DE29923094U1 - Foldable frame - Google Patents

Description

Foldable frame

The invention relates to a foldable frame for stretching a material to be processed, consisting of four interconnected rods which are approximately at right angles to one another and on which the material is stretched via fastening devices.

There are known generic stretcher frames for silk scarves, which consist of four bars arranged at approximately right angles to each other. All bars have guides along their length, into which the other two bars are inserted and secured using metric screws and wing nuts. By moving at least one bar in the guides of the adjacent bars, the frame can be adjusted to the size of the material to be processed.

In other tension frames, the bars have slots for the cross bars at equal intervals, which allows the frame size to be varied.

The silk cloth is attached to the frame with trident pins or claws.

The disadvantage is that the slats have to be screwed together again and again before use and/or adjusted to the size of the fabric. With flat frames, screwing the slats together creates a staircase.

When handling it, not only is the time-consuming stretching and unstretching of the cloth to be processed a disadvantage, but also that, depending on the size of the cloth, two to four strips protrude.

The invention is therefore based on the object of providing a clamping frame which is easy to assemble.

According to the invention, the object is achieved in that two opposing rods are divided approximately in the middle into two sections, wherein a first end of the two sections of each divided rod is movably connected to one another via a first folding device and the first folding device in the unfolded state encloses a first angle of 180 ° between the two sections of a rod, wherein the first axis of rotation of the first folding device runs outside the interior of the frame and each end of an undivided rod is connected to the second end of a section of the divided rod via a second folding device which in the undivided state encloses a second angle of 90 ° between the divided and the undivided rod and the second axis of rotation of the second folding device runs inside the frame, wherein in the folded state the sections of each divided rod are arranged parallel to one another and parallel between the undivided rods.

The invention has the advantage that the frame does not need to be screwed together. After work is completed, the folded frame forms a space-saving, handy unit. There is no risk of injury from protruding ends of the strips. It is also easy to transport when folded, as there are no loose parts at all. The frame can be assembled and disassembled quickly.

Advantageously, in the unfolded state, a locking device is provided in the region of the first folding device, which stabilizes the two first ends of the two sections of the undivided rod in the unfolded state, thereby preventing the frame from collapsing during processing of the material.

In one embodiment, a recess is provided on the first section of the divided rod, into which a tongue, which projects beyond the front surface of the second section and is arranged on the second section, engages in the unfolded state. The recess is designed to be open towards the second section and towards the interior of the frame for the lateral insertion of the tongue.

In order to achieve a secure mechanical locking, the tongue engages in the recess in a form-fitting manner, wherein the tongue has a first opening which lies between a second and a third opening of the first section of the split rod and a pin, a screw, a bolt or a split pin extends through the three continuous openings.

Alternatively, the recess has magnetic areas which, when unfolded, are opposite metallic or magnetic areas of the tongue. Conversely, the recess can also be provided with metallic areas between which the magnetic areas of the tongue engage.

In a particularly simple design, the separately formed tongue itself is made of magnetic material, which is firmly embedded in the second section of the split rod.

In another development, the recess has two opposing snap devices into which the tongue engages in a force-fitting manner.

Advantageously, the recess is formed by the two snap devices themselves, which significantly reduces the manufacturing effort of the frame.

Each snap device consists of a ball that partially protrudes from a housing and is connected via a spring through a screw unit

can be pre-tensioned. The tongue has an area that is shaped opposite to the balls and which, when unfolded, engages force-fittingly between the two snap-in devices of the recess. When snap-in devices are used, additional assembly steps, such as inserting split pins, are not necessary.

Additional stabilization of the frame is achieved by the fact that the ends of the divided and undivided rods connected via the second folding device are designed in such a way that one end has a recess open to the rod end, into which a projection of the other end engages in a form-fitting manner in the unfolded state

In an advantageous embodiment for stretching the material between the rods at a distance, the fastening devices arranged at predetermined distances each have a ring-like holding means, on which means for clamping the material are arranged via an elastic connection. The cloth to be processed is no longer attached to the frame and therefore no longer rests on it. The material is no longer soiled by paint that has dripped onto the frame. The frame also no longer needs to be taped off for protection. The clamps enable the cloth to be attached quickly and easily. If work is interrupted, the frame can either remain standing or it can be folded up with the cloth to be processed. The silk is stretched once and remains attached to the frame until the end of the work, even when the frame is folded up.

The use of clamps avoids holes in the material being worked on, such as those caused by claws or trident pins. In particular, the use of the elastic band as a connection between the clamps and the fastening devices arranged on the frame ensures that the fabric, which gives way under the influence of moisture, is automatically re-tensioned.

In a further development, the elastic connection is designed as a one-piece elastic band which is guided through the fastening devices of all four rods.

However, it is easier to tension the material to be processed if the elastic connection is designed as a multi-part elastic band, with each part of the elastic band being attached to a rod.

There are various ways in which the ends of the elastic bands can be attached to the rod. One end of the elastic band can be glued to the rod. Another option is to hook one end of the elastic band onto the rod.

The elastic band is either pulled loosely through the ring-like holding means or inserted into the ring-like holding means through a gap.

In a particularly simple development, eyebolts are used as holding and fastening devices. The eyebolts simultaneously meet the requirement of fastening to the frame and holding the elastic band.

To ensure that the frame can be placed on a table for processing, at least one leg is mounted on each undivided bar in a pivoting manner. This leg is arranged parallel to the bar on the side of the bar facing away from the inside of the frame and, when pivoted, runs almost perpendicular to the bar, engaging in a foot holder. The legs ensure that the frame is at a greater distance from the base, with the frame forming a predetermined angle with the base.

Alternatively, clamp-like means are provided for fastening the frame to a flat support object. Advantageously, the clamp-like means engage in a bore of a section of a split

bar, which rises within the bar. This also means that the frame is slightly angled to the base.

In a further embodiment, each undivided rod has a guide for fastening to a frame stand device. The guide is designed as at least one bore for receiving a screw device of the frame stand device or as a longitudinal hole extending along the longitudinal extent of the rod.

The invention allows for numerous embodiments. One of these will be explained in more detail with reference to the figures shown in the drawing.

It shows:

Figure 1: Frame according to the invention in the unfolded state

Figure 2: Side view of a split bar in the unfolded state

Figure 3: Side view of a split bar with bolt and magnet

Figure 4: Side view of an unfolded split bar with magnet

Figure 5: Frame according to the invention in the folded state

Figure 6: split strips with magnets in folded state

Figure 7: Eyebolt

Figure 8: first recess with snap-in device

Figure 9: second recess with snap-in device

Figure 10: Recess with magnetic device

Figure 11: Top view of an undivided bar

Figure 12: Side view of an undivided bar

Figure 13: Cushion tensioning device

Figure 14: Side view of a reducing strip

Figure 15: Top view of the frame according to the invention with reducing strip

Figure 16: Frame mask

Figure 17: Foot

Identical features are marked with the same reference symbols.

For painting on textile materials, such as silk painting, a folding frame is used, which can be made of wood, metal, plastic or other natural materials. The folding frame according to the invention consists, as shown in Figure 1, of two undivided strips 1, 2 and two strips 3, 4, each divided into equal sections 5, 6 and 7, 8. The undivided strips 1, 2 form a rectangle with the divided strips 3 and 4 arranged between them.

The sections 5 and 6 of the first split strip 3 arranged one behind the other are connected to one another via a first hinge 9 and the sections 7 and 8 of the second split strip 4 are connected to one another via a second hinge 10. The hinges 9 and 10 are arranged on the surfaces 12 and 13 of the split strips 3 and 4 facing opposite to the frame interior 11, i.e. on the outside of the frame, and enclose an angle of 180° when unfolded. The axis of rotation of the hinges 9 and 10 runs outside the frame interior 11 perpendicular to the stretched frame.

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Each end of an undivided strip 1, 2 is joined to the second end of a section of a divided strip 3 or 4, with both strips enclosing an angle of 90 ^° . Thus, the end 1a of the undivided strip 1 is connected to the section 7 of the divided strip 4 and the end 1b to the section 5 of the divided strip 3.

Equivalently, the end 2a of the undivided bar 2 is joined to the section 6 of the split bar 3 and the end 2b is joined to the section 8 of the split bar 4.

The sections explained are each movably connected to one another via a hinge 14, 15, 16, 17, whereby the two hinge parts form an angle of 90° and are attached to the side of the strips 1, 2, 3, 4 facing the frame interior 11. Consequently, the axis of rotation of the hinges 14, 15, 16, 17 inside the frame also runs perpendicular to the clamped frame.

Eyebolts 24 (Figure 7) are attached at regular intervals to the undivided strips 1 and 2 and the divided strips 3 and 4. A rubber cord 26 is loosely pulled through the ring-shaped heads 25 of the screws 24. Clamps 27 are also attached to the cord 26 at regular intervals. These clamps 27 are used to attach the material to be processed, which is not shown in more detail. In most cases, the material has a rolled edge, which is gripped behind by the clamps 27.

The rubber cord 26 advantageously consists of four separate sections 26a, 26b, 26c and 26d, which are each attached to a rod 1, 2, 3, 4. The attachment is made on one side by gluing, screwing or nailing to the rod 1, 2, 3, 4, while the other end of each rubber cord 26a, 26b, 26c, 26d has a hook 31 which is attached to any eyebolt 24 to set the desired tension state of the material to be processed. In principle, however, it is also possible to attach hooks to both ends of each section 26a, 26b, 26c and 26d of the rubber cord 26 for fastening and tensioning the rubber cord 26.

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The use of the elastic cord 26 has the advantage that the fabric can be stretched at a distance from the frame, so that the fabric can be prevented from becoming dirty with paint residue on the strips 1, 2, 3, 4. In addition, the use of moisture-containing paints leads to a reduction in the tension of the fabric, but this is compensated for by the elasticity of the cord 26, which means that there is no need for laborious re-tensioning of the fabric during the painting process. The use of the cord 26 also makes it very easy to adjust the tensioning device to the respective fabric size. There is no need to adjust the size of the frame itself.

A locking tongue 18 is firmly arranged on section 5 of the split bar 3. Another locking tongue 19, which is also firmly anchored, is attached to section 8 of the split bar 4.

The locking tongue 18 is made of a light metal and is incorporated into the respective section 5 of the divided strip 3 in such a way that it projects beyond the front side of section 5, which is opposite section 6. In section 6, a recess 20 is incorporated which is open towards the front surface of section 5 and is also partially open on the surface of section 6 facing the interior 11 of the frame. In the unfolded state, the locking tongue 18 engages in the recess 20 in a form-fitting manner.

The locking tongue 19 of section 8 is also designed in the manner described. The section 7 opposite section 8 has an equivalently designed recess 21 into which the locking tongue 19 engages.

As can be seen from a side view of the split bar 4 in Figure 2, the locking tongue 19 has a hole 23 which, after the locking tongue 19 has been inserted into the recess 21 of the section 7, lies between two through holes 24a, 24b of the section 7. A pin 22 is passed through the hole 23 of the locking tongue 19 and the holes 24a, b of the section 7 of the split bar 4 and on the opposite side with

a nut 62. An equivalent device, not shown in more detail, is provided for the locking tongue 18 of the divided bar 3, the locking tongues 18 and 19 pointing in opposite directions.

Figure 3 shows a split strip in the unfolded state of the frame. A bolt 22 is guided through the opening 22 of the locking tongue 19 and through the openings 24a, 24b of the section 7. A magnetic plate 42 is arranged in the opening 24b in order to additionally hold the bolt magnetically.

A purely magnetic solution is shown in Figure 4. The sections 7 and 8 of the divided strip 4 each have a magnet 42, which are arranged on the sections 7, 8 such that they are directly opposite each other when the frame is unfolded.

Alternatively, the two sections 5 and 6 or 7 and 8 can be connected and released again using the principle of a "ballpoint pen". In this case, two pins are inserted opposite one another in the section that holds the locking tongue. After inserting the tongue, the pins engage in the tongue on both sides when a button is pressed and hold it. If the connection is to be released again, pressure is also applied to the pins and they are reset.

To fold the frame, the pin 22 is removed and the sections 5, 6 and 7, 8 are pivoted in the direction of the arrow (Figure 1).

Figure 5 shows the frame in the folded state. Due to the special arrangement of the hinges 9 and 10 on the outside of the divided strips 3 and 4 and the hinges 14, 15, 16, 17 on the inside of the undivided or divided strips 1, 2, 3, 4, the ends of the sections 5, 6 and 7, 8 covered with the hinges 9 and 10 move in the direction of the frame interior 11. When the frame is completely folded, the folded sections 5, 6 of the first divided strip 3 and the folded sections 7, 8 of the second divided strip 4 are aligned and parallel to the

undivided strips 1, 2, which almost completely enclose the sections 5, 6, 7, 8 of the divided strips 3, 4. The divided strips 3, 4 are so much shorter that they do not collide with the other divided strip when folded.

A particularly high level of stability is achieved by the locking tongue 18 of the split bar 3 engaging in the recess 21 of the split bar 4 and the locking tongue 19 of the split bar 4 engaging in the recess 20 of the split bar 3.

Figure 6 shows the interlocking of the split strips in the folded state with the aid of the magnetic connection explained in connection with Figure 4. The magnetic plates 42 of section 5 of the split strip 3 and section 7 of the split strip 4 are opposite one another. The same applies to the magnets of section 6 of the split strip 3 and section 8 of the split strip 4. A frame folded in this way has a high packing density.

In order to ensure that the strips fit exactly when unfolded, the undivided strips 1, 2 have a pin 28a, 28b, 29a, 29b at each end 1a, 2a, 1b, 2b pointing outwards in the longitudinal direction of the strip 2. (Figure 5)

When the frame is clamped, each pin 28a, 28b, 29a, 29b engages in a recess 30a, 30b which is formed at the associated end of the sections 5, 6; 7, 8 of the frame. (Figure 2)

As an alternative to the splint solution, the connection of the two sections 5 and 6 of the split bar 3 or the sections 7 and 8 of the split bar 4 can also be made using a snap device. As can be seen from Figure 8, two identically constructed snap devices 33, 34 are embedded in the section 5 in such a way that they are exactly opposite each other in the recess 20.

Each snap device 33, 34 consists of a ball 35a, 35b, which is pre-tensioned by means of a screw device 36a, 36b via a spring 37a, 37b. The ball 35a, b partially projects beyond the pre-tensioning spring 37a,

37b and the screw device 36a, 36b formed by a grub screw and is located in the recess 20. The recess 20 is narrowed on the inside by the opposing balls 35a, 35b of the two snap devices 33, 34. When the locking tongue 18 is inserted into the recess 20, the balls 35a, 35b are displaced. However, since the springs 37a, 37b represent a counterforce, the locking tongue 18 is held in a force-locking manner so that the frame is reliably prevented from collapsing while the material is being processed. The pre-tensioning force of the springs 37a, 37b is simply adjusted from the outside by changing the position of the grub screws 36a, 36b.

In another embodiment of the invention according to Figure 9, the recess 20 is formed by the two snap devices 33, 34 themselves, which are attached to the front face of the section 5 by means of a U-shaped support 39. On the front face of the opposite section 6, a projection 41 having two domes 63 is attached as a counterpart. The domes 63 have the opposite shape of the balls 35a, 35b. When the frame is in the unfolded state, the domes 63 are pressed between the balls 35a, 35b and held there.

In addition to the snap-in device, a magnetic locking of the two sections 5 and 6 or 7 and 8 of the divided rods 3, 4 is also conceivable. For this purpose, several magnetic plates 42, 43, 44 are attached to the inner surfaces of the recess 20. When the locking tongue 18, which has a magnetic or metallic insert 45, is inserted, a stable, force-locking connection is created, which makes further mechanical locking aids such as screws unnecessary. (Figure 10)

To raise the folding frame according to the invention, feet are attached to the undivided strips 1, 2. The attachment of such a foot 46 will be explained with reference to Figure 11. The foot 46 is arranged on the side of the strip 1 (or strip 2) facing away from the frame interior 11 via a lock screw 48 and runs parallel to the strip 1. After loosening the screw threaded through the strip 1 and the foot 46,

•♦ ·

The foot 46 is pivoted in a direction perpendicular to the bar 1 by means of the lock screw 48, the head of which points towards the interior of the frame 11, or the wing nut 70 sitting on the lock screw 48, and in doing so it engages in a receptacle 47 formed on the bar 1. Once the foot 46 has reached this position, the lock screw 48 or the wing nut 70 is tightened again. Depending on the length of the pivoting foot 46, the frame is placed at a predetermined angle to its base, which enables better processing of the material. To attach the foot 46 to a table, each foot 46 has a through-hole 61. A screw clamp (not shown) engages in these holes and thus holds the frame in the desired position. (Figure 17) In addition, a hole 68 is provided on the foot for attachment to the frame using the lock screw.

Figure 12 shows a side view of the undivided strips 1, 2. These have a continuous recess 49 almost over their entire length. This recess 49 serves to accommodate screw devices of a frame stand device (not shown in more detail). (Figure 12a). The longitudinal extent of the recess 49 allows the frame to be attached to the stand device at variable heights. In a simpler design, the undivided strip 1 has only two holes 50, 51 for the screws of the frame stand device. Height adjustment is not possible with this. (Figure 12b)

For processing a cushion, four additional clamping corners 53, 54, 55, 56 are provided, which are each inserted into a cushion corner and are clamped together by individual struts 57, 58, 59, 60. (Figure 13). The corners of the cushion, each provided with a clamping corner 53, 54, 55, 56, are each gripped by a clamp 27 and are clamped by pulling the rubber strands 26a, 26b, 26c, 26d. Cushions can also be processed in this way using the folding frame.

The cushion tensioning device can also be designed in one piece, whereby the struts 57, 58, 59, which firmly connect the tensioning corners 53, 54, 55, 56

60 made of elastic material to facilitate the insertion of the clamping device into the cushion to be worked on.

If materials with a small size are to be processed, the frame described so far can be reduced in size using a freely movable bar 66. This bar engages with both sides in a guide of the undivided bars 1, 2 and is locked in the position that corresponds to the desired clamping surface. The guides of the bars 1, 2, which are designed as elongated holes 49, can be used in a particularly simple manner for this purpose. The reducing bar 66 has projections 66a and 66b that engage in the elongated holes 49. (Figure 14)

The undivided strips 1, 2 have through holes 64 into which a screw engages to secure the reducing strip 66 in the desired position. This screw is guided through the holes 64a or 64b in the projections 66a, 66b of the reducing strip 66. (Figure 15) Instead of a screw, a pin, a split pin or a bolt can also be used.

In order to arrange the frame on a wall, two picture holders are attached to one of the strips 1, 2. When used as a picture, a textile frame mask 65 is stretched over the frame, which covers the frame but has an opening in the middle through which the painted fabric is released. (Figure 16)

In addition, the folded frame can be stored in a waterproof carrying bag, which is made of a durable, strong fabric and has a strap. Pockets can be attached to the outside of the carrying bag using snap fasteners or Velcro fasteners, in which brushes or painting accessories can be stored and transported.

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1 bar / strip, undivided (ends 1a and 1b)

2 bars / strips, undivided (ends 2a and 2b)

3 bars / strips, split

4 bars / strips, split

5 Bar / Strip 3, split, 1st section

6 Bar / Strip 3, split, 2nd section

7 Bar / strip 4, split, 1st section

8 Bar / Strip 4, split, 2nd section

9 External hinge, split bar / strip 3

10 External hinge, split bar / strip 4

11 Frame interior

12 Outer surface to bar / strip 3

13 Outer surface to bar / strip 4

14 Hinge rod / bar, connection 2-4/8

15 Hinge rod / bar, connection 2-3/6

16 Hinge rod / bar, connection 1-3/5

17 Hinge rod / bar, connection 1-4/7

18 Tongue/lock, split bar/bar 3/5

19 Tongue/lock, split bar/bar 3/8

20 Recess split bar / strip 3

21 Recess split bar / strip 4

22 pin, cotter pin, bolt, eyebolt, magnet, ....

23 Opening/bore for 22, split bar / strip 3 /

24 Eyebolt (24a / 24b, opening section / bar 6 /

25 ring-like holding device / eyebolt head

26 elastic connection/rubber cord (sections 26a - 26d)

27 bracket(s)

28 Spring / pin (ends 28a and 28b)

29 Spring / pin (ends 29a and 29b)

30 Recess (ends 30a and 30b

31 hooks

32 Gap of the ring-like holding means/eyebolt

33 Snap-on device split bar / strip 3/4

34 Snap-on device split bar / strip 3/4

35 Ball of the snap device (35a, 35b)

36 Screw device / grub screw of the snap device (36a, 36b)

37 Preload spring (37a, 37b)

38 receiving housing (38a, 38b)

39 U-shaped carrier snap closure

40 Hole on frame for clamp

41 Moulded area/protrusion for snap closure

42 magnetic sheets

43 magnetic sheets

44 magnetic sheets

45 magnetic area/tongue

46 feet/leg

47 Holder for foot

48 carriage bolt

49 Recess/long hole rod / strip 1 /

50 Hole for frame stand device rod / bar 1 /

51 Hole for frame stand device rod / bar 1/2

52 Hole on frame for foot / leg

53 stretch corners for cushions

54 stretch corners for cushions

55 stretch corners for cushions

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56 stretch corners for cushions

57 struts for cushions

58 struts for cushions

59 struts for cushions

60 struts for cushions

61 Hole in the base for clamp-like holding device

62 Mother

63 Calotte

64 Hole on the frame for reducing strip (small towels) (Hole on the rod / reducing strip 64a / 64b)

65 Frame mask / accessories

66 Reducing bar / accessories,

67 Ballpoint pen principle pressure pen

68 Hole on the base (for attachment to the frame)

69 Washer

70 Nut / wing nut for foot / leg fastening

Claims (26)

1. Foldable frame for tensioning a material to be processed, consisting of four bars which are approximately at right angles to one another and are connected to one another, to which the material is tensioned via fastening devices, characterized in that two opposing bars ( 3 , 4 ) are divided approximately centrally into two sections ( 5 , 6 ; 7 , 8 ), wherein a first end of the two sections ( 5 , 6 ; 7 , 8 ) of each divided bar ( 3 , 4 ) is movably connected to one another via a first folding device ( 9 , 10 ) and the first folding device ( 9 , 10 ) in the unfolded state encloses a first angle of 180° between the two sections ( 5 , 6 ; 7 , 8 ) of a bar ( 3 , 4 ), wherein a first axis of rotation of the first folding device ( 9 , 10 ) is outside the Frame interior ( 11 ) and each end ( 28a , 28b , 29a , 29b ) of an undivided rod ( 1 , 2 ) is connected to a second end of a section ( 5 , 6 ; 7 , 8 ) of the divided rod ( 3 , 4 ) via a second folding device ( 14 , 15 , 16 , 17 ) which, in the undivided state, encloses the approximately right angle between the divided ( 3 , 4 ) and the undivided rod ( 1 , 2 ) and whose second axis of rotation runs in the frame interior ( 11 ), wherein in the folded state the sections ( 5 , 6 ; 7 , 8 ) of each divided rod ( 3 , 4 ) are arranged parallel to one another and parallel between the undivided rods ( 1 , 2 ). 2. Foldable frame according to claim 1, characterized in that in the region of the first folding device ( 9 , 10 ) a locking device ( 18 , 19 , 20 , 21 ) is provided, which stabilizes the two first ends of the two sections ( 5 , 6 ; 7 , 8 ) of the divided rod ( 3 , 4 ) in the unfolded state. 3. Foldable frame according to claim 2, characterized in that a recess ( 20 , 21 ) is provided on the first section ( 6 , 7 ) of the divided rod ( 3 , 4 ), into which, in the unfolded state, a tongue ( 18 , 19 ) protruding beyond the end face of the second section ( 5 , 8 ) engages, which is arranged on the second section ( 5 , 8 ). 4. Foldable frame according to claim 3, characterized in that the recess ( 20 , 21 ) for the lateral introduction of the tongue ( 18 , 19 ) is designed to be open towards the second section ( 5 , 8 ) and towards the interior of the frame ( 11 ). 5. Foldable frame according to claim 3 or 4, characterized in that the tongue ( 18 , 19 ) engages in a form-fitting manner in the recess ( 20 , 21 ), wherein the tongue ( 18 , 19 ) has a first opening ( 23 ) which lies between a second and a third opening ( 24a , 24b ) of the first section ( 6 , 7 ) of the divided rod ( 3 , 4 ) and a pin, a screw, a bolt or a split pin ( 22 ) extends through the three continuous openings ( 23 , 24a , 24b ). 6. Foldable frame according to claim 3, characterized in that the recess ( 20 , 21 ) has magnetic regions ( 42 , 43 , 44 ) which, in the unfolded state, are opposed by a magnetic or metallic region ( 45 ) of the tongue ( 18 , 19 ). 7. Foldable frame according to claim 6, characterized in that the separately formed tongue ( 18 , 19 ) is itself made of magnetic material and is firmly embedded in the second section ( 5 , 8 ) of the divided rod ( 3 , 4 ). 8. Foldable frame according to claim 3, characterized in that the recess ( 20 , 21 ) has two opposing snap devices ( 33 , 34 ) into which the tongue ( 18 , 19 ) engages in a force-fitting manner. 9. Foldable frame according to claim 8, characterized in that the recess ( 20 , 21 ) itself is formed by the two snap devices ( 18 , 19 ). 10. Foldable frame according to claim 8 or 9, characterized in that each snap device ( 33 , 34 ) consists of a ball ( 35 ) partially projecting beyond a housing ( 38 ) which can be prestressed via a spring ( 37 ) by a screw unit ( 36 ). 11. Foldable frame according to claim 3 and 10, characterized in that the tongue ( 18 , 19 ) has a region ( 41 ) which is shaped opposite to the balls ( 35 ) and which, in the unfolded state, engages in a force-fitting manner between the two balls ( 35a , 35b ) of the snap devices ( 33 , 34 ) of the recess ( 20 , 21 ). 12. Foldable frame according to claim 1, characterized in that the ends of the divided rod ( 3 , 4 ) and the undivided rod ( 1 , 2 ) connected via the second folding device ( 14 , 15 , 16 , 17 ) are designed such that one end has a recess ( 30a , 30b ) open towards the rod end, into which a projection ( 28a , 28b , 29a , 29b ) of the other end engages in a form-fitting manner in the unfolded state. 13. Foldable frame according to claim 1, characterized in that the fastening devices ( 24 ) arranged at predetermined intervals each have a ring-like holding means ( 25 ) on which means for clamping ( 27 ) the material are arranged via an elastic connection ( 26 ). 14. Foldable frame according to claim 13, characterized in that the elastic connection ( 26 ) is designed as a one-piece elastic band which is guided through the holding means ( 25 ) of the fastening devices ( 24 ) of all four bars ( 1 , 2 , 3 , 4 ). 15. Foldable frame according to claim 13, characterized in that the elastic connection is designed as a multi-part elastic band ( 26 a, 26 b, 26 c, 26 d), each part ( 26 a, 26 b, 26 c, 26 d) of the elastic band being guided through the holding means ( 25 ) of the fastening devices ( 24 ) of a rod ( 1 , 2 , 3 , 4 ). 16. Foldable frame according to claim 15, characterized in that one end of the elastic band ( 26 a, 26 b, 26 c, 26 d) is glued to the rod ( 1 , 2 , 3 , 4 ). 17. Foldable frame according to claim 15, characterized in that one end of the elastic band ( 26 a, 26 b, 26 c, 26 d) is hooked to the rod ( 1 , 2 , 3 , 4 ). 18. Foldable frame according to claim 13, characterized in that the elastic band ( 26 a, 26 b, 26 c, 26 d) is loosely pulled through the ring-like holding means ( 25 ). 19. Foldable frame according to claim 13 or 18, characterized in that the ring-like holding means ( 25 ) has a gap ( 32 ) through which the elastic band ( 26 a, 26 b, 26 c, 26 d) is inserted. 20. Foldable frame according to claim 1, characterized in that at least one foot ( 46 ) is rotatably mounted on each undivided rod ( 1 , 2 ), which is arranged parallel to the rod ( 1 , 2 ) on the side of the rod ( 1 , 2 ) facing away from the frame interior ( 11 ) and, in the pivoted state, runs approximately perpendicular to the rod ( 1 , 2 ), engaging in a foot receptacle ( 47 ). 21. Foldable frame according to claim 20, characterized in that clamp-like means are provided for fastening the frame to a flat support object. 22. Foldable frame according to claim 21, characterized in that the clamp-like means engage in a bore ( 40 ) of a section ( 5 , 8 ) of a divided or undivided rod, which has a slope within the rod ( 1 , 2 , 3 , 4 ). 23. Foldable frame according to claim 21, characterized in that the clamp-like means engages in a bore ( 61 ) of the pivoted-out foot ( 46 ). 24. Foldable frame according to one of the preceding claims, characterized in that each undivided rod ( 1 , 2 ) has a guide for fastening to a frame stand. 25. Foldable frame according to claim 24, characterized in that the guide is designed as at least one bore ( 50 , 51 ) for receiving a screw device of the frame stand device. 26. Foldable frame according to claim 24, characterized in that the guide is an elongated hole ( 49 ) formed along the longitudinal extension of the rod ( 1 , 2 ).