 360 °. The electrical heating element surrounds the axial opening at least in sections when different polar angles for describing the course of the electrical heating element lie in the area of the axial opening. In particular, this is the case when the side of the axial opening facing electric heating element lies on an imaginary cylinder or truncated cone surface, which preferably coaxially encloses the axial opening, which in turn is particularly the case when the electric heating element runs in a spiral or meandering manner on an imaginary cylinder or truncated cone, the slope in the direction parallel to Cylinder or truncated cone axis can vary.

According to the invention, at least the clamping jacket of the electrical heating device is penetrated at least in sections by a recess, which can in particular be designed as a slot. A recess is therefore also to be understood in particular as an opening or perforation; Groups of openings or perforations are also conceivable. The recess penetrates the clamping jacket at least in sections and therefore does not necessarily have to extend over its entire length.

The width of the recess or in particular of the slot, which can be understood as the distance from one another essentially perpendicular to the axis of the axial opening opposite edge points of the recess, must be changeable by means of at least one clamping slide that overlaps the recess at least in sections.

An alternative description of the fact that the width of the recess can be changed by means of the clamping slide which at least partially overlaps the recess can again be made with recourse to a description of the recess in cylinder coordinates: At every point on the cylinder axis at which a recess is present, it covers it a certain polar angle range. If the polar angle range covered by the recess varies at different positions of the clamping slide at such points on the cylinder axis, the width of the recess can be changed by means of the clamping slide.

It is essential to the invention that the tensioning slide, at least in sections, encompasses more than half the circumference of the tensioning jacket of the electrical heating device. In other words, the cocking slide has at least sections in which it extends over a polar angle of more than 180 ° in the coordinates of the cylinder geometry described above. This leads directly to the fact that the cocking slide can no longer be lost because these sections fix the cocking slide in the guide that defines its movement; it can no longer fall out of the guide without the need for complex mechanical reworking, e.g. to create an undercut or even to provide a recess for receiving the clamping slide.

It should be noted in particular that the tensioning jacket in various embodiments of electrical heating devices according to the invention can be implemented on the one hand as a separate, additional component, for example an additional, separate outer jacket, but on the other hand also by different components of the electrical heating device itself.

For example, in electrical heating devices in which the electrical heating element is embedded in a highly thermally conductive powder or granulate, the tensioning jacket can be used to enclose the interior space between a tubular inner jacket with a recess, which can in particular be designed as a slot, and a tubular outer jacket that is usually arranged concentrically therewith Recess, which can in particular be designed as a slot, which are connected to one another by lateral boundary surfaces at the edges of the recesses or slots, are formed by the tubular outer jacket with a recess or slot.

In embodiments in which a coiled electrical heating element in the form of a coiled tubing cartridge is surrounded by a tubular outer jacket with a recess, which can in particular be designed as a slot, on which it rests directly, this outer jacket can also form the clamping jacket.

And in embodiments in which a coiled tubing cartridge is inserted into a groove made in a metal surface, the metal surface being a surface of a metal body preferably in the form of a tube, in particular slotted, but this shape can also be worked through, for example, from the solid A metal plate can be rolled up before or after the insertion of the coiled tubing cartridge, this metal body can form the clamping jacket, which must have the recess.

The clamping jacket can, however, also be formed by an additional outer tube with a recess, in particular a slot, pushed onto the pipe defined in this way with a recess, in particular the slotted pipe defined in this way.

A particularly simple design of the clamping slide provides that it is a sleeve, that is to say that it completely surrounds the clamping sleeve. It then happens that in the tensioned state, parts of the sleeve, in particular those parts of the sleeve furthest away from the areas in which the interaction between the clamping slide and clamping sleeve is established, which is typically the case in the area of the guides, not rest more on the clamping jacket.

If the sleeve has slots or incisions running in its longitudinal direction (i.e. slots in which the two surfaces on the sides of the slot bear against one another but are separable from one another), which are shorter than the sleeve, with adjacent slots or incisions of each different sides of the sleeve, the clamping effect of the sleeve can be further improved and / or lifting of parts of the sleeve from the clamping jacket can be avoided.

An embodiment of the invention is preferred in which the guides are implemented in such a way that the clamping slide has at least one radially inwardly protruding projection on each side of the recess, which can in particular be designed as a slot, and that each projection into one in the clamping casing relative to Axis of the axial opening obliquely or curved recess, in particular groove or opening engages, so that an axial movement of the clamping slide leads to a change in the width of the recess, which can be designed in particular as a slot, because then different sections of the recess differ from the respectively closest edge of this recess or this slot are removed, while the distance between the inwardly protruding projections is constant. If this is the case, the cocking slide can be made of thinner material. Conversely, however, the depressions on the clamping slide and the projections on the clamping jacket can also be provided.

For some purposes it is advantageous if the electrical heating device has an outer tube which is arranged at least in sections between the clamping jacket and the clamping slide and which has an opening in its tube jacket to enable the mechanical interaction between the clamping jacket and the clamping slide.

To establish and release the tension, it is advantageous if the clamping slide has at least one tool holder and / or if the clamping jacket has at least one tool holder outside the area in which the clamping slide is displaceable.

In particular, the tool holder in the clamping jacket can be formed very easily by locally widening the gap.

In particular, pliers whose jaws are modified so that they can be used in such tool holders can be well suited for the adjustment. This need for modification is preferably avoided in that the tool holders in the clamping slide and / or clamping jacket are designed to accommodate a jaw of a pair of pliers.

The tool holders are preferably designed in such a way that the edge of the tool holder is reinforced. This can be achieved in particular by a reinforcing ring, which can also be designed as a conventional clamping ring. This measure enables the use of thinner clamping jackets or clamping slides.

It is particularly advantageous if the interaction between the clamping slide and the clamping jacket is established via separate projections which are attached to the clamping slide or the clamping jacket. Separate means that the projections are not integrally formed, but rather those that were originally additional components, which are then subsequently attached to the clamping slide or clamping sleeve, e.g. by welding, soldering or gluing.

• 1a: eine Gesamtansicht eines ersten Ausführungsbeispiels einer elektrischen Heizvorrichtung in entspanntem Zustand,
• 1b: einen Querschnitt durch die elektrische Heizvorrichtung aus 1a,
• 1c: eine Gesamtansicht der elektrischen Heizvorrichtung aus 1a in gespanntem Zustand,
• 1d: einen Querschnitt durch die elektrische Heizvorrichtung aus 1a,
• 2a: eine Explosionsdarstellung der Komponenten einer ersten Version einer Spannvorrichtung,
• 2b: die aus den in 2a gezeigten Komponenten zusammengesetzte Spannvorrichtung,
• 2c: eine Explosionsdarstellung der Komponenten einer zweiten Version einer Spannvorrichtung,
• 2d: die aus den in 2c gezeigten Komponenten zusammengesetzte Spannvorrichtung,
• 2e: eine Explosionsdarstellung einer Variante der in 2c gezeigten zweiten Version der Spannvorrichtung,
• 2f: die aus den in 2e gezeigten Komponenten zusammengesetzte Spannvorrichtung,
• 3a: eine erste Version eines Spannschiebers,
• 3b: eine zweite Version eines Spannschiebers,
• 3c: eine dritte Version eines Spannschiebers,
• 3d: eine vierte Version eines Spannschiebers,
• 4a: ein zweites Ausführungsbeispiel einer elektrischen Heizvorrichtung,
• 4b: einen Ausschnitt der elektrischen Heizvorrichtung aus 4a in entspanntem Zustand,
• 4c: einen Ausschnitt der elektrischen Heizvorrichtung aus 4a in gespanntem Zustand,
• 5: eine Explosionsdarstellung eines dritten Ausführungsbeispiels einer elektrischen Heizvorrichtung,
• 6: eine Explosionsdarstellung eines vierten Ausführungsbeispiels einer elektrischen Heizvorrichtung,
• 7a: eine Spannvorrichtung mit einer ersten Variante einer Ausnehmung,
• 7b: eine Spannvorrichtung mit einer zweiten Variante einer Ausnehmung,
• 7c: eine Spannvorrichtung mit einer dritten Variante einer Ausnehmung,
• 7d: eine Spannvorrichtung mit einer vierten Variante einer Ausnehmung, und
• 7e: eine Spannvorrichtung mit einer fünften Variante einer Ausnehmung.

The invention is explained in more detail below with reference to figures which represent exemplary embodiments. It shows:

• 1a : an overall view of a first embodiment of an electrical heating device in the relaxed state,
• 1b : a cross section through the electric heater 1a ,
• 1c : an overall view of the electric heater from FIG 1a in tensioned condition,
• 1d : a cross section through the electric heater 1a ,
• 2a : an exploded view of the components of a first version of a clamping device,
• 2 B : those from the in 2a components shown assembled clamping device,
• 2c : an exploded view of the components of a second version of a clamping device,
• 2d : those from the in 2c components shown assembled clamping device,
• 2e : an exploded view of a variant of the in 2c shown second version of the clamping device,
• 2f : those from the in 2e components shown assembled clamping device,
• 3a : a first version of a cocking slide,
• 3b : a second version of a cocking slide,
• 3c : a third version of a cocking slide,
• 3d : a fourth version of a cocking slide,
• 4a : a second embodiment of an electrical heating device,
• 4b : a section of the electric heater 4a in a relaxed state,
• 4c : a section of the electric heater 4a in tensioned condition,
• 5 : an exploded view of a third embodiment of an electrical heating device,
• 6th : an exploded view of a fourth embodiment of an electrical heating device,
• 7a : a clamping device with a first variant of a recess,
• 7b : a clamping device with a second variant of a recess,
• 7c : a clamping device with a third variant of a recess,
• 7d : a clamping device with a fourth variant of a recess, and
• 7e : a clamping device with a fifth variant of a recess.

1a Fig. 10 shows an overall view of an electric heater 100 in a relaxed state and the 1c an overall view of the same electrical heating device in the tensioned state.

The electric heater 100 has an essentially hollow cylindrical geometry, the cylinder axis of which is the axis A. forms their axial opening into which the object to be heated can be inserted. The axial opening is created by an electrical heating element coiled here with alternating helical pitches 110 , which can be a coiled tubing cartridge, for example, which surrounds the axial opening at least in sections.

Around the coiled electrical heating element 110 around is a tension jacket 120 to produce an adjustable, radially in the direction of the axis A. the axial opening towards acting force arranged by a in this embodiment as one of the one end of the electrical heating device 100 to its other end extending gap executed recess 121 is enforced.

The width b the recess designed as a slot 121 is by means of two clamping slides 130 , 140 changeable, which are designed as sleeves, which on the clamping jacket 120 are postponed and thus the circumference of the clamping jacket 120 including the area in which the recess designed as a slot 121 in the tension jacket 120 is introduced, overlap completely (and thus more than half the scope).

The cocking slide 130 , 140 each have one on different sides of the recess designed as a slot 121 symmetrical to the recess designed as a slot 121 arranged pair of protrusions 138 , 148 on, which is in the radial direction inward on the axis A. to extend. As in the 1a and 1c shown are these protrusions 138 , 148 formed by separate parts, which in corresponding openings of the cocking slide 130 , 140 fitted and fixed there, welded here so that they are on the outside with the outer surface of the clamping slide 130 , 140 align and on the inside inwards over the inner, the axis A. facing surface of the clamping slide protrude.

In addition, the cocking slide 130 , 140 a tool holder in its central area 131 , 141 and approximately semicircular access openings located opposite one another on each of the two end-face wheels 132 , 133 , 142 , 143 on, through which a section of a clamping tool in one on the clamping jacket 120 provided tool holders 125 , 126 , 127 can access

For the variability of the width b the recess designed as a slot 121 is responsible that the clamping jacket 120 for each of the cocking slides 130 , 140 each one on different sides of the recess designed as a slot 121 symmetrical to the recess or to the slot 121 arranged pair of recesses, of which in 1a as well as in 1c but only one at a time, namely the depressions 122 for cocking slide 130 and the depression 123 are visible to the cocking slide, especially with their ends 122a and 123a in 1a and with their ends 122b and 123b in 1c , The wells 122 , 123 are designed as a breakthrough, so they penetrate the clamping jacket 120 each complete. They each run relative to the axis A. the axial opening at an angle so that the ends 122b , 123b each less far from the edge of the recess designed as a slot 121 are distant than the ends 122a , 123a . The depressions 122 , 123 take the ledges 131 , 141 the cocking slide 130 , 140 and, in cooperation with them, form a leadership. Because the distance between the respective pairs of protrusions 138 of the cocking slide 130 or of projections 148 of the cocking slide 140 remains constant, this will change the Gap width b forced when moving the clamping slide in this guide.

You can also see the tension jacket 120 in the 1a and 1c three tool holders each 125 , 126 , 127 as a local extension of the recess designed as a slot 121 are executed.

Based on the comparison of each in the area of the cocking slide 130 lying cross-sectional representations of the 1b and 1d it can be seen that the tensioning of the tensioning device in this embodiment of the invention leads to the fact that when the heating device is tensioned 100 in 1d A gap 139 between the cocking slide 130 and the tension jacket 120 arises that of the recess designed as a slot 121 opposite side of the clamping jacket is largest.

the 2a and 2 B respectively. 2c and 2d show two different ways of using the jig 50 respectively. 55 with cocking slide 60 respectively. 80 and tension jacket 70 respectively. 90 build up and from their respective in the 2a respectively. 2c assemble shown components; because the other components of the electrical heating device play no role for this, they are omitted.

In the exploded view of the clamping device 50 according to 2a you can see the cocking slide 60 with tool holder 62 , Access openings 63 , 64 as well as openings 65 , 66 to accommodate two projections 61 , which are initially provided as separate components and the clamping jacket 70 with a recess designed as a slot 71 and depressions 72 , which are designed as an opening, the clamping jacket 70 each completely enforce and each run relative to the axis A. the axial opening at an angle so that the ends 72b less far from the edge of the recess designed as a slot 71 are distant than the ends 72a . By pushing the cocking slide 60 on the tension jacket 70 , Inserting the protrusions 61 in the openings 65 , 66 until it engages the indentations 72 stand and fix, e.g. welding the projections 61 in this position the in 2 B shown clamping device 50 obtain.

the 2c and 2d show an alternative clamping device 55 . In the exploded view according to 2c you can see the cocking slide 80 with tool holder 82 , Access openings 83 , 84 as well as two openings 85 , 86 to accommodate two projections 92 , 93 , which are initially provided as separate components and the clamping jacket 90 with a recess designed as a slot 91 . In this alternative, the openings prevail 85 , 86 the cocking slide 80 each complete and each run relative to the axis A. of the axial opening at an angle, so that the ends 86b are less far from the edge of the recess 91 or the slot which it forms are distant than the ends 86a when the cocking slide 80 so on the clamping jacket 90 is pushed that the tool holder 82 on the slot 92 is centered. By pushing the cocking slide 80 on the tension jacket 90 , Inserting the protrusions 92 , 93 in the openings 85 , 86 until they are on the clamping jacket 90 fit and fix, e.g. welding the projections 92 , 93 in this position the in 2d shown clamping device 55 obtain.

the 2e and 2f show in the form of the jig 55 ' a variant of the 2c and 2d shown clamping device 55 , which are therefore the reference numerals from the 2c and 2d , each provided with an additional ', picks up.

In the exploded view according to 2e you can therefore see the cocking slide 80 ' with tool holder 82 ' , Access openings 83 ' , 84 ' as well as two openings 85 ' , 86 ' to accommodate two projections 92 ' , 93 ' , which are initially provided as separate components and the clamping jacket 90 ' with a recess designed as a slot 91 ' . For the functioning of this variant, reference can be made to the above explanations on the functioning of the clamping device 55 to get expelled.

The difference between the jigs 55 ' and 55 is that at the jig 55 ' Tool holders in the form of bores 94 ' , 95 ' in the tension jacket 90 ' are present, the edge of which with reinforcing rings 96 ' , 97 ' is reinforced, which is what happens with thin clamping sheaths 90 ' provides the necessary strength.

• - dass sie in ihrem mittleren Bereich eine Werkzeugaufnahme 11, 21, 31, 41 aufweisen,
• - dass sie an beiden stirnseitigen Rädern jeweils einander gegenüberliegende, in etwa halbkreisförmige Zugangsöffnungen 12, 13, 22, 23, 32, 33, 42, 43 aufweisen, durch die hindurch ein Abschnitt eines Spannwerkzeugs in eine am Spannmantel vorgesehene Werkzeugaufnahme zugreifen kann, und
• - dass sie jeweils zwei den jeweiligen Spannschieber 10, 20, 30, 40 durchsetzende Aufnahmeöffnungen 14, 15, 24, 25, 34, 35, 44, 45 aufweisen, in die die Vorsprünge, mit denen die Wechselwirkung zwischen dem Spannschieber und dem Spannmantel gewährleistet werden soll, dann eingesetzt und nachfolgend am Spannschieber 10, 20, 30, 40 befestigt werden wenn der Spannschieber 10, 20, 30, 40 auf den Spannmantel oder ein dieses umgebendes Außenrohr aufgeschoben ist.

Based on 3a until 3d are now examples of different basic shapes that a cocking slide 10 , 20th , 30th , 40 an electrical heating device according to the invention can be presented, although the projections to be connected to them subsequently are not shown. What these tensioners have in common 10 , 20th , 30th , 40 :

• - that they have a tool holder in their central area 11 , 21 , 31 , 41 exhibit,
• - That they have approximately semicircular access openings opposite one another on both front wheels 12th , 13th , 22nd , 23 , 32 , 33 , 42 , 43 have through which a section of a clamping tool can access a tool holder provided on the clamping jacket, and
• - that they each have two the respective cocking slide 10 , 20th , 30th , 40 penetrating receiving openings 14th , 15th , 24 , 25th , 34 , 35 , 44 , 45 have in which the projections with which the interaction between the clamping slide and the clamping jacket is to be ensured, then used and subsequently on the clamping slide 10 , 20th , 30th , 40 be attached when the cocking slide 10 , 20th , 30th , 40 is pushed onto the clamping jacket or an outer tube surrounding it.

The difference between the cocking slides 10 , 20th , 30th , 40 lies in its basic geometric shape. The cocking slide 10 is a sleeve and therefore surrounds the electrical heating device and in particular its clamping jacket in a polar angle range of 360 ° over the entire length of the clamping slide.

Compared to the cocking slide 10 material-saving, manufacturable clamping slide 20th is only a segment of a sleeve and therefore encompasses the electrical heating device and in particular its clamping jacket only in a polar angle range of approximately 210 °, but also over the entire length of the clamping slide.

The clamping slide is even more material-saving 30th , which surrounds the electrical heating device and in particular its clamping jacket only in a polar angle range of about 210 °, but also only in two end-side partial regions of the length of the clamping slide.

The cocking slide 40 after all, is like the cocking slide 10 a sleeve, but here a slotted sleeve, the slots running in its longitudinal direction 46 , 47 having, the slots 46 , 47 are shorter than the sleeve and with adjacent slots extending from different sides of the sleeve. In this way, in particular, as will be explained in more detail below, a sleeve-shaped clamping slide can be provided which rests on the clamping jacket both in the relaxed and in the tensioned state.

In the 4a until 4c is a possible use for a cocking slide 430 in the form of a slotted sleeve, the slots running in its longitudinal direction 438 , 439 having, the slots 438 , 439 are shorter than the sleeve and with adjacent slots extending from different sides of the sleeve, shown. The cocking slide 430 furthermore has a tool holder in the middle area 431 have, approximately semicircular access openings located opposite one another on both front-side wheels 432 , 433 through which a section of a clamping tool can access a tool holder provided on the clamping jacket, and two the clamping slide 430 penetrating receiving openings in the projections 434 with which the interaction between the cocking slide 430 and the tension jacket 420 is guaranteed, inserted and welded.

The electric heater 400 that can be seen in these figures has an electrical heating element 410 , which can be designed, for example, as a coiled tubing cartridge and meandering into one in the clamping jacket 420 with exception 421 that here by one of the Spannmaltel 420 The length of the penetrating slot is formed, the metal surface forming the groove is inserted. The depressions in the clamping jacket 420 into which the protrusions 434 of the cocking slide 430 intervene cannot be recognized because they are through the cocking slide 430 be covered.

In the in 4b The position shown is the recess formed by the slot 421 of the clamping jacket to such a width b widened so that the slots 438,439 of the cocking slide spring open. Conversely, this enables the in 4c shown position of the clamping slide 430 this gap-free on the clamping jacket 420 is present.

The electric heaters 200 , 300 that are in the 5 respectively. 6th each shown as an exploded view each also have an electrical heating element 210 , 310 on, which is meandering in grooves that are introduced into a cylindrical shaped metal surface, received. In the embodiment according to 5 this metal surface forms the clamping jacket 220 , with a recess designed as a slot 221 and depressions 224 . Between the cocking slide 230 with tool holder 231 have access openings 232 , 233 and two the cocking slide 230 penetrating receiving openings 234 , 235 , into the protrusions 236 , 237 be inserted and fastened around the interaction with the clamping jacket 220 an outer jacket is to be produced 250 with an opening 251 on the tension jacket 220 postponed.

In contrast, in the case of the electric heater 300 , in the 6th is shown, the metal surface by an inner surface 390 formed, while the outer jacket has the function of the clamping jacket 320 with a recess designed as a slot 321 takes over and in this embodiment with two clamping slides 330 , 340 interacts according to the above based on the 2c and 2d explained principle. Accordingly, the cocking slide 330 , 340 Tool holders 331 , 341 , Access openings 332 , 333 , 342 , 343 as well as two openings 334 , 335 , 344 , 345 to accommodate two projections each 352 , 353 , 354 , 355 which are initially provided as separate components and later on the clamping jacket 320 with a recess designed as a slot 321 be attached.

The ones in the 7a until 7e clamping devices shown 710 , 720 , 730 , 740 , 750 with tension jacket 711 , 721 , 731 , 741 , 751 and clamping slides 713a , 713b , 723a , 723b , 733 , 743 , 753 are intended to exemplify some of the different shapes that the recesses 712a , 712b , 722a , 722b , 732 , 742 , 752 within the meaning of this disclosure. It should be emphasized that although in the variants shown here the width of the recesses is always relatively small compared to their length, this is not absolutely necessary.

Specifically are the jig 710 according to 7a two recesses 712a , 712b provided, which are largely parallel to each other, but opposite ends of the clamping device 710 go out and just before the other end of the jig 710 end up.

Even with the clamping device 720 according to 7b are two recesses 722a , 722b present, which are arranged collinearly, but neither of ends of the clamping jacket 721 go out, but through two separate openings in the clamping jacket 721 are formed.

At the in 7c clamping device shown 730 is just a recess 732 present by one end of the clamping jacket 731 goes out and is only up to just over the middle of the jig 730 extends beyond.

As in the example of the jig 740 , in the 7d is shown, the recess 742 but also have a section which spirals around a section of the clamping jacket 741 winds around.

According to the example of 7e is in addition to that in the clamping jacket 751 introduced, essentially the same as the recess 742 executed recess 752a, a second, somewhat wider recess 752b is also present.

List of reference symbols

10, 20, 30, 40

Cocking slide

11, 21, 31, 41

Tool holder

12, 13, 22, 23, 32, 33, 42, 43

Access opening

14, 15, 24, 25, 34, 35, 44, 45

Receiving opening

46, 47

Slots

50, 55, 55 '

Jig

60, 80, 80 '

Cocking slide

61, 92, 93, 92 ', 93'

head Start

62, 82, 82 '

Tool holder

63, 64, 83, 84, 83 ', 84'

Access opening

65, 66, 85, 86, 85 ', 86'

opening

70, 90, 90 '

Tension jacket

71, 91, 91 '

Recess

72

deepening

72a, 72b

end

94 ', 95'

drilling

96 ', 97'

Reinforcement ring

100, 200, 300, 400

electric heater

110, 210, 310, 410

electric heating element

120, 220, 320, 420

Tension jacket

121, 221, 321, 421

Recess

122, 123, 224

deepening

122a, 123a, 122b, 123b

end

125, 126, 127,

Tool holder

130, 140, 230, 330, 340, 430

Cocking slide

131, 141, 231, 331, 341, 431

Tool holder

132, 133, 142, 143, 232, 233, 332, 333, 432, 433

Access opening

138, 148, 236, 237, 352, 353, 354, 355, 434

head Start

139

gap

234, 235

Receiving opening

250

Outer jacket

251

Access opening

390

Inner surface

438, 439

slot

710, 720, 730, 740, 750

Jig

711, 721, 731, 741, 751

Tension jacket

712a, 712b, 722a, 722b, 732, 742, 752

Recess

713a, 713b, 723a, 723b, 733, 743, 753

Cocking slide

A.

axis

b

Gap width

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102013111303 A1 [0005]
• DE 202011003451 U1 [0005]

Claims (12)

Electric heating device (100, 200, 300, 400) with an axial opening for receiving an object to be heated, with an electric heating element (110, 210, 310, 410) and with a clamping jacket (120, 220, 320, 420) for generating an adjustable force acting radially in the direction of an axis (A) of the axial opening, at least the clamping jacket (120, 220, 320, 420) of the electrical heating device (100,200,300,400) at least in sections through at least one recess (121, 221, 321 , 421), the width (b) of which can be changed by means of at least one clamping slide (130, 140, 230, 330, 340, 430) which engages over the recess (121, 221, 321, 421), characterized in that the The clamping slide (130, 140, 230, 330, 340, 430) at least in sections encompasses more than half the circumference of the clamping jacket (120, 220, 320, 420) of the electrical heating device (100, 200, 300, 400). Electric heater (100, 200, 300, 400) according to Claim 1 , characterized in that the clamping slide (130, 140, 230, 330, 340, 430) has a higher strength than the clamping jacket (120, 220, 320, 420). Electric heater (100, 200, 300, 400) according to Claim 1 or 2 , characterized in that the cocking slide (130, 140, 230, 330, 340, 430) is a sleeve. Electric heater (100, 200, 300, 400) according to Claim 3 , characterized in that the sleeve has slots (438, 439) or incisions running in its longitudinal direction, the slots (438, 439) or incisions being shorter than the sleeve and with adjacent slots or incisions extending from different sides of the sleeve . Electric heating device (100, 200, 300, 400) according to one of the Claims 1 until 4th , characterized in that the clamping slide (130, 140, 230, 330, 340, 430) on each side of the recess (121, 221, 321, 421) has at least one radially inwardly projecting projection (138, 148, 236, 237, 352, 353, 354, 355, 434) and that each projection (18, 148, 236, 237, 352, 353, 354, 355, 434) in a clamping sleeve (120, 220, 320, 420) relative to the axis (A) the axial opening inclined or curved recess (122, 123, 224) engages, so that an axial movement of the clamping slide (130, 140, 230, 330, 340, 430) to a change in the width (b) of the recess (121, 221, 321, 421) leads. Electric heating device (100,200,300,400) according to one of the Claims 1 until 5 , characterized in that the electrical heating device (100, 200, 300, 400) has an outer jacket arranged at least in sections between the clamping jacket (120, 220, 320, 420) and the clamping slide (130, 140, 230, 330, 340, 430) (250) which has a passage opening (251) to enable the mechanical interaction between the clamping jacket (120, 220, 320, 420) and the clamping slide (130, 140, 230, 330, 340, 430). Electric heating device (100,200,300,400) according to one of the Claims 1 until 6th , characterized in that the clamping slide (130, 140, 230, 330, 340, 430) has at least one tool holder (131, 141, 231, 331, 341, 431). Electric heating device (100, 200, 300, 400) according to one of the Claims 1 until 7th , characterized in that the clamping jacket (130, 140, 230, 330, 340, 430) outside the area in which the clamping slide (130, 140, 230, 330, 340, 430) is displaceable, at least one tool holder (125, 126, 127). Electric heater (100, 200, 300, 400) according to Claim 8 , characterized in that the tool holder (125, 126, 127) in the clamping jacket (120, 220, 320, 420) is formed by a local widening of the gap (121, 221, 321, 421). Electric heating device (100, 200, 300, 400) according to one of the Claims 7 until 9 , characterized in that the tool holder (131, 141, 231, 331, 341, 431) is designed to hold the jaw of a pair of pliers. Electric heating device (100, 200, 300, 400) according to one of the Claims 7 until 10 , characterized in that the edge of the tool holder (131, 141, 231, 331, 341, 431) is reinforced. Electric heating device (100, 200, 300, 400) according to one of the Claims 1 until 11 , characterized in that the interaction between the clamping slide (130, 140, 230, 330, 340, 430) and clamping jacket (120, 220, 320, 420) via separate projections (138, 148, 236, 237, 352, 353, 353 , 354, 355, 434), which are attached to the clamping slide (130, 140, 230, 330, 340, 430) or to the clamping jacket (120, 220, 320, 420).

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