DE2725404A1 - Plastics spacer for shuttering used in concrete structures - are tubes with incision-like grooves transversely to axis of spacer, ensuring good adhesion of spacer to concrete - Google Patents

Abstract

Spacer for shutter boards composing shutters for concrete comprises a plastics tube having a surface provided with depressions which are numerous grooves running transversely to the axis of the tube. The grooves are shorter than the circumference of the tube and are circumferentially staggered wrt one another. Used for accurate spacing of concrete shutters, an also double for housing the clamping irons which hold the shutter boards together. When the shuttering is dismantled the spacers are left in the concrete structure whilst ensuring good bonding to the same so that no water can subsequently seep along the surface of contact of spacer and concrete.

Description

Spacers for concrete formwork

The invention relates to spacers for the shuttering boards of concrete formwork, consisting of a plastic tube with a recess spoiled surface.

For precise fixing of the distance between the shuttering boards and concrete shuttering tubular spacers made of plastic are used, which at the same time for Serve to accommodate the clamping iron holding the shuttering boards together. These spacers remain in the concrete after dismantling the formwork and are Passage to prevent water through the concrete masonry via the tubular spacers, sealed watertight on both sides with plastic stoppers. To one too Water passage along the outer surface of the spacer between this and to prevent the concrete and to achieve a good mechanical connection of Spacers and concrete that slip through, especially when closing the pipe ends to prevent the spacer in the masonry, the spacers are on their Provide the outer surface with indentations. In known spacers, the depressions are in the form of a thread, in other known embodiments the outer surface is provided with a multiplicity of point-shaped depressions. It has it has now been shown that with such spacers, although a good mechanical Connection between the concrete masonry and the indented outer surface of the spacer occurs, but the barrier effect against water penetration along the contact surface between spacer and masonry is still considerable leaves a lot to be desired.

This disadvantage is intended to be overcome by the invention. It is Therefore, the object of the invention to provide a spacer that can be used in concrete masonry installed condition, the passage of water along the contact surface of the masonry and spacers securely and at the same time with the concrete a good mechanical Connection is received. In addition, it should require as little technical effort as possible be producible.

According to the invention, this object is achieved in that the depressions a plurality of substantially transverse to the longitudinal axis of the tube and separate grooves are provided, the length of which is less than the outer circumference of the tube and which are offset from one another in the circumferential direction.

As tests have shown, can be trained with such a Spacers have an extremely high sealing effect in the contact area between spacings -holder and masonry with good mechanical connection of both touching each other Reach media.

A particular advantage of the invention is that, as yet will be to show the spacers with an extremely small amount of material and tool can be made.

According to an advantageous embodiment of the invention, the length is each groove smaller than half the outer circumference of the pipe. In this way you can a particularly high sealing effect with a good mechanical connection between the pipe and Reach concrete. A further improvement in the sealing effect can also be achieved can be achieved in that the length of each individual groove is approximately equal to one Quarter of the outer circumference of the pipe is chosen.

The arrangement of the grooves in the context of the invention can be different Way. According to one embodiment of the invention, the grooves are uniform above the circumference of the pipe, overlapping surface line areas in edge zones arranged. In a further development of this inventive concept, the grooves can be Generating line area be arranged parallel to each other and the angle of inclination of the grooves to the longitudinal axis of two adjacent surface line areas are different be made large. Particularly good sealing effect along the contact surface between spacer and concrete can be achieved in that four surface line areas be provided on the spacer tube, two of which are radially opposite one another Areas of grooves with an inclination angle of 45 degrees to the longitudinal axis and the other two grooves with an angle of inclination of 135 degrees to the longitudinal axis of the pipe. In the development of such a pipe jacket, there is thus a Type of herringbone pattern, Xbbei each of the groove ends of a jacket area between the grooves of the adjacent jacket areas end.

According to a particularly advantageous embodiment of the invention the grooves are arranged on at least one helix. Such grooves can, as will be shown later, be incorporated into the Insert the outer surface of the spacers. In addition to the manufacturing advantages, which offers such an embodiment, however, can also be special with it high sealing effects with an extremely good mechanical connection between spacers and achieve concrete masonry. Both effects can also be achieved by this improved be that the grooves on two or more helical lines be arranged with the same slope. It should not go unmentioned, however, that the improvement of the sealing and connecting effects compared to a single helix occurs only to a relatively small extent, so that the last-mentioned Embodiment that is somewhat more complex to manufacture than the embodiment with only one helix, will only be implemented in special cases.

The invention also relates to a method of manufacture the spacers described above. The inventive method is thereby characterized in that in continuous operation initially made of a thermoplastic Plastic a tube is pressed, then the grooves in the soft plastic tube are embossed, then the pipe is passed through a cooling section and then is cut to length. This inventive method has the advantage1 that since the grooves are embossed, there is no waste material, as is the case, if the grooves are milled or cut in a metal-cutting work piece, scratched or otherwise incorporated into the outer surface of the pipe. Another advantage of the method is that due to the non-cutting machining of the pipe a higher production speed can be selected than this machining would be the case.

It has proven to be useful, the spacer tube before To subject the impression of the grooves to a pre-cooling. Otherwise there is a risk of that especially when embossing grooves relatively great depth the pipe what is twisted unfavorable on the mechanical properties of the spacer tube.

Another idea of the invention relates to a device to carry out the procedure described above. The facility includes a press, In particular a screw press for the production of the pipe, a stamping device and at least one cooling bed and optionally one arranged after the cooling bed Cutting device. According to the invention, the embossing device consists of at least a toothed wheel, pressed against the Xohr, which is located on the axial Direction moving pipe unrolls.

For the production of spacers with arranged in surface line areas Grooves, it has proven to be useful to design the embossing device in such a way that that each surface line area a wheel with the pipe cross-section adapted, concave is associated with arched teeth. The inclination of the grooves to the longitudinal axis of the Rohres can be done either by the fact that the wheels on one or the other Circulate helical line around the pipe, or what about as little as possible Device expenditure is much cheaper, in that wheels with inclined Find teeth use.

For the production of spacers with arranged on helical lines A device has proven to be useful in the case of the grooves in the embossing device for each helix at least one gear with axially parallel teeth is present, which is rotatably mounted about the longitudinal axis of the pipe. For the present This can be done using normal gears or straight-toothed edging wheels will.

To ensure that the grooves are perfectly embossed in the outer surface of the To ensure spacer tube, it has been found to be useful two to provide radially opposed wheels that are concentric together on one are arranged to the pipe longitudinal axis rotatably mounted carrier. The carrier can do this consist of a circular plate provided with teeth on its outer circumference is in which a pinion seated on a motor shaft engages.

According to an advantageous embodiment, at least one is the Wheels are arranged on the carrier so that they can be displaced and locked in the radial direction to the tube. Such a displaceability of at least one of the wheels makes the retraction process the set-up is made much easier, since then that from the extruder or respectively the pipe coming from the pre-cooling section does not have to do a laborious job between the rollers must be pulled through, but after pushing up at least one of the wheels can be passed between the wheels without difficulty.

It has also proven to be useful to move all wheels. and to be arranged on the carrier so that it can be locked, since there is then the possibility of the Embossing device also for embossing pipes of different sizes to be able to use.

The or the wheels of the embossing device can with a Provided with drive or also without drive be formed, wherein in the latter case, additionally a pipe through the individual stages of the device pulling trigger may be present. The latter can be saved, if in particular with an embossing device with several wheels this with one Drive are coupled.

The invention is based on the drawing, which is in part schematic Representation contains exemplary embodiments, explained in more detail. Figure 1 shows a perspective view of a spacer, FIG. 2 the developed outer surface of another spacer, Figure 3 is a perspective view of a spacer with grooves arranged on a helical line, FIG. 4 a device for manufacturing of spacers, Figure 5 is a front view of the embossing tool of an embossing device and FIG. 6 shows a section through the embossing tool according to FIG. 5 along the line VI-VI.

The spacer shown in Figure 1 consists of a piece of pipe 1 made of a thermoplastic material, in the outer surface 2 of a large number embossed with grooves 3 Each of the grooves extends above more than a third of the outer circumference of the pipe.

The individual grooves 3 run transversely to the longitudinal axis of the tube and are offset from each other by 120 degrees.

In the case of the spacer according to FIG. 2, from the outer surface of which one The development is shown, the individual grooves in four are evenly across the Surface line areas 4 distributed around the circumference of the pipe. 3 "or 3 '' 'or 3' '' 'of a surface line area each run parallel to one another. The grooves 3 'or 3 "or 3' '' or 3 ''" 'are at an angle of 45 degrees inclined to the longitudinal axis of the pipe and, in addition, the grooves of two close each other adjacent surface line areas an angle of 90 degrees between them. Around To achieve the highest possible density, the individual elements overlap Surface line areas 4 in their edge zones, which can be clearly seen in FIG In the spacer shown in Figure 3, the grooves 3 are on a helical line arranged at a distance from one another. @ Hold with such a spacing particularly high sealing effects can be achieved with a good mechanical connection of Achieve spacers and concrete masonry. In the illustrated embodiment the length of the grooves is significantly smaller than a quarter of the outer circumference of the pipe 1 selected.

The spacers according to the invention can be produced by means of a device take place as shown in Figure 4 This device comprises a screw press 5 in which the granules poured into the hopper 6 processed into a plastic pipe emerging from the head 7 of the screw press will The plastic tube is after it emerges from the head 7 of the screw press 5 passed through a cooling section 8 and then in a Embossing device 9 provided with grooves. The embossing device 9 closes a further cooling section 10, which can be made shorter than the cooling section 8 can. Finally, there is a cutting device at the end of the cooling section 10 11, the spacers of the same length as that produced in continuous operation Cut off pipe string.

As can be seen in particular from FIGS. 5 and 6, is located on the embossing device 9, an embossing tool 12, which consists of a circular There is carrier 13, which is rotatably mounted concentrically to the pipe longitudinal axis Carrier 13 is provided on its outer circumference with a toothing 14 into which a Pinion 16 seated on the shaft 15 of a drive motor engages. On the carrier 13 there are two wheels 17 and 18 which are arranged radially opposite one another are and are provided with axially parallel teeth 19. Either of the two Wheels 17 and 18 are rotatably mounted in a bearing block 20 and 21, respectively. Both bearing blocks 20 and 21 each have two approaches 22 and 23, each with an elongated hole 24 is provided. After loosening the screws 25, the wheels 17 and 18, respectively, can move radially Direction can be shifted, whereby the setup process for the facility is not insignificant is simplified. For the implementation of the pipe in which the grooves 3 are embossed should, through the circular carrier 13 is a central opening 26 provided.

As already mentioned, the device for producing the spacers a pipe emerging from the head 7 of the extruder 5 through the individual processing zones Pulling device included. This would generally be between the cooling section 10 and the cutting device 11 are arranged. Instead of this However, it is also possible, the wheels 17 and 18 of the embossing device 9 with a To provide drive. This can be done, for example, in that the wheels 17 and 18 are each rigidly connected to their shaft 27 and 28, on the one or two drive motors act, for example by means of a belt drive. Likewise exists the possibility of the wheels 17 and 18, which, as already mentioned, are designed as gears can be driven by providing 12 motors on the support, which mesh with the wheels 17 and 18 via a gear wheel seated on their shaft and drive them. In this case it is necessary that the motors with the Gears seated on their drive shaft are also displaceable in the radial direction are attached to the carrier 12.

L e r s e i t e

Claims (19)

Claims s Abxt-ndghalter for the shuttering boards of concrete shuttering consisting of a plastic tube with a surface provided with indentations, d a -d u r c h e k e n n n z e i c h n e t that as wells a multitude of extending essentially transversely to the longitudinal axis of the tube (1) and separated from one another Grooves (3,3 ', 3 ", 3' '', '' '') are provided, the length of which is less than the outer circumference of the tube (i) and which are offset from one another in the circumferential direction. 2. Spacer according to claim 1, d a d u r c h g e k e n n z e i c h n e t that the length of each groove (3,3 ', 3 ", 3' '', 3 '' '') is less than half that The outer circumference of the tube (1) is. 3. Spacer according to claim 2, d a d u r c h g e k e n nz e i c h n e t that the length of each individual groove (3,3 ', 3 ", 3' '', 3 '' '') is approximately the same a quarter of the outer circumference of the tube (1). 4. Spacer according to one of claims 1 to 3, d a d u r c h it is noted that the grooves (3,3 ', 3 "' 3 '~~~ 3' '' ') are evenly spaced Over the circumference of the pipe (1) distributed nantelline areas intersecting in edge zones (4) are arranged. 3. Spacer according to claim 4, d a d u r c h g o k e n n z e i c h n e t that the grooves (3,3 ', 3 ", 3' '', 3 '' '') of a surface line area (4) run parallel to each other and the angles of inclination of the grooves (3 ', 3 ", 3' ~~~ 3 '' '') different sizes to the longitudinal axis of two adjacent nantel line areas (4) are 6. Spacer according to claim 5, d a d u r c h g e k e n n z e i c h n e t that four surface line areas (4) are available, two of which are radially to each other opposite areas grooves (3 ', 3' '') with an inclination angle of 45 degrees to the longitudinal axis and the other two grooves (3 ", 3 '' '') with an angle of inclination of 135 degrees. 7. Spacer according to one of claims 1 to 3, d a d u r c h it is not noted that the grooves (3) are on at least one screw line are arranged. 8. Spacer according to claim 7, d a d u r c h g e k e n n z e i c h n e t that these grooves (3) are the same on two or more helical lines Incline are arranged. 9. A method for producing spacers according to any one of the claims 1 to 8, that is in continuous operation first a tube (1) is pressed from a thermoplastic material, then the grooves (3,3 ', 3 ", 3' '', 3 ''" ') are embossed into the soft plastic tube, on it the pipe (1) is passed through a cooling section (10) and then the pipe is cut to length. 10. The method according to claim 9, d a d u r c h g e -k e n n z e i c h n e t that the tube (1) before the embossing of the grooves (3,3'3 ", 3 '' ~~ 3 '~~ ~) a Pre-cooling (8) is subjected. 11. Device for performing the method according to claim 9 or 10, with a press, in particular a screw press, an embossing device and at least one cooling bed, that is, the embossing device (9) of at least one toothed wheel pressed against the tube (1) (17,18) that rolls on the tube (1). 12. Device according to claim 11 for the production of spacers with grooves arranged in surface line areas, d a d u r c h g e k e n n -z e i c h n e t that each surface line area (4) has a wheel (17, 18) with the pipe cross-section adapted, concavely curved teeth is assigned. 13. Device according to claim 12, d a d u r c h g e k e n n z e i c h n e t that the wheels (17,18) are provided with inclined teeth. 14. Device according to claim 11 for the production of spacers with grooves arranged on helical lines, d u r c h e c o n n z e i c hn e t that for each helical line at least one wheel (17, 18) with axially parallel axes Teeth (19) is provided, which is rotatably mounted about the longitudinal axis of the pipe. 15. Device according to claim 14, d a d u r c h g e -k e n n z e i c h n e t that two radially opposite wheels (17,18) are provided, all of them on a support that is rotatably mounted concentrically to the longitudinal axis of the pipe (12) are arranged 16. Device according to claim 15, d a d u r c h g e -k e n n z e i c h n e t that at least one of the wheels (17, 18) in the radial direction to the tube is arranged displaceably and adjustable af the carrier (13) 17th Device according to Claim 16, d u r c h g o k e n n n z e i c h n e t that each Wheel (17,18) is arranged on the carrier (13) so that it can be displaced and locked. 18. Device according to one of claims 14 to 17, d a d u r c h it is noted that the wheel or wheels (17, 18) are provided with a drive are. 19. Device according to one of claims 14 to 17, d a d u r c h it is noted that the wheel or wheels (17, 18) are designed to be driveless are.