EP1670992B1

EP1670992B1 - Spreader arrangement for a road machine

Info

Publication number: EP1670992B1
Application number: EP04762891A
Authority: EP
Inventors: Soren Thisgaard; Anders Teglgaard Madsen
Original assignee: Epoke AS
Current assignee: Epoke AS
Priority date: 2003-10-07
Filing date: 2004-10-05
Publication date: 2009-12-16
Anticipated expiration: 2024-10-05
Also published as: DK200301473A; WO2005033417A1; DK176222B1; ATE452243T1; EP1670992A1; DE602004024698D1

Abstract

Spreader arrangement for spreading a mixture of salt and water including a funnel (1) attached to a vehicle and from a dosing means leading salt down to a rotatable spreader disc at the lowermost part of the funnel 1. In connection with the spreader disc 5 a mixing chamber is provided to which salt and salt water are fed. The mixing chamber renders a more effective mixing of salt and salt water than hitherto known.

Description

Technical Field

The invention relates to a spreader arrangement for spreading a mixture of granulated material, preferably salt, and a liquid or a solution of salt and water, said arrangement including a funnel attached to a vehicle and leading granulated material from a dosing means on the vehicle to a rotatable spreader disc at the bottom part of the funnel.

Background Art

The use of a mixture of salt and water instead of salt alone offers several advantages. Firstly, a saving in salt consumption of about 23 % is obtained. Secondly, moist salt is not as sensitive to wind as dry salt. Thirdly, the moist salt does not bounce as much when it hits the road during scattering, whereby a more accurate positioning is obtained. Fourthly, the scattered moist salt remains on the road at subsequent traffic. The scattered material is thus not as sensitive to subsequent traffic.
Various spreading mechanism for spreading a mixture of salt and water are known, confer cg. EP 427995 and US 4442979 . The mixing of salt and water is, however, not sufficiently effective.

Description of the Invention

The object of the present invention is to provide a spreader arrangement rendering a more effective mixture of granulated material and liquid.
A spreader arrangement of the above type is according to the invention characterised by the features of claim 1.
The mixing chamber renders a more effective mixing of the granulated material and the liquid than hitherto known.
Moreover, according to the invention, next to the funnel in the rotational direction of the spreader disc the means for feeding the liquid to be mixed with the granulated material may be provided, in the rotational direction of the spreader disc the liquid feeding means preferably being arranged behind the funnel for feeding of granulated material.
Furthermore according to the invention the spreader disc may comprise a motor cone with a built-in motor, preferably a hydraulic motor.
Moreover according to the invention the hydraulic motor may drive the motor cone and thus a hub plate in the mixing chamber connected thereto.
According to the invention the hub plate may be provided with frictional members ensuring that a more uniform scattering of the mixture of salt and salt water.
The frictional members may according to the invention be formed of mixer blades on the hub plate, preferably in form of involutes.
The maximum height of the mixer blades is 4 mm.
Furthermore according to the invention the mixing chamber is rounded at the bottom to ensure that the material is conveyed up the chamber wall and then drops down onto the mixer blades on the hub plate.
The mixing chamber is provided with an inwardly inclined or inwardly curved wall, the material thereby falling back onto the mixer blades instead of being thrown out of the mixing chamber.
The mixer blades may advantageously extend beyond the stationary part of the bottom of the chamber.

Brief Description of the Drawings

The invention is explained in greater detail below with reference to the accompanying drawings, in which

Fig. 1 shows a spreader arrangement according to the invention comprising a telescopic funnel for granulated material and a spreader disc,
Fig. 2 shows the spreader disc in connection with a stationary upper part of the mixing chamber,
Fig. 3 is a sectional view of a hydraulic motor built-in in the mixing chamber,
Fig. 4 shows the spreader disc in connection with the stationary upper part of the mixing chamber, the cover of the stationary upper part being removed,
Fig. 5 illustrates how salt and salt water are mixed in the mixing chamber,
Fig. 6 illustrates the spreader arrangement in connection with a container for discharging granulated material and with a container for discharging liquid,
Fig. 7 is a side view of the container for granulated material shown in Fig. 6, the container for discharging liquid also being showed,
Fig. 8 is a sectional view of the container shown in Fig. 7 provided with a feed worm at the bottom,
Fig. 9 shows the electronic circuit for controlling the spreader disc, the liquid pump, the dosing means and the asymmetry, and
Fig. 10 illustrates a screen around the rotating spreader disc.

Best Mode(s) for carrying out the invention

The spreader arrangement according to the invention shown in Fig. 1 to be arranged on a vehicle such as lorry includes a telescopic funnel 1 feeding granulated material such as salt from an electronically controlled dosing means on the vehicle. Via a bracket attached to the funnel 1 the spreader disc 5 is suspended at the lowermost part of the funnel 1. In connection with the rotatable spreader disc 5 a relatively stationary housing is provided, said housing having a cover 4 at the top with a comparatively large opening 4a for feeding granulated material such as salt and liquid such as salt water, respectively, a tube 1 a for feeding of the liquid being provided next to the funnel 1. At the bottom of the housing a hub plate 2 is provided which is firmly connected to the spreader disc 5 and rotates therewith, confer Fig. 2. The hub plate 2 is provided with frictional members in form of involute-shaped blades 2a of a height of preferably 4 mm.
The spreader arrangement communicates with a container 11 for discharging granulated material such as salt and a container 12 for discharging liquid such as salt water, confer Fig. 6. Fig. 8 shows the container 11 for discharging salt, a conveying means in form of a worm 13 being provided at the bottom of the container 11 for feeding the salt to the end of the container 11 with the spreader arrangement. The discharge of salt and the discharge of salt water are electronically controlled by means of the control circuit shown in Fig. 9 and are described below.

The method of operation of the method of operation is as follows:

A hydraulic motor - confer Figs. 2 and 3 - inserted from below drives a motor cone communicating with the hub plate 2 and the spreader disc 5 and rotating these elements. The mixing chamber and the associated cover 4 are, however, stationary during the rotation of the motor.
The mixing chamber is arranged concentrically in relation to the spreader disc 5.
Salt and salt water are now fed to the mixing chamber through the large opening 4a in the cover of the mixing chamber and conveyed by the mixer blades 2a on the rotating hub plate 2 to the wall 7 of the mixing chamber. The salt and the salt water obtain such a high velocity towards the wall 7 that the mixture is thrown up onto the wall 7 and then drops down onto the mixer blades 2a, confer Fig. 5. The salt and salt water are then conveyed once more to the wall 7 of the mixing chamber and follow the wall until the mixture reaches an opening 8 in the wall 7 and is thrown out therefrom.
The mixing chamber has an inwardly inclined or inwardly curved wall 7 - confer Fig. 5 - so as to ensure that the material drops back onto the mixer blades 2a before being thrown out through the said opening 8 in the wall 7.
Furthermore a curve is provided in the bottom of the mixing chamber at the transition between the hub plate 2 and the inwardly inclined wall 7. As a result, the mixing chamber is comparatively tight and the material is more easily thrown up the upwardly inclined wall 7, whereby a more effective mixing of salt and salt water is obtained before the mixture is thrown out through the opening 8 - confer Fig. 4, which illustrates the mixing chamber with cover.
It is essential for obtaining an effective mixture that the liquid is supplied prior to the supply of salt.
The mixing of salt and salt water is effected in several different manners:

1. The salt hits the already added salt water in the mixing chamber, the salt hitting the hub plate 2 and the mixer blades 2a (salt water having been supplied shortly prior to the supply of salt).
2. The salt and salt water are mixed by the mixer blades 2a not immediately conveying all of the salt and all of the salt water to the wall 7 due to friction. As a result, stirring takes place by some of the salt and salt water being thrown over the mixer blades 2a before reaching the wall 7 of the chamber.
3. The impact with the wall 7 of the chamber provides a degree of mixing.
4. The salt and salt water again drop down onto the mixer blades 2a and the hub plate 2 which results in further mixing.
5. The salt and salt water are conveyed along the wall 7 of the chamber which results in further mixing.
6. The salt and salt water remain inside the mixing chamber for 1/2 to 3/4 of a revolution before being thrown out onto the spreader disc 5 through the opening 8 in the wall 7 of the mixing chamber.

The direction and speed of the material flow which is tangent in relation to the chamber wall 7 renders the advantage that the material being thrown out of the chamber has substantially the same tangential rate as the blades on the spreader disc 5. As result, any splash of salt and salt water is minimised, whereby the risk of clogging of the spreader arrangement is significantly reduced.
The blades 5a on the rotating spreader disc 5 are inclined in relation to vertical. This means that the material flow is gradually cut and thrown down into the rims between the spreader disc 5 and the blades 5a. The gradual cutting and throwing downwards against the rims effect that the material is spread out along the blades 5a. This in turn effects that the spread pattern obtains a wide angle of spread. The angle of the blades 5a in relation to horizontal is about 45-55°. Furthermore, a sharp edge between the spreader disc 5 and the blade 5a is to be provided, the material spreading otherwise not being effected in a satisfactory manner.
An asymmetric setting may be provided by altering the position of the opening 8 in the wall 7 of the mixing chamber by turning the mixing chamber such that the position of the opening 8 is altered. By turning the opening 8 and thus the exit point of the material from the mixing chamber onto the blades 5a on the spreader disc 5, the asymmetry of the spread pattern may thus be adjusted. The means for adjusting the angularity of the mixing chamber may for instance be formed of an articulated-rod mechanism which optionally may be operated manually. Optionally a servomotor may be used. When the mixing chamber is turned clockwise, spreading is effected further to the left when seen in the direction of travel and vice versa. The most important aspect is, however, that no change in the entire angle of spread and the entire spreading range occur.
Fig. 6 shows the spreader arrangement mounted in communication with an oblong V-shaped container 11 for feeding granulate, while Fig. 7 shows the same in a side view. At the bottom of the V-shaped container 11 a conveyor in form of a worm 13 is shown, said worm conveying the granulate to the funnel 1 arranged at the end of the container 11 and wherefrom it is discharged to the mixing chamber. On the side of the V-shaped container 11 a liquid container 12 is arranged wherefrom liquid is discharged to the mixing chamber at the same time via a hose and a pump.
The actual flow of material is electronically controlled through a tachometer attached to for instance one of the rear wheels of the vehicle in question. Remote adjustments from the cab of the vehicle are employed, the driver adjusting the spreading range, the dosage per area unit, etc. Fig. 9 illustrates the electronic circuit adapted to adjust the dosage per area unit, the spreading range, the liquid pump and the symmetry setting.
The supply of salt is controlled separately in relation to the supply of liquid. The adjustment can be effected quite quickly within about 1 second. The adjustment is performed by comparing an adjustment set value with the actual value, an error signal being generated which is used as a feedback signal in a feedback loop with negative feedback.
The supply of liquid is adjusted in a corresponding manner by comparing an adjusted set value with the actual value, an error signal being generated at said comparison and used as a feedback signal in a feedback loop.
The spreading range is adjusted by comparing a set value corresponding to the spreading range of the spreader disc, ie the rpm of the hydraulic motor, with the actual value so as to generate an error signal used in a feedback loop.
The symmetry position is adjusted in a similar manner by comparing a set value corresponding to the desired symmetry position with the actual value so as to generate an error signal which via a feedback signal is used to adjust a separate servomotor controlling the angularity of the opening in the wall 8 of the mixing chamber.
An optional, adjustable screen 15 - confer Fig. 10 - around the spreader disc 5 serves to further ensure that the spreading is effected away from the vehicle.

Claims

Spreader arrangement for spreading a mixture of granulated material, preferably salt, and a liquid or a solution of salt and water, said arrangement including a funnel (1), a spreader disc (5) at the bottom part of said funnel (1), and, a means (1a) for feeding the liquid to be mixed with the granulated material, said funnel (1) being attachable to a vehicle for leading granulated material from a dosing means on the vehicle to said rotatable spreader disc (5) whereby a mixing chamber is provided in connection with the spreader disc (5) to which the granulated material and the liquid are fed, characterised in that said mixing chamber is provided with a rounded bottom and an inwardly inclined or inwardly curved wall.
Spreader arrangement according to claim 1, characterised in that the means (1a) for the feeding liquid is provided next to the funnel (1) in the rotational direction of the spreader disc (5) .
Spreader arrangement according to claim 2, characterised in that the means (1a) for feeding the liquid in the rotational direction of the spreader disc (5) is arranged behind the funnel (1) for feeding the granulated material.
Spreader arrangement according to one or more of the preceding claims characterised in that the spreader disc (5) comprises a motor cone with a built-in motor, for driving the motor cone and a hub plate (2) in the mixing chamber connected thereto
Spreader arrangement according to claim 4, characterised in that the hub plate (2) is provided with frictional members formed of mixer blades (2a) provided on the hub plate (2).
Spreader arrangement according to claim 5, characterised in that the mixer blades (2a) are shaped as involutes.
Spreader arrangement according to claim 5 or 6, characterised in that the mixer blades (2a) extend beyond the stationary part of the bottom of the mixing chamber.
Spreader arrangement according to claim 7, characterised in that mixer blades (2a) extend about 10 mm beyond the stationary part of the bottom of the mixing chamber.