Technical field

The invention relates to a device for dispensing granular gritting material.

Background

Many kinds of dispensing or spreading devices are known for spreading salt, sand or corresponding gritting materials to reduce slipperiness at roads, streets, walkways and yards. For instance, document EP 3215677 A1 discloses a spreading apparatus for dispensing particulate material. It includes a bucket configured to store the particulate material, a cover to openably close the bucket, and a manually-operated dispensing arrangement to dispense the particulate material. Another type of typical known apparatus is described e.g., in document US 3,797,867 A. It is a fixedly in to a vehicle assembled, pneumatically operated sanding apparatus which is used to spread sand on slippery road surfaces and thereby increase vehicle traction. For spreading, it includes a fan to create an air stream which is used as the conveying medium to move the sand from a storage bin onto the road surface just ahead of the vehicle drive wheels. Also document DE 10120378 A1 discloses device for spreading flowable granular material, such as road salt, sand, fertilizer and seeds. This device includes a bottle-like container comprising two compartments: One at its upper part, connected to a pressurized medium source, and a second one at its lower part holding flowable granular material. At the upper end of the container is a nozzle through which the flowable granular material coming through a pipe which extends from the nozzle to the flowable granular material at the second (lower) compartment is sprayed by the aid of pressurized medium introduced in the first (upper) compartment.

However, these devices are in most cases either manually-operated containers which are intended for small-scale use for family-house owners or occupants of small housing companies, unsuitable for spreading granular gritting material as such (i.e., without having special “flowable" particle form, as it is apparently required in the document DE 10120378 A1 ), or such large-size devices that need to be carried in a vehicle limiting their use in areas into which entering by a vehicle is not possible. None of these typical dispensing devices are specifically designed for such occasional situations where, for instance, a truck, bus, or other type of heavy vehicle becomes stuck on an icy road since having lost its traction due to slippery road surface. Furthermore, these devices are not designed for such special situations where the slippery surface exist in a narrow gateway or in a yard having substantially large area but in to which it is not possible to enter by a vehicle incorporated with a gritting device.

Summary

The aim of the present invention is to provide a device for dispensing granular gritting material that is especially suitable for above-described situations when occasionally a vehicle in the road needs help because it has lost its traction due to icy or snowy road surface, or when walkways or substantially large yard inaccessible to vehicle-based gritting apparatuses need to be gritted.

The aim of the invention is achieved because the device for dispensing granular gritting material according to the invention has such a pressurized-air based spreading means which is capable of conveying the granular gritting material stored in a container of the device quickly and effectively out from the container and spreading it to the ground of the area to be gritted. This is because the outlet point of the means for conveying granular gritting material is positioned at the lower part of the container, such that pressurized air and gravity together convey the material out from the container, and because the container includes means for preventing blocking and arching of the gritting material in the container, thus allowing quick and effective spreading of the granular gritting material stored in the container of the device regardless that the material may have rather coarse shape and thus may not be very well- flowable. Consequently, the device according to the invention is characterized by what have been described in the independent claim 1. The dependent claims 2 to 15 describe advantageous embodiments of the device according to the invention.

The advantage of the device for dispensing granular gritting material according to the invention is that it is well adapted for the specific needs where quick and effective gritting by means of coarse-shaped granular gritting material is needed. Especially if a heavy vehicle such as a truck or bus has stopped because of losing its traction on a slippery road the device can be used to provide gritting on the road surface quickly and effectively. Also, when a substantially large area in to which it is not possible to enter by a gritting vehicle needs to be gritted, it is possible to dispense gritting material easily and effectively by the device according to the present invention.

Brief description of the drawings

In the following, the invention will be explained in more detail with reference to the accompanying drawings wherein

Figure 1 is a side view of a first embodiment of the device according to the invention,

Figure 2 is a side view of a second embodiment of the device according to the invention, and

Figure 3 is a side view of a third embodiment of the device according to the invention.

Detailed description of some advantageous embodiments of the invention

Figure 1 shows a first embodiment of a device 10 for dispensing granular gritting material 20 according to the invention. This embodiment works by means of compressed air and is intended for occasional use and is thus preferably made in size and weight that makes it possible to carry by a single person and such that it is easy to store e.g., in a boot of a car or cabin of a truck. For carrying the device, the embodiment of fig. 1 may comprise a handle in a suitable place and/or strap or harness with suitable belts etc. to support the device 10 to the user’s body (not shown in fig. 1 ).

The embodiment of the device shown in fig. 1 comprises a container 11 , which has side-wall, upper end 24 and lower end 25, and which is divided by an gastight partition wall 26 in to compressed air portion 12 and a gritting material portion 13. The former is at the upper portion and the latter is at the lower portion of the container 11 . The walls of both, the compressed gas portion 12 and the gritting material portion 13 are made gas-tight such that air or other gas cannot escape through the walls or their connections. The material of the container 11 may be metal, plastic or composite or corresponding sheet-like material, and should be strong enough to hold the appropriate air-pressure inside the container 11 . In the embodiment of figure 1 , the container 11 has an openably closable inlet opening 17 for filling the granular gritting material 20 in to the container 11 . As can be seen from figure 1 , the openably closable inlet opening 17 is positioned at the side wall of the container just below the gas-tight partition wall 26. Also the openably closable opening is gastight and holds the compressed provided inside the gritting-material portion 13 when the openably closable opening 17 is closed by its gas-tight lid.

The device of figure 1 has also a compressed-gas providing means for providing, in this case compressed air 21 into the container 11 . The purpose of the compressed -gas providing means is to provide suitable overpressure and strong enough air stream in to the gritting material portion 13 to transport the granular gritting material out from the container 11 during the use of the device 10. For this reason, the compressed gas providing means comprises further a compressed gas inlet valve 18, conduit 15 from the compressed gas portion 12 to the gritting material portion 13 and a control valve 14 connected between the compressed gas portion 12 and the conduit 15 to control the airflow from the compressed gas portion 12 to the gritting material portion 13 through the conduit 15. The control valve 14 has a pressure gauge 19 to measure pressure in the compressed gas portion 12.

The compressed gas inlet valve 18 is for charging the compressed gas portion 12 which therefore, acts as a storage of the compressed air used for actuating the device 10. Charging compressed air in to the compressed gas portion 12 can be accomplished, for instance, by means of an external air compressor or air pump connected to the compressed gas inlet valve 18. The compressed gas inlet valve 18 may be an automatically closing valve such that when the air compressor or air pump is disconnected from the compressed gas inlet valve 18 it is immediately closed.

In the embodiment of the figure 1 the conduit 15 of the compressed gas providing means is connected to the gritting-material portion 13 at the connection point 23. In this embodiment, the connection point 23 locates at the upper part of the gritting-material portion 13. The level of the granular gritting material 20 to be filled in to the gritting-material portion 13 is below the connection point 23 when the container 11 is in upright position. Thus, in the embodiment of fig. 1 , an empty space remains between the granular gritting material and the partition wall 26 if the device is kept in upright position when the granular gritting material 20 is in to the gritting material portion 13. Of course, the gritting-ma- terial portion 13 can be filled completely full, but it is better for the function of the device that empty space as shown in figure 1 is left in the upper part of the gritting material-portion 13.

At the lower part of the container 11 there is a connection point 22 of the spreading means 16 to the gritting-material portion 13. Spreading means 16 comprises, in this embodiment a spreading hose 29 which first end is connected to the connection point 22 and which second end has a spraying nozzle 38. The spraying nozzle 38 has been designed to spread the air (or other gas) stream and granular gritting material in suitable manner so that the granular gritting material spreads in appropriate wide area (e.g., 0.5 - 1 .5 meters wide at a distance of 1 -2 meters from the spraying nozzle). The spraying nozzle 38 may be adjustable and it may be openably closable such that the flow of the granular gritting material can be interrupted during the use of the device 10.

The device 10 may have further disengaging means for preventing arching and/or blocking of the granular gritting material 20 into the container 11 . In the embodiment of figure 1 the disengaging means comprises material-pressure decreasing element 28 inside the gritting material portion 13. It is a partial wall or a plate that is placed above the connection point 22 of the spreading means 16 as it is shown in the figure 1. Thus, the material-pressure decreasing element 28 prevents the granular gritting material 20 from being compressed by its weight against the lower end 25 at the area of the connection point 22, and thus from being blocked at the opening of the connection point 22. Therefore, material-pressure decreasing element 28 aids the gritting material 20 to flow out from the gritting-material portion 13 during the use of the device 10.

Before starting to use the embodiment of the device according to fig. 1 the granular gritting material 20 has to be filled in to the container 11 through the openably closable inlet opening 17 and the compressed gas portion 12 must be provided with appropriate air pressure by pumping air through the compressed gas inlet valve 18. The embodiment of fig. 1 is ready for use when there is appropriate pressure inside the compressed gas portion 12 and there is granular gritting material 20 in the gritting-material portion 13. During gritting, the user holds the device 10 in their hand and/or wears the harness for carrying the device with them when walking around the area to be gritted. Dispensing of the granular gritting material is accomplished in the embodiment of fig. 1 by opening the control valve 14 by pressing the valve lever and directing the spraying nozzle of the hose with the other hand desired direction. In the embodiment of fig. 1 , the flow rate of the air flowing from the compressed gas portion 12 to the gritting-material portion 13 depends on extent of the lever deflection of the control valve 14. The chosen flow rate determines the amount of the granular gritting material coming out from the container 11 . Thus, in this embodiment, the user can adjust the degree of gritting by controlling the flow of the granular gritting material through the position of the lever of the control valve 14.

During gritting, the disengaging means (i.e., the material-pressure degreasing element 28) in the container 11 prevents the granular gritting material 20 being blocked from the opening at the connection point 22. This is because the material pressure-degreasing-element 28 carries most of the weight of the granular gritting material 20 above the connection point 22. Consequently, the granular gritting material 20 is not pressed against the opening at the connection point 22 by its full weight.

If the granular gritting material 20 in the gritting material portion 13 runs out, the user closes the control valve 14 and opens the gas-tight lid 39 of the open- ably closable inlet opening 17, fills more granular gritting material 20 into the gritting-material portion 13, closes the gas-tight the lid 39, and continue- their work as described above. When the desired area has been gritted and the user wishes to finish the gritting they release the lever of the control valve 14, which stops the flow of air from the compressed gas portion 12 to the gritting- material portion 13 and hence ends the flow of the granular gritting material 20 through the spreading hose 29.

Figure 2 shows an another embodiment of the device according to the invention. The device 10 of fig. 2 is particularly suitable for gritting larger areas (such as e.g., yards of houses or buildings) which are, however, such that entering there by a vehicle is not possible. Nevertheless, the embodiment of fig. 2 is, of course, also suitable for effective gritting of any other kinds of areas where gritting is needed. The embodiment of the device 10 of fig. 2 comprises a container 11 , having upper end 24 and lower end 25. The container 11 of the embodiment according to fig. 2 may be made from similar materials as the container 11 of the embodiment according to fig. 1. The container 11 of fig. 2 also includes openably closable inlet opening 17 at its upper end 24. The upper part of the container forms a compressed gas portion 12 and the lower part a gritting material portion 13. The embodiment of fig. 2 has also a compressed gas providing means which comprise control valve 14 and conduit 15 connected to the container 10 at the first connection point 23a, which locates at the compressed gas portion 12 and at the second connection point 23b which locates at the gritting-mate- rial portion 13. Also in this embodiment the control valve 14 comprises a pressure gauge 19 which measures, in this embodiment, the air- (or other gas) pressure provided by the external air compressor to the control valve.

The device 10 of fig. 2 comprises further a support frame 34 for securing and holding the container 11 and the other parts of the device 10 together. In embodiment of fig. 2 the support frame 34 is further provided with adjustable legs 35 at its lower part. The purpose of the adjustable legs 35 is that the device 10 can be placed upright on the ground in a desired place during its use. Adjustable legs 35 allow to adjust the orientation of the device and to ensure that all the supporting points carry equally the weight of the device when it is placed on the ground. Thus, especially in case when the ground surface is uneven and/or inclined, the adjustable legs 35 improve the stability of the device.

In the embodiment of fig. 2 the container 11 does not comprise partition wall between the compressed gas portion 12 and the gritting-material portion 13. Thus, the said portions 12 and 13 are inside the same space determined by the upper end 24, lower end 25 and the side-wall of the container 11 .

In the embodiment of fig. 2 the compressed gas providing means comprises an external air-compressor or some other external means for providing pressurized air (or other gas) in to the container 11 . The external air-compressor (or other external means for providing pressurized air or other gas) may be connected to the device through a connection means which may be e.g., provided in connection with the control valve 14 (not shown in the figure 2) or be connected to the control valve 14 by means of an additional conduit. The con- nection means is preferably arranged to allow to connect the external air-com- pressor detachably to the control valve 14 so that it can be connected and disconnected to the device 10.

The spreading means 16 of the embodiment of fig. 2 comprises a spreading hose 29. In this embodiment the spreading hose 29 is preferably substantially long (preferably at least 5 meters) so that substantially large area can be gritted by moving only the spreading hose 29 to places to be gritted. In order to enable handling of the spreading hose 29 in a convenient manner, the device 10 according to fig. 2 may have a spool 37 for storing the spreading hose 29. The spool 37 may be fixed or rotatable so that the spreading hose 29 can be coiled and uncoiled by rotating the rotatably attached spool 37. For rotating the rotatable spool 37 it may comprise crank or corresponding rotating means. A rotatable spool may be also arranged to recoil the spreading hose 29 by means of a driving spring that tends to rotate the spool 27 in recoil direction when the spreading hose 29 is released and provided with automatic locking mechanism which allows to lock and unlock recoiling of the spring driven spool 27 just by pulling and releasing the hose 19.

In the embodiment of fig. 2 the spreading means 16 may further comprise an adjustable spreading connection opening 31 and/or spraying nozzle (not shown in fig. 2) at the end of the spreading hose 29. Either or both of these can also include some kind of adjustable valve by means of which the flow of the air and granular gritting material can be adjusted and/or interrupted. This makes it possible to control of the amount of the granular gritting material to be dispensed during the use of the device 10 remotely. In addition the embodiment of fig. 2 may include some kind of remote control system to control, e.g., the control valve 14 of the device and/or the external air-compressor.

The disengaging means 36 in the embodiment of figure 2 comprises a rotatable screw inside the gritting material portion of the container 11. In this case the disengaging means (i.e., a rotatable screw 36) is operated by an electric motor M. The electric motor M is arranged to rotate the rotatable screw 36 inside the container 11 so that the screw moves the granular gritting material towards the connection point 22 of the spreading means 16 at the lower end 25. The electric motor M is preferably operated by mains electricity but alternative it may be battery operated (in smaller embodiments). Alternatively, in this and in all the other embodiments, the rotatable screw 36 may be rotated by means of some other rotating means such as, e.g., compressed air (or - gas) engine or pneumatic motor. The disengaging means prevents the granular gritting material 20 from blocking or arching in to the container 11 i.e., ensures that the granular gritting material 20 flows out through the spreading means 16 during the use of the device 10.

In the embodiment of fig. 2 the container 11 the upper end 24 has inwardly conical shape that forms a recess to the upper end 25 as shown in fig. 2. As also can be seen from fig. 2, the openably closable inlet opening 17 has been placed at the bottom of that inwardly conical recess. Inwardly conical shape of the upper end 24 helps in filling the granular gritting material 20 in the container 11 since it functions like a funnel which directs the material inside the container 11 through the openably closable inlet opening 17. For closing the opening, the openably closable inlet opening 17 has an gas-tight sealed lid 39 which can be attached to the openably closable inlet opening 17 for closing it gas- tightly so that the container 11 can hold compressed air or other gas inside.

For using the embodiment of fig. 2 the pressurized air (or other gas) needed is preferably provided by connecting the device 10 to an external air compressor (or other suitable means for providing pressurized air or gas) having an appropriate pressure. In the embodiment shown in fig. 2 compressed air is used. Thus, before starting the gritting work the external -air compressor is connected to the connection means at the control valve 14. Also, at latest in that phase, the gas-tight lid 39 of the openably closable inlet opening 17 is opened and suitable amount of granular gritting material 20 is filled in to the container 11 . To start the gritting, the external compressor and the disengaging means are turned on, as well as the control valve 14 is opened and adjusted so that suitable amount of pressurized air flows in to the container 11. Next, the spreading hose 29 of the spreading means 16 is extended in appropriate manner by uncoiling it from the spool 37 and directed towards the ground at the area to be gritted. When the container 11 has been filled with pressurized air, the closing valve of the spraying nozzle is opened which causes that pressurized air and granular gritting material starts to flow out from the container 11 through the spreading hose 29. During gritting, the disengaging means 36 ensures that granular gritting material 20 flows freely from the gritting material portion 13 to the connection point 22 of the spreading means 16. This is ac- complished because the screw 36 of the disengaging means that is rotated by an electric motor moves and mixes the granular gritting material 20 continuously so that it cannot be blocked and/or arched against the walls of the container 11.

A third embodiment of the device according to the invention is shown in the figure 3. It differs from the embodiments of figs. 1 and 2, among others so that it comprises support frame 34 which has wheels 33 for moving by means of a handle 37 the device 10 on the ground during its use. The spreading means 16 does not, in this embodiment, comprise a spreading hose but only a spraying nozzle 38, placed at the lower end 25 of the container 11 , directed so that it spreads the granular gritting material 20 in front of the device 10. The embodiment of fig. 3 is intended for corresponding professional use as the device 10 of figure 2.

Also the embodiment of the device 10 according to fig. 3 has a container 11 comprising compressed gas portion 12 and gritting-material portion 13. In embodiment of fig. 3 there are also not such partition wall as in the embodiment of fig. 1. The compressed air is provided in to the container 11 by the compressed gas providing means which comprises in this case an air-compressor 30 that is fixed to the device 10. The air-compressor 30 is in this embodiment preferably electrically operated but can be also operated, e.g., by an internal combustion engine.

In the embodiment of fig. 3 the air-compressor 30 is fixed to the support frame 34 and/or to the side-wall of the container 11 . Thus, there is no need for connection means for connecting the device 10 to an external air compressor as in the embodiment of fig. 2. Instead, the embodiment of fig. 3 has a cord by means of which the -air compressor 30 can be plugged in to a wall socket to have electricity for it. The cord may be long enough so that the device can be moved along the ground within the area to be gritted in one go. Thus, in the embodiment of fig. 3, the device 10 may include a spool for the cord (not shown in the figure) which may correspond to the spool of the embodiment according to fig. 2. Thus, also in this embodiment the spool may be rotatable so that cord can be uncoiled or pulled (if the spool is freely rotating) out from the spool when the device is in use. Furthermore, in some embodiment, the spool for the cord can be arranged to work, e.g., by corresponding manner as driving spring operated cord spools in vacuum cleaners, i.e., so that cord can be extended by pulling it out from the spool, and retracted back in to the spool by means of, e.g., a press button which releases a lock locking the spool automatically (i.e., when the rotation of the spool in uncoiling direction stops so that it remains in a position corresponding extent of which it has been pulled out from the spool). If the device according to fig. 3 is operated by an internal combustion engine cord and spool is not needed but instead it must have fuel tank for the fuel of the internal combustion engine.

In the embodiment of fig. 3, the disengaging means comprises a rotatable screw or a spiral shaped blender 36 which, during the use of the device 10, moves the granular gritting material 20 so that it won’t be blocked or arched in the container 11 . Also in this embodiment the screw or spiral-shaped blender 36 is rotated preferably by an electric motor M. Furthermore, engaging means comprises in the embodiment of Fig. 3 in addition to rotatable screw or spiralshaped blender a corresponding material pressure decreasing element 28 as in the embodiment of fig. 1. It is placed above the connection point 22 corresponding manner as in the embodiment of fig. 1 , such that it reduces pressure caused at that position by the weight of the material and thus helps the granular gritting material 20 to flow out from the container 11 by means of air-flow caused by the pressure-providing means during the use of the device 10.

For spreading the gritting material, the embodiment according to fig. 3 comprises an adjustable spreading connection opening 31 and spraying nozzle 38 by means of which the granular gritting material 20 is dispensed on the ground surface in the front of the device 10. Thus, during use the embodiment of the device 10 according to fig. 3 is moved on the area to be gritted by pushing it from its handle 37. The flow rate of the granular gritting material 20 can be adjusted either by means of adjustable spreading opening 31 and/or spraying nozzle 38 in addition to the control valve 14 and the pressure provided by the air-compressor 30. The purpose of the adjustable spreading opening is also to fit the device 10 for the particle size and type of the granular gritting material 20 to be used in the device 10.

Before starting to use the device 10 according to fig. 3 the openably closable inlet opening 17 is opened and the granular gritting material 20 is filled in to the container 11 as in the other embodiments. Thereafter the cord of the fixed air-compressor 30 is connected to a wall socket and turned on so that pressurized air will be available for providing in to the container 11 .

When the embodiment of fig. 3 is used, the control valve 14 is opened so that the pressurized air from the air-compressor 30 flows to the container 11 . At that time also the electric motor M of the disengaging means is turned on so that its screw or spiral shaped blender 36 starts to rotate and to move the granular gritting material in the container 11 , and thus to prevent blocking and/or arching of the granular gritting material 20 in the container 11. When these operations have been done the granular gritting material 20 starts to flow from the gritting-material portion 13 to the spreading means 16. Thus, at this phase the spraying nozzle 38 starts to spray the granular gritting material on the ground in front of the device 10. During the work, the device 10 of this embodiment is pushed from its handle 37 around the area to be gritted so that suitable amount of granular gritting material is spread all over the area. After the work has been done, the control valve 14 is closed and the air compressor 30 is turned off. These steps are also carried out during the work if the area to be gritted is so large that it is necessary to add more granular gritting material 20 in to the container 11 during the work to be done. After finishing the work, the cord of the device 10 is detached from the wall socket and coiled to the spool 37 and the device 10 transferred to the storage or packed to a transporting vehicle for moving it to another work site.

For moving the device from a work site to another the embodiment of figs. 2 and 3 are intended to be transported by some suitable transporting vehicle such as van or pick-up truck. The embodiment of the device 10 according to fig. 1 may be also transported, e.g., in a trunk of a car or a cabin of a truck. In case of a truck the pressurized air needed in to the compressed air portion 12 of the container 11 of the device 10 may be taken from the compressed air system of the truck.

Furthermore, it should be understood that instead of compressed air any other compressed gas which is suitable for providing corresponding gas-stream in to the device according to the present invention such that it is capable for transporting the granular gritting material out from the container through the spreading means as the compressed air in the embodiments described above can be applied in this invention. Thus, in embodiments described above as well as in all other possible embodiments of the present invention instead of air other compressed gases can be used as means for conveying the granular gritting material out from the gritting-material portion of the container of the device according to the invention. Suitable other gases can be, e.g., oxygen, nitrogen, nitrogen oxide or some propellant gas which could be in liquid form if it is stored in a compressed vessel acting as the compressed gas providing means or part of it for the device according to the invention.

By the granular gritting material can be meant in this also other kinds material than sand, crushed aggregate, LECA, or other inorganic coarse particle material such as, e.g., saw dust, seeds, or pieces, particles or chips made of some suitable plant-based or other organic materials which have appropriate ability to prevent slipperiness when spread on to the ground.

The compressed gas providing means comprises typically an air-compressor or compressed air portion of the container suitable for storing pressurized air or other gas as well as conduit from the air-compressor or compressed air portion to the control valve and from the control valve to the gritting portion of the container. However, in the other embodiments the compressed gas providing means may comprise alternatively e.g., a propellant gas vessel for liquidized propellant gas which can be either arranged within the container, or be separate part of the device (i.e., e.g., external pressurized gas vessel).

Spreading means, in different embodiments of the invention, comprises a connection at the connection point that locates at the lower end of the gritting- material portion and which have an opening through which the granular gritting material can exit from the gritting-material portion of the container. Spreading means may also comprise some kind of a spraying nozzle which can be connected directly to the connection at its connection point (as in embodiment of fig. 3) or through a spreading hose as in embodiments of Fig. 1 or 2. Furthermore, spreading means can comprise further some kind of adjusting and/or closing valve either at the connection point and/or in connection with the spraying nozzle so that the amount of granular gritting material flowing out from the gritting-material portion of the container can be controlled also by means of the spreading means. Thus, the device for dispensing gritting material according to the present invention is not limited to the embodiments described above but can be varied within the scope of the appended claims.