Claims:
I claim
1. An apparatus for grit blasting the edge of a plate-like workpiece by means of a device enclosing a portion of said edge and, in use, being displaceable with respect to said edge, the device including at least one jet nozzle directed towards the edge, as well as a conduit for sucking away the grit, said apparatus comprising
Description:
BACKGROUND OF THE INVENTION
When welding together plates or beams edge to edge, as well as when attaching beams to plates it is often desirable to be able to clean the edge of the member to be welded by means of grit blasting. The blasting is performed by the aid of sand, grit or other hard, solid matter, which by compressed air is blown towards the portion to be cleaned. In order to prevent dust from seeping out into the workshop and also in order to reclaim the blasting grit the apparatus usually is provided with a shield enclosing a limited portion of the member to be cleaned, and being connected to a suction conduit which collects the grit as well as matter removed from the member thereby. One disadvantage with apparatuses of known design adapted for grit blasting the edges of plates, beams and similar plate like members is that they, in order to provide a satisfactory sealing and re-suction, have been designed to suit a single thickness of the member only, which means that it has been necessary to have a number of differently sized devices at hand, or to perform tedious adjustments.
SUMMARY OF THE INVENTION
The aim of the present invention is to provide a device suited to work upon members of different thicknesses. The invention is characterized in that the device includes first sliding members fixedly mounted upon a frame for maintaining the edge of a plate like member at a predetermined distance from the device, the suction conduit preferably being integral with, or incorporated in said frame, and further sliding members for cooperation with the side faces of the plate like member and mounted on a loaded pincer like tool in a manner to be forced against said side faces independently of the thickness of the plate like member.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic, perspective view of the governing parts of the device, and
FIG. 2 shows an end view of the device, partly in section.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The device may be mounted in a fixed position, the plate like member being pushed through the device, or the latter may be movable and, in use, being displaced along the edge of a stationary member.
FIG. 1 very schematically shows the frame of the device mounted for action upon a beam 10 of generally plate like type. The device includes a tubular base part 11, here serving as conduit for resuction of the grit and removed matter. Two brackets 12 extend from the tubular member and are directed in the plane including the portion of the beam 10 to be cleaned, each bracket terminating in a roller 13. These two rollers will, in use, rest upon the edge of the beam, and will thus determine the distance between the latter and the jet nozzles.
Two pincer like tools 14 are mounted upon the frame to act in parallel. A beam 15 running in the same plane as the plate like member 10 is attached to the shanks of the two tools located to each side of the plate like member, each of said beams being provided with two wheels 16. These are mounted upon shafts running parallel to the side faces of the plate like member, and the wheels will run along said side faces upon a relative movement between the plate like member and the device.
The pincer tools 14 are loaded by means of springs 17 or the like in such a manner that the wheels 16 are forced against the faces of the plate like member and the device may thus, within practical limits, be used for treating plate like members of varying thicknesses.
FIG. 2 shows the apparatus more in detail. The pincer tools 14 carry two nozzles 18, which are directed obliquely upwards against the edge of the plate like member, and are by way of hoses 19 connected to any suitable source (not shown) supplying blasting grit and compressed air. The base of the frame 11 is hollow and is connected to a conduit (not shown) by way of which the used grit and other particles are removed by suction. In order to prevent emission of said grit and particles the pincer tools are provided with shields 20 mounted at beams 15 and containing rows 21 of bristles, or elongated bodies of elastic material, which are forced against the side faces and the edge of the plate like member and which also will seal around the suction tube 11 of the frame. The actual blasting, thus, takes place within a confined space of limited volume, from which an undesirable emission of solid matter is prevented. The distance in the plane of the plate like member between the groups of wheels 16 and rollers 13 at both ends of the tool is sufficient to make possible a location of the shields intermediate said groups. Instead of wheels and rollers antifriction bodies of various kinds may be used, and the shape of the different components of the device may be varied in many ways within the scope of the claims, depending upon the requirements imposed upon the device.