A concrete spraying apparatus

Abstract

 An apparatus for applying a sprayable material, such as concrete (8), to a surface, preferably the roof of a tunnel. The apparatus comprises a spray nozzle (7) which is rotatable such as to coat said roof with concrete (8) in a rotary movement.
A platform (1) on which an operator may stand is attached to a telescopic arrangement (1 c, 1 m, 1 k) carried by a utilised carriage (1f, 1g, 1h) having driven wheels (1g, 1 h).
Arranged on the carriage is a balancing counterweight.

Description

[0001] The present invention relates to an apparatus for applying a sprayable material, such as concrete and the like, to a surface. The invention has particular application on blasted rock-surfaces, such as the surfaces of tunnels or the like formed in rock by blasting. Thus, it is possible to provide on said surface a protective layer in the form of a supporting layer of material. The material is sprayed by means of a spray nozzle mounted on the free end on a nozzle-holding means.

[0002] The invention is particularly suitable for use when it is desired to apply a layer of material on both the ceiling and the walls of a tunnel, or the like, blasted in rock.

[0003] Apparatus which comprises a nozzle fixedly mounted to the free end of a holder means in the form of an operating means by which the spray nozzle can be displaced in a manner such as to try to effectively apply the material layer are known to the art.

[0004] Various apparatus are known for the said purpose and, by way of example reference is made to Swedish Published Specification number 378 ₄₃₆. This prior known apparatus comprises a spray nozzle mounted on the free end of a telescopically extensible holder arm which is movably connected to a platform through an intermediate coupling element. The characterizing features of the known apparatus reside in the fact that the said intermediate coupling element has the form of a carrier arm which extends from the platform in the same direction as the extensible holder arm and is pivotable about its longitudinal axis, and by a link arm which is pivotally connected to the holder arm and the carrier arm in a manner such that, when seen from the side, the holder arm, the link arm and the carrier arm, when in a normal operating position, together take the form of the letter "Z".

[0005] There is also known to the art a method and an apparatus for applying a sprayable material to a surface, in which the spray nozzle is caused to swing in a plane about a pendulum axis, (Swedish Patent Specification Number 399 733). In accordance with the invention described in this Swedish Patent Specification, the nozzle through which concrete is sprayed is arranged to be oscillated about an axis between a first and a second terminal position by means of a drive arrangement, said terminal positions also consituting the turning positions of the nozzle. A basic requisite of the previously known construction is that the speed at which the nozzle oscillates shall be held substantially constant between the two terminal positions.

[0006] To this end there is incorporated an automatic device, which there is obtained automatic oscillation over the sector between the first and the second terminal position. Means are provided, however, whereby the operator is able to override the automatic oscillating device, so that the nozzle will swing beyound the said terminal positions, automatic oscillation of the nozzle being re-commended when the override is released. In this way it is possible to cause the nozzle to oscillate between two new terminal.positions, but in the same direction.

[0007] The object of the present invention is to provide means whereby a layer of material can be readily applied to a surface. The invention is able to solve a problem especially connected with the application of a protective layer to the ceiling and/or a wall of a tunnel.

[0008] The design of prior known apparatus for applying a protective layer to the ceiling of a tunnel, however, is such as to render it difficult to move the spray nozzle along the ceiling parallel thereto, without requiring complicated manoeuvres on the part of the operator. Because of this, proposals have been put forward in which the whole machinery, i.e. a working platform carrying the nozzle-holder means, which platform is pivotally mounted on the free end of a telescopically arranged holder arm, the holder arm and a carriage provided with wheels and supporting said holder arm, is made movable along the tunnel in a manner such that during said movement, the spray nozzle moves parallel to the wall in the manner described. This system is, naturally, extremely complicated and means that the carriage must run on rails in order for the carriage to move smoothly.

[0009] Further, it is extremely important when coating the ceiling of a tunnel with a layer of concrete that the concrete, so-called sprayed or shot concrete, can be applied whilst the nozzle is moving. Previously, the nozzle has been swung manually by the operator and, according to the aforementioned Swedish Patent Specification, this oscillating of the nozzle, although only in one direction, is now to be controlled by an automatic device. It has been touna tnat immediately the speed at which the nozzle is swung changes, in depencence upon the working position in question, the concrete coating becames unever. In order to obtain the desired uniform concrete coating it is essential that the speed at which the nozzle moves does not vary excessively. This places high requirements on the operator and, furthermore, it is especially tiring, particularly if adjustments must be made over extended periods of time. Although the aforedescribed Swedish Patent Specification meets these requirements to some extent, the present invention is intended to provide a further constructional possibility of producing another and completely uniform movement, automatically controlled and lacking abrupt changes in the direction of movement of the nozzle, since in the method of the invention there are no terminal positions.

[0010] A further difficulty encountered is one of spraying concrete with the least possible waste, in a manner which is simple and satisfactory from the aspect of worker protection, and which is also methodical and time saving. From the aspect of worker protection, it is satisfactory if the operator is able always to work from a position in which he is not exposed to falls of rock in the tunnel, whilst allowing him to spray the concrete in a manner which reduces to an absolute minimum discomforts of a harmful nature. By rational and work-saving methods is meant methods .. in which the concrete can always be sprayed in accordance with a pre-set regular method with the nozzle at the correct distance from the surface to be sprayed and at the correct angle therewith. This results in less work, the least possible wastage of material and an optimal quality of the layer applied. To this end it is required of the spray means that the nozzle is able to carry out a limite osciallatory movement at the same time as it is passed forwards and backwards over the surface, in accordance with a predetermined working pattern, preferably in mutually adjacent, parallel "gores", the operator having full control over the progress of the work through the mechanical and more or less automatic design and function of the arrangement, and is sufficiently close to be able to immediately interfere and personally direct the process when so required, e.g. in the case of pronouned irregularities and cavities in the surface being coated.

[0011] A further problem is that, the operator often has to stand on pieces of rock formed when blasting of the tunnel, the distance from the nozzle to the ceiling surface being too great, or from a bucket loader or even directly on the floor.

[0012] The present invention solves the aforementioned problems by the fact that the nozzle holder means is arranged to pivot at its centre part or approximately at its centre part on a vertical shaft, thereby to permit the holder means, when so required, to adopt a position which is parallel with the working direction, e.g. the direction in which the tunnel extends, it being possible by means of the special design of the holder means to displace the spray nozzle along the tunnel ceiling ard parallel to the tunnel walls with the carriage stationary. The holder means is telescopically arranged such that said displacement of the nozzle is effected in the longitudinal direction of the holder means. Further, the centre part of the holder means is connected to a carrier means fixedly mounted on a platform (a basket) for carrying the opera- tcr. It will be understood that movement of the holder means and therewith the spray nozzle can be effected through hydraulic or electrical means or a combination of such control means and, when required, can be controlled fully or partially automatically so that the operator is able to concentrate on monitoring layer being sprayed.

[0013] with regard to the desired movement of _Lne nozzle, in accordance with the invention the nozzle is conveniently mounted in a hclder means of such nature that the nozzle is continuously moved in two right-angled coordinates, for example a rotary oscillatory movement having no terminal positions. Conviently, the holder means may be caused to move in a circular path or in an elliptical path.

[0014] To this end, in accordance with a first embodiment there is provided a motor which is arranged to rotate in the holder means a sleeve having a recess arranged therein. The spray nozzle is arranged in said recess. The recess has a centre axis which is to form an angle with the axis of rotation of the sleeve, which is arranged to spread the sprayed concrete in the most purposeful manner.

[0015] In accordance with a second emobidment of the invention, a motor is arranged to drive an excentric shaft, the movement of which can be transmitted to a tube in which the nozzle is arranged, said tube being resiliently mounted in a holder means, whereby there is obtained a rotary movement without terminal positions.

[0016] By providing an apparatus which resolves the aforementioned problems and which has the aforementioned character, the advantage is afforded whereby it is possible to apply a uniform coating of material on every part of the ceiling of a tunnel and the more or less vertical sides or walls of said tunnel, with the aid of very simple devices and without too much demand on the operator. This uniform concrete on the ceiling can also readily be obtained adjacent the walls by arranging for the nozzle to be moved parallel with said wall. This displacement of the nozzle is effected without it being necessary for the carriage to move.

[0017] The prime object of the present invention is to fulfil the aforementioned objects and the main characterizing features of an apparatus according to the present invention are disclosed in the accompanying

[0018] A proposed embodiment or the invention embodying the essential characterizing features of the invention will now be described in more detail with reference to the accompanying drawings in which,

_Fig. 1 is a side view of a carriage necessary to the invention, on which carriage there is mounted a multiplicity of telescopically arranged elements for carrying a platform, intended for carrying an operator,

Fig. 2 is a side view of the platform pivotally mounted on the free end of the telescopically arranged elements shown in Figure 1,

Fig. 3 is a horizontal view of the apparatus shown in in Fig. 2,

Fig. 4 is a front view of the apparatus shown in Figures 1 and 2,

Fig. 5 is a view showing generally the construction and attachment of a spray-nozzle holder means, said spray nozzle being arranged to rotate in an oscil-- latory manner without terminal positions,

Fig. 6 is a horizontal view of the apparatus shown in Fig. 5,

Fig. 7 is a side view of the apparatus shown in Figure 5 and Figure 6, said figure illustrating the valves arranged on the connecting part of the nozzle for supplying a mixing agent to the concrete,

Fig. 8 is a side view of a further embodiment of the construction and the attachment of a spray-nozzle holder means such that the nozzle can be imparted a holder means such that the nozzle can be imported a rotary or circular oscillator movement without terminal positions,

Fig. 9 is a front view of the apparatus shown in Figure 8, and

Fig. 10 is a horizontal view of the apparatus shown in Figure 8 and Figure 9.

[0019] Thus, Figure 1 is a side view of a carriage 1f, necessary to the invention and being arranged to carry a working platform or working cage for an operator (Figure 2). The cage is mounted, via a pivot shaft la, to the free and 1b' of the one part 1b of a two part telescopic holder arm or jub. The inner and forward part 1b of the holder arm is displaceably arranged in the other, outer and lower part 1c, the lowermost part 1c' of which is attached to a support le through a pivot shaft 1d, said support 1e being, in turn, mounted on and carried by the carriage lf. The carriage 1f has two forward wheels 1g and two rear wheels 1h, the forward wheels being driven by means not illustrated or described. Each of the wheels lh is arranged for rotation of a respective shaft li.

[0020] Neither the manner in which the wheels 1g are driven nor the manner in which the wheels 1h are'rotated about the shaft li form any part of the invention, and since these means are known per se, they will not been described in detail. It should be mentioned, however, that the separate drive of the wheels 1g is controlled by operating means which can be operated by the operator from the cage 1.

[0021] The carriage If carries a counterweight lj which is displaceable rearwardly in dependence upon the prevailing tipping moment (the weight and lenght of part lb). The position of which the counterweight 1j is to be displaced can either be control led in response to the sensed pressure in cylinder lk or by the total axle weight sensed. These control means and sensing means are not described for the sake of clarity.

[0022] The parts lc and lb of the holder arm can be raised and lowered about the shaft ld by means of a hydraulic piston-cylinder arrangement lk, whilst the forward part lb of the holder arm can be extended from or withdrawn into the lower part lc of said holder arm by means of a hydraulic piston-cylinder arrangement 1m or, optionally, by means of a rack arrangment. The working platform 1 can be rotated about the shaft la by means of a hydraulic piston - cylinder arrangement 1a', thereby to adopt a horisontal position. The working platform can be moved to any desired position by means fo the piston-cylinder arrangements lk an 1m within a sector defined by lines "A" and "B" shown in Figure 1 (see also Figure 3).

[0023] Figure 2 illustrates in somewhat larger scale the various elements embodied in the working platform or cage having place for a worker or an operator 3. The cage 1 carries a tie-bar arrangement 2 mounted on a side part of the cage, such that the operator 3 can readily manoeuvre the holder means 6 and the spray nozzle 7 via a hydraulic piston-cylinder arrangement 12. Thus, the holder means 6 and the nozzle 7 can be raised or lowered by means of the piston arrangement 12 and constantly take a horizontal position.

[0024] The tie bar arrangement 2 is mounted on a support 2a, which in turn is pivotally mounted on the forward side part of the cage 1. The pivot axis is referenced 2b. The tie bar arrangement can be rotated about the axis 2b in means not shown and will adopt any selected position between the terminal positions C and D shown in Figure 3. The direction of the nozzle 7 in a plane containing the longitudinal axis of the holder means ₆ can be regulated by means of a hydraulic-piston cylinder arrangement ₉, since the nozzle is pivotally mounted on one end 6a- of the holder means 6 through pivots 9a and 9a'. It should also be mentioned that the nozzle direction can also be regulated manually by the operator, by means of a so called "teleflex-wire".

[0025] The holder means 6 has an inner tube having a free end 6a' which is arranged in an outer tube having a free end 6a. The inner tube 6a' can be displaced out of and into the tube 6a by means of a motor 6b. When a hydraulic piston-cylinder arrangement 9 is used, it is mounted on the inner tube through the pivot 9a'. the motor 6b is arranged to rotate a screw-threaded shaft arranged to mesh with a nut-arrangement mounted on the tube 6a'. By means of this rotary movement, the tube 6a' is displaced out off or into the tube 6a, thereby displacing the nozzle in the manner intended.

[0026] The operator 3 is able to rotate the holder means 6 around a rotational axis 21 alloted to said holder means, through a hydraulic operating device. This rotation of the holder means 6 is effected by activating a motor 21a, which through a transmission means, not shown in detail, causes said tube 6 to rotate about the axis 21. Finally, the holder means 6 can be dispaced in a horizontal position upwardly and downwardly (see Figure 2) by moving part 1b.

[0027] In the given rotation axis 21, two mutually separate movements must take place in two directions at right angles to one another. To this end, the tie point has been provided with two rotary means 2Ca and 2a, which can be called rotary cylinders since the angle of rotation is restricted to 180°. The rotary means 20 causes the nozzle 7 to rotate in a vertical plane (about the axis 20), such that the nozzle 7 can be adjusted to different angles when seen vertically, so as always to adopt a position perpendicular to the ceiling. The axis of rotation 20 of the rotary means 20a is therefore horizontal. It should also be possible to rotate the holder means 6 about its longitudinal axis. The directions of movement of the nozzle 7 are shown by means of arrows in Figure 3.

[0028] The axis of roation 21 of the other rotary means 21a, which is suitable identical to the rotary means 20a, extends perpendicular to the axis 20. The purpose of this is to adjust the holder means 6 to a position parallel with the working direction (the direction in which the tunnel extends) when the arm system 2 is rotated towards one side or the other (the terminal positions C and D) in relation to the working platform shown in Figure 3. Thus, the arm system 2 with the hydraulic piston-cylinder arrangement 12 is mounted on a pivotable (about its vertical axis) support 2a which is pivotally mounted on the floor of the platform, such that the arrangement can be mounted on any suitable platform whatsever.

[0029] The reference 8 indicates a layer of sprayed concrete previously applied and preventing falls rock onto (protecting) the operator, whilst the reference 8' indicates the stream of sprayed concrete, which coats a part of the tunnel with a further layer. The nozzle 7 communicates with one end of a hose 10, the other end of which co-operates with a concrete mixer and a pump not shown.

[0030] The operator has at his disposal in the working cage a plurality of operating means by which the cage 1 and the holder means 6 with the nozzle can be moved in the desired direction. Among these operating means can be mentioned:

a) operating means for actuating the cylinder arrangement 1k,

b) operating means for activating the cylinder arrangement lm,

c) operating means for activating the driving machinery for the wheels lg,

d) operating means for changing the position of the cage 1, by regulating the cylinder arrangement 1a',

e) operating means for activating the cylinder arrangement 12,

f) operating means for activating the rotary cylinder 20a and therewith rotating the holder means 6 about a horizontal rotary shaft 20,

g) operating means for activating the rotary cylinder 21a, and therewith rotating the means 6 about a vertical shaft 21,

h) operating means for activating the motor 6b and therewitr displacing the nozzle smoothly out of and in to the tube 6a of the holder means,

i) operating means for activating the cylinder arrangement 9,

j) operating means for initiating the rotary movement of th nozzle, and

k) operating means for activating valves 63 and 64.

[0031] Although reference is made in the exemplary embodiment to hydrauli piston-cylinder arrangements and hydraulic motors as the activating means, it will be understood that other equivalent means can also be

[0032] It should also be noted that the holder means 6 is provided on the end thereof facing the cage 1 with a motor 6b arranged to rotate a shaft placed in the tube of the holder means 6 such as to displace it into the tube 6a' placed in the holder means 6 in the longitudinal direction of the holder means 6, although other means may also be used.

[0033] Thus, by means of the arrangement according to the invention it is possible to move the holder means 6 into a position parallel with or at least substantially parallel with the longitudinal axis of the tunnel and, by means of operating devices (not shown) arranged in the cage to cause the nozzle 7 to be displaced away from and towards the holder means 6. Illuminating means for illuminating the working area are arranged on the rear part of the holder means 6 (adjacent the motor 6b).

[0034] Figure 5 illustrates a section of the aforementioned holder means for the spray nozzle, which is seated in the end of the arm system 6 and comprises an integral part thereof and which imparts the aforementioned rotary oscillatory movement to the nozzle, thereby to apply a sprayable material, such as concrete or the like, to a surface, particularly a blasted rock surface, such as that formed in tunnels or the like. The nozzle 7 is arranged to be imparted a continuous rotary tilting movement without terminal positions in two right-angle coordinates in the attachment 6c. The embodiment illustrates that the nozzle is moved in a circular parth., To this end, there is provided a motor 41 having a rotary shaft 42 arranged to drive a gear ring 43. The gear ring 43 is mounted on a sleeve 44. Thus, the sleeve 44 is driven round in the attachment 6c, and in particular in a housing 6d formed in the attachment 6c. The sleeve 44 is provided in a recess 45 in which the nozzle 7 is journalled, the recess 45 having a centre axis 45a which forms an angle to the rotary axis 44a of the sleeve 44. This angle shall be located within the range of 5-20°, preferably 10-15°. The nozzle 7 is journalled in the sleeve 44 by means of bearing means 45, meaning that the nozzle 7 will not accompany the rotati.on of the sleeve 44 but can only move in the desired, continuous rotary oscillatory movement path.

[0035] In Figure 7 there is shown the connecting part 7a of the spray nozzle 7, which connecting part is coupled to a connection for adding a further mixing agent to the sprayable material passing through the hose 10.

[0036] In the case of wet concrete, an accelerator can be added through the tube 61 and air through the tube 62.

[0037] When spraying dry concrete, water is added through the tube 61.

[0038] The invention also proposes a particular ejector action. The flow of air guarantees, through said ejector effect, that water admixed with accelerator will constantly be supplied to the spray nozzle, which is an unavoidable necessity when wet spraying. In the case of dry spraying, the accelerator is already mixed in the concrete mass, since it is dry. Only water. without an addition of air, is supplied to the nozzle.

[0039] When dry concrete is to be sprayed and passed to the tube 10 and water is passed to the nozzle 7, the water will be mixed with the concrete in the space 65 and passes out through.hole 66 into the hose 10. When wet-concrete is to be sprayed and passed through the tube 10 and an accelerator and air are supplied to the nozzle 7, the accelerator and air are also supplied to the tube 10 through the hole 66.

[0040] In Figures 8-10 there is illustrated an alternative embodiment of an arrangement for moving the nozzle in e continuous rotary movement exhibiting two right-angles coordinates, without terminal positions. This arrangement comprises a motor 71 arranged to drive an excentric plate 72. The excentric plate 72 is arranged to co-operate with a plate 73. The motor 71 is arranged to drive two excentric plates 72, 72', as best illustrated in Figure 9. The plate 73 co-operates with holding device 74 mounted on the hose 10. The hose 10 is also held in a holding device 75 via a resilient bush 76. When the plate 73 is moved in the continuous rotary movement in the form of a circular movement this movement will be transmitted to the hose 10 through the device 74, which hose will then impart to the nozzle the same movement pattern through the resilient bushes 76.

[0041] It will be understood that the invention is not restricted to the decribed exemplary embodiments, but can be modified within the scope of the accompanying claims.

Claims

1. An apparatus for applying a sprayable material, such as concrete or the like, to a surface, particularly to a blasted rock surface such as tunnels or the like in rock, in which said material is sprayed through a nozzle mounted on a holding means, characterized in that the nozzle is arranged to be moved in a continuous rotary movement without terminal positions.

2. An apparatus according to claim 1, characterized in that the nozzle is moved in a circular or elliptic movement path.

3. An apparatus according to claim 2, characterized d in that a motor is arranged to rotate a sleeve in an attachment, said sleeve having formed therein a recess in which the nozzle is journalled, said recess having a centre axis which forms an angle with the axis of rotation of said sleeve.

4. An apparatus according to claim 3, characterized in that said angle lies between 5-20°, preferably 10-15°.

5. An apparatus according to claim 1, characterized in that a motor is arranged to drive an excentric shaft, the movement of which is arranged to be transmitted to a tube carrying said nozzle, and in that said tube is resiliently mounted in an attachment.

₆. An apparatus according to claim 1, characterized in that the connecting part of said nozzle is coupled to a connection for adding to the sprayable material either an accelerator and air or water, and that valves are provided for manually regulating the addition thereof.

₇. An apparatus according to claim 1, characterized in that the holder means is pivotally mounted on a holder arm which is suitably arranged for displacement in a given working direction, i.e. in the longitudinal direction of said tunnel.

8. An apparatus according to claim 1 or 7, characterizedin that the holder means is pivotally mounted on an arm system which is pivotally mounted on a working platform, such that the holder means can be rotated about two rotary axes directed at right angles to one another and, at the same time, can be raised and lowered whilst retaining a horizontal direction.

9. An apparatus according to claim 7, characterized in that the centre part of the holder means is connected to a carrier means attached to a platform intended to carry an operator.

10. A carriage preferably intended to support an apparatus for applying a sprayable material, such as concrete or the like, to a surface particularly a blasted rock surface, such as that formed in tunnels or the like, characterized in that a counterweight is arranged for movement on the carriage such that said weight can be moved to a position relative to the load.

Drawing