WO1998006591A1

WO1998006591A1 - Sanding machine

Info

Publication number: WO1998006591A1
Application number: PCT/NO1996/000236
Authority: WO
Inventors: John-Egil Bustadmo
Original assignee: Bustadmo John Egil
Priority date: 1996-08-08
Filing date: 1996-10-10
Publication date: 1998-02-19

Abstract

A sand sprinkler (1) for vehicle wheels, with a trapezoidal hopper (4) for sand storage, and a dual rotary feeder (3). On the periphery of the rotary feeder (3) are mounted two sets of blades (6, 7), each set being staggered with a fraction of a rotation in relation to the other set. Rubber flaps (5, 5') are mounted as an extension of the sides at the lower extremity of the trapeze, engaging between the blades (6, 7). A sand retainer (8) is provided at the bottom of the hopper (4) to reduce the quantity of sand available.

Description

SANDING MACHINE

The present invention relates to a device for the sprinkling of sand or equivalent material on winter roads, and in particular in front of the driving wheels of vehicles Such a device can be controlled by the driver in order to sprinkle sand in front of the driving wheels on the road in order to increase friction between the wheels and the road surface

In the regions of the world where the temperature is under 0° C for most of the year, there occur grip problems between vehicle tyres and the road surface In the past, several devices have been developed and put to use in order to improve the grip on the road in winter conditions. Among such devices can be mentioned in particular special tyre patterns for winter conditions, studded tyres and chains When winter conditions occur very suddenly without giving drivers time to prepare themselves for driving under altered conditions of tyre friction on the road surface, and for example in emergency situations when the tyres skid on the road surface and the vehicle cannot be moved, it has been necessary to resort to sand sprinkling on the road

Over the last few years, this technique has developed from using a spade to throw sand in front of the wheel concerned, to devices which sprinkle sand when and as necessary Such devices are mainly formed as containers for sand, with a mechanical feeder which feeds sand from the container via channels to one or several of the vehicle wheels Such solutions are known from US patent no 1,705,878 and 2,063,294, DE patent no. 3,444,007 and 3,620,693 and EP patent no 178,289 The problem with this type of sand sprinklers is that they function solely with fine-grained dry sand (sandblasting sand) or sand with added salt to prevent the sand from freezing in the container Sandblasting sand is expensive, not easily available, and has a limited effect due to its fine grained consistency A mixture of sand and salt is also a more expensive solution, the salt having a corrosive effect on the metal, affecting the closing valve of the sand outlet and requiring added maintenance for effective functioning Sandblasting sand is dried sand which easily blows away and requires to be led and sprinkled as close as possible to the road surface in order to stay in place where it is needed This requires a device more complex than absolutely necessary and therefore less reliable in operation

Another sand sprinkling solution has a hopper-like sand container, mounted so as to be mobile around a horizontal axle, like a pendulum This device is provided with a dosing mechanism which is activated by the driving wheels of the vehicle The dosing mechanism is a drum equipped with spikes which, when in contact with the driving wheels, rotate and thus sprinkle sand The lower part of the sand container (the dosing mechanism) is pressed against the driving wheel by a compressed-air bell The sand sprinkler must be mounted in very close proximity of the driving wheel and is in the way when using chains Moreover it is quite impossible to use this type of device when chains are installed on the driving wheels This device must also be used with dry sand or sand with added salt Ice formation around the dosing mechanism is also a problem, preventing the mechanism from functioning at all This type of equipment is under heavy strain due to the pressure against the driving wheel, and the use of salt in the sand requires systematic and frequent maintenance

Further similar solutions are to be found in the Swedish patent 409,435, DE patent 2,941,952 and EP patent 378,066

The object of the present invention is to provide a solution for sprinkling sand at the level of the wheels of vehicles, such a device having optimal function and price, and satisfying the following requirements

- able to use untreated sand, with no additives,

- can be used with other skid-preventive devices such as chains,

- provides a sprinkling pattern which does not cover the total surface but gives an optimal pattern for twin wheels This is achieved with a set of right-hand blades disposed so as to protrude from the periphery of the feeder on one side of the latter, and a set of left-hand blades also protruding from the periphery on the opposite side of the feeder, the sets of blades being staggered in relation to each other by a fraction of a rotation of the feeder

Further details of the invention will appear from the following description of a preferred embodiment of the mvention and from the claims Figure 1 illustrates the device of the invention mounted in front of the driving wheels of a heavy vehicle, e g a truck

Figure 2 is a vertical section of the invention Figure 3 is a perspective illustration of the rotor inside the chamber Figure 4 is a photograph showing the pattern of sand sprinkling on the road surface in front of the twin wheels of a vehicle

Figure 1 illustrates how the device of the invention, the sand sprinkler 1 , can be mounted for example on the chassis of a truck 2

Figure 2 shows a vertical cross-section of the sand sprinkler 1 It consists of a cylindrical feeder 3 placed at the lower extremity of a trapezoidal hopper 4 containing sand The sides of the lower and narrowest extremity of the trapeze are prolonged by rubber flaps 5, 5' On the periphery of the feeder 3 are provided two sets of blades, left-hand blades 6 and right-hand blades 7 The blades 6,7 are mounted so that they extend parallel to the rotation axis of the feeder 3 and protrude somewhat from the surface of the cylinder, radially, on the feeder 3 The left-hand blades 6 are spaced equally around the surface and so are the right-hand blades 7

The sets of blades 6,7 are staggered relative to each other with 1/8 of a rotation around the surface of the cylinder of the feeder 3 See figure 3

The rubber flaps 5,5' are divided so that one set operates in conjunction with the left-hand blades 6 and the other set operates with the right-hand blades 7 The feeder 3 with blades 6,7 is positioned as previously mentioned at the lower end of the trapeze and so close to the rubber flaps 5,5' that the latter engage between the respective blades 6,7

When the feeder 3 rotates at a regular speed in the direction shown by the arrow, the quantity of sand taken by the left-hand blades 6 from the hopper 4 and sprinkled onto the road surface vertically below the feeder 3 will be somewhat delayed in time relative to the quantity of sand fed by the right-hand blades 7 When the sand sprinkler 1 is mounted in front of twin wheels as shown on figure 1, the left-hand blades 6 will sprinkle sand on the road surface in front of the left wheels and the right-hand blades 7 will sprinkle sand on the road surface in front of the right wheels. In this manner a chequered pattern of sand is obtained in front of the twin wheels, as illustrated in figure 4 If a lesser quantity of sand from the hopper 4 is needed between two blades

6,7, this can be achieved by making less sand available from the hopper 4 and the feeder 3 This can be achieved by placing a sand retainer 8 in the lower extremity of the trapezoidal hopper 4, just above the feeder 3 It is placed halfway above the feeder 3 so as to prevent sand from the hopper 4 to reach part of the blades 6,7 The sand retainer 8 is shaped like a horizontal plate, with its sides which go from one side of the trapeze to the other being bent downward towards the feeder 3, so as to prevent the sand from falling on the part of the feeder 3 which is under the sand retainer 8 The quantity of sand which is retained is dependent on the length of the feeder 3 which is covered by the sand retainer 8 The sand retainer 8 can be easily removed by hand

In this manner, sand can be sprinkled in front of twin wheels to obtain optimal friction conditions between the wheel and the road surface with a minimum consumption of sand, while using a drive unit for this dual feeder 3.

An electrical heating system with, for example, heating cables may be provided in the sand hopper This is not illustrated on the figures

Claims

1. Sand sprinkler for vehicles, with a trapezoidal hopper (4) for the storage of sand and a cylindrical feeder (3) mounted at the narrow end of the trapeze for dosing sand on a road surface in front of the wheels of a vehicle characterized by a set of right-hand blades (6) which protrude from the periphery of the feeder (3) on one side of the latter, and a set of left-hand blades (7) protruding from the periphery of said feeder (3) on its other side, the sets of blades (6,7) being staggered in relation to each other by a fraction of a rotation of the feeder (3)

2. The sand sprinkler for vehicles of the previous claim, characterized in that the sides of the hopper (4) at its lower extremity are prolonged by a set of rubber flaps (5,5') mounted in such a manner as to engage between the blades

(6,7).

3. The sand sprinkler for vehicles of claim 1, characterized in that the right-hand blades (6) are approximately equally spaced, as are the left- hand blades (7).

4. The sand sprinkler for vehicles of the previous claims, characterized in that it provides optimal functional friction conditions for wheels on a road surface with a minimum consumption of sand 5 The sand sprinkler for vehicles of the previous claims, characterized in that a removable sand retainer (8) is provided at the lower extremity of the trapezoidal hopper (4), to cover part of the blades (6,7).