AND PEDESTRIAN SURFACES

Subject of the invention

The subject invention refers to a salt and grit spreader with a transport belt (dispenser) for deicing roads and pedestrian surfaces by spreading various materials. The invention refers to a salt and grit spreader that uses transport belts, be they metal, rubber or belts fabricated from those or other materials for discharging materials to be spread from the spreading material storage container. According to the International Patent Classification, the subject of the invention is classified in class EOIC 19/12 - machines, tools or auxiliary devices for distributing granular or liquid materials, and can alternatively be classified in class EOlHlO/00 - improving gripping of ice-bound or other slippery traffic surfaces, e.g. using gritting or thawing materials.

Technical problem

One of the largest problems posed when using a device with transport belts for spreading material on roads and pedestrian surfaces is the material itself (salt, sand, rock, a mixture thereof), which is retained on the lower, return portion of the transport belt after the transport belt has drawn the spreading material from the dispenser container and dispatched it towards the distribution system, which then spreads the material on a traffic or pedestrian surface. The purpose of the spreading material is to prevent the formation of ice on traffic and pedestrian surfaces, and to melt existing ice from traffic and pedestrian surfaces, i.e. to increase the friction between vehicle wheels, pedestrian footwear and the ice-bound surfaces.

Alongside the array of technical solutions applied by various manufacturers, such as special fixed and rotating brushes, the spreading material cannot be completely removed, eliminated or wiped off the transport system. It remains "glued" or is retained on various parts of the transport system that are not accessible for mechanical methods of cleaning the transport belts. The spreading material is shaken off the lower, return portion of the transport belt onto the bottom of the truck bed or on the truck chassis, which causes many problems. The spreading material is a corrosive, aggressive material (salt or a salt mixture and sand or rock), which accelerates corrosive activity on the bottom of the truck bed or on parts of the chassis that are made of steel, cast iron or grey cast iron. Such spreading material that has been shaken off the transport belt can accumulate in large amounts during extended interventions arid consecutive spreadings to the degree that such may cause blockages or very often damages to the transport system of the transport belts, which causes delays and very high costs. The aforementioned fact is the subject of very frequent conflict between the manufacturer and the consumer of such equipment, whereby the manufacturers insist on more frequent cleaning out of the shaken-off salt from the bottom of the truck bed, while the consumers claim that the system for cleaning the return portion of the transport belt has not been constructed properly and that is it not functional.

The stated technical problem is completely resolved with the subject invention, whereby the entire transport belt is located inside the spreading material storage container i.e. both belts of the transport belt are located inside the spreading material, both the belt that carries the spreading material to the distribution system and the return belt of the transport system.

Current state of the art

Manufacturers have detected the problem of spreading material accumulating on the lower return belt of the transport belt after the transport belt has dispatched the spreading material from the spreader container. Attempts have been made to solve the problem, i.e. manufacturers have solved the problem in various ways. Various transport belt cleaners in the form of stationary or rotating brushes are installed, which attempt to remove or rhore or less remove the spreading material that has adhered to the belt. However, a system does not exist that completely resolves that problem in respect to salt and grit spreaders with transport belts. The subject invention is the first to foresee a new structure in which the entire transport belt is located inside the spreading material storage container, i.e. both transport belts are inside the spreading material, both the belt that carries the spreading material to the distribution system as well as the other return belt of the transport belt. Due to this, no possibility exists of spreading material to accumulate at the bottom of the vehicle bed, since the entire transport belt is located inside the spreading material storage container.

Figure 1 depicts a salt and grit spreader for dispensing various materials onto roads and pedestrian surfaces known from the state of the art, for the purpose of preventing the formation of ice on these surfaces, for melting ice or for increasing the friction between vehicle wheels and ice-bound road surfaces. This solution is well-known and regardless of whether it comprises a rubber or metal transport belt, or a combination thereof, it has its limitations that primarily manifest when excess spreading material is shaken off the belt, and when that same material accumulates under the belt, which may ultimately lead to a blockage of the transport belt and/or its breakage. The figure clearly shows that the upper portion of the transport belt 2 is situated against and slides along the container bottom 3. Spreading material is situated on that portion of the transport belt. Drive elements, which consist of a hydraulic motor, a reducer and drive pulleys 5, move the transport belt linearly to the right (arrow "A"), draw spreading material from the device's spreading material storage container 1 , and convey it to the distribution system, which consists of the dispersing canal 8 and the rotating disk 9 for spreading material. It is clearly shown that only the upper portion of the transport belt is exposed to the spreading material and that the drive pulleys 5, idler pulleys 6, the entire belt tensioner 7, the lower (return) transport belt 2 as well as the system of brushes for cleaning 4 the fastened spreading material are situated outside of the spreading material storage container 1. The belt covering the drive pulleys 5 shakes off the material and makes its return under the container bottom 3 to the left (arrow "B"). The action is continually repeated until desired or until all spreading material is expended from the container 1. On the return portion of the belt, due to the inability of achieving a high-quality cleaning, the accumulated material is separated from the belt and falls to the bottom of the truck bed, where it is accumulated and causes the previously mentioned problem. Additionally, the belt is able to transport more material than is necessary and hence the material accumulates in the back portion of the container 1 as well, significantly altering the position of the center of gravity and changing the load on the vehicle shaft, possibly causing poorer maneuverability of the vehicle due to insufficient load on the vehicle's control shaft. It is also possible that larger clumps of spreading material block the exit 10 of the spreading material from the container 1, which will certainly cause a delay or damage to the belt or result in a decreased flow of material into the distribution system, making it impossible to reach the spreading intensity as was selected on the control unit in the driver's compartment of the vehicle.

Disclosure of the invention

The main objective of this invention for a salt and grit spreader for dispensing materials onto roads and pedestrian surfaces that uses a transport belt to convey spreading material outside of the container is to prevent any type of leakage of salt outside the spreader's container, in order to completely avoid the above-mentioned technical problem. The following objective of this invention is to prevent clumps of rigid salt or iced sand and rock from falling onto traffic or pedestrian surfaces, and that these clumps do not affect the spreading intensity.

A further objective to be achieved is for the position of the center of gravity of the spreader with the remaining spreading material in the container to remain unchanged in relation to a full spreader during the discharge of spreading material from the container. All currently known transport systems cause a significant change in the spreader's center of gravity when spreading material from the container. This can cause an overload of one of the vehicle's shafts where the spreader is installed, which further leads to poorer maneuverability of the vehicle due to insufficient load on the vehicle's control shaft.

For achieving these objectives, it was necessary to create a transport system with a transport belt, where the entire transport system is located inside the spreading material storage container; hence, no part is found outside of the container. An impermeable bottom made of stainless steel is located under the entire transport system. This fact has allowed that the remaining spreading material is not shaken off the return belt portion of the transport system, which is located outside of the spreading material storage container.

To achieve this solution, other than the modification of the position of the bottom of the spreading material storage container, in this invention, it was necessary to reverse the direction of rotation of the transport belt so that the bottom portion of the transport belt is that which transports spreading material from the container to the distribution system. According to the invention, it was also necessary to alter the belt tensioner system and the idler pulley system.

Brief description of the figures

The accompanying figures that are included in the description and constitute a portion of the description of the invention, show the most favorable implementation of the invention and assist in explaining the basic principles of the invention. Below are figures and explanations of the present state of art and the subject invention for the purpose of easier differentiation of the two.

• Figure 1 shows a salt and grit spreader with a transport belt on which spreading material is lead out of the container toward the distribution system with the corresponding cross section A-A (solution from current state of art) • Figure 2 shows a salt and grit spreader having a transport belt that is situated in its entirety in the container from which the spreading material is lead out of the container toward the distribution system with the corresponding cross section A-A (new solution according to the subject invention)

Description of an embodiment of the invention

Figure 2 shows the device according to the subject invention, which has a transport system with a transport belt and the following characteristics:

the entire transport system: the transport belt system 2 and its individual belts, the belt for dispatching material 2a and the return belt 2b, drive pulleys 5, idler pulleys 6, a part of the belt tensioner 7, are located inside the spreading material storage container 1. When located inside the container 1 , spreading material surrounds the mentioned elements.

the container bottom 3 is located under all the above-mentioned, which completely closes off the spreading material storage container 1 so that absolutely no spreading material can exit the container 1, other than the material spread onto roads and pedestrian surfaces and it exits the container through the exit 10 and through the distribution system, i.e. through the dispersing canal 8 and the rotating disk for spreading material 9.

the transport belt moves in the opposite direction so that the bottom portion of the belt moves to the right (arrow "A") and takes the spreading material and transports it to the distribution system.

the upper return belt 2b of the transport belt system 2 moves in the opposite direction (arrow "B") thereby crumbling and loosening the spreading material, which ensures that the spreading material that is on the belt for transporting material 2a of the transport belt system is without clumps.

since the entire transport belt 2 is in salt, an extra system of cleaning brushes 4 (figure 1) is not necessary, which is not the case in older systems, and additionally lowers the cost of the system itself.

The salt and grit spreader for spreading various materials onto roads and pedestrian surfaces, equipped with a transport belt for dispatching spreading material from the spreading material storage container 1 in the form of a transport belt 2 according to this invention, consists of a belt tensioner 7, drive pulleys 5 and idler pulleys 6. The transport belt 2 draws material from the container 1 and transports it with the lower supply belt 2a to the exit 10 of the dispensing canal 8, and the material is further spread on the road by the rotating disk for spreading material 9. The basic characteristic of the transport belt system 2 is that the whole transport belt system 2 is in its entirety situated inside the spreading material storage container 1 , i.e. both belts of the transport system 2a and 2b are situated inside the spreading material itself, specifically, the lower belt 2a, which transports the spreading material to the dispensing canal 8, and the other return belt 2b of the transport belt system 2.

During operation of the device, the transport belt 2 rotates in the direction of arrow "A", and the lower belt of the transport belt system 2a draws spreading material from the container 1. When executing the spreading procedure, the material from the container lightly falls from the upper return belt 2b of the transport belt system 2, which is thereby crumbled and loosened, eliminating the possibility of large pieces of spreading material arriving on the transport belt 2a and being spread on the road.

When the contents of the container 1 are being spread, the upper belt 2a of the transport belt system 2 rotates in the driving direction of the salt and grit spreader vehicle, and as a result, the lower belt rotates opposite of the driving direction of the salt and grit spreader vehicle, which results in the uniform discharging of the container, and the position of the vehicle's center of gravity remains unchanged during operation.

Directly under the transport belt system 2, which is completely submerged in the spreading material, the firm and impermeable container bottom 3 is situated, which prevents the spreading material from exiting the container 1.

When executing the spreading procedure, the material from the container lightly falls through the upper return belt 2b of the transport belt system 2 (direction of arrow "B"), which is thereby crumbled and loosened, eliminating the possibility of large pieces of spreading material arriving on the lower transport belt 2a and being spread on the road or blocking the exit 10 of material.

The upper return belt 2b also serves to crumble large pieces of spreading material, and additional mechanisms for crumbling large pieces of spreading material are not necessary. Even though the subject invention deals with a transport belt that calls for the necessity to be cleaned according to the current state of equipment, due to the fact that the entire transport belt is submerged in the spreading material in this invention, cleaners in the form of brushes, rollers or other types of cleaners for the lower return portion of the belt are not necessary. All material that becomes attached to the belt remains in the spreading material storage container.

This invention completely resolves the largest problem for salt and grit spreaders with transport systems for dispatching spreading material from a container that have different types of transport belts. That problem is residual salt that is shaken from the lower return portion of the transporter to the bottom of the vehicle bed or chassis, which causes well-known problems of accumulation of spreading material.

The device as described with the innovative transport belt system can be installed on a truck, or any other vehicle with a cargo area or it is possible to set the device up on a trailer that is pulled by a truck or another towing vehicle. The device has also been conceived so that it can be assembled directly onto the chassis of a vehicle.

Experts in this field will find it obvious that several modifications and changes could be made to the described salt and grit spreader for roads and pedestrian surfaces according to this invention, without abandoning the scope or essence of the invention.

List of reference designations

1 - spreading material storage container

2 - transport belt

2a - belt for transporting material toward the distribution system

2b - return belt

3 - container bottom

4 - system of cleaning brushes

5 - drive pulleys

6 - idler pulleys

7 - belt tensioner

8 - dispensing canal - rotating disk for spreading material - exit

- bottom of the truck bed