GB2108181A

GB2108181A - Distributing apparatus

Info

Publication number: GB2108181A
Application number: GB08131635A
Authority: GB
Inventors: Peter Kenneth Slade
Original assignee: Berger Traffic Markings Ltd
Current assignee: Berger Traffic Markings Ltd
Priority date: 1981-10-20
Filing date: 1981-10-20
Publication date: 1983-05-11
Also published as: GB2108181B

Abstract

Apparatus for distributing particulate material e.g. Ballotini beads, onto a stripe of marking material A applied to a surface comprises a housing 1 vertically displaceably mounting a dispensing means 3. The latter comprises a tube 54 to which the beads are supplied, and which meters the beads through a gap between the lower end of the tube 54 and a closure plug 82, the gap being controlled by a cylinder 58. Beads emerging from the feed tube pass by gravity over the plug 82 and the outer surface of a distributing member 84 which shapes the flow of beads so that they fall in a desired pattern onto an inclined plate 12. The beads then slide down the plate 12 and through a slot 10 in the housing whence as they fall off the free edge of the plate 12 they are caught by blades 34 of a rotating impeller 30 and are propelled thereby onto the marking material A with considerable force. The marking material A is still wet and the beads therefore penetrate the material to a certain extent. <IMAGE>

Description

SPECIFICATION Distributing apparatus This invention relates to apparatus for distributing particulate materials onto a stripe of marking material applied to a surface area such as a roadway, pavement or other area to constitute an indicating line for vehicular or other traffic using such surface area, the distribution more especially being performed while the marking material is still wet.

The marking material may be any commonly available marking material such as paint or a cementitious compound that is applied to the surface area in a liquid or flowable condition.

The particulate materials which may be distributed onto the stripe of marking material by the apparatus of this invention include small solid particles of skid resistant materials or aggregates, and reflective glass beads commonly known in the art as Ballotini beads, or a mixture of skid resistant materials and Ballotini beads. For convenience, the particulate materials will hereafter be referred to generically as "beads".

It is already known to distribute such beads onto a stripe of marking material while the latter is still wet with the intention that the beads will adhere to the marking material as it dries. Known apparatus and methods rely on a gravity feed system whereby the beads are allowed to drop onto the stripe, or low pressure air assisted feeder systems whereby the beads are blown onto the stripe. In both cases however the beads essentially merely drop onto the stripe under the action of gravity. In order to obtain adequate coverage of the stripe with the known apparatus and methods, it is necessary to overfeed the beads, which is wasteful of the beads and also requires a subsequent sweeping operation to remove loose surplus material. In addition the adherence of the beads to the marking material is commonly found to be less than satisfactory, especially after a period of time.

Among the objects of this invention are to provide an apparatus for distributing particulate materials onto a stripe of marking material, which apparatus affords accurate and simple control of the width and volume of the particulate materials distributed and is also capable of affording substantially even distribution of the individual particles across the width of the stripe.

The invention provides an apparatus for distributing particulate materials onto a stripe of marking material applied to a surface area while such marking material is still wet, comprising means for controllably feeding particulate materials continuously to a distributor means adapted to distribute the material over a supporting member according to a pattern which represents a substantially even distribution of material across the width of the stripe, the supporting member being inclined and having a free edge so that the material slides in a flat stream across the member and falls off the free edge into an impeller means which mechanically propels the flat stream of particulate material onto the strip of marking material.

Preferably the feed means is controllable to control the volume of particulate material (beads) supplied to the distributor means and the the distributor means is adjustable relative to the support member which is for example an inclined diverter plate, to control the width of the impingement pattern of beads on the plate so as to correspond to the stripe width.

The impeller means may be a rotatable bladed impeller the blades of which strike the beads in the flat stream leaving the free edge of the diverter plate to propel or project them against the marking material.

The beads (particulate material) are projected onto the marking material while the latter is still wet so that as the marking material dries the beads become bonded in at least the surface layer of the marking material to impart skid resistance and/or reflectivity (according to the nature of the beads sprayed) to the marking stripe. The projection of the beads onto the marking material affords good penetration into the wet marking material and thus good adherence for a substantial period of time.

An embodiment of an apparatus according to the invention is illustrated by way of example in the accompanying drawings in which: Figure 1 is a front view of the apparatus, partly broken away, and Figure 2 is a vertical cross-sectional view of the apparatus.

The apparatus shown in the drawings comprises an upright housing 1, an impeller 2 and a dispenser means 3.

The housing 1 is rectangular in cross-section and has a slot 10 in one side wall.

Extending across the full interior width of the housing is secured a diverter plate 1 2 which slopes rearwardly and downwardly towards the slot 1 0. The upper surface of the plate 1 2 is provided with baffles in the form of parallel upstanding plates 14 which define channels perpendicular to the slot 1 0.

The impeller 2 is mounted on the exterior of the housing 1 in registry with the slot 1 0. An impeller casing 20 in the form of a cylindrical member from which a 90 segment has been removed along its entire length to form an opening 1 6 communicating with the slot 10 is welded to the housing. A stiffening bracket 23 is provided. The ends of the casing 20 are closed by circular end plates 24 and 25 which carry bearings 26 and 28 for an impeller 30. The impeller 30 comprises a shaft 32 journalled in the bearings and carrying a plurality of longitudinally extending blades 34 of metal or plastics material mounted in radial slots 36 in the shaft 32.

The impeller 30 is rotated either directly by means of a motor (not shown) coupled to an end of the shaft 32, or by means of a pulley (not shown) fitted on shaft end 36 and driven either from its own prime mover or may be driven from a lining machine which applies a stripe of marking material to a road surface and with which the present apparatus is associated.

The end plate 25 is removable to enable the impeller to be removed and also to enable two or more of the apparatuses shown to be secured together side by side to distribute beads onto a stripe of marking material of greater width than a single apparatus, without the need for a separate drive to each apparatus.

The dispensing means 3 is supported within the housing 1 by two studs 50 slidable in verticle slots 51 in the side walls of the housing and releasably secured in position by wing nuts 52. The studs 50 are welded to a feed tube 54 having a branch 56 which is connected by a flexible pipe (not shown) to a hopper containing a bulk supply of the beads to be dispensed. A pneumatic or hydraulic single acting cylinder assembly comprising a cylinder 58 and a piston 60 is mounted at the upper end of the feed tube 54. The cylinder incoporates a return spring 62 acting against the underside of the piston.

Two radially projecting pins 64 mounted on the piston rod 66 project through longitudinal slots 68 in the wall of tube 54 to prevent relative rotation between the cylinder assembly and the feed tube 54 and also between piston 60 and the cylinder 58. The cylinder 58 includes a fluid connection 70 which is externally threaded and carries a knurled nut 72 which rests on the upper end of the tube 54. A releasable clamp 74 surrounds the upper end of the feed tube 54, which due to the presence therein of the slots 68 is somewhat deformable.

A connecting rod 76 is screwed into the piston rod 66 and is iocked by a lock nut. The connecting rod 76 extends axially down the feed tube and at its lower end carries a valve and distributor assembly 80. The latter comprises a valve member 82 in the form of a frustum of a right circular cone. Mounted beneath member 82 on the connecting rod 76 is a distributor member 84. Locating pins 86 prevent relative rotation between the members.

The operation of the apparatus will now be described. It is assumed that the apparatus is moving from right to left in Fig. 1 above a line of marking material A.

Beads are fed through branch 56 into the tube 54 above the valve member 82 which initially closes the lower end of the tube 54 due to the force exerted by the return spring 62 on the underside of the piston. When the fluid is admitted to cylinder 58, the piston and connecting rod 76 moves downwards and beads commence to flow out of the lower end of the tube 54 over the conical surface of the valve member 82 and down the outer surface of the distributor member 84. The distributor member 84 shapes the flow of beads so that they fall in a desired pattern onto the diverter plate 1 2. The channels in the plate 1 2 prevent the beads from scattering sideways on impingement with the plate.The beads then slide down the plate and through slot 10 whence as they fall off the lower edge of the plate 1 2 they are caught by the blades 34 of the rotating impeller 30 and are propoelled thereby onto the marking material A with considerably greater force than if they were allowed merely to fall onto the marking material by gravity alone. The stripe of marking material A, which has been laid down by the lining machine previously mentioned, is still wet and the beads therefore penetrate the material to a certain extent.

The volume of beads discharged from feed tube 54 is determined by the gap between the valve member 82 and the lower edge of the feed tube 54. The actuating cylinder assembly can be raised or lowered by turning the knurled nut 72 in the appropriate direction after releasing the clamp 74 so that the size of the cap can be preset as desired. The stroke of piston 60 in cylinder 58 is constant.

The width of the impingement pattern of the beads on the plate 1 2 is determined by the vertical distance between the lower edge of the distributor member 84 and the plate 1 2 and is preset by adjustment of the dispenser means vertically in the slots 51 of the housing to correspond to the desired width of stripe A, the wing nuts 52 being released and resecured as necessary.

An even distribution of beads across the width of stripe A is achieved by suitably shaping the distributor member 84 so that each quadrant of the impingement pattern on plate 1 2 receives an equal quantity of beads.

A distributor member 84 which in transverse cross-section has an ellipsoidal or a paraboloid shape with its minor axis aligned in the direction of movement of the apparatus has been found satisfactory although other shapes may be determined to provide the desired result.

The speed of rotation of the impeller is chosen so that there is effectively a substantially constant stream of beads propelled onto the marking material. The actual speed of rotation of the impeller depends upon the rate of speed of the beads, the number of blades and the blade diameter and can readily be determined for any particular construction of apparatus.

The impeller blades 34 can be replaced by brushes.

A centering spider may be fitted on the connecting rod 76 to ensure that the assembly 80 is located coaxially in relation to the feed tube 54.

Claims

1. An apparatus for distributing particulate materials onto a stripe of marking material applied to a surface area while such marking material is still wet, comprising means for controllably feeding particulate materials continuously to a distributor means adapted to distribute the material over a supporting member according to a pattern which represents a substantially even distribution of material across the width of the stripe, the supporting member being inclined and having a free edge so that the material slides in a flat stream across the member and falls off the free edge into an impeller means which mechanically propels the flat stream of particulate material onto the stripe of marking material.

2. Apparatus according to Claim 1, wherein the feed means is controllable to control the volume of particulate material supplied to the distributor means.

3. Apparatus according to Claim 1 or Claim 2, wherein the distributor means is adjustable relative to the supporting member to control the width of the impingement pattern of material on the supporting member so as to correspond to the stripe width.

4. Apparatus according to Claim 3, comprising a rectangular housing having a slot extending transversely across a rear side wall near a lower end thereof, and the supporting member comprises an inclined plate mounted within the housing and sloping rearwardly and downwardly towards the slot, the free edge of said plate being located substantially in the slot.

5. Apparatus according to Claim 4, wherein the upper surface of the plate is provided with upstanding baffles which define channels perpendicular to the slot.

6. Apparatus according to any one of the preceding Claims, wherein the impeller means comprises a casing, a shaft rotatably mounted within the casing and a plurality of longitudinally extending radially directed blades mounted on the shaft.

7. Apparatus according to Claim 6 and either of Claims 4 and 5, wherein the casing is a cylindrical casing having a 90 opening therein, and the upper edge of the opening communicates with the slot in the rectangular housing.

8. Apparatus according to Claim 7, wherein the casing further comprises circular end plates at least one of which is removable.

9. Apparatus according to any one of the preceding Claims, wherein the distributor means comprises a member having an outer surface over which the particulate material fed by the feed means flows under gravity and from which the particulate material falls onto the supporting member.

10. Apparatus according to Claim 9, further comprising means for adjusting the distance between the distributor member and the supporting member.

11. Apparatus according to Claim 9 or Claim 10, wherein the distributor member is so shaped that each quadrant of the impingement pattern of the material on the supportintg member receives an equal quantity of material.

1 2. Apparatus according to Claim 11, wherein the distributor member has an ellipsoidal or a paraboloid shape in transverse crosssection.

1 3. Apparatus according to any one of the preceding Claims wherein the feed means comprises a feed tube, means for connecting the feed tube to a supply of the particulate materials to be distributed, and a valve member arranged to close a lower end of the feed tube.

14. Apparatus according to Claim 13, wherein the valve member is a frusto conical plug.

1 5. Apparatus according to Claim 1 3 or Claim 14 and any one of Claims 9 to 1 2, wherein the distributor member is mounted on the underside of the valve member.

16. Apparatus according to Claim 15, wherein the valve member is biased towards the closed position, and operating means for opening the valve member are mounted on the upper end of the feed tube.

1 7. Apparatus according to Claim 16, wherein the operating means are connected to the valve member for displacing the valve member axially away from the lower end of the feed tube a controlled distance for regulating the volume of particulate material discharged through the gap between the valve member and the lower end of the feed tube.

18. Apparatus according to Claim 4 and any one of Claims 1 3 to 17, wherein the feed tube is longitudinally displaceably mounted within the rectangular housing.

1 9. Apparatus according to Claim 6, modified in that the radially directed blades are replaced by radially directed brushes.

20. Apparatus for distributing particulate materials, constructed, arranged and adapted to operate substantially as hereinbefore described with reference to the accompanying drawings.