GB2115466A - Compacting and levelling concrete - Google Patents

Abstract

Vibrating device for compacting and levelling concrete has an electric motor 24 mounted on a base plate 22 and which drives an unbalance. Runners 38 are arranged beneath this base plate. On drawing the device through a mortar layer and with the electric motor running, vibrations are introduced into the said layer by the runners. The layer is compacted and at the same time levelled. Smoothing cloths 78 are arranged at either end of the base plate for further smoothing the mortar layer surface. <IMAGE>

Description

SPECIFICATION Vibrating device for compacting and levelling concrete and plaster mortar layers The present invention relates to a vibrating device for compacting or consolidating concrete and plaster mortars and for levelling the surface thereof with a base plate, with an electric motor which can be switched on and off and which is arranged on said base plate, with an unbalance driven by said motor, and with a handle.

The application of concrete and plaster mortar layers to the floors of rooms, halls, etc can, roughly speaking, be subdivided into three operations. These are the application and spreading of the concrete and plaster mortar over the floor area, the compacting or consolidating of the mortar and the levelling out of its surface. A vibrating device of the aforementioned type can be used for compacting purposes. The flat bottom of its base plate is placed on the mortar layer and, with the electric motor running and with the unbalance driven by it is moved backwards and forwards over the mortar layer. Whilst such a device makes it possible to mechanically compact the mortar layer, according to the prior art, the levelling of its surface must be performed manually by skilled labour.A skilled labourer smooths the surface with a long board, scrapes off raised portions of the mortar layer and presses the freed material into depressions. However, this is hard, tedious work and must be carried out in the crouching or kneeling position. Such skilled labour is expensive and is often unavailable, even if high wages are paid.

The problem of the invention is therefore to provide a device which, not only compacts the concrete and plaster mortar layer, but also levels it in a single operation.

According to the invention, this problem is solved by a vibrating device of the aforementioned type, in that on the bottom of the base plate are fixed at least two runners directed at a right angle to the electric motor shaft carrying the unbalance and said runners have recesses at both ends.

Unlike the known vibrating devices, whose base plates rest on the mortar layer, the runners of the vibrating device according to the invention penetrate the mortar. The bottom of the base plate is kept at a distance above the surface of the mortar layer. This is made possible by the fact that the mortar is generally reinforced with rails, steel wires, structural steel fabric mats and the like and the runners can stand on these rods or mats. As a result, the vibrations are no longer merely introduced into the mortar layer surface by the base plate resting thereon, whereby the mortar layer is made heavier by the weight of the vibrating device and instead the vibrations are introduced into the depth of the mortar by the runners inserted therein.The runners resting on the rods or mats, vibrations are also introduced into the latter and are consequently distributed over a very large mortar surface. At the same time, its surface remains free and is no longer made heavy by the weight of the vibrating device resting on it so that the mortar is vibrated over a large surface area. As a result of the vibrations and the simultaneous action of gravity, displacements of the material particles on the surface take place.

These material particles dissociated from adjacent particles by the vibrations flow into the lower area.

This flow towards lower areas is favoured by the fact that the mortar is still very wet or aqueous. As a result of these different movements of the individual mortar particles, the mortar surface is levelled in a very short time. During these displacements of the mortar, large quantities of mortar can pass through the recesses provided in the runners. These recesses also ensure that in the case of a possible transverse movement of the runners, the mortar does not accumulate on one side thereof. The recesses are shaped like triangular cutouts. In other words, the bottom of the runners have projecting ends. If, with the device operating, approximately half the height of the runners in introduced into the mortar, said projecting ends are located below the mortar surface, so that the latter is vibrated.Thus, grooves or depressions remaining open behind the following end of the runner are more rapidly closed. It is very easy to work with the vibrating device according to the invention and less skilled labour is required. The device is moved through the mortar in the longitudinal direction of the runners. This linear movement is assisted by the revolving unbalance. It is driven in such a way that components of its movement and the forces resulting from its eccentric mounting act in the direction of movement of the vibrating device.

Tests carried out with the vibrating device according to the invention have shown that the mortar is not only compacted and its surface levelled, but also the water contained therein rises upwards and the individual particles in the water sink downwards and form a pool on the mortar. As a result, the mortar can dry more rapidly and harden. Simultaneoulsy, crack formation is prevented by the water on the mortar surface.

To ensure that the runners do not abut against the heating pipes of a floor heating system, reinforcing rods, etc, during its passage through the mortar, according to an appropriate development, the two ends thereof are directed somewhat upwards, accompanied by the formation of a bevel.

It is also possible for depressions or grooves to stay open in the mortar behind the following ends of the runners. They result from the fact that the mortar is displaced by the runners and does not immediately flow together again after their passage. Such grooves or unevennesses in the mortar surface form more particularly in the corners of an area through which the vibrating device is moved along a curved path. Along such a curve, the mortar builds up on the inside of the runners, whereas it sinks at the outside thereof. To avoid such irregularities in the mortar surface, according to an appropriate development, the runners are in the form of rods fixed to supports.

Preference is given to round rods or bars and two, three or five of these can be juxtaposed. These rods transfer the vertical forces occurring during vibrations into the mortar. As compared with runners, they have the advantage that they also introduce said forces in the upwards direction into the mortar, because they are completely immersed in the latter. As a result, grooves and depressions are closed more rapidly as soon as they are formed in the mortar surface. In addition, they only have a small surface area in the horizontal direction, so that there is no accumulation of mortar on one side of the runner.

For the same reason, the supports are preferably very narrow, which also ensures limited lateral accumulation of mortar. Furthermore, the ends of the rods are chambered, so that they do not abut against the reinforcing mat bars, rails, etc.

It has been stated that grooves can form in the mortar surface and for the purpose of closing these, a further development provides for the fixing of smoothing cloths to both ends of the base plate and they extend down to the mortar layer and rest partly thereon. The weight of said cloths rests on the mortar surface and, due to their rigidity, also exert a certain pressure. They also follow the vibrations of the base plate, so that they smear the mortar surface and even out irregularities thereof. The grooves formed behind the following ends of the runners close rapidly.

According to an appropriate development, arms are provided on both ends of the base plate and the smoothing cloths are fixed thereto. The arms are appropriately so long that an adequate part of their length rests on the rough surface, so that they smooth the latter when passing over the same as a result of their weight and consequently close the grooves formed by the runners. This effect can be increased by making the arms and consequently the smoothing cloths wider than the base plate.

The ends of the smoothing cloths resting on the mortar surface can have numerous different shapes. They can be straight or curved inwards or outwards. In addition, they can be laterally cut away or spread out.

It has been stated that the vibrating device is held and guided by a handle, which is connected by means of rubber elements to a U-shaped frame mounted on the base plate. It has been found that the damping of these rubber elements also has an effect on the vibrations of the runners or base plates, so that they are undesirably damp.

According to the invention, an embodiment has been developed in which they are not damped and can nevertheless be held away from the handle. In this embodiment, the U-shaped frame is fixed to the base or assembly plate and the handle is connected thereto via a pivot joint. Appropriately, a shaft is mounted on the frame and the pivot joint fixed to its upper end. As the rubber elements are rendered superfluous their damping action is eliminated. Vertical movements, in this case initiated by the rotating unbalance, are kept away from the handle by the pivot joint.

In the case of the present vibrating device, the vibrations are introduced into the mortar layer via the runners, so that the individual mortar particles move towards one another, so that the mortar is compacted and its surface level. For this purpose, the device is moved backwards and forwards in the mortar. The runners and the supports holding them can lead to the formation of grooves in the mortar surface. The smoothing cloths hanging down from either end of the base plate are used for removing these.

They rest by their own weight on the mortar layer surface and scrape over the latter during the movement of the device. Thus, they move materials from raised points into depressed points, so that the surface is made level. The smoothing cloths must have a certain weight and rigidity to enable them to perform this function and laterally displace the material particles. They would otherwise slide off the raised points. If the worker operating the device comes to the end of a movement, e.g. on a room wall, stops the device there and then performs the same travel in the opposite direction, this rigidity can lead to the smoothing cloth pressing into the mortar surface at the reversal point at the end of the travel. At this point, it leaves behind a groove or depression.

As no smoothing cloth will now come into contact with this depression at the end of the travel, it is left behind and gives an unattractive appearance.

It is clear that the device will remain at the reversal point for a short time, so that the smoothing cloth will press into the mortar. When the device reverses its direction of movement at the reversing point, the smoothing cloth tilts over its lower edge located below the mortar surface, so that such grooves can be particularly deep.

According to a further embodiment of the invention, smoothing cloths are provided which ensure that such depressions or grooves no longer occur at the reversing points. This embodiment is characterized in that in each case two smoothing cloths are arranged successively in vertically adjustable manner in the direction of movement of the device and with a short reciprocal spacing at the ends of the base plate. As a function of the composition of the concrete or plaster mortar, its water content and/or degree of drying, as a function of the position of the reinforcing rods in the mortar down to which the device can sink, etc, the smoothing cloth sinks to a greater or lesser extent in the mortar or rest more or less strongly thereon. As a function of the resulting forces, the aforementioned depressions or grooves are more or less deep. In the case of the first-mentioned embodiments, the smoothing cloths are fixed to the base plate and are consequently only set in optimum manner to a single mortar layer height.

In the case of high or excessively high mortar layers, they will press too strongly into the latter and in the case of low or excessively low mortar layers, will not press adequately thereinto, with corresponding effects on the smoothing action. As stated, this is particularly noticeable at the reversal point as a result of the aforementioned depressions or grooves. According to a further embodiment, two vertically adjustable smoothing cloths are provided. They are vertically adjusted in accordance with the mortar layer height and are consequently adapted to the latter. At the reversal points, at which the device is stopped and consequently the smoothing cloths act for this period on the mortar, they no longer press into the latter. They only rest on the mortar surface with a force ensuring the removal of raised areas and the filling of depressed areas.Through the provision of two smoothing cloths and consequently the distribution of the forces over a larger surface area, there is also a drop in the pressures acting on the mortar surface. This also contributes to depressions or grooves not being formed.

The basic principle of the invention of making the smoothing cloths vertically adjustable, can be constructionally realised in many ways. According to an appropriate embodiment, the smoothing cloths are fixed to the carrier and this is mounted in raisable and lowerable manner on the ends of the base plate. It is particularly advantageous to hang the carrier on a worm gear mounted in the base plate. According to an appropriate development, bushes are fixed in the base plate and threaded spindles are inserted in the latter, the carriers are fixed to the lower ends of the threaded spindles and threaded rings are screwed onto these spindles and rest on the upper and lower end of the bushes.

Such threaded spindles are simple, nonsensitive machine elements. With the threaded rings loosened, they can be moved up and down with the carriers and consequently the smoothing cloths and after tightening said rings are fixed in the desired height position. Appropriately, radially directed shafts are fixed to the threaded rings, which form handles and permit an easy turning of the threaded rings.

According to a preferred development, the base plate has projections integrally constructed therewith at both ends and the bushes are arranged on said projections.

To increase the smoothing and straightening action, a further smoothing cloth can be fixed beneath and to the base plate in the central area thereof. A plastic foil a few millimetres thick is preferably used for these smoothing cloths and this foil must be flexible, but adequately stiff. It is then ensured that the smoothing cloths resting on the mortar surface press the raised areas into depressions and consequently smooth the surface.

Advantageously, the smoothing cloths are made from a semi-rigid plastics material. They can be perforated to increase the flexibility.

An embodiment of the invention is described in non-limitative manner hereinafter relative to the drawings, wherein show: Fig. 1 a perspective simplified overall view of the device and a steel wire reinforcing mat carrying the same.

Fig. 2 a partial view from the front with the simultaneous representation of a mortar layer.

Fig. 3 a perspective overall view according to Fig. 1 of the embodiment in which the runners are in the form of rods.

Fig. 4 a cross-section through this embodiment.

Fig 5 a simplified plan view of the embodiment of Fig. 3 with partly drawn apart parts.

Figs. 6 to 11 in each case a simplified plan view of the smoothing cloth in various embodiments.

Fig. 12 a simplified diagrammatic view of an embodiment with the representation of a particular connection of the handle via a pivot joint.

Fig. 1 3 a diagrammatic perspective view of the embodiment with a vertically adjustable suspension of the smoothing cloth.

Fig. 14 a larger scale side view, partly in section, of one end of this embodiment.

Fig. 1 5 a side view corresponding to Fig. 14, the device being shown in operation with runners immersed in the mortar.

Fig. 1 6 a view from the front in the direction of the arrow in Fig. 1 5.

Fig. 1 7 a perspective view of a perforated smoothing cloth.

The vibrating device shown in Fig. 1 contains base plate 22 with the electric motor 24 mounted thereon. The unbalance, of which details are not visible, is located on the driven shaft of said motor.

Electric motor 24 is connected to a power supply via an electric lead 26 and the reversing switch 28 located therein. A handle 30, which is used for holding and guiding the device, is connected by rubber elements 32 to a U-shaped frame 34, which is mounted on base plate 22. The vibrating device has two runners 38. Fig. 2 shows in section a mortar layer 50 applied to a floor 52. On the latter then rest metal rails 54, one of which is visible. it has recesses with the same reciprocal spacings, in which are placed the heating pipes 56 of a floor heating system. On these are placed reinforcing wires 58, which form a steel wire reinforcing mat. The vibrating device rests on the latter by its runners. It can be seen that the length of a runner exceeds the spacing of two reinforcing rods 38. At the ends of the runners are provided recesses 70.According to Fig. 2, the projecting ends 42 of runners 38 are positioned beneath the rough surface 60 of mortar layer 50. Grooves formed behind the following ends of the runners when the device is running, are consequently vibrated and closed. According to Figs. 2 and 3, arms 72 are fixed to the ends of base plate 22 by welding, screwing or riveting. Arms 72 have angle-shaped edge strips 74, on which are placed ledges 76. Between these are inserted the smoothing cloths 78 and are held with pins 80.

When the vibrating device is moved to the left, the smoothing cloth 78 assume the represented shape and are pulled behind the device. Under the action of their weight and material rigidity, they press on the rough surface 60 of mortar layer 50.

They press in the raised areas and level out irregularities in the surface. The surface of mortar layer 50 is smoothed. In particular, the grooves formed behind runners 38 are closed.

In the case of the embodiments shown in Figs.

3 to 5, the arms 72 have laterally widened portions 82, so that the smoothing cloths 78 are also made wider and scraped over a larger surface area. The special nature of the embodiments shown in these drawings is based on the fact that the runners are in the form of wound rods or bars.

They are fixed beneath narrow supports 86, which are positioned below sleepers. 88, to which is fixed base plate 22. The bars 84 also have chamfered ends 90. The embodiment using bars 84 is particularly appropriate when working in small spaces, in which the vibrating device frequently has to be advanced along curved paths.

In the previously described embodiments, the mortar would accumulate on one side of the runners due to the large surface area thereof and would become thinner at the other side thereof.

This is prevented when the runners are in the form of bars 84, because they then only laterally have a small surface area. However, in the decisive vertical direction, they have the same surface area as runners 36 and 38.

Figs. 6 to 11 show various forms of the smoothing cloth. In Fig. 6, the smoothing cloth has a simple rectangular shape. In Fig. 7, the corners are cut away. In Fig. 8, the end is additionally drawn in arcuate manner. In Fig. 9, there are no cut away ends. In Fig. 10, the end of the smoothing cloth is bent out in arcuate manner. In Fig.11, the end is spread out to either side.

Fig. 12 shows as a further feature of this embodiment that the lateral runners 38 are in the form of narrow supports. Their main function is to support an assembly plate 92. However, it is particularly shown in Fig. 12 that the handle 30 is connected by means of a shaft 94 and a pivot joint 96 to U-shaped frame 34, instead of by means of rubber elements. Thus, there is no damping of the vibrations produced by the revolving unbalance.

As a result of these vibrations, the shaft 94 moves up and down to a limited extent. These vibrations are absorbed in pivot joint 96 and are not transferred to handle 30. Thus, they are kept away from the person holding handle 30.

Figs. 13 to 1 6 show the embodiment with the vertically adjustable mounting of the smoothing cloth. These drawings show the device with its base plate 22, the electric motor 24 arranged thereon and which drives the unbalance and the two handles 30. Fig. 4 also shows the floor 52 of a room, e.g. a concrete floor. Rails 54 are arranged in reciprocally spaced manner thereon and in these are held heating pipes 56. The reinforcing rods 58 of structural steel mats rest thereon.

According to Figs. 15 and 16, a mortar layer 50 is placed on floor 52.

Base plate 22 has projections 102 at both its ends, which are integral therewith. Struts 104 are fixed to these projections and these struts can be in the form of welded flat bars. These struts 1 04 reinforce the projections 102, to which are fixed bushes. Threaded spindles 108 are displaceable in the bushes and to the lower end thereof are fixed, e.g. welded carriers 110. Carriers 110 have the downwardly bent edge strips 74, which cooperate with ledges 76 and pins 80. The smoothing cloths 78 are secured between the edge strips 74 and the ledges 76. The vibrating device rests by its runners 84 on reinforcing rods 58. The runners are fixed to supports 86, which emanate from sleepers 88 fixed beneath the base plate. The runners 84 comprise flat bars with slightly upwardly bent ends 90, so that they are shaped like wide sledge runners.These drawings also show the threaded rings 112 screwed onto the threaded spindles 108. Two threaded rings 11 2 are provided for each threaded spindle 108. The rings engage from above or below on bushes 106.

Both threaded rings 11 2 also have shafts 114.

Preferably, four shafts are provided on the lower threaded rings 112 and one each on the upper threaded rings. Figs. 13 to 1 5 also show that the smoothing cloths 78 are arranged not only at the ends, but also beneath the centre of base plate 22.

Fig. 1 7 shows the holes 120 provided in smoothing cloths 78, which increase the flexibility thereof. Through the choice of the number and size of the holes 1 20, it is possible to control the flexibility increase.

Figs. 1 5 and 1 6 show the device in operation with runners immersed in a mortar layer 50.

According to the invention, the height position of the smoothing cloths 78 provided at the ends is adapted to the thickness of mortar layer 50. Fig.

1 5 roughly shows the height position to which the smoothing cloths 78 are adjusted with the represented mortar layer height. Fig. 1 6 shows one end of the vibrating device. Two identical smoothing cloths are fitted to the not shown end of the vibrating device. For adjusting the height of the smoothing cloths, the two threaded rings 112 with shafts 114 are loosened. The upper threaded rings 11 2, which rest on bushes 106, are turned so far in one or other direction that the spindles 108 and consequently smoothing cloths 78 reach the desired height. The lower threaded rings 112 are then tightened. Thus, threaded spindles 108 and consequently smoothing cloths 78 are secured in the desired height position.

Fig. 1 5 shows a working example. It is assumed that the device, in the viewing direction of this drawing, is moved to the left and has reached a reversing point there. The two smoothing cloths 78 have moved mortar particles in front of them and have smoothed the mortar layer surface behind them. To the far left or in front of the smoothing cloths 78, surface 60 is still rough. The surface is already smoothed behind or to the right of the smoothing cloths. On reversing the device and when it moves to the right, the surface portion between the two smoothing cloths 78 is scraped again, so that it is further smoothed and is also lowered somewhat.

Fig. 1 7 shows the holes 120 in smoothing cloths 78. Such a perforated smoothing cloth 78 can be provided at the end and also below the centre of a base plate 22. Fig. 13 shows such a smoothing cloth 78 with holes 120 in the centre below base plate 22. The holes 120 increase the elasticity and flexibility of the foil forming the smoothing coils with an otherwise unchanged ridigity.

In connection with runners 84, it is pointed out that, in the embodiment of Figs. 1 3 to 16, they are in the form of flat bars, whereas in the embodiment of Figs. 3 to 5 they are round. The different runner shapes can be interchanged as a function of requirements.

Claims (25)

1. Vibrating device for compacting concrete and plaster mortars and for levelling the surface thereof with a base plate, with an electric motor which can be switched on and off and arranged thereon, with an unbalance driven by this electric motor, and with a handle, characterized in that at least two runners (36, 38) are fixed to the bottom of base plate (22), which are at a right angle to the shaft of the electric motor (24) carrying the unbalance, said runners having recesses (70) at their two ends.

2. Device according to claim 1, characterized in that the bottoms (44) of runners (36, 38) point upwards somewhat at their two ends (42), accompanied by the formation of a bevel.

3. Device according to claim 1, characterized in that the runners are in the form of bars (84) fixed to supports (86).

4. Device according to claim 3, characterized in that the bars (84) are round bars.

5. Device according to claims 3 and 4, characterized in that the bars (84) have chambered ends (90).

6. Device according to claim 3, characterized in that the supports (86) are narrow.

7. Device according to claim 1, characterized in that the runners are flat bars with raised ends (90).

8. Device according to claims 1 to 7, characterized in that smoothing cloths (78) are fixed to both ends of base plate (22), extend down to the mortar layer (50) and rest partly thereon.

9. Device according to claim 8, characterized in that arms (72) are provided on both ends of base plate (22) and the smoothing cloths (78) are fixed to said arms.

1 0. Device according to claim 9, characterized in that the two arms (72) and consequently the smoothing cloths (78) are wider than the base plate (22).

11. Device according to claims 8 to 10, characterized in that the smoothing cloths have straight ends.

12. Device according to claims 8 to 11, characterized in that the ends of the smoothing cloths (78) are bent inwards or outwards in arcuate manner.

13. Device according to claims 8 to 11, characterized in that the ends of the smoothing cloths (78) are laterally cut away.

14. Device according to claims 8 to 11, characterized in that the ends of the smoothing cloths (78) are laterally spread out.

1 5. Device according to claim 1, characterized in that a U-shaped frame (34) is fixed to base plate (22) and handle (30) is connected by means of a pivot joint (96) to said frame.

1 6. Device according to claim 14, characterized in that a shaft (94) is mounted on U-shaped frame (34) and the latter carries pivot joint (96) at its upper end.

17. Device according to claims 1 to 16, characterized in that in each case two smoothing cloths (78) are successively vertically adjustably arranged with short reciprocal spacing in the movement direction of the device on the ends of base plate (22).

1 8. Device according to claim 17, characterized in that the smoothing cloths (78) are fixed to a carrier (110) and the latter is mounted so as to move up and down at the two ends of base plate (22).

1 9. Device according to claim 18, characterized in that carrier (110) is suspended on a worm gear mounted in base plate (22).

20. Device according to claim 19, characterized in that bushes (106) are fixed in base plate (102) and threaded spindles (108) are inserted therein, the carriers (110) are fixed to the lower ends of threaded spindles (108) and threaded rings (112) engaging on the upper and lower ends of bushes (106) are screwed onto threaded spindles (108).

21. Device according to claim 20, characterized in that radially directed shafts (114) are fixed to the threaded rings (112).

22. Device according to claims 20 and 21, characterized in that at its two ends, base plate (22) has projections (102) constructed integrally therewith and the bushes (106) are arranged thereon.

23. Device according to claims 1 to 22, characterized in that further smoothing cloths (78) are fixed below and to the base plate (22) in the central area thereof.

24. Device according to claims 1 to 23, characterized in that the smoothing cloths (78) are made from a semi-rigid plastics material.

25. Device according to claim 24, characterized in that the smoothing cloths (78) have holes (120) to increase their flexibility.