EP0730932A1 - Belt tensioner - Google Patents

Abstract

The belt tensioner mechanism has its belt (22) wrapped around two workpieces (24,26) whose edges are protected by protection pieces fixed to the belt. The handle (20) of the mechanism is connected to a pressure plate (18) via a spindle (16) which moves it from its zero position so that it clamps the belt sides (25,26) between it and the upper part of the body (14) of the device. The belt passes into the tensioning mechanism through channels and goes through curved sections (30,32) which produce a double pulley effect when the free end of the belt is pulled in a downwards direction (23).

Description

The invention relates to a belt tensioner with a tensioning strap, which forms an outer loop for looping around one or more workpieces, and with a tensioning device, by means of which the outer loop can be contracted for tensioning the workpiece or the workpieces.

Such belt tensioners are used for reclamping workpieces of various shapes.

Such belt tensioners are particularly suitable for holding together shapeless parts or parts with interrupted peripheral surfaces, such as, for. B. backrests or feet. The bulky parts also include columns, kidney-shaped furniture or oval-shaped workpieces.

With such band tensioners, normal frames can be stretched in a square, hexagon or octagon shape.

It is particularly advantageous to use corner elements - or also called clamping corners - in such belt tensioners for better and gentle clamping of workpieces with corners in the area of the corners.

Belt tensioners are known in a wide variety of designs.

For example, belt tensioners are known in which a lashing strap with a ratchet is used. Other embodiments of belt tensioners use a spindle with a spindle nut to actuate the belt guide. With these solutions, however, it is necessary to clamp the two sides of the band or the ends of the band, and the way the band is held during tensioning depends on how good the clamping is.

If textile straps are used as tensioning straps, their great elongation is disadvantageous, which is particularly noticeable when the loop is very large. For this reason, metal straps are also used in strap tensioners, but they have the disadvantage that they are cumbersome to handle and snap open.

In one embodiment of a belt tensioner known from EP-0 302 806, the tensioning device is designed in such a way that it pulls at both ends of the outer loop, the textile strap used as tensioning strap being wound up on two rollers during tensioning. However, this solution has the disadvantage that, due to the different circumferential dimensions when the tensioning band is wound onto the rollers, there is an uneven pulling on both sides of the outer loop.

In addition, the handling of the tensioning device via a single rotary knob, which has different functions in several positions, is also disadvantageous. One position serves for the free pulling out of the tightening strap, one for fast winding up of the tightening strap and a third position for tightening the tightening strap in small rest positions.

The invention is therefore based on the object of improving a belt tensioner of the generic type in such a way that it can be handled as advantageously as possible.

This object is achieved according to the invention in a belt tensioner of the type described at the outset in that the tensioning device has a base element supported on the loop with a loop passage, that the tensioning device comprises a tension element, that the tension element and the base element are movable relative to one another by means of an adjusting device and that the loop runs between the base element and the tension element and engages them in such a way that when the base element and tension element move relative, the outer loop can be contracted under the action of a double pulley block.

The advantage of the solution according to the invention can be seen in the fact that, with a simple relative movement between the tension element and the base element, a rapid and efficient shrinking of the outer loop and thus tensioning due to the double pulley effect during the relative movement from basic element to traction element.

In addition, the belt tensioner according to the invention is simple to operate, since only a relative movement between the base element and the tension element can be carried out by means of the adjusting device in order to pull the outer loop together.

The effect of a double block and tackle can be achieved with a wide variety of guides for the sling between the base element and the tension element.

An embodiment which is particularly advantageous on account of its simplicity provides that the loop rests with a first point on the base element and with at least two further points on the tension element.

It is particularly expedient if the loop forms two loops, the bends of which form the two further points with which the loop abuts the tension element. With these two loops, the effect of the double pulley system can be represented in a simple manner, preferably at one end of each loop one end of the loop and at the other end of the loop the tension band continues to the outer loop.

With regard to the way in which the sling is placed on the workpieces before the tensioning strap is tensioned, no further details have so far been given. It is particularly advantageous if the size of the loop can be varied so that it can be placed on a wide variety of workpieces.

This can be achieved, for example, in that a separate adjustment device acts on the loop at some point in order to vary its size.

A particularly simple embodiment of the strap tensioner according to the invention provides that a first end of the loop is arranged at a fixed point on the strap and that the strap continues beyond a second end of the loop as a strap reserve and that the size of the loop is reduced or enlarged the tensioning band reserve can be varied, the size of the loop being able to be determined by exact positioning of the first end relative to the second end.

This solution creates the possibility of varying the size of the sling in a simple and also transparent manner for an operator.

The first and second ends of the sling could, for example, be arranged on a separate locking device which serves to vary the size of the sling.

However, it is particularly advantageous if the first end and the second end of the loop engage the tensioning device.

In this case, a fixing device is preferably provided, with which the second end can be fixed in the clamping device.

For example, it would be possible to fix the first end in the tensioning device independently of the fixing device.

A particularly expedient solution provides, however, that the first end and the second end can be fixed in the fixing device of the tensioning device, so that the tensile force at one end of the loop acts directly on the other end of the loop.

In order to enable the tightening strap to be fixed in any position in the fixing device, it is preferably provided that the fixing device acts non-positively on the tightening strap.

In this case, it is particularly advantageous if both the first end and the second end of the loop can be fixed in the fixing device, since the fixing device then acts on both ends and, for example, presses both ends against one another, which is particularly the case with one
braided or textile strap due to the high surface friction leads to the fact that the two ends are fixed directly relative to each other in the fixing device due to the friction between them.

The fixing device can be designed in a wide variety of ways. An advantageous embodiment of the fixing device provides that it has a fixing element and an abutment, between which the tightening strap can be clamped.

In principle, a separate actuation device, for example with a toggle mechanism, can be provided for clamping the tension band between the fixing element and the abutment.

A particularly easy-to-use solution provides that the fixing device and the adjusting device can be actuated at the same time, in particular by means of the same actuating element, so that, in addition to simple handling, it is also ensured that the fixing device in the sense of actuating the adjusting device for tensioning the tensioning strap a setting of at least one end of the loop can be actuated.

A solution in which the fixing device is actuated inevitably takes place particularly safely when the adjusting device is actuated in the sense of tensioning the tensioning strap.

A particularly advantageous embodiment of the solution according to the invention provides, however, that the fixing element can be actuated by the adjusting device when the base element and the pulling element are moved relative to one another.

In the simplest case, it is provided that the adjusting device is supported on the base element via the fixing device and thus the fixing device fixes at least the second end of the loop and optionally also the first end relative to the base element.

In this case, it is particularly advantageous if the end of the loop, which is fixed by the fixing device, represents the point at which the loop is in contact with the base element.

With regard to the effect of the tension element on the sling, no further details have been given in connection with the previous explanation of the individual exemplary embodiments. An advantageous exemplary embodiment provides that the tension element has two tension bodies, one of which acts on the loop at one of the at least two further points.

The tension members are preferably arranged on both sides of the adjusting device on the tension element.

With regard to the adjusting device, no further details have been given in connection with the previous explanation of the individual exemplary embodiments. Any type of actuator which generates a relative movement between the base element and the tension element is conceivable as an adjustment device.

An adjustment device which is particularly favorable due to its simplicity in terms of construction and ease of use and with which high forces can also be generated comprises a spindle and a spindle nut running on the spindle.

Such a spindle has the advantage that it is able to generate a high force over relatively large distances with simple operability, which is particularly the case here, in which the relative movement between the tension element and the base element has that of a double pulley block on the outer loop , is important.

Such an adjustment device can now act on the base element and the tension element in a wide variety of ways. A structurally particularly favorable and simple embodiment provides that the spindle nut is held on the tension element and the spindle is supported on the base element.

In the simplest case, it is provided that the spindle is supported with a spindle end on the fixing element of the fixing device.

In order to guide the tension element carrying the spindle nut in a rotationally fixed manner relative to the adjusting spindle, it is preferably provided that the tension element is guided on a linear guide connected to the base element in the direction of and away from it, but is non-rotatably guided.

This linear guide could be designed in a wide variety of ways. An advantageous embodiment of the linear guide provides that this part of a housing, preferably formed by walls thereof, on which in particular the base element is held.

In the simplest case, it is provided that the base element forms part, preferably a base part, of the housing.

With regard to the design of the basic element, no further details have so far been given with regard to the design of the loop passage. For example, it would be conceivable to provide a single opening in the base element, through which the loop is guided to the tension element. However, it is particularly advantageous if the base element has two guide openings for each strand of the loop.

The guide openings are preferably laid such that the respective strand of the loop extends through the respective guide opening following the loop formed between the base element and the tension element.

With regard to the way in which the tensioning band reserve is to be arranged on or in the tensioning device, no further details have so far been given. In principle, it would be possible to simply let the tension band reserve run freely out of the tensioning device or to provide a cavity in which the tension band reserve can be stored in an unordered manner.

A particularly advantageous embodiment provides, however, that the tensioning device has a carrier for the tensioning band reserve, on which in particular the tensioning band reserve can be deposited in an orderly manner.

This carrier is preferably designed as a winding body for the tension band reserve, on which the tension band reserve can thus be wound up in an orderly manner.

The winding body could on the one hand be formed by the housing itself, so that the tension band reserve can be easily wound onto the winding body formed by the housing.

However, it is even more advantageous if the winding body forms a spool that can be rotated relative to the housing and on which the tension band reserve can be wound in the form of a winding.

The spool is preferably rotatable with a crank for winding up the strap reserve.

With regard to the loading of the workpieces by the outer loop of the clamping band, no further details have been given in connection with the previous explanation of the individual exemplary embodiments.

An advantageous solution provides that the outer loop is provided with corner elements for loading the workpieces.

These corner elements could, for example, be freely insertable between the tensioning strap and the respective workpieces when the outer loop is put around the workpieces. However, this has the disadvantage that simple operation of the belt tensioner according to the invention is no longer possible.

For this reason, it is preferably provided that the corner elements can be fixed captively on the tension band.

The corner elements are preferably provided with holding elements which engage on the tensioning strap and can be designed in a wide variety of ways for fixing to the tensioning strap.

A particularly advantageous embodiment provides that the holding elements are designed such that the tensioning strap can be inserted transversely to its longitudinal direction into a position on the corner elements which is fixed by the holding elements, so that there is no need to open the outer loop and, for example, the tensioning strap to pass through a bushing surrounding this on all sides.

The holding elements are preferably designed so that they overlap the tension band from a side edge on a flat side.

In order to additionally secure the tightening strap against sliding out of the respective holding element, a securing element is expediently provided, which secures the tightening strap against sliding out of the holding element. In the simplest case, this securing element can be a nose, on which the tensioning band lies with the side edge, which is not overlapped by the holding element.

It is particularly expedient if the securing element likewise represents a holding element and thus the two holding elements extend from the opposite side edges of the tensioning strap.

The corner elements can be designed in a wide variety of ways.

In order to ensure that corners of workpieces with different angles can be overlapped, it is preferably provided that the corner elements encompass a cavity in a U-shape and have end faces of the legs of the U with which the corner elements act on the workpieces. For example, the corner elements can be placed on corners of workpieces in such a way that the pressure lugs rest on opposite sides of the corners.

The corner elements can be designed so that they act directly on the workpiece with their pressure lugs. However, it is even more advantageous if the corner elements in the area of their pressure lugs are provided with pressure parts pivotably mounted on them, which in turn have pressure surfaces with which the pressure parts act on the workpiece.

For example, the pressure parts are provided with flat or slightly curved pressure surfaces.

The corner elements are preferably designed in such a way that the tensioning band rests on the entire surface transversely to its longitudinal direction in order to achieve the best possible pressure effect.

In addition, the corner elements are also preferably designed such that the pressure lugs are arranged symmetrically to a center line of the tensioning strap.

In addition, the pressure parts are preferably designed so that they extend symmetrically to a central plane of the tension band.

A particularly advantageous embodiment of the strap tensioner according to the invention provides that it for reclamping workpieces of symmetrical and shapeless shape with textile strap and several clamping corners to be underlaid to protect the workpieces and to better slide the tensioning strap along them when tensioning by means of a conventional tensioning element within a tensioning device or a tensioning device is formed, the tensioning strap being guided within the tensioning device or the tensioning device in tensioning channels of deflecting corners - or also called tension members - so that the effect of a double pulley is obtained and, when tensioning, preferably with a spindle between a pressure plate attached at the end and the surrounding housing, the two strap sides are clamped.

It is even more advantageous if, in this solution, the tensioning device - or the tensioning device - consists of the band guide, the housing of the tensioning device and the tensioning element and the tensioning band, the housing enclosing the banding guide in such a way that there is exact guidance for the band no evasion allowed.

Another advantageous variant of the solution according to the invention provides that there are two through openings in the housing on the side toward the workpiece to the strip exit, through which the strip is pulled inward on a radius when tensioning.

Another inexpensive variant provides that the band guide has band channels for deflecting to the depth of the band width and, for ease of installation, markings are fixed on the open side, preferably in the form of an injection molded part made of plastic.

Furthermore, it is expedient in the solution according to the invention if the tape is guided in the tape guide in such a way that the end which is suspended at the fixed point and the opposite side which is pulled in and out are clamped between the pressure plate and the top of the housing can. The stronger the tension on the spindle, the firmer the straps hold.

As an alternative to this, it is advantageous if a depression is provided for the pressure plate in order to be able to completely relieve the tensioning straps for better pulling through by turning back.

Another expedient solution within the scope of the invention provides that a marking is provided on the outside of the housing, which indicates the direction of extension and contraction.

Cams are preferably attached to the housing, which are used to wind up the tape when the tensioning device is stored, and a slot for securing the tape.

Another expedient solution according to the invention provides that the clamping device or the clamping device is additionally equipped with two or more corner elements or clamping corners to protect the workpiece edges and for better sliding of the clamping band around these edges, these being stepless for edges or miter angles of 45 to 120 ° usable and captive can be retrofitted to the strap as required.

Preferably, the clamping corner or the corner element is made in one piece from an open cylindrical shape, the opening being defined such that acute angles and obtuse angles have space in the inner cavity of the hollow cylinder.

It is also expediently provided that the tape is guided in a slot which is open at the top and has a shoulder at the bottom and an insertion bevel at the top and a cam on each side.

This cam is expediently formed on the cylinder and has an insertion bevel with an attachment for band securing that functions as a barb. The approach is deeper than the slot drain.

Furthermore, it is advantageous if parts provided with clamping surfaces are clipped onto a cylindrical section of the clamping corners with a diameter for better contact with the workpiece.

An advantageous embodiment of a belt tensioner according to the invention makes it possible to achieve high clamping force quickly after gripping the workpiece with the simplest operating comfort.

The strap tensioner is also designed as a compact device with strap entry and exit.

For operation, this belt tensioner should be provided with a generally known tensioning element.

The belt tensioner is also preferably equipped with protective or clamping corners for the most common miter angles.

When tensioning, the tensioning strap should be drawn in evenly on both sides. The clamping corners should be able to be used continuously for miter angles or spanned corners from 45 to 120 °, adapt to the manufactured angle and lie slightly springy. Depending on requirements, they should be able to be attached to the tape without having to unwind or wind it up, in order to quickly switch to tensioning with or without tensioning corners. They should also be held captive on the strap. For storage, it is advantageous to be able to wind up the tensioning strap and to attach the protective corners captively to the tensioning device.

Fig. 1

eine Gesamtdarstellung eines ersten Ausführungsbeispiels eines erfindungsgemäßen Bandspanners;

Fig. 2

eine Darstellung einer Spannvorrichtung des ersten Ausführungsbeispiels des erfindungsgemäßen Bandspanners mit teilweise aufgebrochenem Gehäuse;

Fig. 3

einen Schnitt durch einen Teilbereich der Spannvorrichtung längs Linie 3-3 in Fig. 2;

Fig. 4

eine Draufsicht auf die Spannvorrichtung in Richtung des Pfeils A in Fig. 2;

Fig. 5

eine Seitenansicht eines Eckelements ohne Druckteile;

Fig. 6

eine Seitenansicht des Eckelements mit Druckteilen;

Fig. 7

einen Schnitt längs Linie 7-7 in Fig. 6;

Fig. 8

eine Draufsicht auf das Eckelement in Richtung des Pfeils B in Fig. 5;

Fig. 9

eine Draufsicht auf ein zweites Ausführungsbeispiel eines erfindungsgemäßen Bandspanners;

Fig. 10

einen Schnitt längs Linie 10-10 in Fig. 9;

Fig. 11

eine vergrößerte Gesamtansicht des zweiten Ausführungsbeispiels des erfindungsgemäßen Bandspanners beim Spannen mit Eckelementen oder Spannecken;

Fig. 12

einen Schnitt längs Linie 12-12 in Fig. 11;

Fig. 13

einen Schnitt längs Linie 13-13 in Fig. 11;

Fig. 14

eine Seitenansicht eines zweiten Ausführungsbeispiels eines Eckelements;

Fig. 15

eine Draufsicht auf das Eckelement in Richtung des Pfeils C in Fig. 14;

Fig. 16

eine Seitenansicht eines zweiten Ausführungsbeispiels des Eckelements in Fig. 14 mit Druckteilen und

Fig. 17

eine Ansicht eines montierten Druckteils in Richtung des Pfeils D in Fig. 16.

Further features and advantages are the subject of the following description and the drawing of some exemplary embodiments. The drawing shows:

Fig. 1

an overall view of a first embodiment of a belt tensioner according to the invention;

Fig. 2

a representation of a tensioning device of the first embodiment of the belt tensioner according to the invention with partially broken housing;

Fig. 3

a section through a portion of the clamping device along line 3-3 in Fig. 2;

Fig. 4

a plan view of the clamping device in the direction of arrow A in Fig. 2;

Fig. 5

a side view of a corner element without pressure parts;

Fig. 6

a side view of the corner element with pressure parts;

Fig. 7

a section along line 7-7 in Fig. 6;

Fig. 8

a plan view of the corner element in the direction of arrow B in Fig. 5;

Fig. 9

a plan view of a second embodiment of a belt tensioner according to the invention;

Fig. 10

a section along line 10-10 in Fig. 9;

Fig. 11

an enlarged overall view of the second embodiment of the belt tensioner according to the invention when tensioning with corner elements or clamping corners;

Fig. 12

a section along line 12-12 in Fig. 11;

Fig. 13

a section along line 13-13 in Fig. 11;

Fig. 14

a side view of a second embodiment of a corner element;

Fig. 15

a plan view of the corner element in the direction of arrow C in Fig. 14;

Fig. 16

a side view of a second embodiment of the corner element in Fig. 14 with pressure parts and

Fig. 17

a view of an assembled pressure part in the direction of arrow D in Fig. 16th

A belt tensioner shown as a whole in FIG. 1 comprises an outer loop 12a formed from a tensioning belt 10, preferably a textile belt, which, for example, wraps around two workpieces 14 and 16 on its outside and is guided to a tensioning device designated as a whole by 20, which serves to pull the outer loop 12a together.

The tensioning device 20 comprises a housing 22, in which, as shown in FIG. 2, a tension element 24 is arranged, which by means of an adjusting device designated as a whole as 26 relative to a base element designated as 28, which forms a base side of the housing 22 and which has two loop passages 30 and 32, via which the tensioning strap 10 is guided from the outer loop 12a into an interior of the housing 22.

The outer loop 12a is provided with a lock Z with interconnectable and detachable lock elements Z ₁ and Z ₂ , which makes it possible to open the outer loop 12a in order to be able to put the outer loop 12a around the workpieces 14 and 16 without being able to these have to be pushed through the side of the loop. Furthermore, the lock Z creates the possibility, in the event that a particularly large outer loop 12a is required, to open the lock Z and to insert an extension piece between the lock parts Z ₁ and Z ₂ , which is connected at both ends to the lock part Z ₁ or Z _{2 has} connectable lock parts.

As shown in FIGS. 2 and 3, the tension element 24 comprises two parallel side cheeks 40 and 42, between which a spindle nut 44 lies and between which there are also on both sides of the spindle nut 44 and preferably tension rollers 46 and 48 lying symmetrically to the latter extend, which are each rotatably mounted on the side cheeks 42 and 44, so that their axes of rotation 50 and 52 preferably run parallel and in a plane 56 lying perpendicular to an axis 54 of the spindle nut 44.

In addition, on a side of the plane 56 facing away from the base element 28, guide rollers 60 and 62 are provided in a plane 58 parallel to this, which also extend between the side cheeks 40 and 42. The guide rollers 60 and 62 are offset relative to the pull rollers 46 and 48 towards the spindle nut 44, to the extent that a circumferential surface 64, 66 facing the spindle nut 44 has a smaller distance from the spindle nut 44 than one facing the spindle nut 44 Circumferential surface 68, 70 of the pull rollers 46, 48.

The entire pulling element 24 is preferably constructed from two parts 24a and 24b, the part 24a comprising the side cheek 40 and a bearing for the pulling rollers 46 and 48 and the guide rollers 60 and 62, which are integrally formed thereon. Furthermore, the spindle nut 44 is also integrally formed on the cheek 40.

The second part 24b preferably comprises the side cheek 42 and receptacles for the bearings of the pull rollers 46 and 48 and the guide rollers 60 and 62 and a support element 72 which bears against the spindle nut 44 and additionally stabilizes it. The two parts 24a and 24b are connected to one another by conventional securing elements.

As further shown in FIG. 2, the loop 12 starts from a first end 82 that can be fixed in a fixing device 80 and, following the first end, forms with a first loop center 12e a U-shaped loop starting from the fixing device 80 and looping around the pulling roller 46 Loop 84, following which the strand 12e then exits from the housing 22 through the loop passage 30 in the form of a curved passage slot through the base element 18, in order then to form the outer loop 12a lying outside the tensioning device 20.

Furthermore, the tensioning strap 10 extends beyond the first end 82 of the loop 12 and forms an end piece 86 which is fixed to the base element 28 by means of a holding pin 88, the holding pin 88 passing through an eyelet 90 formed by the end piece 86.

From a second end 92, which can also be fixed in the fixing device 80, a second strand 12z of the loop 12 also extends in the form of a U-shaped loop 94 over the pull roller 48, and then
likewise to pass through the loop passage 32 in the form of a curved slot in the base element 28 and to emerge from the housing 22 in order to form the outer loop 12a lying outside the tensioning device 20.

Furthermore, following the second end 92 of the loop 12, the tension band 10 extends beyond the fixing device 80 and forms a tension band reserve 96, which is guided over the peripheral surface 64 of the guide roller 60 of the tension element 24 facing the spindle nut 44 and following the guide roller 60 can be wound on a spool 98 in the form of a winding 100.

As shown in FIG. 4, the coil 98 is arranged between two side walls 102 and 104 of the housing 22 and is rotatably mounted about an axis 108 by means of a shaft 106 passing through the side walls 102 and 104. On one side, a crank 110 is connected in a rotationally fixed manner to the shaft 106, with which the tension band reserve 96 in the form of the winding 100 can be wound on the spool 98.

As further shown in FIGS. 2 and 3, the side walls 102 and 104 are also provided with longitudinal slots 112 and 114, in which the tension element 24 is movably guided in an adjustment direction 116 relative to the base element 28, the tension element 24 being inserted into the longitudinal slots 112 and 114 engages with projections 118 and 120, respectively. Furthermore, that is

Tension element 24 on the inner sides 122 and 124 of the side walls 102 and 104 with outer sides 126 and 128, respectively, and is thereby additionally non-rotatably but displaceably guided in the adjustment direction 116.

The longitudinal slots 112 and 114 run parallel to the adjustment direction 116.

The adjusting device 26 provided for moving the tension element 24 relative to the base element 28 comprises a spindle 130 which passes through the spindle nut 44 and engages with its spindle end 132 in a pressure piece 134 which is additionally provided with a fixing shoe 136.

The spindle 130 with the pressure piece 134 arranged at its spindle end 132 is preferably equipped as a tensioning spindle, which is customary in the case of clamping clamps, with a customary pressure piece 134, the spindle 130 being rotatable by means of a spindle handle 138 which is also common in the case of clamping clips.

The fixing shoe placed on the pressure piece 134 forms, together with an abutment 140 arranged on the base element 28, the fixing device 80, in which the first end 82 and the second end 92 of the loop 12 can be fixed. The fixing takes place in that the two ends 82 and 92 of the loop 12 are clamped between the abutment 140 and the fixing shoe 136 when the spindle 130 is through Turning the spindle handle 138 is rotated so that the tension element 24 moves away from the base element 28 and thus the tension rollers 46 and 48 acting on the loops 84 and 94 in the sense of enlarging them ultimately lead to both the first strand 12e and the second run 12z the tension band of the outer loop 12a is pulled through the loop passages 30 and 32 into the housing 22 while reducing the size of the outer loop 12a. In order to exert the force with which the pulling rollers 46 and 48 act on the loops 84 and 94 to enlarge them, the spindle 130 must ultimately be supported on the base element 28 via the pressure piece 134 and the fixing shoe 136, this being done via that between the fixing shoe 136 and the abutment 140 clamped ends 82 and 92 of the loop 12, so that ultimately the spindle 130 is supported by the fixing device 80 on the base element 28 and thereby also fixes the ends 82 and 92 of the loop relative to the base element 28.

The path traversed by the tension element 24 during its movement away from the base element 28 ultimately has a fourfold effect on the outer loop 12a lying outside the tensioning device 20 by shortening the two loops 84 and 94.

To clamp the workpieces 14 and 16, the outer loop 12a lying outside the clamping device 20 is first placed around the workpieces 14 and 16 either with or without corner elements 140 to be explained, and by winding the tension band reserve 96 on the spool 98 with the adjusting device 26 released outer loop 12a contracted so far that either this directly or via the corner elements, the workpieces 14, 16 enclosing them.

In this released position of the adjusting device 26, the tension element 24 lies in its position closest to the basic element, and thus the fixing shoe 136 is not supported on the abutment 140, so that the tensioning strap 10 continues over the second strand 12z in the form of the tensioning strap reserve 96 can be pulled through the fixing device 80, and then the second end 92 then lies in the fixing device 80 when the outer loop 12a is in contact with the workpieces 14 and 16.

If the spindle handle 180 is now rotated such that the tension element 24 moves away from the base element 28 due to the action of the spindle 130, the spindle end 132 is inevitably supported by the pressure piece 134 and the fixing shoe 136 on the abutment 140, so that the fixing shoe 136 and the abutment 140 formed fixing device 80 non-positively fixes the ends 82 and 92 of the loops by clamping and now the enlargement of the loops 84 and 94 caused by the movement of the tension element 24 has the effect of reducing the size of the outer loop 12a lying outside the tensioning device 20, so that the workpieces 14 and 16 are clamped together.

In order to be able to act upon the workpieces 14, 16 in a targeted manner, preferably in the region of their corners, with a tension force originating from the outer loop 12a, corner elements 140 can preferably be used within the scope of the belt tensioner according to the invention.

5 and 6, each of these corner elements 140 comprises a base body 142, which forms two pressure lugs 144 and 146, between which there is a cavity 148, which the base body 142, which extends up to the pressure lugs 144 and 146, has a cross section U- encompasses.

The cavity 148 serves to receive a corner of one of the workpieces 14 or 16, the base body 142 being supported on the workpiece on both sides of the corner.

The base body 142 can be supported directly with the pressure lugs 144 and 146, provided that there is no superficial damage to the workpieces 14 or 16.

It is particularly advantageous if the pressure lugs 144 and 146 are also provided with pressure parts 148, 150 which, as shown in FIGS. 6 and 7, have flat pressure surfaces 152 with which the pressure parts 148 and 150 on the surface of the respective workpiece 14 , 16 can be placed. The pressure surfaces 152 form the surface of a pressure plate 154, from the opposite narrow sides of which on one side of the pressure plate 154 opposite the pressure surface 152, support plates 156 and 158 project, with which the pressure parts 148 are pivotally mounted on the pressure lugs 144 or 146 about an axis 160 .

The bearing plates 156 and 158 preferably have bores 162 into which a cylindrical projection 168 and 170 arranged on opposite outer sides 164, 166 of the pressure lugs engages, thereby forming a pivot bearing for the pressure parts 148.

The base body 142 has an extension in the direction of the pivot axis 160 and thus also in the longitudinal direction of the pressure surface 152, which ensures a secure support of the tension band 10 with its entire width transverse to its longitudinal direction.

For this purpose, the base body 142, as shown in FIGS. 5 and 8, forms on its side opposite the cavity 148 a preferably arched bearing surface 180 for the Tensioning strap 10, whereby on both sides of the support surface 180 of the base body 142, lateral webs 182 and 184 rising up over the support surface 180 are formed, between which the tensioning strap 10 is guided resting on the support surface 180 and which prevent the tensioning strap from sliding sideways over the support surface 180.

In addition, from each of the side webs 182 and 184 extend approximately to a center line 186 of the support surface 180, which also represents a center line of the tensioning band 10 lying thereon, and in the longitudinal direction of the tensioning band 10, spaced apart projections 188 and 190, which overlap the support surface 180 at a distance therefrom and leave a space 192 or 194 between itself and the support surface 180, so that the tensioning band 10 can be pulled through this space. Thus, the tensioning strap 10 can be fixed to the base body 142 not only on both sides of the support surface 180 by the side webs 182 and 184 but also opposite the support surface 180 by means of the projections 188 and 190 such that the tensioning strap 10 cannot slide over the base body 142 by itself, so that the base body 142 is also guided on the loose tensioning strap in the longitudinal direction thereof, since the projections 188 and 190 prevent a complete detachment from the bearing surface 180.

Due to the fact that the projections 188 and 190 each only extend to the center line 186 of the support surface 180, the insertion of the tensioning band 10 into the spaces 192 and 194 is possible in a simple manner, namely by the fact that the tensioning band in the direction of the respective projection 188 or 190 carrying side web 182 or 184 can be inserted into the space 192 or 194.

The base body 142 is preferably formed by two halves 142a and 142b, which are of identical design and abut one another in a plane running along the center line 186 and are fixed relative to one another.

In a second exemplary embodiment, shown in FIGS. 9 to 15, the tensioning device designated 210 in FIG. 9 comprises a tape guide 212 - which represents the tension element - a housing 214, a tensioning spindle 216 with a pressure plate 218 and a spindle handle 220.

The tensioning strap 222 is shown exposed, for example with its outer loop, around two workpieces 224 and 226.

In the simplest case, when the tensioning strap is pulled in the direction of arrow 223, the tensioning strap lies directly against the workpieces 224 and 226. On the spindle handle 220 is about Spindle 216 guides the pressure plate 218 out of its zero position in a depression 213 and rests on the upper part 215 of the housing 214, which forms the basic element.

The pressure plate 218 clamps between itself and the upper part of the housing 214 the strap sides 225 and 227 - or also called the ends of the loop of the tensioning strap - and makes an additional tightening of the strap sides 225 and 227 unnecessary with the tensioning process.

Locking elements that are otherwise necessary are thus eliminated.

The band end 225 shown at the top in FIG. 9 is held firmly in a region 203 of the housing 214 and is guided in the other direction around a deflection corner 230 through a housing opening 209 of the housing 214 to the outside. The lower band end 227 shown is led out of the housing 214 around a corner 233 to an actuation side.

In the other direction, it runs around a deflection corner 232 and, after passing through a housing opening 207, forms the opposite side of the workpiece enclosure.

By means of a nut thread 217 in the band guide 212, the pressure plate 218 pushes the housing 214 in the direction of the workpiece 26 and pulls the tension band twice around the deflection corners 230 and 232 of the band guide 212.

, also $\text{s = 4h}$

.As a result, a double pulley comes into effect and doubles the stroke of the spindle 216 during the tensioning process on both sides. If the stroke of the spindle is 216 hours, the total travel of the belt is $\text{s = 2x2h}$

, so $\text{s = 4h}$

.

The housing 214 tightly surrounds the band guide 212 - or also called the tension element - and with lateral inner surfaces 234 or 235 results in an exact guide for the band guide 212 during the tensioning process.

In order to prevent the belt guide 212 from completely falling out, latching cams of generally known design can be provided on one of the two parts 212 and 214, which are preferably made of plastic.

The tape guide 212 - or also called the tension element - is preferably provided with arrow markings 236, which facilitate insertion of the tensioning tape, as shown in FIG. 9.

Protrusions are provided on the housing 214, preferably represented by cams 237 and 238, between which the tensioning strap 222 can be wound up while the tensioning device is stored. One end of the tensioning strap can be secured in a slot 239 against unintentional winding.

10 shows a plan view of a clamping device 210 without the workpieces 224 and 226. The tensioning strap 222 that is brought out is drawn cut off on both sides.

The preferably provided reinforced wide tension band 222 is exactly between a longitudinal side 240 of the housing 214 and the band guide 212, i. H. the traction element, guided, twisting and deflection is not possible.

The band channels provided for the tension band 222 in the band guide 212 have a depth up to a stable lower part 241 of the band guide 212, which corresponds to the band width with some additional play. This gives a belt center or an actuation axis 205 an asymmetrical position which accommodates manual actuation when resting on a support.

12, the clamping device 210 is shown together with four suspended corner elements or clamping corners 250 and an inserted workpiece 252. An enlarged representation 254 of one of the four clamping corners 250 shows the structural embodiment more clearly.

A base body 256 is designed as a hollow body, preferably with its own spring, in the present case as an open one Cylinder that resiliently spans the corners and mitres with an opening 258. The workpiece 252 abuts with a rounding 260 which is suitable for all angles.

In an interior of the base body 256, which is designed as a hollow body, there is space for workpiece tips which are exposed for observation, for example alternatively for acute angles 261 or obtuse angles 262 in the region of the workpiece tips in FIG. 3.

The likewise cylindrical outer shape of the tensioning corner 254 allows the tensioning strap 222 to slide along during tensioning without great friction losses. It runs within a slot 264 on the shoulder 265 visible in section along a line 12-12 (in FIG. 12).

An insertion slope 266 is provided on the opposite side. Two barbs 267 and 268 prevent accidental loss of the corners 254.

In a section along line 13-13 shown in FIG. 13, a corresponding shoulder 269 and an insertion bevel 270 are shown.

In order to make it easy for a user to see, in the embodiment shown a double arrow 271 is provided on the housing 214, which clearly indicates the direction for pulling the tensioning strap in or out.

The arrangement of lugs 267 and 268 and the shoulder 269 is again clearly shown in FIGS. 14 and 15, the shoulder 269 of the lugs 267 and 268 being clearly below one end 272 of the slot, so that the tensioning strap is secured against slipping out.

16 and 17, clamping corners 250 with a rotatably arranged clamping surface 274 are shown. In an opening, which ends at a height, indicated by a point 275, and allows clearance at a depth, indicated by a point 276, a part 277 is rotatably clipped onto a section of the base body 256 forming a cylindrical surface with a diameter 278.

The clamping surface 274 has around a transition radius 280. The axis of rotation 279 of the pressure plate 277 corresponds to the asymmetrically arranged axis 205 in FIG. 10.

A strap tensioner with a tensioning device or tensioning device 210, which is additionally provided with, is particularly advantageous two or more clamping corners 250 for protecting the workpiece edges and for better sliding of the clamping band 222 around these edges is provided.

It is particularly expedient if the clamping corners 250 or corner elements can be used continuously for edge or miter angles from 45 ° to 120 °.

These clamping corners 250 or corner elements are expediently captively mountable on the clamping band 222 as required.

Furthermore, it is particularly expedient if, as shown in FIGS. 14 and 15, the clamping corner 250 is made in one piece in an open cylindrical shape. Preferably, the opening 258 - as shown in FIG. 11 - is defined in such a way that acute angles - denoted by reference number 261 - or even obtuse angles - denoted by reference number 262 - have space in the inner space or cavity of the hollow cylinder.

Furthermore, it is particularly advantageous if the tape is guided in a slot 264 which is open at the top, has a shoulder 265 at the bottom and has an insertion bevel 266 at the top and a cam 267 and 268 is formed on the cylinder on each side, with a Entry chamfer 270 and a barb 269 acting as a barb to secure the strap. The approach 269 is lower than the slot outlet 272.

Furthermore, as shown in FIGS. 16 and 17, the respective clamping corner 250 - or also called corner element - is provided with parts 277 - or also called pressure parts - provided with clamping surfaces 274 - or also called pressure parts - for better contact with the workpiece 252, which have a rounded shape a part of the clamping corner 256 forming a diameter 278 are clipped on.

In addition, it is advantageously provided that the center line 279 of the recess provided in the clamping corner 256, formed by the boundaries 275 and 276, corresponds to the center line marked with 205 in FIG. 10.

Claims (36)

Belt tensioner with a tensioning strap (10, 222), which forms an outer loop (12a) for looping around one or more workpieces (14, 16, 224, 226) and with a tensioning device (20, 210), by means of which the outer loop (12a ) for clamping the workpiece or the workpieces (14, 16, 224, 226) can be contracted, characterized in that the clamping device (20, 210) is a base element supported on the loop (12) with a loop passage (30, 32; 209) (28; 215) that the tensioning device (20, 210) comprises a tension element (24; 212), that the tension element (24; 212) and the base element (28; 215) relative to each other by means of an adjustment device (26, 216) are movable and that the loop (12) runs between the base element (28; 215) and the tension element (24; 212) and engages on it in such a way that with a relative movement of the base element (28; 215) and tension element (24; 212) the outer loop (12a) under the action of a double pulley is contractible. Belt tensioner according to claim 1, characterized in that the loop (12) with a first point (82, 92; 225, 227) on the base element (28; 215) and at least two further points (84, 94) on the tension element (24; 212 ) is attacking. Belt tensioner according to claim 2, characterized in that the loop (12) forms two loops (84, 94), the bends of which form the two further points with which the loop (12) rests on the tension element (24, 212). Belt tensioner according to one of the preceding claims, characterized in that the size of the loop (12) can be varied. Belt tensioner according to claim 4, characterized in that a first end (82; 225) of the loop (12) is arranged at a fixed point on the tensioning strap (10; 220) and that the tensioning strap (10; 220) extends over a second end ( 92; 227) of the loop (12) continues as a tension band reserve (96) and that the size of the loop (12) can be varied by reducing or increasing the tension band reserve (96). Belt tensioner according to claim 5, characterized in that the first end (82; 225) and the second end (92; 227) of the loop (12) act on the tensioning device (20, 210). Belt tensioner according to claim 6, characterized in that a fixing device (80) is provided with which the second end (92; 227) can be fixed to the tensioning device (20, 210). Belt tensioner according to claim 7, characterized in that the first end (82; 225) and the second end (92; 227) can be fixed in the fixing device (80) of the tensioning device (20, 210). Belt tensioner according to claim 7 or 8, characterized in that the fixing device (80) acts non-positively on the tensioning belt (10, 222). Belt tensioner according to one of claims 7 to 9, characterized in that the fixing device (80) has a fixing element (136; 218) and an abutment (140; 215), between which the tensioning band (10; 222) can be clamped. Belt tensioner according to one of claims 7 to 10, characterized in that the fixing device (80) and the adjusting device (26) can be actuated simultaneously. Belt tensioner according to claim 11, characterized in that the fixing element (136; 218) can be actuated by the adjusting device (26) when the base element (28; 215) and the tension element (24; 212) are moved relative to one another. Belt tensioner according to claim 12, characterized in that the adjusting device (26) is supported on the base element (28; 215) via the fixing device (80). Belt tensioner according to one of the preceding claims, characterized in that the tension element (24; 212) has two tension bodies (46, 48; 230, 252), one of which in each case at one of the at least two points (84, 94) on the loop ( 12) works. Belt tensioner according to claim 14, characterized in that the tension members (46, 48; 230, 232) are arranged on both sides of the adjusting device (26) on the tension element (24; 212). Belt tensioner according to one of the preceding claims, characterized in that the adjusting device comprises a spindle (130; 216) and a spindle nut (44; 213) running on the spindle (130; 216). Belt tensioner according to claim 16, characterized in that the spindle nut (44; 213) is held on the tension element (24; 212) and the spindle (130; 216) is supported on the base element (28; 215). Belt tensioner according to claim 17, characterized in that the spindle (130, 216) is supported with a spindle end (132) on the fixing element (136; 218) of the fixing device (80). Belt tensioner according to one of the preceding claims, characterized in that the tension element (24; 212) is guided on a linear guide connected to the base element (28; 215) in the direction of or away from it, but is non-rotatably guided. Belt tensioner according to claim 19, characterized in that the linear guide is part of a housing (22; 214) of the tensioning device (20, 210). Belt tensioner according to one of the preceding claims, characterized in that the base element (28; 215) is part of the housing (22; 214). Belt tensioner according to one of the preceding claims, characterized in that the base element (28; 215) has two guide openings (30, 32; 209) for each strand (12e, 12z) of the loop (12). Belt tensioner according to claim 22, characterized in that the guide openings (30, 32; 209) are placed in such a way that the respective strand (12e, 12z) of the loop (12) adjoins the loop (84, 94) formed in each case Basic element (28; 215) and tension element (24; 212) extends through the respective guide opening (30, 32; 209). Belt tensioner according to one of claims 5 to 23, characterized in that the tensioning device (20; 210) has a carrier (98; 214) for the tensioning band reserve (96). Belt tensioner according to claim 24, characterized in that the carrier (98; 214) is designed as a winding body for the tensioning band reserve (96). Belt tensioner according to one of the preceding claims, characterized in that the outer loop (12a) is provided with corner elements (140; 250) for loading the workpieces (14, 16; 252). Belt tensioner according to claim 26, characterized in that the corner elements (140; 250) can be fixed captively on the tensioning belt (10, 222). Belt tensioner according to claim 27, characterized in that the corner elements (140; 250) are provided with holding elements (188, 190) which engage on the tensioning belt (210; 222). Belt tensioner according to claim 28, characterized in that the holding elements (188, 190) are designed such that the tensioning band (10) can be pushed transversely to its longitudinal direction into a position on the corner elements (140) fixed by the holding elements (188, 190) . Belt tensioner according to claim 28 or 29, characterized in that the holding elements (188, 190) overlap the tensioning belt (10) from a side edge on a flat side. Belt tensioner according to one of claims 28 to 30, characterized in that the tensioning band (10) is secured against sliding out of the respective holding element (188, 190). Belt tensioner according to one of claims 26 to 31, characterized in that the corner elements (140; 250) encompass a cavity (148) in a U-shape and have the ends of the legs of the U pressure lugs (144, 146) with which the corner elements (140; 250) act on the workpieces (14, 16; 252). Belt tensioner according to claim 32, characterized in that the pressure lugs (144, 146) rest on opposite sides of the corners of the workpieces (14, 16). Belt tensioner according to claim 32 or 33, characterized in that the corner elements (140, 250) in the region of their pressure lugs (144, 146) are provided with pressure parts (148, 150) which are pivotably mounted on these and which in turn have pressure surfaces (152; 274) with which the pressure parts (148, 150) act on the workpiece (14, 16; 252). Belt tensioner according to claim 34, characterized in that the pressure parts (148, 150) are provided with flat or slightly curved pressure surfaces (152; 274). Belt tensioner according to one of Claims 26 to 35, characterized in that the corner elements (140; 250) are designed such that the tensioning belt (10; 222) lies on the entire surface of the latter.

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